SIGNALS TO FEED: BIOLOGICAL AND ASSOCIATIVE MECHANISMS

调节喂食行为的模型通常假设动物(包括人类)吃东西，并参与有助于获得食物的行为，以响应与它们的能量需求水平相关的相互感知信号。因此，许多研究致力于确定引起这些类型的信号的代谢和荷尔蒙事件，并指定与它们的检测和传输有关的神经底物。这项工作已经确定了促进或抑制食物摄取的各种生理和药理操作。然而，很难将这些操作的潜在“饥饿”或“饱足”信号特性与它们对适口性、学习、非特异性行为唤醒或其他已知影响进食的机制的可能影响分开，即使在没有能量需求变化的情况下也是如此。结合心理生物学和巴甫洛夫条件反射的方法和概念，这项拟议的研究将开发和开发一个新的调节喂养行为模型，该模型描述能量的相互感觉信号如何与食物提示(例如，食物的味道和其他感官特性)以及摄入的摄食后后果一起作用，以确定食欲和完善性喂养行为的强度或可能性。该模型基于对传统听觉和视觉刺激的巴甫洛夫条件性调制的研究，假设能量状态信号通过调节食物相关刺激的能力来激活对进食后食欲后果的记忆，从而影响进食行为。提出了新的研究策略，以检查代谢、激素、隔膜下迷走神经和中枢神经系统机制在这一“记忆调制”过程中的参与。此外，几个实验将评估动物编码的关于它们吃的食物的信息的性质，以及与该信息的检索/激活有关的信号的性质。人类进食行为的无序模式似乎涉及能量状态信号的检测、利用或调节功能或食物信息编码方面的障碍。因此，这项拟议的研究可能对了解这些疾病的病因和开发有效的治疗方法具有重要意义。

Models of regulatory feeding behavior often assume that animals (including humans) eat, and engage in behaviors that are instrumental to obtaining food, in response to interoceptive signals that are correlated with their level of energy need. Accordingly, much research has been devoted to specifying the metabolic and hormonal events that give rise to these types of signals and to specifying the neural substrates involved with their detection and transmission. This work has identified a variety of physiological and pharmacological manipulations that promote or suppress food intake. However, it has been difficult to separate the potential "hunger" or "satiety" signal properties of these manipulations from their possible effects on palatability, learning, nonspecific behavioral arousal or other mechanisms that are also known to influence feeding even in the absence of changes in energy need. Integrating methods and concepts from psychobiology and Pavlovian conditioning, the proposed research will develop and exploit a novel model of regulatory feeding behavior that describes how interoceptive signals of energy need act in conjunction with food cues (e.g., tastes and other sensory properties of food) and the postingestive consequences of intake to determine the strength or probability of appetitive and consummatory feeding behavior. Based on studies of Pavlovian conditioned modulation involving conventional auditory and visual stimuli, this model assumes that energy state signals influence feeding behavior by modulating the capacity of food-related stimuli to activate the memory of the appetitive postingestive consequences of intake. New research strategies are proposed to examine the involvement of metabolic, hormonal, subdiaphragmatic vagal, and central nervous system mechanisms in this "memory modulation" process. In addition, several experiments will assess the nature of the information that animals encode about the foods that they eat as well as the nature of the signals involved with the retrieval/activation of that information. It seems likely that disordered patterns of human feeding behavior involve impairments in the detection, utilization, or modulatory function of energy state signals or in the encoding of information about food. Thus, the proposed research may have important implications with respect to understanding the etiology and developing effective treatments for these disorders.