The transplantation of neural stem/progenitor cells (NPCs) is a promising therapeutic strategy for spinal cord injury (SCI). However, to date NPC transplantation has exhibited only limited success in the treatment of chronic SCI. Here, we show that chondroitin sulfate proteoglycans (CSPGs) in the glial scar around the site of chronic SCI negatively influence the long-term survival and integration of transplanted NPCs and their therapeutic potential for promoting functional repair and plasticity. We targeted CSPGs in the chronically injured spinal cord by sustained infusion of chondroitinase ABC (ChABC). One week later, the same rats were treated with transplants of NPCs and transient infusion of growth factors, EGF, bFGF, and PDGF-AA. We demonstrate that perturbing CSPGs dramatically optimizes NPC transplantation in chronic SCI. Engrafted NPCs successfully integrate and extensively migrate within the host spinal cord and principally differentiate into oligodendrocytes. Furthermore, this combined strategy promoted the axonal integrity and plasticity of the corticospinal tract and enhanced the plasticity of descending serotonergic pathways. These neuroanatomical changes were also associated with significantly improved neurobehavioral recovery after chronic SCI. Importantly, this strategy did not enhance the aberrant synaptic connectivity of pain afferents, nor did it exacerbate posttraumatic neuropathic pain. For the first time, we demonstrate key biological and functional benefits for the combined use of ChABC, growth factors, and NPCs to repair the chronically injured spinal cord. These findings could potentially bring us closer to the application of NPCs for patients suffering from chronic SCI or other conditions characterized by the formation of a glial scar.

See the original post:
Synergistic effects of transplanted adult neural stem ...

Spinal Cord Stem Cells Comments Off on Synergistic effects of transplanted adult neural stem … | September 27th, 2016

SAN FRANCISCO Researchers have successfully transplanted healthy human cells into mice with spinal cord injuries, bringing the world one step closer to easing the chronic pain and incontinence suffered by people with paralysis.

The research team did not focus on restoring the rodents ability to walk; rather, it helped remedy these two other debilitating side effects of spinal cord injury.

If successful in humans, thefindingscould someday ease the lives of those with these distressing conditions, said Dr. Arnold Kriegstein, co-senior author of the study and director of the Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research at UC San Francisco. The research was published in Thursdays issue of the journal Cell Stem Cell.

This is a very important step, Kriegstein said. The treated animals improved in pain relief and bladder function.The research offers the promising potential of using a new therapeutic approach cell therapy to repair damaged neural tissue, showing that new cells can be integrated into an injured spinal cord.

A similar approach also has helped mice with epilepsy and Parkinsons disease.

More than aquarter of a million Americans live with spinal cord injuries, and 17,000 new cases occur each year, according to the National Spinal Cord Injury Statistical Center. More than half of those people go on to develop chronic pain in their limbs, called neuropathy. And nearly all develop bladder problems, which can result in kidney damage.

The spinal cord is the major highway for nerve cells to relay information between the brain and the rest of the body. When the spinal cord is injured, tears and inflammation harm surrounding cells.

The field has been very focused on restoring patients ability to walk, perhaps because thats often their most visible impairment, study co-authorLinda Noble-Haeusslein, a professor of physical therapy and rehabilitation at UCSF, said in a statement.

But a recent study showing that patients complained of pain and loss of bladder control more than paralysis suggested that we had really missed the boat as a field, she said. It caused us to dramatically shift what we do in the lab.

The cells used in the study, called neurons, were grown from human embryonic stem cells the bodys building blocks, capable of generating more than1,000 different types of adult cells.

They arent just any garden-variety neuron. These cells have the ability to inhibit, rather than excite, the neural network of the spine. Thats important because the pain and loss of bladder control are believed to be caused by overactivated neural circuits.

The healthy body keeps this excitable circuitry under control.But inflammation caused by a spinal cord injury causes a loss of this control.

The UCSF team grew the replacement cells in a South San Francisco biotech lab ofNeurona Therapeutics, founded by study co-authorCory Nicholasand Kriegstein, UCSFprofessor of developmental and stem cell biology. The company hopes to mass-produce these cells for use in future clinical trials.

They injected the young human cells into the spines of mice about two weeks afterinjury. They targeted the thoracic region about halfway up the spinal cord because thats a common site of injury for humans.But they were careful not to inject the young cells directly into the injured areas because that is a toxic place full of inflammation.

Remarkably, over the next six months the human cells matured, migrated toward the site of the injury and made connections with the spinal cords of the mice.

Compared to untreated mice, the treated rodents showed significantly less hypersensitivity to touch and painful stimuli and reduced abnormal scratching. Treated mice also had improved bladder function and produced more normal, voluntary patterns of urination in their cages.

A different research team is focusing on a fix for paralysis. This necessitatesa different strategy, requiring treatment with stem cell-derived neurons whose job it is to conduct electrical impulses down the spine. And these cells may face a more daunting environment if injected directly into injured areas.

The first trial by Geron Corp. stalled in late 2011, mostly because of financial concerns. But a Fremont-based biotech company calledAsterias Biotherapeutics, a subsidiary of BioTime, bought Gerons intellectual property and is continuing the research. It recently received approval fromthe U.S. Food and Drug Administration for a safety and early trial of the cells for treating spinal cord injury.

Meanwhile, the UCSF team is working to replicate their findings of improved bladder control and chronic pain. And they seek to learn the best time to inject the cells. Funders for the research included the National Institutes of Health and the California Institute of Regenerative Medicine.

The team is hoping to scale up their production of their specialized cells with the goal of entering human trials, after proving to the FDA that their effort is safe.

We are eager to move in that direction as quickly as we can, Kriegstein said.

Read more here:
spinal cord injury, embryonic stem cells, paralysis, pain ...

Spinal Cord Stem Cells Comments Off on spinal cord injury, embryonic stem cells, paralysis, pain … | September 26th, 2016

GETTY

They suffer many complications in addition to paralysis and numbness and some of these problems are caused by a lack of the neurotransmitter GABA in the injured spinal cord.

A new University of California, San Francisco study in mice found human embryonic stem cells reduced two of the most severe side effects - incontinence and pain sensitivity.

Co-first author Assistant Professor Dr Cory Nicholas said: Chronic pain and bladder dysfunction remain significant quality-of-life issues for many people with spinal cord injuries.

Inhibitory cell-based neuro-therapy is a new approach and has shown promise to date in early animal studies, warranting further development."

The stem cell treatment differentiated into medial ganglionic eminence (MGE)-like cells, which produce GABA (gamma-Aminobutyric acid), an inhibitory neurotransmitter that is found throughout the central nervous system.

Our hope is that this treatment would last a long time, or maybe even be permanent

Dr Thomas Fandel

It plays an important role in reducing the excitability of neurons by binding to receptors that act on synapses.

Neuropathic pain and bladder dysfunction are at least in part attributed to overactive spinal cord circuits.

GETTY

Senior author Professor Dr Arnold Kriegstein said: We reasoned if we could take inhibitory neurons and directly place them into the spinal cord in the regions that are overactive, they might integrate into those circuits and suppress the activity.

In the study researchers used GABAergic inhibitory neuron precursors called MGE-like cells that were derived from human embryonic stem cells.

The neural precursor cells were placed into the spinal cords of mice two weeks after injury had been induced, where they could differentiate into GABA-producing neuron subtypes and form synaptic connections.

Co-author Dr Thomas Fandel, a research specialist at UCSF added: Rather than implanting these cells into the site of injury, at the mid-thoracic level, we injected them in the lumbosacral region, where the circuits are known to be overactive.

GETTY

Six months later we could see broad dispersion of the cells in that area. They were integrated into the spinal cord.

Tests showed the mice were not incontinent and had significantly reduced pain sensitivities.

Current treatments for neuropathic pain in people with spinal cord injuries most often involve opioids and other pain medications, as well as certain antidepressants, which have many side effects and tend to have limited efficacy.

Treatments for bladder dysfunction are often anticholinergics, but these drugs have side effects like dizziness and dry mouth.

GETTY

Botox may help with bladder spasms, but the benefits tend to be transient.

Dr Fandel added: The current approaches for treatment are not very effective and clearly more options are needed.

Our hope is that this treatment would last a long time, or maybe even be permanent.

The study was published in the journal Cell Stem Cell.

Here is the original post:
Human stem cells could provide relief for spinal cord ...

Spinal Cord Stem Cells Comments Off on Human stem cells could provide relief for spinal cord … | September 26th, 2016

Engrafted NSPCs Form Presynaptic Connectivity with Spared Host Neurons after SCI (A) The gene expression levels of pan-presynaptic markers in engrafted NSPCs at 6weeks after transplantation, as determined by qRT-PCR, are shown (n= 8 mice per group). (B) Triple-staining for GFP (green), HU (blue), and the presynaptic marker BASSOON (red) at 6weeks after transplantation. The images showed that the engrafted NSPCs expressed BASSOON-positive synaptic boutons (arrowhead) in their axon terminals, which surrounded HU-positive host neurons. The right image is a magnification of the boxed area in the left image. (C) Quantification of the GFP/BASSOON-positive synaptic boutons in engrafted NSPCs is shown (n= 60 neurons; six mice per group). (D and E) The gene expression levels of inhibitory presynaptic markers (Vgat, Gad65, and Gad67) and excitatory presynaptic markers(Vglut1 and Vglut2) in engrafted NSPCs at 6weeks after transplantation, as determined by qRT-PCR, are shown (n= 8 mice per group). (F) Triple-staining for GFP (green), HU (blue), and the excitatory presynaptic marker VGLUT2 (red) at 6weeks after transplantation. The images showed that the GFP/VGLUT2-positive excitatory synaptic boutons (arrowhead) contacted HU-positive host neurons. The right image is a magnification of the boxed area in the left image. (G) Quantification of the GFP/VGLUT2-positive synaptic boutons in engrafted NSPCs is shown (n= 60 neurons; six mice per group). p< 0.05, p< 0.0001, Wilcoxon rank-sum test (A, C, D, E, and G). The data are presented as the means SEM. Scale bars, 20m (B and F) and 2m (insets).

Read the original here:
Engrafted Neural Stem/Progenitor Cells Promote Functional ...

Spinal Cord Stem Cells Comments Off on Engrafted Neural Stem/Progenitor Cells Promote Functional … | September 7th, 2016

3.1 Introduction

Figure 3.1 Schematic dorsal and lateral view of the spinal cord and four cross sections from cervical, thoracic, lumbar and sacral levels, respectively.

The spinal cord is the most important structure between the body and the brain. The spinal cord extends from the foramen magnum where it is continuous with the medulla to the level of the first or second lumbar vertebrae. It is a vital link between the brain and the body, and from the body to the brain. The spinal cord is 40 to 50 cm long and 1 cm to 1.5 cm in diameter. Two consecutive rows of nerve roots emerge on each of its sides. These nerve roots join distally to form 31 pairs of spinal nerves. The spinal cord is a cylindrical structure of nervous tissue composed of white and gray matter, is uniformly organized and is divided into four regions: cervical (C), thoracic (T), lumbar (L) and sacral (S), (Figure 3.1), each of which is comprised of several segments. The spinal nerve contains motor and sensory nerve fibers to and from all parts of the body. Each spinal cord segment innervates a dermatome (see below and Figure 3.5).

3.2 General Features

Although the spinal cord constitutes only about 2% of the central nervous system (CNS), its functions are vital. Knowledge of spinal cord functional anatomy makes it possible to diagnose the nature and location of cord damage and many cord diseases.

3.3 Segmental and Longitudinal Organization

The spinal cord is divided into four different regions: the cervical, thoracic, lumbar and sacral regions (Figure 3.1). The different cord regions can be visually distinguished from one another. Two enlargements of the spinal cord can be visualized: The cervical enlargement, which extends between C3 to T1; and the lumbar enlargements which extends between L1 to S2 (Figure 3.1).

The cord is segmentally organized. There are 31 segments, defined by 31 pairs of nerves exiting the cord. These nerves are divided into 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal nerve (Figure 3.2). Dorsal and ventral roots enter and leave the vertebral column respectively through intervertebral foramen at the vertebral segments corresponding to the spinal segment.

Figure 3.2 Drawing of the 8, 12, 5, 5 and 1 cervical, thoracic, lumbar, sacral and coccygeal spinal nerves and their exit from the vertebrate, respectively.

The cord is sheathed in the same three meninges as is the brain: the pia, arachnoid and dura. The dura is the tough outer sheath, the arachnoid lies beneath it, and the pia closely adheres to the surface of the cord (Figure 3.3). The spinal cord is attached to the dura by a series of lateral denticulate ligaments emanating from the pial folds.

