NERVOUS CONTROL OF COLONIC MOTILITY

粗大的神经束，称为分流束，在颅尾部运行 轴，最近被描述在远端的肌间神经丛中 各种哺乳动物的结肠。这些似乎连接了肌层 肛门直肠区与更近端部分的神经丛 冒号。从他们的立场来看，他们似乎是一种协调的手段 肛门直肠功能随手术近端节段的增加 冒号。此外，直肠远端的肌间神经丛也被发现 显示不规则和稀疏性，以区分该区域和 结肠的其余部分。这两个新发现都是直肠神经丛和 在几种食肉动物中发现了远端结肠的分流束， 在有袋类动物和一种灵长类动物(食蟹猴)中。这项建议 概述了旨在发现这些解剖特征是否 描述包括人类在内的其他灵长类动物的特征。此外，还建议审查 从病人的结肠标本中取出这一区域进行治疗 肛门直肠或便秘的症状。这些研究将利用 整体和平面部分的浸银方法，以及更多 常规神经染色方法。此外，分流器的连接方式 肌间神经丛的其他成分和外源性的神经束 在猫身上，结肠的神经支配将通过使用 辣根过氧化物酶示踪和神经退行性变技术。另外， 分流束的生理学将通过以下方法进行体外检测： 大肠和结肠括约肌反射的体内外研究 随着分流束中电活动的记录，(2) 股骨头分流束复合动作电位的分析 埃克尔斯室，以及(3)电气效应的检测 分流束刺激对心脏收缩和肌电的影响 近端结肠。在这些分析中，神经节、分流节 神经束、神经刺激和自主神经拮抗剂药物将用于 解释所见影响的机制。这些实验将与以下内容相关 我们对定义功能的神经的特征的理解 并可能扩大我们对远端结肠段的理解 肛门直肠或消化不良便秘的发病机制。

Thick nerve bundles, called shunt fascicles, running in the cranio-caudad axis, have recently been described in the myenteric plexus of the distal colon of a variety of mammals. These appear to connect the myenteric plexus of the anorectal region to that of more proximal parts of the colon. From their position, they appear to be a means to coordinate anorectal function with the operation of more proximal levels of the colon. Also, the myenteric plexis of the distal rectum has been found to display an irregularity and sparsity that distinguish that region from the rest of the colon. Both of these new findings, the rectal plexus and the shunt fascicles of the distal colon have been found in several carnivores, in marsupials and in one primate (the Cynomolgus monkey). This proposal outlines projects designed to discover if these anatomic features characterize other primates including man. Also, it is proposed to examine this region of the colon in specimens removed from patients for treatment of anorectal or dyschetic constipation. These studies will make use of silver-impregnation methods in whole-mounts and planar sections, and more conventional nerve staining methods. Also, the connections of the shunt fascicles to other elements of the myenteric plexus, and to the extrinsic innervation of the colon will be determined in the cat by the use of horseradish peroxidase tracing and nerve degeneration techniques. Also, the physiology of the shunt fascicles will be examined in vitro by (1) the study of colo-colonic and colo-sphincteric reflexes in vivo and in vitro with recording of electrical activity in the shunt fascicles, (2) the analysis of the compound action potentials evoked in shunt fascicles in an Eccles chamber, and (3) the examination of the effect of electrical stimulation of shunt fascicles upon the contractions and electromyogram of the proximal colon. In these analyses, nerve section, section of shunt fascicles, nerve stimulation and autonomic antagonist drugs will be used to explain mechanisms of effects seen. The experiments will be relevant to our understanding of the character of the nerves that define the function of the distal colonic segment and may expand our understanding of the pathogenesis of anorectal or dyschetic constipation.