Morrison J F, Sato A, Sato Y, Suzuki A
Department of the Autonomic Nervous System, Tokyo Metropolitan Institute of Gerontology, Japan.
Neurosci Lett. 1996 Jul 5;212(1):25-8. doi: 10.1016/0304-3940(96)12759-2.
The effects of single electrical shocks to myelinated A and unmyelinated C afferent fibers of perineal and limb somatic nerves on the reflex discharges in pelvic parasympathetic (L6/S1) efferent nerves to the bladder were examined in anesthetized central nervous system (CNS)-intact and acute spinal rats. When the bladder was empty, stimulation of perineal somatic inputs to the L6 and S1 segments from the perineo-femoral branch of a pudendal nerve produced excitatory A- and C-reflex discharge components in postganglionic parasympathetic efferent nerve branches on the bladder surface. When the bladder was expanded and pelvic efferent neurons were rhythmically active, additional inhibitory A- and C-reflex components could be seen. After acute spinal transection, the same stimuli elicited excitatory A- and C-reflex discharges of similar latency as those observed before the spinal transection, but were of larger amplitude and longer duration; resting activity in the pelvic nerve was low, and no evoked inhibitory reflex components could be observed. Electrical stimulation of afferents in the tibial nerve had no effect when the bladder pressure was low, but when the bladder was distended, early and late components of reflex inhibition and excitation of parasympathetic activity were visible in CNS-intact rats; these reflex responses were abolished following spinalization.
在麻醉的中枢神经系统（CNS）完整和急性脊髓损伤的大鼠中，研究了对会阴和肢体躯体神经的有髓鞘A传入纤维和无髓鞘C传入纤维进行单次电击，对膀胱盆部副交感神经（L6/S1）传出神经反射放电的影响。当膀胱空虚时，刺激来自阴部神经会阴 - 股分支至L6和S1节段的会阴躯体传入神经，会在膀胱表面的节后副交感神经传出神经分支中产生兴奋性A和C反射放电成分。当膀胱扩张且盆部传出神经元有节律地活动时，还可观察到额外的抑制性A和C反射成分。急性脊髓横断后，相同刺激引发的兴奋性A和C反射放电潜伏期与脊髓横断前观察到的相似，但幅度更大、持续时间更长；盆神经的静息活动较低，且未观察到诱发的抑制性反射成分。当膀胱压力较低时，电刺激胫神经传入神经无影响，但当膀胱充盈时，在CNS完整的大鼠中可见副交感神经活动反射抑制和兴奋的早期和晚期成分；脊髓损伤后这些反射反应消失。