Figure 3.3 The three spinal cord meninges. The denticulate ligament, the dorsal root ganglion (A), and an enlarged drawing of the meninges (B).

During the initial third month of embryonic development, the spinal cord extends the entire length of the vertebral canal and both grow at about the same rate. As development continues, the body and the vertebral column continue to grow at a much greater rate than the spinal cord proper. This results in displacement of the lower parts of the spinal cord with relation to the vertebrae column. The outcome of this uneven growth is that the adult spinal cord extends to the level of the first or second lumbar vertebrae, and the nerves grow to exit through the same intervertebral foramina as they did during embryonic development. This growth of the nerve roots occurring within the vertebral canal, results in the lumbar, sacral, and coccygeal roots extending to their appropriate vertebral levels (Figure 3.2).

All spinal nerves, except the first, exit below their corresponding vertebrae. In the cervical segments, there are 7 cervical vertebrae and 8 cervical nerves (Figure 3.2). C1-C7 nerves exit above their vertebrae whereas the C8 nerve exits below the C7 vertebra. It leaves between the C7 vertebra and the first thoracic vertebra. Therefore, each subsequent nerve leaves the cord below the corresponding vertebra. In the thoracic and upper lumbar regions, the difference between the vertebrae and cord level is three segments. Therefore, the root filaments of spinal cord segments have to travel longer distances to reach the corresponding intervertebral foramen from which the spinal nerves emerge. The lumbosacral roots are known as the cauda equina (Figure 3.2).

Each spinal nerve is composed of nerve fibers that are related to the region of the muscles and skin that develops from one body somite (segment). A spinal segment is defined by dorsal roots entering and ventral roots exiting the cord, (i.e., a spinal cord section that gives rise to one spinal nerve is considered as a segment.) (Figure 3.4).

Figure 3.4 (A) Drawing of the spinal cord with its spinal roots. (B) Drawing of the spinal vertebrate. (C) Section of the spinal cord, its meninges and the dorsal and ventral roots of three segments.

A dermatome is an area of skin supplied by peripheral nerve fibers originating from a single dorsal root ganglion. If a nerve is cut, one loses sensation from that dermatome. Because each segment of the cord innervates a different region of the body, dermatomes can be precisely mapped on the body surface, and loss of sensation in a dermatome can indicate the exact level of spinal cord damage in clinical assessment of injury (Figure 3.5). It is important to consider that there is some overlap between neighboring dermatomes. Because sensory information from the body is relayed to the CNS through the dorsal roots, the axons originating from dorsal root ganglion cells are classified as primary sensory afferents, and the dorsal root's neurons are the first order (1) sensory neuron. Most axons in the ventral roots arise from motor neurons in the ventral horn of the spinal cord and innervate skeletal muscle. Others arise from the lateral horn and synapse on autonomic ganglia that innervate visceral organs. The ventral root axons join with the peripheral processes of the dorsal root ganglion cells to form mixed afferent and efferent spinal nerves, which merge to form peripheral nerves. Knowledge of the segmental innervation of the cutaneous area and the muscles is essential to diagnose the site of an injury.

Figure 3.5 Innervation arising from single dorsal root ganglion supplied specific skin area (a dermatome). The numbers refer to the spinal segments by which each nerve is named C = cervical; T = thoracic; L = lumbar; S = sacral spinal cord segments (dermatome).

3.4 Internal Structure of the Spinal Cord

A transverse section of the adult spinal cord shows white matter in the periphery, gray matter inside, and a tiny central canal filled with CSF at its center. Surrounding the canal is a single layer of cells, the ependymal layer. Surrounding the ependymal layer is the gray matter a region containing cell bodies shaped like the letter H or a butterfly. The two wings of the butterfly are connected across the midline by the dorsal gray commissure and below the white commissure (Figure 3.6). The shape and size of the gray matter varies according to spinal cord level. At the lower levels, the ratio between gray matter and white matter is greater than in higher levels, mainly because lower levels contain less ascending and descending nerve fibers. (Figure 3.1 and Figure 3.6).

Figure 3.6 Spinal cord section showing the white and the gray matter in four spinal cord levels.

The gray matter mainly contains the cell bodies of neurons and glia and is divided into four main columns: dorsal horn, intermediate column, lateral horn and ventral horn column. (Figure 3.6).

The dorsal horn is found at all spinal cord levels and is comprised of sensory nuclei that receive and process incoming somatosensory information. From there, ascending projections emerge to transmit the sensory information to the midbrain and diencephalon. The intermediate column and the lateral horn comprise autonomic neurons innervating visceral and pelvic organs. The ventral horn comprises motor neurons that innervate skeletal muscle.

At all the levels of the spinal cord, nerve cells in the gray substance are multipolar, varying much in their morphology. Many of them are Golgi type I and Golgi type II nerve cells. The axons of Golgi type I are long and pass out of the gray matter into the ventral spinal roots or the fiber tracts of the white matter. The axons and dendrites of the Golgi type II cells are largely confined to the neighboring neurons in the gray matter.

A more recent classification of neurons within the gray matter is based on function. These cells are located at all levels of the spinal cord and are grouped into three main categories: root cells, column or tract cells and propriospinal cells.

The root cells are situated in the ventral and lateral gray horns and vary greatly in size. The most prominent features of the root cells are large multipolar elements exceeding 25 m of their somata. The root cells contribute their axons to the ventral roots of the spinal nerves and are grouped into two major divisions: 1) somatic efferent root neurons, which innervate the skeletal musculature; and 2) the visceral efferent root neurons, also called preganglionic autonomic axons, which send their axons to various autonomic ganglia.

The column or tract cells and their processes are located mainly in the dorsal gray horn and are confined entirely within the CNS. The axons of the column cells form longitudinal ascending tracts that ascend in the white columns and terminate upon neurons located rostrally in the brain stem, cerebellum or diencephalon. Some column cells send their axons up and down the cord to terminate in gray matter close to their origin and are known as intersegmental association column cells. Other column cell axons terminate within the segment in which they originate and are called intrasegmental association column cells. Still other column cells send their axons across the midline to terminate in gray matter close to their origin and are called commissure association column cells.

The propriospinal cells are spinal interneurons whose axons do not leave the spinal cord proper. Propriospinal cells account for about 90% of spinal neurons. Some of these fibers also are found around the margin of the gray matter of the cord and are collectively called the fasciculus proprius or the propriospinal or the archispinothalamic tract.

3.5 Spinal Cord Nuclei and Laminae

Spinal neurons are organized into nuclei and laminae.

3.6 Nuclei

The prominent nuclear groups of cell columns within the spinal cord from dorsal to ventral are the marginal zone, substantia gelatinosa, nucleus proprius, dorsal nucleus of Clarke, intermediolateral nucleus and the lower motor neuron nuclei.

Figure 3.7 Spinal cord nuclei and laminae.

Marginal zone nucleus or posterior marginalis, is found at all spinal cord levels as a thin layer of column/tract cells (column cells) that caps the tip of the dorsal horn. The axons of its neurons contribute to the lateral spinothalamic tract which relays pain and temperature information to the diencephalon (Figure 3.7).

Substantia gelatinosa is found at all levels of the spinal cord. Located in the dorsal cap-like portion of the head of the dorsal horn, it relays pain, temperature and mechanical (light touch) information and consists mainly of column cells (intersegmental column cells). These column cells synapse in cell at Rexed layers IV to VII, whose axons contribute to the ventral (anterior) and lateral spinal thalamic tracts. The homologous substantia gelatinosa in the medulla is the spinal trigeminal nucleus.

Nucleus proprius is located below the substantia gelatinosa in the head and neck of the dorsal horn. This cell group, sometimes called the chief sensory nucleus, is associated with mechanical and temperature sensations. It is a poorly defined cell column which extends through all segments of the spinal cord and its neurons contribute to ventral and lateral spinal thalamic tracts, as well as to spinal cerebellar tracts. The axons originating in nucleus proprius project to the thalamus via the spinothalamic tract and to the cerebellum via the ventral spinocerebellar tract (VSCT).

Dorsal nucleus of Clarke is a cell column located in the mid-portion of the base form of the dorsal horn. The axons from these cells pass uncrossed to the lateral funiculus and form the dorsal (posterior) spinocerebellar tract (DSCT), which subserve unconscious proprioception from muscle spindles and Golgi tendon organs to the cerebellum, and some of them innervate spinal interneurons. The dorsal nucleus of Clarke is found only in segments C8 to L3 of the spinal cord and is most prominent in lower thoracic and upper lumbar segments. The homologous dorsal nucleus of Clarke in the medulla is the accessory cuneate nucleus, which is the origin of the cuneocerebellar tract (CCT).

Intermediolateral nucleus is located in the intermediate zone between the dorsal and the ventral horns in the spinal cord levels. Extending from C8 to L3, it receives viscerosensory information and contains preganglionic sympathetic neurons, which form the lateral horn. A large proportion of its cells are root cells which send axons into the ventral spinal roots via the white rami to reach the sympathetic tract as preganglionic fibers. Similarly, cell columns in the intermediolateral nucleus located at the S2 to S4 levels contains preganglionic parasympathetic neurons (Figure 3.7).

Lower motor neuron nuclei are located in the ventral horn of the spinal cord. They contain predominantly motor nuclei consisting of , and motor neurons and are found at all levels of the spinal cord--they are root cells. The a motor neurons are the final common pathway of the motor system, and they innervate the visceral and skeletal muscles.

3.7 Rexed Laminae

The distribution of cells and fibers within the gray matter of the spinal cord exhibits a pattern of lamination. The cellular pattern of each lamina is composed of various sizes or shapes of neurons (cytoarchitecture) which led Rexed to propose a new classification based on 10 layers (laminae). This classification is useful since it is related more accurately to function than the previous classification scheme which was based on major nuclear groups (Figure 3.7).

Laminae I to IV, in general, are concerned with exteroceptive sensation and comprise the dorsal horn, whereas laminae V and VI are concerned primarily with proprioceptive sensations. Lamina VII is equivalent to the intermediate zone and acts as a relay between muscle spindle to midbrain and cerebellum, and laminae VIII-IX comprise the ventral horn and contain mainly motor neurons. The axons of these neurons innervate mainly skeletal muscle. Lamina X surrounds the central canal and contains neuroglia.

Rexed lamina I Consists of a thin layer of cells that cap the tip of the dorsal horn with small dendrites and a complex array of nonmyelinated axons. Cells in lamina I respond mainly to noxious and thermal stimuli. Lamina I cell axons join the contralateral spinothalamic tract; this layer corresponds to nucleus posteromarginalis.

Rexed lamina II Composed of tightly packed interneurons. This layer corresponds to the substantia gelatinosa and responds to noxious stimuli while others respond to non-noxious stimuli. The majority of neurons in Rexed lamina II axons receive information from sensory dorsal root ganglion cells as well as descending dorsolateral fasciculus (DLF) fibers. They send axons to Rexed laminae III and IV (fasciculus proprius). High concentrations of substance P and opiate receptors have been identified in Rexed lamina II. The lamina is believed to be important for the modulation of sensory input, with the effect of determining which pattern of incoming information will produce sensations that will be interpreted by the brain as being painful.

Rexed lamina III Composed of variable cell size, axons of these neurons bifurcate several times and form a dense plexus. Cells in this layer receive axodendritic synapses from A fibers entering dorsal root fibers. It contains dendrites of cells from laminae IV, V and VI. Most of the neurons in lamina III function as propriospinal/interneuron cells.

Rexed lamina IV The thickest of the first four laminae. Cells in this layer receive A axons which carry predominantly non-noxious information. In addition, dendrites of neurons in lamina IV radiate to lamina II, and respond to stimuli such as light touch. The ill-defined nucleus proprius is located in the head of this layer. Some of the cells project to the thalamus via the contralateral and ipsilateral spinothalamic tract.

Rexed lamina V Composed neurons with their dendrites in lamina II. The neurons in this lamina receive monosynaptic information from A, Ad and C axons which also carry nociceptive information from visceral organs. This lamina covers a broad zone extending across the neck of the dorsal horn and is divided into medial and lateral parts. Many of the Rexed lamina V cells project to the brain stem and the thalamus via the contralateral and ipsilateral spinothalamic tract. Moreover, descending corticospinal and rubrospinal fibers synapse upon its cells.

