Multisensory Integration for Food Perception and Behavior in Drosophila

描述(申请人提供)：动物和人类的感官世界都非常复杂。我们目前对大脑如何处理多感官输入以进行感知和行为的理解充其量对任何动物来说都是初级的。遗传上易驯化的果蝇幼虫为行为和神经生物学研究感知和行为的多种感觉模式的整合提供了独特的机会。蝇类幼虫表现出丰富的复杂行为，并具有高度进化但在数字上简单的中枢神经系统(CNS)。蝇幼虫的大脑与人类大脑有许多相似之处，包括两个大脑半球，具有高度局部聚集的神经元(又称局部处理单元，LPU)和远程投射，六种主要神经递质，各种神经肽。越来越多的强大的分子、遗传和神经生物学工具将进一步使我们能够对神经过程或感兴趣的行为背后的神经底物和过程进行深入的后续研究。我们最近发现，像哺乳动物一样，诱人的食物气味会引发果蝇幼虫对容易获得的富含糖分的食物的过度进食。多巴胺(DA)系统的缺陷阻止了食欲气味诱导食欲行为的能力。我们还发现了一小部分合成DA的三级嗅觉神经元。这些DA神经元的激活模拟了食欲气味刺激的行为效应。另一方面，OA系统调节幼虫对容易获得的糖基的取食反应。这项应用将通过测试一种新的工作模式的几个关键方面来探索苍蝇幼虫模型中食物感知和行为的多感官整合。该提案有两个具体目标：1)多种嗅觉和味觉模式整合在调节美味食物食欲中的行为和神经生物学研究；2)大脑状态对嗅觉和味觉模式整合调节美味食物食欲的影响的分析。我们期望这些研究的成功结果将为整合不同的嗅觉和味觉方式来调节对美味食物的胃口提供新的见解。此外，从这些研究中获得的知识将有助于对感知和行为的多感觉模式的整合以及相关的神经障碍的总体理解。

DESCRIPTION (provided by applicant): The sensory world of animals and humans alike is enormously complex. Our current understanding of how multisensory inputs are processed in the brain for perception and behavior remains rudimentary at best in any animals. The genetically tractable Drosophila larva offers a unique opportunity for behavioral and neurobiological studies of the integration of multiple sensory modalities for perception and behavior. Fly larvae display a rich repertoire of complex behaviors, and have a highly evolved yet numerically simple central nervous system (CNS). The brain of fly larvae shares many similarities with the human brain including two hemispheres with high local clustering of neurons (also named the local processing unit or LPU) and long-range projections, six major neurotransmitters, a variety of neuropeptides. An increasingly large set of powerful molecular genetic and neurobiological tools available will further allow us to perform in- depth follow-up studies of the neural substrates and processes underlying a neural process or behavior of interest. We have recently shown that like in mammals, attractive food odors elicited reward-driven overeating of readily accessible sugar-rich food in Drosophila larvae. Deficiencies in the dopamine (DA) system blocked the capacity of the appetitive odor to elicit the appetitive behavior. We have also identified a small number of third-order olfactory neurons that synthesize DA. Activation of these DA neurons mimicked the behavioral effect of appetitive odor stimulation. On the other hand, the OA system mediates larval feeding response to readily available sugar media. This application will be focused on exploring multisensory integration for food perception and behavior in the fly larva model by testing several key aspects of a novel working model. The proposal has two specific aims: 1) behavioral and neurobiological studies of integration of multiple olfactory and gustatory modalities in modulating appetite for palatable food; 2) analyses of the effects of brain states on integration of olfactory and gustatory modalities in modulating appetite for palatable food. We expect that the successful outcomes of these studies will provide novel insights into integration of different olfactory and gustatory modalities in modulating appetite for palatable food. Furthermore, the knowledge gained from these studies will contribute to the general understanding of the integration of multisensory modalities for perception and behavior as well as related neurological disorders.