Ciliary neurotrophic factor (
CNTF) has been implicated in the pathophysiology of injury to the central nervous system. The rapid increase in
CNTF production following
spinal cord injury (SCI) in rats is thought to serve a role in the neuronal survival and functional recovery. In this study, 40 SD rats were divided into four groups:
sham-operated group, saline-treated group, 5- and 10-microg
CNTF group. Saline and
CNTF were given through lumbar intrathecal
catheter for 10 days after T10 segment of spinal cord were injured by modified Allen
contusion method. Animals were behaviorally tested for 6 weeks using the Basso, Beattie, Bresnahan locomotor rating scale and inclined plane test. At the end of 6 week, rubrospinal neurons of five rats in each group were labeled by retrograde transport of the
horseradish peroxidase (HRP) from the lesion site, and then the labeled red nucleus neuron (RN) numbers were counted. Additional rats were histologically assessed for tissue sparing and neuronal loss and reactive
gliosis at the injury site and adjacent areas. Rats treated with
CNTF regained greater improvements in hindlimb function than controls. The amount of spared tissue was significantly higher in
CNTF-treated animals than in controls. After
CNTF treatment, the number of HRP-labeled RN neurons were significantly increased. Astrocytes and microglia reactivity was more pronounced in
CNTF-treated animals than in controls. These results indicate that intrathecal infusion of exogenous
CNTF following SCI may significantly reduce tissue damage and protect the rubrospinal descending tracks and enhances functional recovery, and may also induce more
gliosis.