Axonal Regeneration is Detected After Olfactory Ensheathing Cell Or Fibroblast Transplantation in Sprague-Dawley Rats with Completely Transected Spinal Cords

Axonal Regeneration is Detected After Olfactory Ensheathing Cell Or Fibroblast Transplantation in Sprague-Dawley Rats with Completely Transected Spinal Cords
Author: Michael Andrew Thornton
Publisher:
Total Pages: 68
Release: 2016
Genre:
ISBN:

Olfactory ensheathing cells (OECs) are unique glia that support axon outgrowth in the olfactory system and have shown some success as a cellular transplant therapy for the recovery of sensorimotor control after spinal cord injury. A pilot study was designed in which 10 female Sprague-Dawley rats received acute transplantation of skin fibroblasts (FB, control, n=5) or OECs (n=5) after a complete mid-thoracic spinal cord transection. All rats were implanted with epidural stimulating electrodes at spinal cord levels L1 and S2 and trained to climb an inclined grid while receiving sub-threshold stimulation for 20 min., 3 times/week for 6 months. We injected the Bartha-152 (EGFP-expressing) strain of pseudorabies virus (PRV) into the soleus and/or tibialis anterior muscles 6 days before termination to identify hindlimb motor circuits and assess connectivity across the injury site. Viral transport to cholinergic somatic motor neurons and premotor interneurons was detected in 8 rats (4 FB, 4 OEC). Three rats (2 FB, 1 OEC) had evidence of viral labeling rostral to the transection site (T3-6), including cholinergic and Chx10-positive V2a interneurons. Serotonergic axons crossed from the rostral to the caudal stump on GFAP-positive astrocyte bridges in 2 of the 3 rats with evidence of PRVeGFP labeling above the injury site (1 FB, 1 OEC). Together these data imply that long-term axonal regeneration occurred in two of our complete spinal rats after epidural stimulation, climb training, and olfactory ensheathing cell or fibroblast transplantation.

Mechanisms of Olfactory Ensheathing Cell-enhanced Neurite Outgrowth and Axon Regeneration After Spinal Cord Injury

Mechanisms of Olfactory Ensheathing Cell-enhanced Neurite Outgrowth and Axon Regeneration After Spinal Cord Injury
Author: Rana R. Khankan
Publisher:
Total Pages: 120
Release: 2015
Genre:
ISBN:

Olfactory ensheathing cells (OECs) provide a pro-regenerative environment for the axons of olfactory receptor neurons and therefore are a promising candidate for cell transplantation therapy following spinal cord injury. We previously showed that OEC transplantation supports axon regeneration and functional re-connectivity following complete spinal cord injury, yet lack of an OEC-specific marker limited our ability to determine how they promoted these beneficial effects. Using both in vitro and in vivo models, we investigated the mechanisms by which OECs mediate axon regeneration. OECs enhance neurite outgrowth of postnatal cortical neurons in a scar-like culture model. We provide strong evidence that direct OEC-neurite alignment is critical to enhance neurite outgrowth in scar-like astrocyte and meningeal fibroblast inhibitory environments. We also tested eGFP-OECs from transgenic rats and showed that they facilitate neurite outgrowth in vitro. Then in a short-term study, we analyzed OEC survival, migration, and distribution within the lesion site of complete spinal cord transected rats. We found that rats transplanted with OECs preserve and associate with axons and neurons in the lesion core, reduce the presence of inhibitory CSPGs and myelin debris, and reduce secondary tissue damage due to microglial and macrophage activation and infiltration post-injury. Collectively, these data support a neuroprotective and proregenerative role of OECs through the modulation of glial scar formation following a complete spinal cord transection.

