A study of the excitatory spinal reflex pathway related to the bladder contraction in cats.

桥脑排尿中枢是排尿收缩的关键。在刺激其它膀胱分支后，盆神经的膀胱分支中的反射放电也被认为是经由该中枢诱发的。本研究的重点是是否有一个骶反射中心，最近没有被考虑。所有实验均切断双侧腹下神经。(1)脊髓横断后观察到的具有小幅度和相对快的间隔的收缩-舒张波动依赖于膀胱内压，在膀胱内压约100-150 mmH 20时显示最大幅度（80-100 mmH 20）。在去除脊髓后，这些波动显著减少（10-30 mmH 2 O），表明波动是由脊髓反射以及神经节反射诱发的。(2)在盆神经的两个膀胱神经分支之间的所有侧支被分裂的准备中，一个膀胱分支的电刺激在另一个膀胱分支上诱发早期（20-40 ms）和晚期（约100 ms）反射。当用玻璃微电极从骶部副交感节前神经元记录时，刺激盆神经的膀胱分支也诱发早期（14-26 ms）和晚期（62-106 ms）反射。两种制剂中早期反射的潜伏期表明，这是通过脊髓诱发的。早期和晚期反射之间的放电减少，这表明，从细胞内研究来看，这是由IPSPs引起的。早反射在排尿收缩时比膀胱放松时大，表明早反射类似于长反射依赖于膀胱活动。

The pontine micturition centre is essential for the micturition contraction. Reflex discharges in the bladder branch of the pelvic nerve after stimulation of other bladder branch are also thought to be evoked via this centre. The present study focuses on whether there is a sacral reflex centre that has not recently been considered. The hypogastric nerves of both sides were cut in all experiments. (1) Contraction-relaxation fluctuations with small amplitudes and relatively fast intervals observed after transection of the spinal cord were dependent on the intravesical pressure, showing maximal amplitudes (80-100 mmH20) at around 100-150 mmH20 of the intravesical pressure. After removal of the spinal cord, these fluctuations dramatically reduced (10-30 mmH20), suggesting that the fluctuations were evoked by a spinal reflex as well as by a ganglion reflex. (2) In preparations where all collaterals between the two bladder nerve branches of the pelvic nerve were split, electrical stimulation of one bladder branch evoked early (20-40 ms) and late (around 100 ms) reflexes on the other bladder branch. When recording from the sacral parasympathetic preganglionic neurones with a glass microelectrode, stimulation of the bladder branch of the pelvic nerve also evoked early (14-26 ms) and late (62-106 ms) reflexes. The latency of the early reflex in both preparations indicated that this was evoked via the spinal cord. Firings between the early and late reflex were reduced, suggesting that, from the intracellular study, it was caused by IPSPs. The early reflex was larger during micturition contraction than when the bladder was relaxed, indicating that the early reflex was dependent on the bladder activity similar to the long reflex.