Fukuda H, Fukai K
Brain Res. 1986 Aug 20;380(2):287-96. doi: 10.1016/0006-8993(86)90224-6.
The reflex centres for straining for defaecation, micturition and presumably for parturition were located electrophysiologically in decerebrate dogs. Stimulation of pelvic afferent fibres initially induced a sustained increase in nervous outflow to the diaphragm, rectus abdominis and lateral cricoarytenoid muscles and subsequently induced rhythmic increases which were superimposed on the sustained increase. The rhythmic increases occurred even after transection at the most rostral pons, but they were abolished by a partial cut at the most lateral part of the rostral pons following transection of the contralateral half of the rostral medulla oblongata. The sustained increase continued after transection 1.5 mm caudal to the obex, but disappeared after transection about 5 mm caudal to the obex. This result shows that straining is brought about by both sustained and rhythmic straining reflexes. Both sustained and rhythmic straining, but not defaecation and micturition, could be elicited by stimulation of an area of the Kölliker-Fuse nucleus. The discharges of about half of the units in the nucleus and the neighbouring rostrolateral pontine area which responded to stimulation of the pelvic afferent fibres changed synchronously with the rhythmic straining. These results show that the rhythmic and sustained straining reflex centres are located in the Kölliker-Fuse nucleus and in the lower medulla oblongata, respectively.
在去大脑的狗身上通过电生理学方法确定了排便、排尿以及推测的分娩用力的反射中枢。刺激盆神经传入纤维最初会使支配膈肌、腹直肌和环杓侧肌的神经传出持续增加，随后会诱发有节律的增加，并叠加在持续增加之上。即使在脑桥最前端横断后，有节律的增加仍会出现，但在横断延髓最前端对侧的一半后，在脑桥最外侧部分进行部分切断后，这种有节律的增加就会消失。在闩尾侧1.5毫米处横断后，持续增加仍会持续，但在闩尾侧约5毫米处横断后就会消失。这一结果表明，用力是由持续和有节律的用力反射共同引起的。刺激 Kölliker-Fuse 核的一个区域可诱发持续和有节律的用力，但不能诱发排便和排尿。该核以及邻近的脑桥嘴外侧区域中约一半对盆神经传入纤维刺激有反应的神经元放电与有节律的用力同步变化。这些结果表明，有节律的和持续的用力反射中枢分别位于 Kölliker-Fuse 核和延髓下部。
