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

脑桥排尿中心对于排尿收缩是必不可少的。刺激其他膀胱支后，盆神经膀胱支的反射放电也被认为是通过这个中枢诱发的。目前的研究集中在是否存在一个最近没有被考虑过的骶骨反射中心。所有实验均切断双侧腹下神经。(1)脊髓切断后出现幅度较小、间隔较短的收缩-松弛波动与膀胱内压有关，在膀胱内压100-150 mm-H20附近出现最大幅度(80-100 mm H20)。在脊髓切除后，这些波动显著减少(10-30 mm H20)，这表明这种波动既由脊髓反射也由神经节反射引起。(2)在盆神经膀胱神经支的所有侧支均被切断的准备过程中，电刺激一个膀胱支可引起另一个膀胱支的早反射(20-40ms)和晚反射(约100ms)。当用玻璃微电极记录到副交感神经节前神经元时，刺激盆神经膀胱支也可引起早反射(14~26ms)和迟反射(62~106ms)。两种方法的早期反射潜伏期都表明这是通过脊髓诱发的。早期反射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IPSP引起的。早期反射在排尿收缩时大于膀胱松弛时，表明早期反射依赖于膀胱活动，类似于长反射。

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.