An Experimental Study On Anatomical Observation And Functional Foundation Of Construction Of "Abdominal Wall-spinal Cord Center-bladder" Artificial Reflex Arc In SD Rat

Objective: To provide anatomical and functional basis for the construction of abdominal wall-spinal cord center-bladder reflex in SD rat.Methods: T13 and S2 nerve were dissected on 20 SD rats after anaesthesia,and Carried on the function appraisal by the neuroelectricity physiology. There were 13 pairs costal bones in SD rat in total.The T13 was the most far-end costa fluctuantes.The T13 intercostal nerve was dissected under the T13 costal bones.T13 spinal nerve was Traced to the intervertebral hole direction until its ventral root and dorsal root were found.The active potential of T13 nerve root was recorded by stimulating The abdominal wall, while the T13 nerve root's spontaneous neural discharge was recorded as the comparison without stimulation. There were 4 pairs sacral nerves.The ventral root and dorsal root of S2 spinal nerve were dissected under microscope. The active potential of plexus vesica and the myoelectricity of bladder smooth muscle were recorded by stimulating S2 nerve root,while the S2 nerve root's spontaneous neural discharge was recorded as the comparison without stimulation.Then,it was achieved by intradural microanastomosis of the left T13 ventral root was anastomosed under microscope to S2 ventral root by autogenous nerve grafting intraduraly, with the left T13 dorsal root remaining intact. Result: Twenty SD rats resulted as follow:In anatomy,the diameter of T13's ventral root was about 0.4mm,and the diameter of S2's ventral root was about 0.3mm.Both of diameters were close,and both of ventral roots located at ventralis medialis and had no spinal ganglion.In electrophysiology, The figure and amplitude of the active potential was different from that of spontaneous neural discharge in T13 nerve root,so, the active potential of T13 nerve root was produced by stimulating The abdominal wall;The figure and amplitude of the active potential of the plexus vesica different from that of spontaneous neural discharge of S2 nerve root,and The figure of myoelectricity of bladder smooth muscle can be produced by stimulating S2 nerve root.T13 nerve root and S2 nerve root can produce the similar figures by stimulation.So,it can be achieved by intradural microanastomosis of the left T13 ventral root was anastomosed under microscope to S2 ventral root by autogenous nerve grafting intraduraly, with the left T13 dorsal root remaining intact.Then,"the abdominal wall-spinal cord center-bladder"artificial reflex was constructed.Conclusion:T13 intercostal nerve mainly dominated the abdominal wall's feeling and the movement,and S2 nerve mainly dominated bladder function.The anatomical and functional characteristic of T13 and S2 nerve root is the foundation to construct"the abdominal wall-spinal cord center-bladder"artificial reflex in SD rat.