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Spinal Cord Regeneration (spinal + cord_regeneration)
Selected AbstractsNanofibrous Patches for Spinal Cord RegenerationADVANCED FUNCTIONAL MATERIALS, Issue 9 2010Yiqian Zhu Abstract The difficulty in spinal cord regeneration is related to the inhibitory factors for axon growth and the lack of appropriate axon guidance in the lesion region. Here scaffolds are developed with aligned nanofibers for nerve guidance and drug delivery in the spinal cord. Blended polymers including poly(L -lactic acid) (PLLA) and poly(lactide- co -glycolide) (PLGA) are used to electrospin nanofibrous scaffolds with a two-layer structure: aligned nanofibers in the inner layer and random nanofibers in the outer layer. Rolipram, a small molecule that can enhance cAMP (cyclic adenosine monophosphate) activity in neurons and suppress inflammatory responses, is immobilized onto nanofibers. To test the therapeutic effects of nanofibrous scaffolds, the nanofibrous scaffolds loaded with rolipram are used to bridge the hemisection lesion in 8-week old athymic rats. The scaffolds with rolipram increase axon growth through the scaffolds and in the lesion, promote angiogenesis through the scaffold, and decrease the population of astrocytes and chondroitin sulfate proteoglycans in the lesion. Locomotor scale rating analysis shows that the scaffolds with rolipram significantly improved hindlimb function after 3 weeks. This study demonstrates that nanofibrous scaffolds offer a valuable platform for drug delivery for spinal cord regeneration. [source] Electroporation as a tool to study in vivo spinal cord regenerationDEVELOPMENTAL DYNAMICS, Issue 2 2003K. Echeverri Abstract Tailed amphibians such as axolotls and newts have the unique ability to fully regenerate a functional spinal cord throughout life. Where the cells come from and how they form the new structure is still poorly understood. Here, we describe the development of a technique that allows the visualization of cells in the living animal during spinal cord regeneration. A microelectrode needle is inserted into the lumen of the spinal cord and short rapid pulses are applied to transfer the plasmids encoding the green or red fluorescent proteins into ependymal cells close to the plane of amputation. The use of small, transparent axolotls permits imaging with epifluorescence and differential interference contrast microscopy to track the transfected cells as they contribute to the spinal cord. This technique promises to be useful in understanding how neural progenitors are recruited to the regenerating spinal cord and opens up the possibility of testing gene function during this process. Developmental Dynamics 226:418,425, 2003. © 2003 Wiley-Liss, Inc. [source] Nanofibrous Patches for Spinal Cord RegenerationADVANCED FUNCTIONAL MATERIALS, Issue 9 2010Yiqian Zhu Abstract The difficulty in spinal cord regeneration is related to the inhibitory factors for axon growth and the lack of appropriate axon guidance in the lesion region. Here scaffolds are developed with aligned nanofibers for nerve guidance and drug delivery in the spinal cord. Blended polymers including poly(L -lactic acid) (PLLA) and poly(lactide- co -glycolide) (PLGA) are used to electrospin nanofibrous scaffolds with a two-layer structure: aligned nanofibers in the inner layer and random nanofibers in the outer layer. Rolipram, a small molecule that can enhance cAMP (cyclic adenosine monophosphate) activity in neurons and suppress inflammatory responses, is immobilized onto nanofibers. To test the therapeutic effects of nanofibrous scaffolds, the nanofibrous scaffolds loaded with rolipram are used to bridge the hemisection lesion in 8-week old athymic rats. The scaffolds with rolipram increase axon growth through the scaffolds and in the lesion, promote angiogenesis through the scaffold, and decrease the population of astrocytes and chondroitin sulfate proteoglycans in the lesion. Locomotor scale rating analysis shows that the scaffolds with rolipram significantly improved hindlimb function after 3 weeks. This study demonstrates that nanofibrous scaffolds offer a valuable platform for drug delivery for spinal cord regeneration. [source] Strategies for identifying genes that play a role in spinal cord regenerationJOURNAL OF ANATOMY, Issue 1 2004M. Wintzer Abstract A search for genes that promote or block CNS regeneration requires numerous approaches; for example, tests can be made on individual candidate molecules. Here, however, we describe methods for comprehensive identification of genes up- and down-regulated in neurons that can and cannot regenerate after injury. One problem concerns identification of low-abundance genes out of the 30 000 or so genes expressed by neurons. Another difficulty is knowing whether a single gene or multiple genes are necessary. When microchips and subtractive differential display are used to identify genes turned on or off, the numbers are still too great to test which molecules are actually important for regeneration. Candidates are genes coding for trophic, inhibitory, receptor and extracellular matrix molecules, as well as unknown genes. A preparation useful for narrowing the search is the neonatal opossum. The spinal cord and optic nerve