BRAINSTEM ESOPHAGEAL - GASTRIC CONTROL REFLEXES

脑干食管 - 胃控制反射

• 批准号: 6177696
• 负责人: Richard C. Rogers
• 金额: $ 11.6万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-09-01 至 2004-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6177696
• 关键词: autonomic reflex; brain stem; corticotropin releasing factor; esophagus motility /pressure; hormone regulation /control mechanism; laboratory rat; neuroregulation; psychological stressor; reflux esophagitis; stomach motility /pressure; swallowing; vagus nerve

The esophageal distension-gastric relaxation response or "receptive relaxation reflex" [RRR] is an autonomic mechanism which normally increases gastric volume and reduces intragastric pressure to assure that swallowed food is efficiently transported to and retained by the stomach. There is a large body of descriptive literature which supports the existence of the RRR in a number of species including rats and humans. This reflex is mediated largely, is not exclusively by a vagal afferent-CNS-vagal efferent pathway. Failure of this reflex mechanism has been held responsible for a number of serious swallowing and reflux disorders. This circuitry, which produces gastric relaxation, may also play a critical role in the perception of nausea and the production of emesis. Our preliminary results suggest that the central RR circuitry of esophageal vagal afferent connections with the nucleus of the solitary tract, pars centralis (NSTc] which, in turn, projects throughout the entire dorsal motor nucleus of the vagus [DMN]. DMN efferents which control the motility and compliance functions of the stomach are separable into two distinct vagal pathway. The other DMN projection to the stomach probably activates a non-adrenergic non-cholinergic [NANC] enteric circuit. Based on our preliminary physiological data we formulate the following hypotheses: the NSTc neurons activated by esophageal afferent input operate on these two separate DMN pathways to the stomach such that the muscarinic ["excitatory"] pathway is inhibited while the NANC ["inhibitory"] pathway is activated. The combination of effects produces a profound relaxation. Furthermore, we predict that a previously identified corticotrophin releasing hormone [CRH]- ergic CNS mechanism activated by psychological stress produces gastric stasis by activating RR circuit elements in the dorsal vagal complex. These predictions will be tested by a combination of in vivo and in vitro neurophysiological and immunocytochemical protocols.

食管扩张-胃松弛反应或“接受性松弛反射”[RRR]是一种自主机制，通常会增加胃容量并降低胃内压力，以确保吞咽的食物有效地输送到胃并由胃保留。有大量描述性文献支持 RRR 在包括大鼠和人类在内的许多物种中的存在。这种反射很大程度上是由迷走神经传入-中枢神经系统-迷走神经传出通路介导的。这种反射机制的失败被认为是导致许多严重吞咽和反流障碍的原因。这种产生胃松弛的回路也可能在恶心感和呕吐的产生中发挥关键作用。我们的初步结果表明，食管迷走神经传入的中央 RR 回路与孤束核、中央部 (NSTc) 连接，而孤束核又投射到迷走神经的整个背运动核 [DMN]。DMN 传出神经控制胃的运动性和顺应性功能可分为两个不同的迷走神经通路，另一个 DMN 投射到胃可能会激活非肾上腺素能通路。根据我们的初步生理数据，我们提出以下假设：由食管传入输入激活的 NSTc 神经元对这两条通往胃的独立 DMN 通路进行操作，从而使毒蕈碱 [“兴奋性”] 通路处于非胆碱能 [NANC] 肠道回路中。当 NANC [“抑制”] 途径被激活时，这些效应的组合会产生显着的放松。此外，我们预测先前发现的促肾上腺皮质激素释放激素。 [CRH]-由心理应激激活的中枢神经系统能机制通过激活背侧迷走神经复合体中的RR回路元件产生胃瘀滞。这些预测将通过体内和体外神经生理学和免疫细胞化学方案的组合进行测试。