Apoptosis of motor neurons following transection of the sciatic nerve in adult rats

Objective To investigate the relationship between sciatic nerve transection and motor neuron apoptosis in adult rats. MethodsTBZ24 male Sprague Dawley rats, aged 5 to 6 weeks and weighted 120 to 150 g , were randomly divided into the experimental group (n = 18) and the control group (n = 6). In the experimental group, the right sciatic nerve was transected at 1 cm distal to the periform muscle, and the proximal stump was ligated to prevent nerve regeneration. The rats were sacrificed on the 5th (group A), 14th (group B), and 21th (group C) postoperative day respectively, with 6 rats each. After the rats were transcardially perfused with 4 % paraformaldehyde, the spinal cord of L4 to L6 was harvested and post fixed in 4 % paraformaldehyde for 24 hours, and then embodied in paraffin. Terminal deoxy nucleotidyl transferase (TdT)mediated digoxingenindUTP nicked end labeling (TUNEL) technique was applied for detection of apoptotic motor neurons. Results No positive labeled neurons appeared in the control group. 3 apoptotic motor neurons were detected in 1 rat in group A. There were 2.2 1.2, 5.2 2.3 ( ) apoptotic motor neurons in group B and group C respectively. Conclusions Apoptosis of motor neurons can be induced by transection and ligation of sciatic nerve in adult rats, owing to inhibition of the retrograde transportation of neurotrophic factors.