Rexed lamina VI Is a broad layer which is best developed in the cervical and lumbar enlargements. Lamina VI divides also into medial and lateral parts. Group Ia afferent axons from muscle spindles terminate in the medial part at the C8 to L3 segmental levels and are the source of the ipsilateral spinocerebellar pathways. Many of the small neurons are interneurons participating in spinal reflexes, while descending brainstem pathways project to the lateral zone of Rexed layer VI.

Rexed lamina VII This lamina occupies a large heterogeneous region. This region is also known as the zona intermedia (or intermediolateral nucleus). Its shape and boundaries vary along the length of the cord. Lamina VII neurons receive information from Rexed lamina II to VI as well as visceral afferent fibers, and they serve as an intermediary relay in transmission of visceral motor neurons impulses. The dorsal nucleus of Clarke forms a prominent round oval cell column from C8 to L3. The large cells give rise to uncrossed nerve fibers of the dorsal spinocerebellar tract (DSCT). Cells in laminae V to VII, which do not form a discrete nucleus, give rise to uncrossed fibers that form the ventral spinocerebellar tract (VSCT). Cells in the lateral horn of the cord in segments T1 and L3 give rise to preganglionic sympathetic fibers to innervate postganglionic cells located in the sympathetic ganglia outside the cord. Lateral horn neurons at segments S2 to S4 give rise to preganglionic neurons of the sacral parasympathetic fibers to innervate postganglionic cells located in peripheral ganglia.

Rexed lamina VIII Includes an area at the base of the ventral horn, but its shape differs at various cord levels. In the cord enlargements, the lamina occupies only the medial part of the ventral horn, where descending vestibulospinal and reticulospinal fibers terminate. The neurons of lamina VIII modulate motor activity, most probably via g motor neurons which innervate the intrafusal muscle fibers.

Rexed lamina IX Composed of several distinct groups of large a motor neurons and small and motor neurons embedded within this layer. Its size and shape differ at various cord levels. In the cord enlargements the number of motor neurons increase and they form numerous groups. The motor neurons are large and multipolar cells and give rise to ventral root fibers to supply extrafusal skeletal muscle fibers, while the small motor neurons give rise to the intrafusal muscle fibers. The motor neurons are somatotopically organized.

Rexed lamina X Neurons in Rexed lamina X surround the central canal and occupy the commissural lateral area of the gray commissure, which also contains decussating axons.

In summary, laminae I-IV are concerned with exteroceptive sensations, whereas laminae V and VI are concerned primarily with proprioceptive sensation and act as a relay between the periphery to the midbrain and the cerebellum. Laminae VIII and IX form the final motor pathway to initiate and modulate motor activity via , and motor neurons, which innervate striated muscle. All visceral motor neurons are located in lamina VII and innervate neurons in autonomic ganglia.

3.8 White Matter

Surrounding the gray matter is white matter containing myelinated and unmyelinated nerve fibers. These fibers conduct information up (ascending) or down (descending) the cord. The white matter is divided into the dorsal (or posterior) column (or funiculus), lateral column and ventral (or anterior) column (Figure 3.8). The anterior white commissure resides in the center of the spinal cord, and it contains crossing nerve fibers that belong to the spinothalamic tracts, spinocerebellar tracts, and anterior corticospinal tracts. Three general nerve fiber types can be distinguished in the spinal cord white matter: 1) long ascending nerve fibers originally from the column cells, which make synaptic connections to neurons in various brainstem nuclei, cerebellum and dorsal thalamus, 2) long descending nerve fibers originating from the cerebral cortex and various brainstem nuclei to synapse within the different Rexed layers in the spinal cord gray matter, and 3) shorter nerve fibers interconnecting various spinal cord levels such as the fibers responsible for the coordination of flexor reflexes. Ascending tracts are found in all columns whereas descending tracts are found only in the lateral and the anterior columns.

Figure 3.8 The spinal cord white matter and its three columns, and the topographical location of the main ascending spinal cord tracts.

Four different terms are often used to describe bundles of axons such as those found in the white matter: funiculus, fasciculus, tract, and pathway. Funiculus is a morphological term to describe a large group of nerve fibers which are located in a given area (e.g., posterior funiculus). Within a funiculus, groups of fibers from diverse origins, which share common features, are sometimes arranged in smaller bundles of axons called fasciculus, (e.g., fasciculus proprius [Figure 3.8]). Fasciculus is primarily a morphological term whereas tracts and pathways are also terms applied to nerve fiber bundles which have a functional connotation. A tract is a group of nerve fibers which usually has the same origin, destination, and course and also has similar functions. The tract name is derived from their origin and their termination (i.e., corticospinal tract - a tract that originates in the cortex and terminates in the spinal cord; lateral spinothalamic tract - a tract originated in the lateral spinal cord and ends in the thalamus). A pathway usually refers to the entire neuronal circuit responsible for a specific function, and it includes all the nuclei and tracts which are associated with that function. For example, the spinothalamic pathway includes the cell bodies of origin (in the dorsal root ganglia), their axons as they project through the dorsal roots, synapses in the spinal cord, and projections of second and third order neurons across the white commissure, which ascend to the thalamus in the spinothalamic tracts.

3.9 Spinal Cord Tracts

The spinal cord white matter contains ascending and descending tracts.

Ascending tracts (Figure 3.8). The nerve fibers comprise the ascending tract emerge from the first order (1) neuron located in the dorsal root ganglion (DRG). The ascending tracts transmit sensory information from the sensory receptors to higher levels of the CNS. The ascending gracile and cuneate fasciculi occupying the dorsal column, and sometimes are named the dorsal funiculus. These fibers carry information related to tactile, two point discrimination of simultaneously applied pressure, vibration, position, and movement sense and conscious proprioception. In the lateral column (funiculus), the neospinothalamic tract (or lateral spinothalamic tract) is located more anteriorly and laterally, and carries pain, temperature and crude touch information from somatic and visceral structures. Nearby laterally, the dorsal and ventral spinocerebellar tracts carry unconscious proprioception information from muscles and joints of the lower extremity to the cerebellum. In the ventral column (funiculus) there are four prominent tracts: 1) the paleospinothalamic tract (or anterior spinothalamic tract) is located which carry pain, temperature, and information associated with touch to the brain stem nuclei and to the diencephalon, 2) the spinoolivary tract carries information from Golgi tendon organs to the cerebellum, 3) the spinoreticular tract, and 4) the spino-tectal tract. Intersegmental nerve fibers traveling for several segments (2 to 4) and are located as a thin layer around the gray matter is known as fasciculus proprius, spinospinal or archispinothalamic tract. It carries pain information to the brain stem and diencephalon.

Descending tracts (Figure 3.9). The descending tracts originate from different cortical areas and from brain stem nuclei. The descending pathway carry information associated with maintenance of motor activities such as posture, balance, muscle tone, and visceral and somatic reflex activity. These include the lateral corticospinal tract and the rubrospinal tracts located in the lateral column (funiculus). These tracts carry information associated with voluntary movement. Other tracts such as the reticulospinal vestibulospinal and the anterior corticospinal tract mediate balance and postural movements (Figure 3.9). Lissauer's tract, which is wedged between the dorsal horn and the surface of the spinal cord carry the descending fibers of the dorsolateral funiculus (DFL), which regulate incoming pain sensation at the spinal level, and intersegmental fibers. Additional details about ascending and descending tracts are described in the next few chapters.

Figure 3.9 The main descending spinal cord tracts.

3.10 Dorsal Root

Figure 3.10 Spinal cord section with its ventral and dorsal root fibers and ganglion.

Information from the skin, skeletal muscle and joints is relayed to the spinal cord by sensory cells located in the dorsal root ganglia. The dorsal root fibers are the axons originated from the primary sensory dorsal root ganglion cells. Each ascending dorsal root axon, before reaching the spinal cord, bifurcates into ascending and descending branches entering several segments below and above their own segment. The ascending dorsal root fibers and the descending ventral root fibers from and to discrete body areas form a spinal nerve (Figure 3.10). There are 31 paired spinal nerves. The dorsal root fibers segregate into lateral and medial divisions. The lateral division contains most of the unmyelinated and small myelinated axons carrying pain and temperature information to be terminated in the Rexed laminae I, II, and IV of the gray matter. The medial division of dorsal root fibers consists mainly of myelinated axons conducting sensory fibers from skin, muscles and joints; it enters the dorsal/posterior column/funiculus and ascend in the dorsal column to be terminated in the ipsilateral nucleus gracilis or nucleus cuneatus at the medulla oblongata region, i.e., the axons of the first-order (1) sensory neurons synapse in the medulla oblongata on the second order (2) neurons (in nucleus gracilis or nucleus cuneatus). In entering the spinal cord, all fibers send collaterals to different Rexed lamina.

Axons entering the cord in the sacral region are found in the dorsal column near the midline and comprise the fasciculus gracilis, whereas axons that enter at higher levels are added in lateral positions and comprise the fasciculus cuneatus (Figure 3.11). This orderly representation is termed somatotopic representation.

Figure 3.11 Somatotopical representation of the spinal thalamic tract and the dorsal column.

3.11 Ventral Root

Ventral root fibers are the axons of motor and visceral efferent fibers and emerge from poorly defined ventral lateral sulcus as ventral rootlets. The ventral rootlets from discrete spinal cord section unite and form the ventral root, which contain motor nerve axons from motor and visceral motor neurons. The motor nerve axons innervate the extrafusal muscle fibers while the small motor neuron axons innervate the intrafusal muscle fibers located within the muscle spindles. The visceral neurons send preganglionic fibers to innervate the visceral organs. All these fibers join the dorsal root fibers distal to the dorsal root ganglion to form the spinal nerve (Figure 3.10).

3.12 Spinal Nerve Roots

The spinal nerve roots are formed by the union of dorsal and ventral roots within the intervertebral foramen, resulting in a mixed nerve joined together and forming the spinal nerve (Figure 3.10). Spinal nerve rami include the dorsal primary nerves (ramus), which innervates the skin and muscles of the back, and the ventral primary nerves (ramus), which innervates the ventral lateral muscles and skin of the trunk, extremities and visceral organs. The ventral and dorsal roots also provide the anchorage and fixation of the spinal cord to the vertebral cauda.

3.13 Blood Supply of the Spinal Cord

The arterial blood supply to the spinal cord in the upper cervical regions is derived from two branches of the vertebral arteries, the anterior spinal artery and the posterior spinal arteries (Figure 3.12). At the level of medulla, the paired anterior spinal arteries join to form a single artery that lies in the anterior median fissure of the spinal cord. The posterior spinal arteries are paired and form an anastomotic chain over the posterior aspect of the spinal cord. A plexus of small arteries, the arterial vasocorona, on the surface of the cord constitutes an anastomotic connection between the anterior and posterior spinal arteries. This arrangement provides uninterrupted blood supplies along the entire length of the spinal cord.

Figure 3.12 The spinal cord arterial circulation.

At spinal cord regions below upper cervical levels, the anterior and posterior spinal arteries narrow and form an anastomotic network with radicular arteries. The radicular arteries are branches of the cervical, trunk, intercostal & iliac arteries. The radicular arteries supply most of the lower levels of the spinal cord. There are approximately 6 to 8 pairs of radicular arteries supplying the anterior and posterior spinal cord (Figure 3.12).

Test Your Knowledge

The spinal cord...

A. Occupies the lumbar cistern

B. Has twelve (12) cervical segments

C. Contains the cell bodies of postganglionic sympathetic efferent neurons

D. Ends at the conus medullaris

E. Has no arachnoid membrane

The spinal cord...

A. Occupies the lumbar cistern This answer is INCORRECT.

The spinal cord does not occupy the lumbar cistern.

B. Has twelve (12) cervical segments

C. Contains the cell bodies of postganglionic sympathetic efferent neurons

D. Ends at the conus medullaris

E. Has no arachnoid membrane

The spinal cord...

A. Occupies the lumbar cistern

B. Has twelve (12) cervical segments This answer is INCORRECT.

The spinal cord has seven (7) cervical segments.

C. Contains the cell bodies of postganglionic sympathetic efferent neurons

D. Ends at the conus medullaris

E. Has no arachnoid membrane

The spinal cord...

A. Occupies the lumbar cistern

B. Has twelve (12) cervical segments

C. Contains the cell bodies of postganglionic sympathetic efferent neurons This answer is INCORRECT.

More here:
Anatomy of the Spinal Cord (Section 2, Chapter 3 ...

Spinal Cord Stem Cells Comments Off on Anatomy of the Spinal Cord (Section 2, Chapter 3 … | November 2nd, 2015

An illustration of GRNOPC1, a drug based on human embryonic stem cells, which contains oligodendrocyte progenitor cells.

