Moda Y, Yamane M, Fukuda H, Okada H
Department of Physiology, Kawasaki Medical School, Okayama, Japan.
J Auton Nerv Syst. 1993 Apr;43(1):59-68. doi: 10.1016/0165-1838(93)90322-l.
To examine whether or not the pontine micturition center (PMC) is involved in the inhibition of the micturition reflex by pelvic rectal and pudendal anal afferents, neuronal activity in the PMC was observed during inhibition of this reflex in paralyzed decerebrate dogs. Discharge of pelvic vesical branches (VBs) waxed and waned at a rhythm of about 2 Hz during the micturition reflex, which was activated by continuous stimulation of the contralateral VBs. This rhythmic discharge was modulated by continuous stimulation of contralateral pelvic rectal branches (RBs) superimposed on the VB stimulation. The modulation was composed of three effects; initial inhibition, augmentation and late inhibition. However, not all of the three effects were obvious in some dogs. One-sixth of 118 neurons examined in the pontine area ventromedial to the locus ceruleus exhibited rhythmic burst firings which preceded the rhythmic discharge of VBs by about 150 ms. Therefore, these pontine neurons are assumed to be output neurons of the PMC. The rhythmic firings of pontine neurons were augmented during continuous RB stimulation independent of the inhibitory and/or augmentative effects of the RB stimulation on the reflex discharge of the VBs. In contrast, the rhythmic firings of the pontine neurons and the reflex discharge of VBs were inhibited by mechanical stimulation of the anal canal and perineal hairs. These results suggest that the PMC is involved in the inhibition of the micturition reflex produced via pudendal afferents but not in that produced by pelvic rectal afferents, and that pelvic and pudendal afferents project to the PMC through separate pathways.
为了研究脑桥排尿中枢（PMC）是否参与盆直肠和阴部肛门传入神经对排尿反射的抑制作用，在瘫痪的去大脑狗抑制该反射期间观察了PMC中的神经元活动。在排尿反射期间，盆膀胱分支（VBs）的放电以约2Hz的节律增强和减弱，该反射由对侧VBs的持续刺激激活。这种节律性放电受到叠加在VB刺激上的对侧盆直肠分支（RBs）持续刺激的调节。这种调节由三种效应组成：初始抑制、增强和晚期抑制。然而，在一些狗中并非所有这三种效应都很明显。在脑桥蓝斑腹内侧区域检查的118个神经元中，六分之一表现出节律性爆发放电，其比VBs的节律性放电提前约150毫秒。因此，这些脑桥神经元被认为是PMC的输出神经元。在持续RB刺激期间，脑桥神经元的节律性放电增强，与RB刺激对VBs反射放电的抑制和/或增强作用无关。相反，脑桥神经元的节律性放电和VBs的反射放电受到肛管和会阴毛发机械刺激的抑制。这些结果表明，PMC参与通过阴部传入神经产生的排尿反射抑制，但不参与盆直肠传入神经产生的抑制，并且盆神经和阴部神经通过不同的途径投射到PMC。
