Homeostatic Origins of Motivation

描述（由申请人提供）：这是一个竞争性续期申请 资助研究，其总体目标是了解 动机行为的生物学基础，特别是口渴，盐的食欲， 饥饿和饱足感。提出了三个系列的实验。实验1 试图确定影响口渴的早期摄食后信号， 加压素（VP）和催产素（OT）的分泌。为了实现这一 目的，我们将确定（a）饮水是否会减少VP的分泌， OT对兴奋性刺激的反应，而不是由静脉注射 （B）最后区和孤束核是否受损 (NTS)减弱饮水或胃内氯化钠的快速作用 负荷，对VP和OT分泌的影响;以及（c）是否维持大鼠 高盐饮食减弱了饮水对VP的快速抑制作用， OT分泌。实验2旨在确定口渴的兴奋性刺激 在动脉低血压或低血容量期间， 动脉高血压时口渴。为了实现这一目标，我们将确定 (a)血管紧张素II和来自动脉压力感受器的神经信号 在低血压期间显著促进口渴;（B）是否肾性 低血容量时大鼠的口渴与传入神经有关 NTS病变;以及（c）窦主动脉压力感受器是否有助于 显著降低动脉高血压对口渴的抑制作用。 实验3旨在确定神经垂体的生理功能 给予NaCl负荷或动脉低血压期间大鼠的OT分泌。在 为了实现这一目标，我们将确定（a）OT是否有重大贡献 当大鼠维持高盐饮食时作为利尿钠激素;和（B） OT是否显著促进动脉期间的肾素分泌 低血压，并因此调解引起的口渴。

DESCRIPTION (provided by applicant): This is a competing renewal application for grant support of research whose general goal is to understand the biological bases of motivated behavior, especially thirst, salt appetite, hunger and satiety. Three series of experiments are proposed. Experiment 1 seeks to determine the early postingestive signals that influence thirst and the secretion of vasopressin (VP) and oxytocin (OT) in rats. In pursuit of this aim, we will determine (a) whether water drinking reduces secretion of VP and OT in response to excitatory stimuli other than that provided by an intravenous NaCl load; (b) whether lesions of area postrema and nucleus tractus solitarius (NTS) blunt the rapid effect of water drinking, or of an intragastric NaCl load, on secretion of VP and OT; and (c) whether maintenance of rats on high-salt diet blunts the rapid inhibitory effect of water drinking on VP and OT secretion. Experiment 2 seeks to determine the excitatory stimuli for thirst during arterial hypotension or hypovolemia, and the inhibitory stimulus for thirst during arterial hypertension. In pursuit of this aim, we will determine (a) whether angiotensin II and neural signals from arterial baroreceptors contribute significantly to thirst during hypotension; (b) whether renal afferent nerves contribute significantly to thirst during hypovolemia in rats with NTS lesions; and (c) whether sinoaortic baroreceptors contribute significantly to the inhibitory effect of arterial hypertension on thirst. Experiment 3 seeks to determine the physiological functions of neurohypophyseal OT secretion in rats given NaCl loads or during arterial hypotension. In pursuit of this aim, we will determine (a) whether OT contributes significantly as a natriuretic hormone when rats are maintained on high-salt diet; and (b) whether OT contributes significantly to secretion of renin during arterial hypotension, and thus to mediation of the induced thirst.