Regeneration and Plasticity of Descending Propriospinal Neurons After Transplantation of Schwann Cells Overexpressing Glial Cell Line-derived Neurotrophic Factor Following Thoracic Spinal Cord Injury in Adult Rats

Regeneration and Plasticity of Descending Propriospinal Neurons After Transplantation of Schwann Cells Overexpressing Glial Cell Line-derived Neurotrophic Factor Following Thoracic Spinal Cord Injury in Adult Rats
Author: Lingxiao Deng
Publisher:
Total Pages: 218
Release: 2015
Genre: Axons
ISBN:

After spinal cord injury (SCI), poor axonal regeneration of the central nervous system, which mainly attributed to glial scar and low intrinsic regenerating capacity of severely injured neurons, causes limited functional recovery. Combinatory strategy has been applied to target multiple mechanisms. Schwann cells (SCs) have been explored as promising donors for transplantation to promote axonal regeneration. Among the central neurons, descending propriospinal neurons (DPSN) displayed the impressive regeneration response to SCs graft. Glial cell line-derived neurotrophic factor (GDNF), which receptor is widely expressed in nervous system, possesses the ability to promote neuronal survival, axonal regeneration/sprouting, remyelination, synaptic formation and modulate the glial response. We constructed a novel axonal permissive pathway in rat model of thoracic complete transection injury by grafting SCs over-expressing GDNF (SCs-GDNF) both inside and caudal to the lesion gap. Behavior evaluation and histological analyses have been applied to this study. Our results indicated that tremendous DPSN axons as well as brain stem axons regenerated across the lesion gap back to the caudal spinal cord. In addition to direct promotion on axonal regeneration, GDNF also significantly improved the astroglial environment around the lesion. These regenerations caused motor functional recovery. The dendritic plasticity of axotomized DPSN also contributed to the functional recovery. We applied a G-mutated rabies virus (G-Rabies) co-expressing green fluorescence protein (GFP) to reveal Golgi-like dendritic morphology of DPSNs and its response to axotomy injury and GDNF treatment. We also investigated the neurotransmitters phenotype of FluoroGold (FG) labeled DPSNs. Our results indicated that over 90 percent of FG-labeled DPSNs were glutamatergic neurons. DPSNs in sham animals had a predominantly dorsal-ventral distribution of dendrites. Transection injury resulted in alterations in the dendritic distribution, with dorsal-ventral retraction and lateral-medial extension of dendrites. Treatment with GDNF significantly increased the terminal dendritic length of DPSNs. The density of spine-like structures was increased after injury and treatment with GDNF enhanced this effect.

Spinal Cord Injury (SCI) Repair Strategies

Spinal Cord Injury (SCI) Repair Strategies
Author: Giuseppe Perale
Publisher: Woodhead Publishing
Total Pages: 346
Release: 2019-10-30
Genre: Medical
ISBN: 0081028083

Spinal Cord Injury (SCI) Repair Strategies provides researchers the latest information on potential regenerative approaches to spinal cord injury, specifically focusing on therapeutic approaches that target regeneration, including cell therapies, controlled drug delivery systems, and biomaterials. Dr. Giuseppe Perale and Dr. Filippo Rossi lead a team of authoritative authors in academia and industry in this innovative reference on the field of regenerative medicine and tissue engineering. This book presents all the information readers need to understand the current and potential array of techniques, materials, applications and their benefits for spinal cord repair. Covers current and future repair strategies for spinal cord injury repair Focuses on key research trends, clinics, biology and engineering Provides fundamentals on regenerative engineering and tissue engineering

The Spinal Cord

The Spinal Cord
Author: Charles Watson
Publisher: Academic Press
Total Pages: 408
Release: 2009-11-27
Genre: Medical
ISBN: 0080921388

