EXPRESSION OF C-JUN AND NEURONAL NITRIC-OXIDE SYNTHASE IN RAT SPINAL MOTONEURONS FOLLOWING AXONAL INJURY

Expression of neuronal NOS, c-jun and c-fos in spinal motoneurons foll owing axonal damage were investigated in the present study. Although e ither distal spinal root axotomy or root avulsion induced expression o f c-jun, expression of c-jun was predominantly found in distal root-ax otomized motoneurons. In contrast, expression of NOS was exclusively o bserved in avulsed motoneurons. c-fos was not expressed in spinal moto neurons following either distal root axotomy or root avulsion. The dif ferent expression patterns of c-jun and NOS in the injured neurons sug gest that these molecules may involve in different cellular processes and might play different roles in response to the injury. Since distal root axotomy did not cause motoneuron death and root avulsion did, ex pression of c-jun is likely related to regenerative process while indu ction of NOS may be involved in the degenerative process.