Geron/UC Irvine

The hope: that one day this treatment may help the paralyzed walk again.

On Friday at the Shepherd Center, a spinal cord and brain injury rehabilitation center in Atlanta, a patient with a recent spinal cord injury made medical history: The paraplegic was injected with two million embryonic stem cells.

The goal: To regenerate spinal cord tissue.

The process, reports CBS Station KPIX correspondent Dr. Kim Mulvihill, involves coaxing the cells into becoming specialized nerve cells, and then injecting them directly into the injured area of the spinal cord.

The embryonic stem cells come from a donated human embryo left over from a fertility treatment, an embryo that would have otherwise been discarded.

Embryonic stem cells have been at the center of funding controversies because the research involves destroying the embryos, which some have argued is akin to abortion. But, many researchers consider embryonic stem cells the most versatile types of stem cells, as they can morph into any type of cell.

While there are some restrictions on federal funding for stem cell lines for research, companies such as Geron do not use federal funding and are therefore free from those restrictions.

The study is approved by the FDA but is privately funded.

The drug - known as GRNOPC1 - contains cells called oligodendrocyte progenitor cells. Those progenitor cells turn into oligodendrocytes, a type of cell that produces myelin, a coating that allows impulses to move along nerves. When those cells are lost because of injury, paralysis can follow.

If GRNOPC1 works, the progenitor cells will produce new oligodendrocytes in the injured area of the patient's spine, potentially allowing for new movement.

The therapy will be injected into the patients' spines one to two weeks after they suffer an injury between their third and 10th thoracic vertebrae, or roughly the middle to upper back. Later trials would include patients with less severe spinal injuries and damage to other parts of the spine.

In lab animals, the results were dramatic - paralyzed rodents moved again.

Dr. Thomas Okarma, President and CEO of Geron, told CBS Station KPIX, "This therapy goes far beyond the reach of pills or scalpels and will achieve a new level of healing with a single injection of healthy replacement cells."

So far, Geron of Menlo Park, Calif., has spent $175 million in developing this treatment.

However, Dr. Arnold Kriegstein, who heads Regeneration Medicine & Stem Cell Research at University of California-San Francisco, told KPIX, "People are just so different from rodents."

Though optimistic, he urged caution. "I think that people looking at the outcome of this trial should really lower their expectations if they're really thinking people will get out of their wheelchairs. It's unlikely to happen."

The drug still faces many years of testing for effectiveness and tolerance if all goes well in the early stage study.

This initial trial is not aimed at a cure for patients, but to establish if the treatment is safe.

Patients must be treated within 14 days of a spinal cord injury and they must undergo short term immune suppression therapy to make sure their bodies don't reject the cells.

If the treatment is deemed safe, the next trial will aim at testing effectiveness and will use a higher quantity of stem cells.

Shepherd Center is one of seven potential sites in the United States for the trial.

The company has said it plans to enroll eight to 10 patients in the study at sites nationwide. The trial will take about two years, with each patient being studied for one year.

Geron is among several companies focusing on embryonic stem cell therapy. Advanced Cell Technology Inc. hopes to develop the embryonic stem cell therapy called retinal pigment epithelium, or RPE. That therapy is designed to treat Stargart disease, an inherited condition that affects children and can lead to blindness in adulthood.

Meanwhile, other companies such as StemCells Inc. are focusing on adult stem cells, which can be gathered from a person's skin.

For more info: clinicaltrials.goc - Safety Study of GRNOPC1 in Spinal Cord Injury

2010 CBS Interactive Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.

The rest is here:
Embryonic Stem Cell Test on Spinal Cord Injury - CBS News

Spinal Cord Stem Cells Comments Off on Embryonic Stem Cell Test on Spinal Cord Injury – CBS News | October 4th, 2015

Combined NSC transplantation and VPA administration improves functional recovery of hind limbs without CST axon reextension. As VPA has been shown to have effects that are likely to be beneficial to treatment of the injured CNS, such as neuroprotection (2731), induction of neuronal differentiation (26), and promotion of neurite outgrowth (32), we examined the response of SCI model mice to different combinations of VPA administration and NSC transplantation. We prepared NSCs from embryonic forebrains of 3 different Tg mouse lines ubiquitously expressing either GFP (GFP-Tg) (33), GFP and LUC (GFP.LUC-Tg), or GFP, LUC, and the diphtheria toxin (DT) receptor human heparin-binding EGF-like growth factor (TR6) (TR6.GFP.LUC-Tg) (see Methods). The expression of GFP, LUC, and TR6 in NSCs enabled us to distinguish transplanted cells from host cells, to trace the survival of transplanted cells based on LUC activity in a noninvasive fashion, and to specifically ablate transplanted cells (see below), respectively. To obtain a homogeneous population of NSCs, we used adherent monolayer culture (3436). The embryonic forebrains were dissociated and cultured with EGF and basic FGF (bFGF) (36) (Supplemental Figure 1, A and B; supplemental material available online with this article; doi:10.1172/JCI42957DS1). These cells uniformly expressed the stem cell markers Sox2 and nestin but did not express differentiation markers (Supplemental Figure 1, C and D). Under the appropriate conditions for each lineage, these NSCs differentiated into neurons, astrocytes, or oligodendrocytes (Supplemental Figure 1, E and F). NSCs from different Tg mice behaved similarly in these culture conditions (data not shown). NSCs that had been cultured and passaged 510 times in the presence of both EGF and bFGF to maintain the undifferentiated state were used for transplantation studies.

Undifferentiated NSCs were transplanted into the SCI epicenter 7 days after injury. Nontransplanted control and transplanted mice were then intraperitoneally administered VPA or saline daily for 7 days (Figure 1A), whereafter we monitored their hind limb motor function using the open field locomotor scale (BBB score) (79, 37) for 6 weeks. Remarkably, we found that the simultaneous treatment of SCI model mice with NSCs and VPA resulted in a dramatic recovery of hind limb function compared with either treatment alone (Figure 1B and Supplemental Videos 14). There were no significant differences among the data obtained from each SCI model mouse group transplanted with the 3 distinct NSCs. Functional recovery of each treated SCI model mouse reached a plateau at around 6 weeks, the level of which was sustained for more than 3 months. Since mice treated with VPA alone showed no further improvement compared with untreated mice, it is most likely that VPA affected the function of transplanted cells.

A combination of NSC transplantation and VPA administration improves functional recovery of hind limbs without CST axon reextension. (A) Schematic of the NSC transplantation and VPA injection protocol. (B) Time course of functional recovery of hind limbs after SCI. GFP-NSCs, GFP.LUC-NSCs, and TR6.GFP.LUC-NSCs were transplanted into the SCI epicenter 7 days after injury as indicated. Combined treatment with NSC transplantation and VPA administration resulted in the greatest functional recovery. Data represent mean SEM. **P < 0.001 compared with SCI models with no treatment; *P < 0.01 compared with SCI models with no treatment (repeated measures ANOVA). NSC+VPA, total n = 21. (C) Representative pictures of BDA-labeled CST fibers at 5 mm rostral and 5 mm caudal to the lesion site. BDA was injected into the motor cortices 12 weeks after SCI. 2 weeks after the injection, mice were fixed and spinal cord sections were stained. Representative results for a GFP-NSCtransplanted spinal cord are shown. Blue, Hoechst nuclear staining. Scale bar: 20 m. (D) Quantification of the labeled CST fibers in the spinal cords of intact mice, SCI mice receiving no treatment, and SCI mice undergoing combined NSC/VPA treatment. Eight 30-mthick serial parasagittal sections from individual spinal cords were evaluated. The x axis indicates specific locations along the rostrocaudal axis of the spinal cord, and the y axis indicates the ratio of the number of BDA-labeled fibers at the indicated site to that at 6 mm rostral to the lesion site (Th9). **P < 0.001 compared with SCI models without treatment; *P = 0.188 There is no significant difference in the number of BDA-labeled fibers between NSC+VPA-treated mice (blue line) and SCI model mice with no treatment (yellow line) (repeated measures ANOVA). All data shown are from at least 3 experiments in parallel conditions, with error bars representing SEM.

We next sought to determine the basis for this improvement in locomotor function. Since transplanted NSCs have been reported to play a supportive role in the reextension of injured axons (14), we analyzed whether CST axons were regenerated by anterograde labeling using biotinylated dextran amine (BDA) (6, 16, 17). Because BDA was injected into the motor cortex, only the axons of first-order neurons in the CST could be visualized (Figure 1C). In our SCI model mice, the caudal part of the injured site was completely devoid of CST axons (Figure 1, C and D), and the same was true in mice that had undergone combined NSC transplantation and VPA administration (Figure 1, C and D). These data indicated that CST axons did not reextend in mice treated with both NSCs and VPA and therefore that some other mechanism was responsible for the animals dramatic functional locomotor improvement.

Transplanted NSCs encompass the lesion site and extend their processes. Given that host CST axon reextension was not involved in the observed hind limb recovery, we decided to focus on the transplanted cells. We analyzed the migration, morphology, neuronal marker expression, and viability of these cells after coadministration with VPA. Transplant-derived cells migrated to both rostral and caudal areas and displayed processes that extended into the gray matter and dorsal funiculus within 5 weeks of transplantation (Figure 2). Between 20% and 40% of the transplanted cells were found to be surviving in the injured spinal cord after 8 weeks, and 17% still remained viable more than 1 year after transplantation (data not shown). About 20% of the surviving cells had differentiated into microtubule-associated protein 2positive (MAP2-positive) neurons with elongated processes within 5 weeks after transplantation (Figure 2, B and C, and Figure 3, E and F). Survival of the transplanted NSCs was not significantly influenced by VPA administration (Supplemental Figure 8).

Transplanted NSCs migrate from the injection site and encompass the lesion site. Representative results of GFP-NSCtransplanted SCI model mice are shown. (A) A series of immunostaining images of injured spinal cord at 6 weeks after injury. SCI mice received combination treatment with NSC transplantation and VPA administration. Specimens were picked up every 150 m and stained with anti-GFP (green) and MAP2 (not shown) antibodies and Hoechst (blue). The epicenter of the SCI is indicated (*). Scale bar: 1 mm. (B and C) Higher-magnification images of the white boxes in A. GFP-positive transplanted NSCs differentiated into MAP2-positive neurons and extended their processes. Scale bar: 50 m.

VPA promotes neuronal differentiation of transplanted NSCs. Representative results of GFP-NSCtransplanted SCI model mice are shown. (A) Confocal images of NSCs 1 week after transplantation into the injured spinal cords. Spinal cord sections from VPA-treated (+) and untreated () mice were stained with anti-GFP (green), anti-doublecortin (DCX) (immature neuronal marker, red) and anti-GFAP (magenta) antibodies, and Hoechst (blue). VPA administration resulted in an increase in the number of DCX-positive neuronal precursors among transplanted cells (lower panel). Scale bar: 20 m. (BD) The percentages of DCX-, GFAP-, and MBP-positive cells in GFP-positive transplanted cells were quantified. **P < 0.01; *P < 0.05 compared with controls (Students t test). (E) Confocal images of NSCs 5 weeks after transplantation into injured spinal cords. Spinal cord sections from VPA-treated (+) and untreated () mice were stained with anti-GFP (green), anti-MAP2 (neuronal marker, red) and anti-GFAP (magenta) antibodies, and Hoechst (blue). VPA administration increased the numbers of MAP2-positive neurons (lower panel). Scale bar: 20 m. (F and G) The percentages of cells positive for MAP2 or GFAP in GFP-positive transplanted cells in E were quantified. **P < 0.01; *P < 0.05 compared with control (Students t test). All data shown in BD, F, and G are from at least 15 confocal images of 3 individuals in parallel experiments, with error bars representing the SD.

HDAC inhibition promotes neuronal differentiation of NSCs and is critical for transplantation-induced hind limb recovery. In contrast to previous studies, which have indicated that very few transplanted NSCs differentiate into neurons in the injured CNS environment (8, 10, 11, 20), many neurons were observed in the spinal cord after coadministration with VPA. We next examined in more detail the contribution of VPA to differentiation of cultured and transplanted NSCs. To analyze differentiation in vitro, NSCs were treated with either VPA or valpromide (VPM), an amide analog of VPA that is also an antiepileptic but is not an HDAC inhibitor (24), under differentiation culture conditions. VPA enhanced histone acetylation (Supplemental Figure 2A) and promoted neuronal differentiation and neurite outgrowth of the NSCs (Supplemental Figure 3, AC); it also inhibited astrocytic and oligodendrocytic differentiation of NSCs (Supplemental Figure 3, DG). A different HDAC inhibitor, trichostatin A (TSA), also enhanced histone acetylation (Supplemental Figure 2A) and neuronal differentiation of NSCs (not shown) (26). In contrast, VPM neither enhanced histone acetylation nor induced neuronal differentiation, suggesting that HDAC inhibition has an important role in regulating fate determination in NSCs.