Many hundreds of thousands suffer spinal cord injuries leading to loss of sensation and motor function in the body below the point of injury. Spinal cord research has made some significant strides towards new treatment methods, and is a focus of many laboratories worldwide. In addition, research on the involvement of the spinal cord in pain and the abilities of nervous tissue in the spine to regenerate has increasingly been on the forefront of biomedical research in the past years. The Spinal Cord, a collaboration with the Christopher and Dana Reeve Foundation, is the first comprehensive book on the anatomy of the mammalian spinal cord. Tens of thousands of articles and dozens of books are published on this subject each year, and a great deal of experimental work has been carried out on the rat spinal cord. Despite this, there is no comprehensive and authoritative atlas of the mammalian spinal cord. Almost all of the fine details of spinal cord anatomy must be searched for in journal articles on particular subjects. This book addresses this need by providing both a comprehensive reference on the mammalian spinal cord and a comparative atlas of both rat and mouse spinal cords in one convenient source. The book provides a descriptive survey of the details of mammalian spinal cord anatomy, focusing on the rat with many illustrations from the leading experts in the field and atlases of the rat and the mouse spinal cord. The rat and mouse spinal cord atlas chapters include photographs of Nissl stained transverse sections from each of the spinal cord segments (obtained from a single unfixed spinal cord), detailed diagrams of each of the spinal cord segments pictured, delineating the laminae of Rexed and all other significant neuronal groupings at each level and photographs of additional sections displaying markers such as acetylcholinesterase (AChE), calbindin, calretinin, choline acetlytransferase, neurofilament protein (SMI 32), enkephalin, calcitonin gene-related peptide (CGRP), and neuronal nuclear protein (NeuN). The text provides a detailed account of the anatomy of the mammalian spinal cord and surrounding musculoskeletal elements The major topics addressed are: development of the spinal cord; the gross anatomy of the spinal cord and its meninges; spinal nerves, nerve roots, and dorsal root ganglia; the vertebral column, vertebral joints, and vertebral muscles; blood supply of the spinal cord; cytoarchitecture and chemoarchitecture of the spinal gray matter; musculotopic anatomy of motoneuron groups; tracts connecting the brain and spinal cord; spinospinal pathways; sympathetic and parasympathetic elements in the spinal cord; neuronal groups and pathways that control micturition; the anatomy of spinal cord injury in experimental animals The atlas of the rat and mouse spinal cord has the following features: Photographs of Nissl stained transverse sections from each of 34 spinal segments for the rat and mouse; Detailed diagrams of each of the 34 spinal segments for rat and mouse, delineating the laminae of Rexed and all other significant neuronal groupings at each level. ; Alongside each of the 34 Nissl stained segments, there are additional sections displaying markers such as acetylcholinesterase, calbindin, calretinin, choline acetlytransferase, neurofilament protein (SMI 32), and neuronal nuclear protein (NeuN) All the major motoneuron clusters are identified in relation to the individual muscles or muscle groups they supply

Spinal Cord Interneurons are Identified with Pseudorabies Viral Injections Into Hindlimb Muscles of Spinal Rats Treated with Olfactory Ensheathing Cells and Epidural Stimulation

Spinal Cord Interneurons are Identified with Pseudorabies Viral Injections Into Hindlimb Muscles of Spinal Rats Treated with Olfactory Ensheathing Cells and Epidural Stimulation
Author: Alexa Marie Tierno
Publisher:
Total Pages: 49
Release: 2020
Genre:
ISBN:

Transplantation of olfactory bulb-derived olfactory ensheathing cells (OECs) is a promising therapy to facilitate the regrowth of axons and promote functional recovery following injury. This study combines OEC transplantation and epidural stimulation during a climbing task following a severe transection of the thoracic spinal cord of inbred Fischer 344 rats. To examine propriospinal connectivity of axons across the injury site, we injected two strains of a transsynaptic retrograde tracer, pseudorabies virus (PRV); GFP-PRV was injected into the tibialis anterior of one rat hindlimb and RFP-PRV was injected into the soleus of the other. We analyzed the PRV-labeled neurons in the lumbar spinal cord to evaluate the extent of each PRV injection and to detect populations of cholinergic and Pax2-expressing PRV-labeled interneurons. Several dually infected PRV interneurons from antagonistic muscles were detected in the lumbar cord. We also found that there were more Pax2-expressing PRV-labeled interneurons in media- compared to OEC- or fibroblast-treated rats. Next, we looked at the injury site block and found that many rats displayed incomplete lesions and that a proportion of PRV-labeled neurons above the lesion site are V2a or cholinergic interneurons. In addition, we located PRV-labeled neurons several segments above the injury site in a location and distribution characteristic of sympathetic preganglionic neurons. PRV-labeled V2a interneurons were detected near sympathetic preganglionic neurons, as well as in the intermediate thoracic spinal cord. Overall, our results demonstrate that tissue sparing may facilitate regeneration or reorganization of propriospinal circuits following injury after cellular transplantation and epidural stimulation.