NEURAL BASIS OF TASTE ELICITD INGESTION AND REJECTION

这项研究计划的目标是确定神经 啮齿动物后脑中的底物，味觉刺激通过它来调节 喜庆的行为。尽管对摄食行为的监管是 极其复杂，涉及中枢神经系统的许多区域，基本的 味觉的调节功能，可引起摄取或排斥 反应，在尾侧脑干是完整的。慢性肌电记录 实验已经表征了摄取和拒绝的行为 通过确定Sapid刺激的子集的激活序列 三叉神经肌、面肌、疑肌和舌下肌支配。一个 盐酸奎宁(苦味)的排斥反应特征 通过收回舌头(茎舌肌收缩)结合 张开下巴(二腹肌前收缩)与进食相反 舌头突出(颧舌肌收缩)的顺序 同时张开下巴。这些千篇一律的发动机部件 摄取和排斥也是明显的受抑的，麻醉的 可以进行中央记录的准备工作。神经基质 这些口部运动反应的中介是多发性的和解剖学的。 实验描绘了脑干网状结构的几个区域 投射到所有(或一部分)口腔运动核团的形成(RF) 制作它们。因此，这些RF区域是协调和 对摄取和排斥的复杂协同效应进行排序。vbl.使用 神经生理学技术，这些网状区的神经元 研究(1)对味觉、口腔内触觉和口腔的敏感度 本体感觉刺激，(2)特定运动部件的反应 肌电定义的摄取和排斥，(3)连接性 使用逆行刺激的口述运动核团。额外的实验 利用辣根过氧化物酶的逆行运输将确定 这些网状区接受味觉核团的投射。 脑干或其他中间神经元是否被插入。摄取和 拒绝代表补货所需的最终行为决定 能量、液体和电解液储存库。慢性疾病，如肥胖， 高血压和神经性厌食症与摄食障碍有关。 理解这一基本生物学的神经学基础 决定是接受还是拒绝将有助于最终解决 这些慢性衰弱疾病。

The objective of this research proposal is to determine the neural substrate in the rodent hindbrain through which gustatory stimuli modulate ingestive behavior. Although the regulation of ingestive behavior is exceedingly complex, involving many regions of the CNS, the basic regulatory function of taste to evoke either an ingestion or rejection response, is complete in the caudal brain stem. Chronic EMG recording experiments have characterized the behaviors of ingestion and rejection to sapid stimuli by determining the activation sequences of a subset of trigeminal, facial, ambiguus and hypoglossal innervated muscles. A rejection response to quinine monohydrochloride (bitter) is characterized by retraction of the tongue (styloglossus contraction) in conjunction with jaw opening (anterior digastric contraction) in contrast to an ingestion sequence in which tongue protrusion (genioglossus contraction) is simultaneous with jaw opening. These stereotypic motor components of ingestion and rejection are also evident in a restrained, anesthetized preparation in which central recording is possible. The neural substrate mediating these oro-motor responses is polysnaptic and anatomical experiments have delineated several regions of the brain stem reticular formation (RF) that project to all (or a subset) of the oral motor nuclei producing them. Thus, these RF regions are candidates for coordinating and sequencing the complex synergies of ingestion and rejection. Using neurophysiological techniques, neurons in these reticular regions will be studied for (1) Sensitivities to gustatory, intra-oral tactile and oral proprioceptive stimuli, (2) responsiveness during specific motor components of ingestion and rejection defined electromyographically, (3) connectivity with oro-motor nuclei using antidromic stimulation. Additional experiments using retrograde transport of horseradish peroxidase will determine if these reticular regions receive projections from gustatory nuclei in the brain stem or whether other interneurons are interposed. Ingestion and rejection represent the final behavioral decision required for replenishing energy, fluid, and electrolyte stores. Chronic disorders such as obesity, hypertension and anorexia nervosa are related to disordered ingestion. Understanding the neurological basis of this fundamental biological decision, to ingest or reject will contribute to the eventual solution of these chronic debilitating disorders.