Neural mechanisms underlying integration of taste and smell

项目总结摘要 虽然嗅觉和味觉之间的相互作用是指导食物选择的关键因素，但 气味和味道的多感官整合背后的神经机制在很大程度上仍不清楚。A更多 对这些神经生物学过程的透彻了解将有助于更好地洞察疾病的特点 不健康的食物选择，如肥胖或糖尿病。吃东西会同时激活嗅觉和 味觉系统产生持久的气味-味觉联系。味觉的主要皮层区域，味觉 大脑皮质(GC)是味觉和嗅觉信息汇聚的主要部位。我们实验室最近的工作 确定GC中功能不同的神经元群体代表不同的个体属性 不成对的气味或味道。然而，GC中的神经元如何代表气味-味道混合物，以及神经 嗅觉和味觉的整合和处理的基础机制仍然不清楚。最近的行为和 生理学研究表明，感觉皮质之间的皮质-皮质相互作用是 多感觉整合，提示来自功能不同的前部(APC)和后部的投射 梨状皮质(即嗅皮层)的(PPC)区调控GC的多模式化学感觉加工。 以大鼠为模型系统，这一建议将结合行为电生理学和光遗传学技术 探讨GC内神经元与梨状皮质不同功能区域之间的回路 调节气味和味道的多感官整合。具体的目标将检验以下假设：目标 1：GC中不同种类的神经元编码气味-味道混合物的化学特性和享乐值。 目标2：GC中对气味和味道都有反应的神经元接受代表化学特性的APC输入 气味-味道的混合物。目标3：GC中同时对气味和味道做出反应的神经元接受PPC输入 代表气味和气味-味道混合物的享乐性价值。每个具体目标的结果都将有助于 关于嗅觉和味觉整合的皮质-皮质回路的基础知识 为研究这些皮质环路在引导食物中所起的作用提供了必要的前奏 选择。

PROJECT SUMMARY ABSTRACT Although interactions between the senses of smell and taste are a key factor for guiding food choices, the neural mechanisms underlying the multisensory integration of odors and tastes remain largely unknown. A more thorough understanding of these neurobiological processes will provide better insight into diseases characterized by unhealthy food choices, such as obesity or diabetes. Eating food simultaneously activates the olfactory and gustatory systems to generate enduring odor-taste associations. The primary cortical area for taste, gustatory cortex (GC), is a principal site of convergent gustatory and olfactory information. Recent work from our lab determined that functionally distinct populations of neurons in GC represent different properties of individual unpaired odors or tastes. However, how neurons in GC represent odor-taste mixtures, as well as the neural mechanisms that underlie integration and processing of smell and taste remain unclear. Recent behavioral and physiological studies show that cortico-cortical interactions between sensory cortices are fundamental to multisensory integration, suggesting that projections from the functionally distinct anterior (aPC) and posterior (pPC) regions of piriform cortex (i.e., olfactory cortex) modulate multimodal chemosensory processing in GC. Using rats as a model system, this proposal will combine behaving electrophysiology and optogenetic techniques to investigate how the circuit between neurons in GC and the functionally distinct regions of piriform cortex mediates multisensory integration of odors and tastes. The Specific Aims will test the following hypotheses: Aim 1: Different populations of neurons in GC encode the chemical identity and hedonic value of odor-taste mixtures. Aim 2: Neurons in GC that respond to both odors and tastes receive aPC input representing the chemical identity of odor-taste mixtures. Aim 3: Neurons in GC that respond to both odors and tastes receive pPC input representing the hedonic value of odors and odor-taste mixtures. The results of each Specific Aim will contribute fundamental knowledge about the cortico-cortical circuitry underlying the integration of smell and taste and provide a necessary prelude for investigating the role that these cortico-cortical circuits play in guiding food choices.