The natural ability of the adult central nervous system of higher vert
ebrates to recover from injury is highly limited. This limitation is m
ost likely due to an inhospitable environment and/or intrinsic incapac
ities of the neurons to re-extend their neurites after injury or axoto
my. The rat corticospinal tract is the largest tract leading from brai
n to spinal cord and is often used as a model in developmental and reg
eneration studies. The extensive know-how of factors involved in the d
evelopment of the corticospinal tract did provide the foundation for m
any studies on corticospinal tract regrowth after injury in the adult
spinal cord. The results of these experiments, as discussed in this re
view, have led to important contributions to the further understanding
of central nervous system regeneration. (C) 1997 Elsevier Science.