can regenerate after injury at 9 days but cannot at 12 days after birth. This narrow window allows genes responsible for the turning off of regeneration to be identified. As a next step, sites at which they are expressed (forebrain, midbrain, spinal cord, neurons or glia, intracellular or extracellular) must be determined. An essential step is to characterize proteins, their levels of expression, and their importance for regeneration. Comprehensive searches for molecular mechanisms represent a lengthy series of experiments that could help in devising strategies for repairing injured spinal cord. [source] The case for sequencing the genome of the electric eel Electrophorus electricusJOURNAL OF FISH BIOLOGY, Issue 2 2008J. S. Albert A substantial international community of biologists have proposed the electric eel Electrophorus electricus (Teleostei: Gymnotiformes) as an important candidate for genome sequencing. In this study, the authors outline the unique advantages that a genome sequencing project of this species would offer society for developing new ways of producing and storing electricity. Over tens of millions of years, electric fish have evolved an exceptional capacity to generate a weak (millivolt) electric field in the water near their body from specialized muscle-derived electric organs, and simultaneously, to sense changes in this field that occur when it interacts with foreign objects. This electric sense is used both to navigate and orient in murky tropical waters and to communicate with other members of the same species. Some species, such as the electric eel, have also evolved a strong voltage organ as a means of stunning prey. This organism, and a handful of others scattered worldwide, convert chemical energy from food directly into workable electric energy and could provide important clues on how this process could be manipulated for human benefit. Electric fishes have been used as models for the study of basic biological and behavioural mechanisms for more than 40 years by a large and growing research community. These fishes represent a rich source of experimental material in the areas of excitable membranes, neurochemistry, cellular differentiation, spinal cord regeneration, animal behaviour and the evolution of novel sensory and motor organs. Studies on electric fishes also have tremendous potential as a model for the study of developmental or disease processes, such as muscular dystrophy and spinal cord regeneration. Access to the genome sequence of E. electricus will provide society with a whole new set of molecular tools for understanding the biophysical control of electromotive molecules, excitable membranes and the cellular production of weak and strong electric fields. Understanding the regulation of ion channel genes will be central for efforts to induce the differentiation of electrogenic cells in other tissues and organisms and to control the intrinsic electric behaviours of these cells. Dense genomic sequence information of E. electricus will also help elucidate the genetic basis for the origin and adaptive diversification of a novel vertebrate tissue. The value of existing resources within the community of electric fish research will be greatly enhanced across a broad range of physiological and environmental sciences by having a draft genome sequence of the electric eel. [source] Fibroblast growth factor-2 mRNA expression in the brainstem and spinal cord of normal and chronic spinally transected urodelesJOURNAL OF NEUROSCIENCE RESEARCH, Issue 15 2008Marie Moftah Abstract Descending pathways in the spinal cord of adult urodele amphibians show a high regenerative ability after body spinal cord transection; regenerated axons regrow into the transected spinal cord, and hindlimb locomotor recovery occurs spontaneously. Little is currently known about the molecular basis of spinal cord regeneration in urodeles, but it is believed that fibroblast growth factor-2 (FGF2) may play an important role by inducing proliferation of neural progenitor cells. The aim of our study, using in situ hybridization in adult Pleurodeles waltlii, was twofold: 1) to document FGF2 mRNA expression pattern along the brainstem-spinal cord of intact salamanders and 2) to investigate the changes in this pattern in animals unable to display hindlimb locomotor movements and in animals having fully recovered hindlimb locomotor activity after body spinal cord transection. This design establishes a firm basis for further studies on the role of FGF2 in functional recovery of hindlimb locomotion. Our results revealed a decreasing rostrocaudal gradient in FGF2 mRNA expression along the brainstem-spinal cord in intact animals. They further demonstrated a long-lasting up-regulation of FGF2 mRNA expression in response to spinal transection at the midtrunk level, both in brainstem and in the spinal cord below the injury. Finally, double immunolabeling showed that FGF2 was up-regulated in neuroglial, presumably undifferentiated, cells. Therefore, we propose that FGF2 may be involved in cell proliferation and/or neuronal differentiation after body spinal cord transection in salamander and could thus play an important role in functional recovery of locomotion after spinal lesion. © 2008 Wiley-Liss, Inc. [source] |