Brain-derived neurotrophic factor prevents the death of motor neurons following sciatic nerve injury in rats

Objective To investigate the relationship between sciatic nerve injury and motor neuron apoptosis in adult rats and the inhibitory effect of brain derived neurotrophic factor (BDNF) on the apoptosis.Methods Twenty seven Sprague Dawley rast,weighing 180 to 220 g,were randomly divided into control group (n=3),BDNF group (n=12) and normal saline (NS) group (n=12).In the BDNF group and NS group,the right sciatic nerve was transected at 0.5?cm distal to the periform muscle,and the proximal stump was sutured into silicone chamber.BDNF or NS solution was injected into the silicone chambers.The rats were sacrificed on the 3rd,6th,12th and 24th postoperative days respectively,with 3 rats each.The spinal cord of 14 16 was harvested.Terminal deoxy nucleotidyl transferase (TDT) mediated digoxingenin dUTP nicked end labeling (TUNEL) technique was applied for detection of apoptosis motor neurons.Results Compared with the NS and control groups,the mount of apoptosis motor neurons in BDNF group was reduced within 6 days from (12.5±2.2)% to (9.3± 1.8)%  (P  0.05) and the survival rate for motor neurons was increased from (82.6±1.2)% to (88.1± 1.4)% (P0.05).Conclusion Apoptosis of motor neurons can be induced by transection of sciatic nerve in adult rats,and BDNF prevents the apoptosis.