Protective effect of epidural electrical stimulation on dorsal root ganglion and spinal cord motoneuron after sciatic nerve transection

Abstract

Objective To observe the effect of epidural electrical stimulation on spinal cord motoneuron and dorsal root ganglion after sciatic nerve transection.Methods The model of sciatic nerve injury were established,and the rats were divided into 2 groups randomly.In the experimental group,the epidural stimulator was inserted into the correspond segments of spinal cord.In the control group,the same stimulator was inserted but no output current was given.The number of spinal cord motoneurons and dorsal root ganglion neurons was counted,and their ultrastructures were observed.The thickness of the myelin sheat of the regenerated nerve fiber and its conduction velocity at properly time were measured.Results At 1st,4th and 8th week after operation,the number of neurons of dorsal root ganglion in experimental group was 15.74 ± 1.47,14.17 ± 1.20 and 13.33 ±0.47,and that in control group was 10.99 ± 1.38,10.33 ±0.78 and 9.20 ±0.56 respectively.The number of neurons of anterior horn of spinal cord in experimental group was 17.16 ± 0.50,15.86 ± 1.27 and 11.55 ± 0.95,and that in control group was 12.16 ±0.92,10.27 ± 0.44 and 9.24 ± 0.78 respectively.Statistically,there was significant difference in the number of neurons between experimental group and control group (P ＜ 0.05 ).Conclusion Epidural pulse-electrical stimulation could prevent the apoptosis of perikaryon and protect the normal structures of the spinal cord motoneurons and dorsal root ganglions. Key words: Sciatic nerve injury; Electrical stimulus; Spinal cord; Motoneuron; Dorsalroot ganglion