REFLEX PATHWAYS IN THE CONTROL OF INTESTINAL MOTILITY

胃肠道的正常运动模式主要是 依赖于内在的神经反射。这些组织的病理变化 肠神经元是许多运动障碍的潜在原因。我们在这方面的进展 了解胃肠道运动是如何被控制的 由于我们缺乏对神经的了解而受到相当大的阻碍 牵涉到电路。这项提案中概述的实验包括 旨在解决这一缺陷。这项研究将确定 回肠运动反射的内在神经回路， 豚鼠近端结肠和远端结肠。细胞内 记录技术将被用来关联反射反应 肠神经细胞的扩张，粘膜的机械刷洗和 纵向上对粘膜的化学刺激(HCL)反应 和环状平滑肌细胞对相似刺激的反应。一种新型制剂 由一段开口的肠段组成的，肠段上固定着粘膜 最上面的一个或两个气球的设计是为了方便 肠神经细胞和平滑肌的细胞内记录 细胞。该制剂允许施加上述任何刺激 在口腔、肛门甚至周围区域分开或相互作用 到录音点。一旦被刺穿的神经元对一个或多个 每一种刺激物都已确定将注入一种染料 通过记录微电极。神经元的投射 通过肌间神经丛或通向任何一层肌肉 被追踪到，神经元的功能被鉴定为要么是感觉， 特定神经反射通路中的中间神经元或运动神经元 几条反射通路共有的神经元。在肠道运动中 预计会由以下因素引起 对粘膜绒毛的机械和化学刺激以及通过 管腔扩张。粘膜在扩张中的作用 反射，以及反射通路之间的相互作用 将对三种刺激进行调查。通过比较派生电路 在胃肠道的这三个功能不同的区域 肠道组织的一些关键原则将是 下定决心。

The normal motility patterns of the gastrointestinal tract are largely dependent on intrinsic nervous reflexes. Pathological changes in these enteric neurons underly many motility disorders. Our progress in understanding how movements of the gastrointestinal tract are controlled has been considerably hampered by our lack of understanding of the nerve circuits involved. The experiments outlined in this proposal are designed to address this deficiency. This study will determine the intrinsic neuronal circuitry underlying motility reflexes in the ileum, proximal colon and distal colon of the guinea pig. Intracellular recording techniques will be used to correlate reflex responses of enteric neurons to distension, mechanical brushing of the mucosa and chemical stimulation (Hcl) of the mucosa with responses in longitudinal and circular smooth muscle cells to similar stimuli. A novel preparation consisting of an opened segment of intestine pinned with the mucosa uppermost over 1 or 2 balloons has been designed to facilitate intracellular recordings from both enteric neurons and smooth muscle cells. This preparation allows any of the above stimuli to be applied separately or interacted at areas oral and anal and even circumferential to the recording site. Once the response of an impaled neuron to one or each of the stimuli has been determined it will be injected with a dye through the recording microelectrode. The projections of the neuron through the myenteric plexus or to either muscle layer will then be traced, and the neuron functionally identified as either a sensory, interneuron or motor neuron in a particular nervous reflex pathway or as a neuron common to several reflex pathways. In the intestine motility would be expected to result from the summation of reflexes activated by mechanical and chemical stimulation of the mucosal villi as well as by distension of the lumen. The contribution of the mucosa to distension reflexes, and interactions between reflex pathways initiated by the three stimuli will be investigated. By comparing the derived circuitry in these three functionally different regions of the gastrointestinal tract some crucial principles of enteric organizations will be determined.