Neural Systems of Ingestive Behavior

描述(申请人提供)：肥胖是一种全国性的流行病。在其他疾病中，肥胖是大多数2型糖尿病和相当大比例高血压的基础。肥胖的发生是因为个人摄入的卡路里多于消耗的卡路里。当食物的奖励价值大于肠道中产生的饱腹感信号的总和时，就会发生这种情况。这项研究的目的是了解支配决定摄取或拒绝口腔内容物的神经机制，口腔内容物是喂养行为的基本行为。这个决定的神经基础在脑干中是完整的。引导进食行为的口腔触觉、温度和味觉传入活动首先到达脑桥和延髓的大脑。产生摄食行为的运动神经元也位于脑干。这些口服刺激引起的反应可以通过迷走神经内脏活动首先到达延髓的中枢神经系统而从摄取切换到排斥。然而，控制摄取需要连接到前脑和从前脑连接，因为切断前脑与脑干的连接会消除自愿进食。利用行为学、神经解剖学、神经化学和电生理学分析，这个项目将测试关于味觉和其他口头刺激的奖赏价值如何在大脑中阐述的假说。具体的实验考察(1)味觉感觉活动如何影响被认为涉及产生奖励的大脑区域，(2)这些奖励感觉效果的神经通路，以及(3)其他奖励口头刺激，如温度和质地，与享乐领域的味道有何不同。这些问题的答案将帮助我们理解正常的良好调节行为，如饮食，如何会偏离到导致流行病的地步。

DESCRIPTION (provided by applicant): Obesity is a national epidemic. Among other maladies, obesity underlays most type 2 diabetes and a significant proportion of hypertension. Obesity occurs because individuals ingest more calories than they expend. This takes place when the reward value of the food is greater than the sum of the satiety signals arising in the gut. The goal of this research is to understand the neural mechanisms that govern the decision to ingest or reject the contents of the oral cavity, the fundamental act of feeding behavior. The neural substrates for this decision are complete in the brainstem. The oral tactile, thermal, and gustatory afferent activity that guides ingestive behavior first reaches the brain in the pons and medulla. The motor neurons that produce ingestive behavior also are located in the brainstem. The response elicited by these oral stimuli can be switched from ingestion to rejection by vagal visceral activity that first reaches the CNS in the medulla. Nevertheless, control of ingestion requires connections to and from the forebrain because disconnecting it from the brainstem eliminates voluntary eating. Using behavioral, neuroanatomical, neurochemical, and electrophysiological analysis, this project will test hypotheses about how the reward value of gustatory and other oral stimuli are elaborated in the brain. Specific experiments examine (1) how the gustatory sensory activity influences brain areas thought to be involved in producing reward, (2) the neural pathways for these rewarding sensory effects and (3) how other rewarding oral stimuli, such as temperature and texture, differ from taste in the hedonic domain. The answers to these questions will help us understand how a normally well regulated behavior, such as eating, can go so far awry as to cause an epidemic.