2021  1,540
2020  1,374
2019  1,023
2018  0,932
2017  0,977
2016  0,799
2015  0,662
2014  0,740
2013  0,739
2012  0,637
2011  0,658
2010  0,654
2009  0,570
2008  0,849
2007  0,805
2006  0,330
2005  0,435
2004  0,623
2003  0,567
2002  0,641
2001  0,490
2000  0,477
1999  0,762
1998  0,785
1997  0,507
1996  0,518
1995  0,502
Vol 42(2008) N 5 p. 729-737;
E.N. Kozlova

Strategies to repair lost sensory connections to the spinal cord

Department of Neuroscience, Neuroanatomy, Uppsala University Biomedical Center, PO Box 587, SE-751 23, Uppsala, Sweden
Received - 2008-04-17; Accepted - 2008-04-17

Failure of injured axons to regenerate in the central nervous system (CNS) is the main obstacle for repair of stroke and traumatic injuries to the spinal cord and sensory roots. This regeneration failure is high-lighted at the dorsal root transitional zone (DRTZ), the boundary between the peripheral (PNS) and central nervous system where sensory axons enter the spinal cord. Injured sensory axons regenerate in the PNS compartment of the dorsal root but are halted as soon as they reach the DRTZ. The failure of regenerating dorsal root axons to re-enter the mature spinal cord is a reflection of the generally nonpermissive nature of the CNS environment, in contrast to the regeneration supportive properties of the PNS. The dorsal root injury paradigm is therefore an attractive model for studying mechanisms underlying CNS regeneration failure in general and how to overcome the hostile CNS environment. Here we review the main lines that have been pursued to achieve growth of injured dorsal root axons into the spinal cord: (i) modifying the inhibitory nature of the DRTZ by breaking down or blocking the effect of growth repelling molecules, (ii) stimulate elongation of injured dorsal root axons by a prior conditioning lesion or administration of specific growth factors, (iii) implantation of olfactory ensheathing cells to provide a growth supportive cellular terrain at the DRTZ, and (iv) replacing the regeneration deficient adult dorsal root ganglion neurons with embryonic neurons or neural stem cells.

nerve degeneration, nerve regeneration, spinal cord, sensory system, transplantation