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Promoting axonal regeneration in the central nervous system by enhancing the cell body response to axotomy
Author(s) -
Plunet Ward,
Kwon Brian K.,
Tetzlaff Wolfram
Publication year - 2002
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.10176
Subject(s) - axotomy , neuroscience , regeneration (biology) , neurotrophic factors , central nervous system , biology , spinal cord injury , neurotrophin , neuroregeneration , spinal cord , peripheral nerve injury , lesion , receptor , medicine , pathology , microbiology and biotechnology , biochemistry
Neurons projecting into the peripheral nervous system (PNS) regenerate their axons after injury, in contrast to those confined to the central nervous system (CNS). Both neuronal and nonneuronal factors contribute to the lack of CNS regeneration. In this review we concentrate on the differential gene expression response to axotomy in PNS vs. CNS neurons. In general CNS neurons fail to up‐regulate or sustain the expression of regeneration‐associated proteins (RAGs), including trophic factors and their receptors. The presumed lack of trophic support of axotomized CNS neurons provided the rationale for the exogenous application of trophic factors, either to the lesion site or to the cell bodies. Here, we review our data on the application of trophic factors to rubrospinal and corticospinal neurons. Cell body treatment of axotomized rubrospinal neurons with brain‐derived neurotrophic factor (BDNF) reversed atrophy, increased GAP‐43 and Tα‐1 tubulin mRNA expression, and promoted axonal regeneration into peripheral nerve grafts. Importantly, BDNF cell body treatment was still effective in the chronic setting, i.e., when initiated 1 year after injury, but BDNF had no effect when applied to the chronic spinal cord injury site. The ability to promote regeneration in chronically injured neurons will hopefully contribute to the development of treatment strategies for chronic spinal injuries. © 2002 Wiley‐Liss, Inc.