We then assessed the histone acetylation status and differentiation profiles of transplanted NSCs. VPA administration enhanced histone acetylation in transplanted cells in the spinal cord (Supplemental Figure 2, B and C). When we examined the differentiation status of transplanted cells 1 week after transplantation, neuronal but not glial differentiation was greatly enhanced by VPA administration (Figure 3, AD, and Supplemental Figure 4A). A similar differentiation tendency of transplanted NSCs to that at 1 week was observed at 5 weeks after transplantation: there was a dramatic increase in the number of cells positive for MAP2 (a relatively late differentiation marker of neurons in comparison with DCX) in VPA-administered mice (Figure 3, EG, and Supplemental Figure 4B). Furthermore, VPM administration to the SCI mice neither promoted neuronal differentiation nor enhanced hind limb motor function, suggesting that HDAC inhibition has an essential role in regulating fate determination of transplanted NSCs and improvement of motor function in vivo (Supplemental Figure 5, AC). In light of the above findings that the percentage of neurons generated from transplanted NSCs increased dramatically with VPA administration, whereas those of astrocytes and oligodendrocytes declined, we anticipated that these neurons would be likely to play a major role in regenerating the disrupted neuronal circuitry of the injured spinal cord.

Transplant-derived neurons reconstruct disrupted neuronal circuits in a relay manner. We next asked how the disrupted neuronal circuits were regenerated following the combined treatment with NSC transplantation and VPA administration. Wheat germ agglutinin (WGA), which can be transsynaptically transported, is one of the best known tracers of neural pathways (38). WGA protein can be transferred across synapses to second- and third-order neurons, permitting functional neuronal circuits to be tracked in the CNS. We injected WGA-expressing adenoviruses into the motor cortex of mouse brain 12 weeks after SCI. In uninjured mice, WGA was detected as intracellular granule-like structures in neurons localized in the ventral horn throughout the spinal cord (Figure 4, A and B). In untreated SCI model mice, WGA granules were almost completely absent from the caudal region below the injured site (Figure 4, A and C). Surprisingly, although we could not observe CST axonal reextension through the lesion site (Figure 1, C and D), WGA granules were clearly present in caudal large neurons located in the spinal cords of mice treated with both NSC and VPA (Figure 4, A and D). Intriguingly, moreover, transplant-derived neurons in or close to the lesion site contained WGA granules (Figure 4E), which were received from more rostral neurons. These data imply that WGA was conveyed through the lesion site to the caudal area via transplant-derived neurons. Considering this finding, together with the fact that WGA could be detected in caudal neurons without CST axonal reextension in mice that had undergone the combined treatment, it seemed conceivable that the transplant-derived neurons reconstructed the disrupted neuronal circuits, thereby acting as relays for transmitting signals between endogenous neurons whose interconnection had been abolished by the injury. In mice that received NSC transplantation alone after SCI, the percentage of WGA-positive cells among MAP2ab-positive cells in the caudal region was higher than that in untreated mice (Figure 4C) but lower than that in mice receiving combined NSC transplantation and VPA administration (Supplemental Figure 6), reflecting the degree of hind limb functional improvement (Figure 1C).

Transplant-derived neurons reconstruct disrupted neuronal circuits in a relay manner. (A) Representative pictures of WGA-labeled neuronal cell bodies located in the ventral horn at 14 weeks after SCI. Spinal cord sections were stained with anti-WGA (red) and -MAP2ab (magenta) antibodies and Hoechst (blue). Scale bar: 20 m. Intense WGA immunoreactivity was observed as intracellular granule-like structures. Left panels show the rostral area (Th4Th7), and right panels show the caudal area (Th11 to lumbar vertebra [L] 1). In uninjured mice, WGA injected into the bilateral motor cortices was transsynaptically transported to neurons in areas rostral and caudal to the injured site (top panels). In the SCI model mice that did not receive treatment, very little WGA was observed in caudal areas (middle panels). However, in spinal cords of animals that underwent dual treatment with NSC and VPA, WGA was clearly observed in neurons in the caudal areas (bottom panels). Representative results of GFP-NSCtransplanted SCI model mice are shown. (BD) The percentages of WGA-positive cells in the neurons localized in the ventral horn were quantified. **P < 0.05 (Students t test). All data shown are from at least 30 images, containing more than 600 cells, from 3 individuals (5 images per area) in parallel experiments, with error bars representing SD. (E) Representative confocal images of WGA-labeled transplant-derived MAP2-positive neurons. Sections were stained with anti-WGA (red), anti-MAP2ab (magenta) and anti-GFP (green) antibodies, and Hoechst (blue). Granule-like WGA structures (yellow arrowheads) could be seen in the GFP and MAP2abdouble-positive transplant-derived neurons. Scale bar: 10 m.

In support of the notion of a relay function for transplant-derived neurons, immunoelectron microscopy revealed that GFP-positive transplant-derived neurons received projections from endogenous neurons (Figure 5, A and B) and that the axon terminals of transplant-derived neurons made synapses with endogenous neurons localized in the ventral horn (Figure 5, CE).

Transplant-derived neurons make synapses with endogenous neurons. (A) Immunoelectron microscopy image of a sagittal section of dual-treated (GFP-NSC and VPA) injured spinal cord (rostral area). A GFP-positive dendrite (Den) made synapses with GFP-negative endogenous axon termini (At) (yellow arrowheads). Scale bar: 1 m. (B) In other rostral regions, a dendrite of a GFP-positive transplant-derived neuron made a synapse (yellow arrowheads) with the axon terminus of a GFP-negative endogenous neuron. Scale bar: 1 m. (C) Sagittal section of dual-treated (NSC and VPA) injured spinal cord (caudal area) stained with anti-GFP antibody (dark brown). The epicenter of the SCI is indicated (*). Scale bar: 500 m. (D) High-magnification image of a large neuron localized in the ventral horn in the white rectangle in C. GFP-positive transplanted neurons extended their processes toward an endogenous neuron (yellow arrowheads). Scale bar: 100 m. (E) Immunoelectron microscopy image of the boxed area in D. GFP-positive axon termini made synapses with the dendrite of a GFP-negative endogenous large neuron (yellow arrowheads). Scale bar: 1 m.

Transplanted cells contribute directly to functional recovery of hind limb movement in SCI mice. To determine whether the transplanted cells made a direct contribution to the functional recovery of hind limbs after SCI, we performed specific ablation of transplanted cells using the toxin receptormediated cell knockout (TRECK) method (Figure 6A and refs. 39, 40). For this purpose, we prepared NSCs from the embryonic forebrains of GFP.LUC Tg and TR6.GFP.LUC Tg mice (Figure 6A and Supplemental Figure 7, A and B). Almost all of the transplanted TR6.GFP.LUC-NSCs were specifically ablated following DT administration (Figure 6, B and C). Furthermore, after ablation of the transplanted cells, the BBB scores of SCI model mice that had undergone combined TR6.GFP.LUC-NSC transplantation and VPA administration declined rapidly to levels similar to those observed in untreated and VPA onlytreated mice. These results were superimposed on the graph in Figure 1B, with the observation period extended to 12 weeks after SCI, as shown in Figure 6D (for clarity, the data for GFP-NSC.VPA and GFP.LUC-NS in Figure 1B were removed). These data indicate that the transplanted cells, in the presence of VPA, made a direct and major contribution to the functional recovery of hind limb movement in SCI model mice.

Ablation of transplanted cells abolishes hind limb motor function recovery. (A) Schematic of the protocols for NSC transplantation and for detection and ablation of transplanted cells. NSCs derived from GFP.LUC- or TR6.GFP.LUC-Tg mice were transplanted into SCI model mice 1 week after injury. VPA was intraperitoneally administered every day for 1 week. Survival of transplanted cells and locomotor function of the mice were monitored weekly for 14 weeks. (B) Survival of transplanted cells was checked every week using a bioluminescence imaging system. 6 weeks after injury (5 weeks after transplantation), each mouse received 2 DT administrations. By the following week, LUC activity had completely disappeared in mice transplanted with TR6.GFP.LUC-NSCs (lower panel). (C) Sagittal sections from SCI model mice transplanted with GFP.LUC- and TR6.GFP.LUC-NSCs 2 weeks after DT injection. All transplanted cells were ablated with DT (lower panel). Scale bar: 1 mm. (D) Time course of the changes in BBB scores in SCI model mice. The hind limb function of mice that had undergone dual treatment with TR6.GFP.LUC-NSCs and VPA dropped drastically after DT administration (black line). *P < 0.0001 compared with GFP.LUC-NSCtransplanted, VPA-administered, and DT-injected SCI model mice (blue line) (repeated measures ANOVA). Data are mean SEM. VPA, n = 8; no treatment, n = 8. (E) Twelve weeks after injury, groups of SCI model mice received NMDA injections, as indicated, into the injury epicenter, to ablate local neurons in the gray matter (blue, black, and yellow lines with triangles). *P < 0.0001 compared with non-NMDAinjected mice in each group (blue, black, and yellow lines with circles) (repeated measures ANOVA). Data represent mean SEM.

Both endogenous and transplant-derived local neurons play an important role in improving hind limb motor function. It has been shown recently that local neurons in the spinal cord play an important role in spontaneous functional recovery after SCI (41, 42). In our SCI model, we also observed slight but significant spontaneous recovery of hind limb function in untreated mice, and similar levels of recovery were sustained after ablation of transplanted cells (Figure 6D). We thus hypothesized that these recoveries were attributable to endogenous local neurons in the spinal cord. Furthermore, it seemed likely that the much higher recovery observed in mice with the combined treatment but without cell ablation (Figure 6D) was effected by transplant-derived local neurons in addition to the endogenous ones. To evaluate the involvement of these local neurons in our treatment regime, we divided each treated mouse group analyzed in Figure 6D into 2 subgroups (except for the TR6.GFP.LUC-NCStransplanted only and VPA-administered only groups). The axon-sparing excitotoxin NMDA was injected at 12 weeks after SCI into the injury epicenter in the injured spinal cords of the mice in 1 subgroup for each treatment to ablate local neurons in the gray matter (4345). In uninjured mice, NMDA injections had no significant effect on hind limb function (data not shown). However, as shown in Figure 6E, NMDA injections completely reversed both spontaneous and treatment-provoked functional recovery of hind limb movement in SCI model mice, indicating that both endogenous and transplant-derived local neurons indeed play an important role in the restoration of hind limb motor function.

Originally posted here:
JCI - Neurons derived from transplanted neural stem cells ...

Spinal Cord Stem Cells Comments Off on JCI – Neurons derived from transplanted neural stem cells … | September 25th, 2015

Ankylosing Spondilytis, is a kind of inflammatory, autoimmune disorder of unknown etiology primarily affecting the spine, axial skeleton and large proximal joints of the body, this may inturn lead to eventual fusion of the spine.It can rage from mild to progressively degenerating diseases.

Although autoimmune, 90% of the patients suffering from the condition have proved to express the presence of HLA-B27 geneotype, confirming the genetic association of the disorder. Estimates may vary but it is observed that young men between the age group 20-40 are affected. The characterization of AS is done various symptoms, three of them occur most generally and they are pain, stiffness,excessive fatigue etc. Although the symptoms are very generalized there are some telltale conditions such as severe back pain.

The current treatments include severe physiotherapy, medication and other rehabilitation approach. However with these treatment regimen the pathophysiology of the disease is not reversed neither the further progression is stopped. On the contrary, the cutting edge stem cell treatment can offer the solution for the condition. Stem cells are the original, naive cells capable of forming any cells of the same or different lineage.

Ankylosing Spondilytis is a kind of arthritis mainly affecting the spine, but sometimes other organs are also involved.

Mentioned below is case analysis of a patient who had been suffering from Ankylosing Spondilytis. And at a young age of 25 years, he was unable to walk. Now after stem cells treatment he has started walking and his quality of life has improved.

Case Study

Name of the patient:- Rahul (name is changed for privacy reasons)

Disease: Ankylosing Spondilytis

Rahul was suffering from Ankylosing Spondilytis since past 14 years. Painful joints, restricted movements and stiffness in the body was his way of life. Although Rahul doesn't have any family history of joint diseases.

