NERVOUS CONTROL OF COLONIC MOTILITY

粗神经束，称为分流束，在颅尾侧走行 轴，最近已被描述在肌间神经丛的远端 各种哺乳动物的结肠。 这些似乎连接了 肛门直肠区域的神经丛到肛门直肠区域的更近端部分的神经丛， 结肠 从他们的位置来看，他们似乎是一种协调 肛门直肠功能与操作的更近端水平的 结肠 此外，已发现远端直肠的肌间神经丛 显示不规则性和稀疏性，将该区域与 剩下的结肠。 这两个新发现，直肠神经丛和 远端结肠的分流束已经在几种食肉动物中发现， 有袋类动物和一种灵长类动物（食蟹猴）。 这项建议 概述了旨在发现这些解剖特征 描述包括人类在内的其他灵长类动物的特征。此外，建议检查 从病人身上取出的用于治疗的样本中的结肠的这个区域 肛门直肠或便秘的症状 这些研究将利用 整体安装和平面部分的银浸渍方法等 常规神经染色方法。 另外，分流器的连接 束到肌间神经丛的其他成分，以及到外在的 在猫中结肠的神经支配将通过使用 辣根过氧化物酶示踪和神经变性技术。 还有， 分流束的生理学将在体外通过（1） 结肠-结肠和结肠-括约肌反射在体和离体研究 记录分流束的电活动，（2） 分析在一个正常人的分流束中诱发的复合动作电位， Eccles室;（3）电刺激效应的检测 刺激分流束后的收缩和肌电图 近端结肠 在这些分析中，神经切片、分流切片 神经束，神经刺激和自主神经拮抗剂药物将用于 解释观察到的效果的机制。 这些实验将与 我们对神经特性的理解 远端结肠段，并可能扩大我们的理解， 肛门直肠或排便障碍性便秘的发病机制。

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.