Rahul's symptoms started with sudden onset of the back pain, which went on to be severe with the whole body aches, upto the extent that he could hardly walk or if he could, he started walking like an old man. Although the initial X ray analysis showed nothing, may be because practically it take several years to show changes associated with the spine. Consequently Rahul had to visit rheumatologists, who confirmed after almost 3 years that he is suffering from AS. His treatment regimen involved diet plan, some oral medications and restricted sports activities.

Continued here:
Spinal Cord Injury Treatment, Stem Cell Therapy For Spinal ...

Spinal Cord Stem Cells Comments Off on Spinal Cord Injury Treatment, Stem Cell Therapy For Spinal … | August 1st, 2015

Characterization of isolated human SHEDs and DPSCs for use in transplantation studies. Flow cytometry analysis showed that the SHEDs and DPSCs expressed a set of mesenchymal stem cell (MSC) markers (i.e., CD90, CD73, and CD105), but not endothelial/hematopoietic markers (i.e., CD34, CD45, CD11b/c, and HLA-DR) (Table 1). Like human BMSCs, both the SHEDs and DPSCs exhibited adipogenic, chondrogenic, and osteogenic differentiation as described previously (refs. 16, 17, and data not shown). The majority of SHEDs and DPSCs coexpressed several neural lineage markers: nestin (neural stem cells), doublecortin (DCX; neuronal progenitor cells), III-tubulin (early neuronal cells), NeuN (mature neurons), GFAP (neural stem cells and astrocytes), S-100 (Schwann cells), and A2B5 and CNPase (oligodendrocyte progenitor cells), but not adenomatous polyposis coli (APC) or myelin basic protein (MBP) (mature oligodendrocytes) (Figure 1A and Table 1). This expression profile was confirmed by immunohistochemical analyses (Figure 1B).

Characterization of the SHEDs and DPSCs used for transplantation. (A) Flow cytometry analysis of the neural cell lineage markers expressed in SHEDs. Note that most of the SHEDs and DPSCs coexpressed neural stem and multiple progenitor markers, but not mature oligodendrocytes (APC and MBP). (B) Confocal images showing SHEDs coexpressed nestin, GFAP, and DCX. SHEDs also expressed markers for oligodendrocyte progenitor cells (A2B5 and CNPase), but not for mature oligodendrocytes (APC and MBP). Scale bar: 10 m. (C) Real-time RT-PCR analysis of the expression of neurotrophic factors. Results are expressed as fold increase compared with the level expressed in skin fibroblasts. Data represent the average measurements for each cell type from 3 independent donors. This set of experiments was repeated twice and yielded similar results. Data represent the mean SEM. *P < 0.01 compared with BMSCs and fibroblasts (Fbs).

Flow cytometry of stem cells from humans

Next, we examined the expression of representative neurotrophic factors by real-time PCR. Both the SHEDs and DPSCs expressed glial cellderived neurotrophic factor (GDNF), brain-derived neurotrophic factor (BDNF), and ciliary neurotrophic factor (CNTF) at more than 3 to 5 times the levels expressed by skin-derived fibroblasts or BMSCs (Figure 1C).

We further characterized the transcriptomes of SHEDs and BMSCs by cDNA microarray analysis. This gene expression analysis revealed a 2.0-fold difference in the expression of 3,318 of 41,078 genes between SHEDs and BMSCs. Of these, 1,718 genes were expressed at higher levels in the SHEDs and 1,593 genes were expressed at lower levels (data not shown). The top 30 genes showing higher expression in the SHEDs were in the following ontology categories: extracellular and cell surface region, cell proliferation, and tissue/embryonic development (Table 2).

Functional gene classification in SHEDs versus BMSCs

SHEDs and DPSCs promoted locomotor recovery after SCI. To compare the neuroregenerative activities of human SHEDs and DPSCs with those of human BMSCs and human skin fibroblasts, we transplanted the cells into the completely transected SCs, as described in Methods, and evaluated locomotion recovery using the Basso, Beattie, Bresnahan locomotor rating scale (BBB scale) (24). Remarkably, the animals that received SHEDs or DPSCs exhibited a significantly higher BBB score during the entire observation period, compared with BMSC-transplanted, fibroblast-transplanted, or PBS-injected control rats (Figure 2A). Importantly, their superior recoveries were evident soon after the operation, during the acute phase of SCI. After the recovery period (5 weeks after the operation), the rats that had received SHEDs were able to move 3 joints of hind limb coordinately and walk without weight support (P < 0.01; Supplemental Videos 1 and 2), while the BMSC- or fibroblast-transplanted rats exhibited only subtle movements of 12 joints. These results demonstrate that the transplantation of SHEDs or DPSCs during the acute phase of SCI significantly improved the recovery of hind limb locomotor function. Since the level of recovery was similar in the SHED- and DPSC-transplanted rats, we focused on the phenotypical examination of SHED-transplanted rats to elucidate how tooth-derived stem cells promoted the regeneration of the completely transected rat SC.

Engrafted SHEDs promote functional recovery of the completely transected SC. (A) Time course of functional recovery of hind limbs after complete transection of the SC. A total of 1 106 SHEDs, DPSCs, BMSCs, or fibroblasts were transplanted into the SCI immediately after transection. Data represent the mean SEM. **P < 0.001, *P < 0.01 compared with SCI models injected with PBS. (BD) Representative images (B and C) and quantification (D) of NF-Mpositive nerve fibers in sagittal sections of a completely transected SC, at 8 weeks after SCI. Dashed lines outline the SC. Insets are magnified images of boxed areas in B and C. (D) Nerve fiber quantification, representing the average of 3 experiments performed under the same conditions. The x axis indicates specific locations along the rostrocaudal axis of the SC (3 mm rostral and caudal to the epicenter), and y axis indicates the percentage of NF-Mpositive fibers compared with that of the sham-operated SCs at the ninth thoracic spinal vertebrate (Th9) level. Data represent the mean SEM. *P < 0.05 compared with SCI models injected with PBS. Scale bars: 100 m and inset 20 m (B) and 50 m (C). Asterisks in B and C indicate the epicenter of the lesion.

SHEDs regenerated the transected corticospinal tract and raphespinal serotonergic axons. To examine whether engrafted SHEDs affect the preservation of neurofilaments, we performed immunohistochemical analyses with an antineurofilament M (NF-M) mAb, 8 weeks after transection. Compared with the PBS-treated control SCs, the SHED-transplanted SCs exhibited greater preservation of NF-positive axons from 3 mm rostral to 3 mm caudal to the transected lesion site (Figure 2, B and C; asterisk indicates epicenter). The percentages of NF-positive axons in the epicenter of the SHED-transplanted and control SCs were 35.8% 13.0% and 8.7% 3.4%, respectively, relative to sham-treated SCs (Figure 2D).

Regeneration of both the corticospinal tract (CST) and the descending serotonergic raphespinal axons is important for the recovery of hind limb locomotor function in rat SCI. We therefore examined whether these axons had extended beyond the epicenter in the SHED-transplanted SCs. The CST axons were traced with the anterograde tracer biotinylated dextran amine (BDA), which was injected into the sensorimotor cortex. The serotonergic raphespinal axons were immunohistochemically detected by a mAb that specifically reacts with serotonin (5-hydroxytryptamine [5-HT]), which is synthesized within the brain stem. We found that both BDA- and 5-HTpositive fibers extended as far as 3 mm caudal to the epicenter in the SHED-transplanted but not the control group (Figures 3 and 4). Furthermore, some BDA- and 5-HTpositive boutons could be seen apposed to neurons in the caudal stump (Figure 3D and Figure 4C), suggesting that the regenerated axons had established new neural connections. Notably, although the number of descending axons extending beyond the epicenter was small, we observed many of them penetrating the scar tissue of the rostral stump (Figure 3A and Figure 4A). The percentages of 5-HTpositive axons of the SHED-transplanted SCs at 1 and 3 mm rostral to the epicenter were 58.9% 3.9% and 78.3% 7.4% relative to sham-treated SC, respectively (Figure 4D). These results demonstrate that the engrafted SHEDs promoted the recovery of hind limb locomotion via the preservation and regeneration of transected axons, even in the microenvironment of the damaged CNS.

View post:
Human Dental Pulp-Derived Stem Cells Promote Locomotor ...

Spinal Cord Stem Cells Comments Off on Human Dental Pulp-Derived Stem Cells Promote Locomotor … | July 17th, 2015

World J Stem Cells. 2014 Apr 26; 6(2): 120133.

Venkata Ramesh Dasari, Krishna Kumar Veeravalli, Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, Peoria, IL 61656, United States

Dzung H Dinh, Department of Neurosurgery and Illinois Neurological Institute, University of Illinois College of Medicine at Peoria, Peoria, IL 61656, United States

Correspondence to: Dzung H Dinh, MD, Department of Neurosurgery and Illinois Neurological Institute, University of Illinois College of Medicine at Peoria, One Illini Drive, Peoria, IL 61605, United States. ude.ciu@hnidd

Telephone: +1- 309-6552642 Fax: +1-309-6713442

Received 2013 Oct 30; Revised 2014 Feb 19; Accepted 2014 Mar 11.

With technological advances in basic research, the intricate mechanism of secondary delayed spinal cord injury (SCI) continues to unravel at a rapid pace. However, despite our deeper understanding of the molecular changes occurring after initial insult to the spinal cord, the cure for paralysis remains elusive. Current treatment of SCI is limited to early administration of high dose steroids to mitigate the harmful effect of cord edema that occurs after SCI and to reduce the cascade of secondary delayed SCI. Recent evident-based clinical studies have cast doubt on the clinical benefit of steroids in SCI and intense focus on stem cell-based therapy has yielded some encouraging results. An array of mesenchymal stem cells (MSCs) from various sources with novel and promising strategies are being developed to improve function after SCI. In this review, we briefly discuss the pathophysiology of spinal cord injuries and characteristics and the potential sources of MSCs that can be used in the treatment of SCI. We will discuss the progress of MSCs application in research, focusing on the neuroprotective properties of MSCs. Finally, we will discuss the results from preclinical and clinical trials involving stem cell-based therapy in SCI.

Keywords: Spinal cord injury, Mesenchymal stem cells, Bone marrow stromal cells, Umbilical cord derived mesenchymal stem cells, Adipose tissue derived mesenchymal stem cells

Core tip: Despite our deeper understanding of the molecular changes that occurs after the spinal cord injury (SCI), the cure for paralysis remains elusive. In this review, the pathophysiology of SCI and characteristics and potential sources of mesenchymal stem cells (MSCs) that can be used in the treatment of SCI were discussed. We also discussed the progress of application of MSCs in research focusing on the neuroprotective properties of MSCs. Finally, we discussed the results from preclinical and clinical trials involving stem cell-based therapy in SCI.

Traumatic spinal cord injury (SCI) continues to be a devastating injury to affected individuals and their families and exacts an enormous financial, psychological and emotional cost to them and to society. Despite years of research, the cure for paralysis remains elusive and current treatment is limited to early administration of high dose steroids and acute surgical intervention to minimize cord edema and the subsequent cascade of secondary delayed injury[1-3]. Recent advances in neurosciences and regenerative medicine have drawn attention to novel research methodologies for the treatment of SCI. In this review, we present our current understanding of spinal cord injury pathophysiology and the application of mesenchymal stem cells (MSCs) in the treatment of SCI. This review will be more useful for basic and clinical investigators in academia, industry and regulatory agencies as well as allied health professionals who are involved in stem cell research.

See the article here:
Mesenchymal stem cells in the treatment of spinal cord ...

Spinal Cord Stem Cells Comments Off on Mesenchymal stem cells in the treatment of spinal cord … | July 13th, 2015

Tobi is a six-year-old cocker spaniel whose hind legs were paralyzed after he suffered a herniated disc in his spine. Although Tobi will never fully regain the use of his legs, he has benefitted from a clinical trial involving stem cell transplantation in dogs that is currently underway at North Carolina State University.

See video presentation: Stem cell treatments for paralyzed dogs.

Dr. Natasha Olby, professor of neurology at the NC State College of Veterinary Medicine, specializes in researching treatments for long-term paralysis in dogs. According to Dr. Olby, even in the case of severe spinal cord injury all may not be lost in terms of spinal cord function there may still be salvageable, living nerves and nerve fibers, or axons, bridging the site of the injury that could still transmit signals if they had a little help.

Obviously, researchers would love to be able to replace all the lost neurons and axons and restore normal connections in a damaged spinal cord. But that sort of treatment is not yet possible. On the other hand, targeting surviving nerves and axons that are still crossing the site of the injury and restoring their conductivity is more attainable.

Often, these damaged nerves have lost the myelin sheath, fatty material that coats axons and allows them to conduct signals. Dr. Olby wants to restore the myelin sheath to these surviving axons by taking fat cells from the patient and turning them into stem cells that can be combined with nerve cells and injected into the site of the damage, regrowing the sheath. Even though she is still in the early stages of a randomized clinical trial, the results thus far are encouraging.

Dogs like Tobi will not be the only beneficiaries of Dr. Olbys research. If the therapy produces positive results in dogs, then translating the treatment to humans is a natural next step. And in humans, even very small improvements have the capacity to radically transform quality of life.

Even if this procedure produced an effect in a person as small as giving him or her partial control of one finger, that could allow the patient to use a computer, which opens up a whole new world of possibilities in terms of communication and interaction with the outside world, Dr. Olby says.

-- Tracey Peake

Dr. Olbys research is funded by the Morris Animal Foundation and is one of the clinical trials underway in the Neurology Service within the Randall B. Terry, Jr. Companion Animal Veterinary Medical Center. For more information on the clinical trial, visit the "call for patients" web page.

Posted Feb. 14, 2012

View original post here:
CVM Stem Cell Study Benefits Dogs with Spinal Cord Injuries

Spinal Cord Stem Cells Comments Off on CVM Stem Cell Study Benefits Dogs with Spinal Cord Injuries | July 3rd, 2015

Are there stem cell therapies available for spinal cord injury?

To our knowledge, no stem cell therapy has received Health Canada or U.S. Food and Drug Administration approval for treatment of spinal cord injury at this time. Patients who are researching their options may come across companies with Web sites or materials that say otherwise and offer fee-based stem cell treatments for curing this disease. Many of these claims are not supported by sound scientific evidence and patients considering these therapies are encouraged to review some of the links below before making crucial decisions about their treatment plan.

For the latest developments read our blog entrieshere.

For moreabout stem cell clinical trials for spinal cord injuryclick here. For printed version:http://goo.gl/ZpNLg)

The basis of using stem cells to treat spinal cord injury would be as a source of new cells and products that could prevent further spinal cord damage, restore nerve function, generate new nerve cells and guide the regrowth of severed nerve fibres. Stem cells have an unparalleled regenerative capacity with the flexibility to grow into hundreds of different cell types and make factors that can support a range of physiological functions. Researchers are evaluating which types of stem cells are the best for growing neurons and other support cells in the brain, and making factors that promote nerve function. They want to develop strategies that transplant the support cells that wrap myelin insulation around nerve fibres to conduct electrical signals. A steady supply of these cells grown from stem cells could be a tremendous asset for studies that are exploring how to restore nerve function across damaged spinal cords.

Two main strategies for using stem cells to treat spinal cord injury are being explored: exogenous and endogenous repair (exo meaning outside the body and endo meaning inside the body). In exogenous repair the required cells are first grown from stem cells in the laboratory and then transplanted into patients. In endogenous repair stem cells are transplanted into the patient and the outcome depends on the bodys ability to coax the stem cells to grow into the required cells. Either way, the goal is to use stem cells to improve nerve function. There are no existing therapies that are able to repair spinal cord injuries.

Many research teams around the globe are working to develop stem cell therapies for spinal cord injury. Their common goals are to identify which stem cells are best suited for the job, which signals will be able to coax them into becoming neurons or support cells, and which large scale lab methods are effective at ramping up the production of the required cells.

The discovery of neural stem cells in Canada in 1992 kindled great hope among that stem cells could someday be used to regenerate the damage caused by spinal cord injury. Until around 1998, it was believed that the brain could not repair itself by regenerating new neurons. We now know that patients who have partial lesions to the spinal cord do experience a degree of spontaneous recovery arising from the ability of the brain to reorganize new connections. These observations spurred researchers to test their theories in animal models of spinal cord injury, and the positive results have provided the proof of principle that stem cells can potentially improve function after spinal cord injury.

Stem cell research is continuing on a number of different avenues and some of the successful stops along the way have yielded early Phase 1and 2 clinical trials for spinal cord injury. These trials are very small, mostly testing the safety of putting adult stem cells into patients. The results should yield information about the viability of this kind of therapy, but further clinical trials will be required to answer the question of whether a stem cell therapy can improve nerve function. For patients, the answer to that question is still many years away.

A North American clinical trial is using adult neural stem cell injections to treat spinal cord injury. Find out morehere.

See the article here:
Spinal Cord Injury | Canadian Stem Cell Foundation

Spinal Cord Stem Cells Comments Off on Spinal Cord Injury | Canadian Stem Cell Foundation | June 20th, 2015

NEWARK, Calif., Jun 04, 2015 (GLOBE NEWSWIRE via COMTEX) --

StemCells, Inc. STEM, +0.00% a world leader in the research and development of cell-based therapeutics for the treatment of central nervous system diseases and disorders, announced today that it has enrolled its first subject in Cohort 2 of its Phase II Pathway Study. The study is designed to assess the efficacy of the Company's proprietary HuCNS-SC platform technology (purified human neural stem cells) for the treatment of cervical spinal cord injury. Cohort 2 will enroll 40 patients and forms the single-blinded controlled arm of the Phase II study. The primary efficacy outcome being tested in Cohort 2 is the change in motor strength of the various muscle groups in the upper extremities innervated by the cervical spinal cord.

The Pathway Study is the first clinical trial designed to evaluate both the safety and efficacy of human neural stem cells transplanted into the spinal cord of patients with cervical spinal cord injury. Traumatic injuries to the neck can damage the cervical spinal cord and result in impaired sensation and motor function of the arms, legs, and trunk, also referred to as quadriplegia. The trial has 3 cohorts. The primary Cohort is Cohort 2 which is being conducted as a randomized, controlled, single-blind Cohort and efficacy will be primarily measured by assessing motor function according to the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI). The trial will follow the participants for one year and will enroll up to 52 subjects.

Cohort 1 of the Pathway Study is an open-label, HuCNS-SC dose-escalation arm involving six patients. Safety data from all six subjects was reviewed by an independent Data Monitoring Committee and approval was provided to commence with Cohort 2. No safety or tolerability issues were seen at any of the dosing levels. The six-month outcome from Cohort 1 will be disclosed as interim data later this year.

Cohort 3 is an optional open label Cohort targeted to enroll 6 patients. This Cohort is designed to assess safety and preliminary efficacy in patients with less severe injuries (AIS C).

"The initiation of Cohort 2 begins the next phase of our clinical efforts towards a potential breakthrough therapy for spinal cord injury," said Stephen Huhn, M.D., FACS, FAAP, Vice President, Clinical Research and Chief Medical Officer at StemCells, Inc. "This is the first blinded, controlled clinical trial to be conducted using human neural stem cells. The goal of this proof-of-concept study is to demonstrate the potential efficacy of our cells as a treatment for victims of spinal cord injury. We currently have seven sites enrolling patients and expect to reach a total of fourteen active North American sites by year end. Conducting a multi-center study on this scale should allow us to efficiently enroll the study."

The Company completed enrollment and dosing in its open-label Phase I/II study in thoracic spinal cord injury in April 2014 and has reported top-line results. Sustained post-transplant gains in sensory function were demonstrated in seven of the twelve patients. Two patients in the Phase I/II study converted from a complete injury (AIS A) to an incomplete injury (AIS B). The final results also continue to confirm the favorable safety profile of the cells and the surgical procedure.

About the Pathway Cervical Spinal Cord Injury Clinical Trial

The Company's Phase II Pathway Study, titled "Study of Human Central Nervous System (CNS) Stem Cell Transplantation in Cervical Spinal Cord Injury," will evaluate the safety and efficacy of transplanting the Company's proprietary human neural stem cells (HuCNS-SC cells), into patients with traumatic injury in the cervical region of the spinal cord. Conducted as a randomized, controlled, single-blind study, the trial will measure efficacy by assessing motor function according to the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI). The primary efficacy outcome will focus on change in upper extremity strength. The trial will enroll approximately 52 subjects and follow the patients for 12 months post-transplant. The first cohort of six patients completed enrollment in April and was designed to establish the cell dose for onward testing in the second cohort of the study.

Information about the Company's spinal cord injury program can be found on the StemCells, Inc. website at:

Original post:
StemCells, Inc. Announces Commencement of the Second ...

Spinal Cord Stem Cells Comments Off on StemCells, Inc. Announces Commencement of the Second … | June 4th, 2015

DURHAM N.C. May. 27 2015 /PRNewswire-iReach/ A new study appearing today inSTEM CELLS Translational Medicinedesigned to test how stem cell injections affect primates with spinal cord injury (SCI) showed the treatments significantly improved the animals motor function recovery and promoted faster healing too. The researchers call their findings a step forward toward the goal of improving outcomes for humans with chronic SCI.

Previous research conducted by various groups had indicated stem cell treatments helped rats with SCI. But because there are distinct differences in the nervous system and immunological responses between rodents and primates it is critical to determine how effective and safe the injections might be in a non-human primate SCI model as part of the translational research required for clinical trials explained Hideyuki Okano M.D. Ph.D. of Keio University School of Medicines physiology department and a co-author of the new study.

In this study the researchers grafted neural stem/progenitor cells (NS/PCs)derived from marmoset (a type of monkey) embryonic stem cells into adult marmosets suffering from a moderately bruised spinal cord. The advantage of using common marmosets is the similarity between their nervous system and immunological responses and those of humans Dr. Okano said.

The injections were given 14 days after the SCI occurred which research shows is an optimal time window for SCI therapy as inflammation has generally subsided by then and scar tissue has not yet had time to form.(Doctors believe that an incomplete spinal cord injury such as those of the study animals offers better chance for recovery than a complete SCI injury.) The results were promising.

Eventually motor function recovery significantly improved in the transplantation group compared to a control group that did not receive stem cells reported co-author Masaya Nakamura M.D. Ph.D. of Keios Department of Orthopedic Surgery. An animal in the control group for example could not raise her hands up to head height at 12 weeks after injury when motor function almost plateaus. On the other hand at the same point in time a transplanted animalwas able to jump successfully and run so fast it was difficult for us to catch her. She could also grip a pen at 3 cm. above head-height.

In addition he added there were no signs of immune rejection or tumors which have been a side effect of some stem cell therapies.

The researchers say this study is a step forward in their goal is to improve patients with complete SCI at the chronic phase. But we believe it will require a combination of stem cell transplantation rehabilitation and pharmacological therapy with the stem cells a key part of the treatment Dr. Okano added.

This translational research using a nonhuman primate model is a critical step in eventually applying these cells to injured spinal cord in human patients said Anthony Atala M.D. Editor-in-Chief ofSTEM CELLS Translational Medicineand director of the Wake Forest Institute for Regenerative Medicine.

Continued here:
Stem Cell Treatment Speeds Up Recovery after Spinal Cord ...

Spinal Cord Stem Cells Comments Off on Stem Cell Treatment Speeds Up Recovery after Spinal Cord … | June 2nd, 2015

John W. McDonald, M.D., Ph.D. an associate professor of neurology at the Johns Hopkins University School of Medicine and director of the International Center for Spinal Cord Injury at Kennedy Krieger Institute taps into the bodys own repair mechanisms in search of treatments for spine injury.

Stem cells allow us to address questions Ive thought about forever. These are really exciting times for the repair of the nervous system, because we can move beyond mere correlation and get definitive answers.

Despite what I was taught in medical school, nervous system cells do divide and grow. Not all of them. But oligodendrocytes are the most prominent ones that do. If we were to follow newly born cells in an adult human brain for an hour, the majority of those cells would go on to become oligodendrocytes.

Injury and the consequence of injury disrupts the turning over of cells, basically because of reduced electrical activity, which oligodendrocytes depend on for survival and myelination.

Im convinced that endogenous stem cells in the spinal cordthose naturally born there by the million, every hour, even in spinal cord injured adultsrepresent an important therapeutic target.

Through the transplantation work were doing in mice, were learning a lot about the natural environment of cells in the nervous system. For example, mouse embryonic stem cells have the innate mechanism to overcome physical and chemical barriers. Their presence changes the microenvironment enough so that endogenous cells are able to cross barriers such as scars. We are working on figuring how to activate the same cues that cause those microenvironment changes without actually transplanting stem cells.

The whole nervous systemall the signaling between cellsruns by electrical activity. Were just now getting access to the imaging tools to be able to see and begin to understand it. If that ensemble of activity is disrupted by injury, what percent of connections remain, and how can we use what remains to recreate the orchestra?

New imaging methods now are confirming earlier animal studies that as much as 30 percent of connections can still remain below the level of spinal cord injury, even in the severe injury scenarios. This realizationthat we dont need to cure the nervous system, we just need partial repairis born out in people whove had bad spinal cord injuries who now can regain substantial function and even walk..

Our strategy is to maximize the physical integrity of your body so it can meet a cure halfway when a cure comes. We discovered that we can make a great impact on an individuals own spontaneous recovery by facilitating the bodys own micro-repair system.

What we do in lab is geared toward understanding these mechanisms of microrepair. We already know that myelination and birth of oligodendrocytes are incredibly dependent on electrical activity.

More here:
Stem Cell Research at Johns Hopkins Medicine: Spinal ...

Spinal Cord Stem Cells Comments Off on Stem Cell Research at Johns Hopkins Medicine: Spinal … | May 31st, 2015

SAN DIEGO -

Two years ago, Brenda Guerra's life changed forever.

"They told me that I went into a ditch and was ejected out of the vehicle," Guerra said.

The accident left the 26-year-old paralyzed from the waist down and confined to a wheelchair.

"I don't feel any of my lower body at all," she said.

Guerra has traveled from Kansas to UC San Diego to be the first patient to participate in a groundbreaking safety trial, testing stem cells for paralysis.

"We are directly injecting the stem cells into the spine," said Dr. Joseph D. Ciacci, professor of neurosurgery at UC San Diego.

The stem cells come from fetal spinal cords. The idea is when they're transplanted they will develop into new neurons and bridge the gap created by the injury by replacing severed or lost nerve connections. They did that in animals, and doctors are hoping for similar results in humans. The ultimate goal is to help people like Guerra walk again.

"The ability to walk is obviously a big deal not only in quality of life issues, but it also affects your survival long-term," Ciacci said.

Guerra received her injection and will be followed for five long years. She knows it's only a safety trial, but she's hoping for the best.

Here is the original post:
Health Beat: Stem cells for paralysis: 1st of its kind study

Spinal Cord Stem Cells Comments Off on Health Beat: Stem cells for paralysis: 1st of its kind study | April 13th, 2015

A spinal cord injury (SCI) is an injury to the spinal cord resulting in a change, either temporary or permanent, in the cord's normal motor, sensory, or autonomic function.[1] Common causes of damage are trauma (car accident, gunshot, falls, sports injuries, etc.) or disease (transverse myelitis, polio, spina bifida, Friedreich's ataxia, etc.). The spinal cord does not have to be severed in order for a loss of function to occur. Depending on where the spinal cord and nerve roots are damaged, the symptoms can vary widely, from pain to paralysis to incontinence.[2][3] Spinal cord injuries are described at various levels of "incomplete", which can vary from having no effect on the patient to a "complete" injury which means a total loss of function.

Treatment of spinal cord injuries starts with restraining the spine and controlling inflammation to prevent further damage. The actual treatment can vary widely depending on the location and extent of the injury. In many cases, spinal cord injuries require substantial physical therapy and rehabilitation, especially if the patient's injury interferes with activities of daily life.

Research into treatments for spinal cord injuries includes controlled hypothermia and stem cells, though many treatments have not been studied thoroughly and very little new research has been implemented in standard care.

The American Spinal Injury Association (ASIA) first published an international classification of spinal cord injury in 1982, called the International Standards for Neurological and Functional Classification of Spinal Cord Injury. Now in its sixth edition, the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) is still widely used to document sensory and motor impairments following SCI.[4] It is based on neurological responses, touch and pinprick sensations tested in each dermatome, and strength of the muscles that control ten key motions on both sides of the body, including hip flexion (L2), shoulder shrug (C4), elbow flexion (C5), wrist extension (C6), and elbow extension (C7).[5] Traumatic spinal cord injury is classified into five categories on the ASIA Impairment Scale:

Dimitrijevic[6] proposed a further class, the so-called discomplete lesion, which is clinically complete but is accompanied by neurophysiological evidence of residual brain influence on spinal cord function below the lesion.[7]

Signs recorded by a clinician and symptoms experienced by a patient will vary depending on where the spine is injured and the extent of the injury. These are all determined by the area of the body that the injured area of the spine innervates. A section of skin innervated through a specific part of the spine is called a dermatome, and spinal injury can cause pain, numbness, or a loss of sensation in the relevant areas. A group of muscles innervated through a specific part of the spine is called a myotome, and injury to the spine can cause problems with voluntary motor control. The muscles may contract uncontrollably, become weak, or be completely paralysed. The loss of muscle function can have additional effects if the muscle is not used, including atrophy of the muscle and bone degeneration.

A severe injury may also cause problems in parts of the spine below the injured area. In a "complete" spinal injury, all functions below the injured area are lost. An "incomplete" spinal cord injury involves preservation of motor or sensory function below the level of injury in the spinal cord.[8] If the patient has the ability to contract the anal sphincter voluntarily or to feel a pinprick or touch around the anus, the injury is considered to be incomplete. The nerves in this area are connected to the very lowest region of the spine, the sacral region, and retaining sensation and function in these parts of the body indicates that the spinal cord is only partially damaged. This includes a phenomenon known as sacral sparing which involves the preservation of cutaneous sensation in the sacral dermatomes, even though sensation is impaired in the thoracic and lumbar dermatomes below the level of the lesion.[9] Sacral sparing may also include the preservation of motor function (voluntary external anal sphincter contraction) in the lowest sacral segments.[8] Sacral sparing has been attributed to the fact that the sacral spinal pathways are not as likely as the other spinal pathways to become compressed after injury.[9] The sparing of the sacral spinal pathways can be attributed to the lamination of fibers within the spinal cord.[9]

A complete injury frequently means that the patient has little hope of functional recovery.[citation needed] The relative incidence of incomplete injuries compared to complete spinal cord injury has improved over the past half century, due mainly to the emphasis on better initial care and stabilization of spinal cord injury patients.[10] Most patients with incomplete injuries recover at least some function.[citation needed]

Determining the exact "level" of injury is critical in making accurate predictions about the specific parts of the body that may be affected by paralysis and loss of function. The level is assigned according to the location of the injury by the vertebra of the spinal column closest to the injury on the spinal cord.

Cervical (neck) injuries usually result in full or partial tetraplegia (Quadriplegia). However, depending on the specific location and severity of trauma, limited function may be retained.

Continued here:
Spinal cord injury - Wikipedia, the free encyclopedia

Spinal Cord Stem Cells Comments Off on Spinal cord injury – Wikipedia, the free encyclopedia | April 8th, 2015

SAN DIEGO. (Ivanhoe Newswire) -- According to the Christopher and Dana Reeve Foundation, nearly one in 50 people is living with paralysis. Until now, there wasn't much hope. But a new study involving stem cells has doctors and patients excited.

Two years ago, Brenda Guerra's life changed forever.

Guerra told Ivanhoe, They told me that I went into a ditch and was ejected out of the vehicle.

The accident left the 26-year-old paralyzed from the waist down, and confined to a wheelchair.

I don't feel any of my lower body at all she said.

Guerra has traveled from Kansas to UC San Diego to be the first patient to participate in a ground-breaking safety trial, testing stem cells for paralysis.

Joseph D. Ciacci, MD, Professor of Neurosurgery at UC San Diego told Ivanhoe, We are directly injecting the stem cells into the spine.

The stem cells come from fetal spinal cords. The idea is when they're transplanted they will develop into new neurons and bridge the gap created by the injury by replacing severed or lost nerve connections. They did that in animals and doctors are hoping for similar results in humans. The ultimate goal is to help people like Brenda walk again.

The ability to walk is obviously a big deal not only in quality of life issues, but it also affects your survival long-term Dr. Ciacci said.

Guerra received her injection and will be followed for five long years. She knows it's only a safety trial but she's hoping for the best

More:
Stem Cells for Paralysis: First of Its Kind Study

Spinal Cord Stem Cells Comments Off on Stem Cells for Paralysis: First of Its Kind Study | April 6th, 2015

According to the Christopher and Dana Reeve Foundation, nearly one in 50 people are living with paralysis.

Until now, there wasn't much hope.

But, a new study involving stem cells has doctors and patients excited.

Two years ago, Brenda Guerra's life changed forever.

"They told me that I went into a ditch and was ejected out of the vehicle," says Brenda.

The accident left the 26-year-old paralyzed from the waist down and confined to a wheelchair.

"I don't feel any of my lower body at all," says Brenda.

Brenda has traveled from Kansas to UC San Diego to be the first patient to participate in a ground-breaking safety trial, testing stem cells for paralysis.

"We are directly injecting the stem cells into the spine," says Dr. Joseph Ciacci, a neurosurgeon at UC San Diego.

The stem cells come from fetal spinal cords. The idea is when they're transplanted they will develop into new neurons and bridge the gap created by the injury by replacing severed or lost nerve connections. They did that in animals and doctors are hoping for similar results in humans. The ultimate goal: to help people like Brenda walk again.

Read more:
Stem cell procedures for paralysis patients

Spinal Cord Stem Cells Comments Off on Stem cell procedures for paralysis patients | April 2nd, 2015

Damage to neural tissue is typically permanent and causes lasting disability in patients, but a new approach has recently been discovered that holds incredible potential to reconstruct neural tissue at high resolution in three dimensions. Research recently published in the Journal of Neural Engineering demonstrated a method for embedding scaffolding of patterned nanofibers within three-dimensional (3D) hydrogel structures, and it was shown that neurite outgrowth from neurons in the hydrogel followed the nanofiber scaffolding by tracking directly along the nanofibers, particularly when the nanofibers were coated with a type of cell adhesion molecule called laminin. It was also shown that the coated nanofibers significantly enhanced the length of growing neurites, and that the type of hydrogel could significantly affect the extent to which the neurites tracked the nanofibers.

"Neural stem cells hold incredible potential for restoring damaged cells in the nervous system, and 3D reconstruction of neural tissue is essential for replicating the complex anatomical structure and function of the brain and spinal cord," said Dr. McMurtrey, author of the study and director of the research institute that led this work. "So it was thought that the combination of induced neuronal cells with micropatterned biomaterials might enable unique advantages in 3D cultures, and this research showed that not only can neuronal cells be cultured in 3D conformations, but the direction and pattern of neurite outgrowth can be guided and controlled using relatively simple combinations of structural cues and biochemical signaling factors."

The next step will be replicating more complex structures using a patient's own induced stem cells to reconstruct damaged or diseased sites in the nervous system. These 3D reconstructions can then be used to implant into the damaged areas of neural tissue to help reconstruct specific neuroanatomical structures and integrate with the proper neural circuitry in order to restore function. Successful restoration of function would require training of the new neural circuitry over time, but by selecting the proper neurons and forming them into native architecture, implanted neural stem cells would have a much higher chance of providing successful outcomes. The scaffolding and hydrogel materials are biocompatible and biodegradable, and the hydrogels can also help to maintain the microstructure of implanted cells and prevent them from washing away in the cerebrospinal fluid that surrounds the brain and spinal cord.

McMurtrey also noted that by making these site-specific reconstructions of neural tissue, not only can neural architecture be rebuilt, but researchers can also make models for studying disease mechanisms and developmental processes just by using skin cells that are induced into pluripotent stem cells and into neurons from patients with a variety of diseases and conditions. "The 3D constructs enable a realistic replication of the innate cellular environment and also enable study of diseased human neurons without needing to biopsy neurons from affected patients and without needing to make animal models that can fail to replicate the full array of features seen in humans," said McMurtrey.

The ability to engineer neural tissue from stem cells and biomaterials holds great potential for regenerative medicine. The combination of stem cells, functionalized hydrogel architecture, and patterned and functionalized nanofiber scaffolding enables the formation of unique 3D tissue constructs, and these engineered constructs offer important applications in brain and spinal cord tissue that has been damaged by trauma, stroke, or degeneration. In particular, this work may one day help in the restoration of functional neuroanatomical pathways and structures at sites of spinal cord injury, traumatic brain injury, tumor resection, stroke, or neurodegenerative diseases of Parkinson's, Huntington's, Alzheimer's, or amyotrophic lateral sclerosis.

###

The work was carried out at the University of Oxford and the Institute of Neural Regeneration & Tissue Engineering, a non-profit charitable research organization.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.

See the article here:
3-D neural structure guided with biocompatible nanofiber scaffolds and hydrogels

Spinal Cord Stem Cells Comments Off on 3-D neural structure guided with biocompatible nanofiber scaffolds and hydrogels | April 2nd, 2015