Integration of taste and olfactory signals in gustatory cortex

描述（由申请人提供）：来自多种模式的感觉信息的整合被认为可以增强对聚合刺激的检测。这种多模态整合最初被认为只发生在高阶皮层区域，如前额皮质。然而，最近的研究表明，包括味觉皮层（GC）在内的每个初级感觉皮层都存在多模态感觉反应。GC是负责处理与味觉相关信息的主要皮层，已知它编码与味觉相关的多感官信息，如温度、触觉和预期提示。然而，最明显的感觉相互作用，即味觉和嗅觉，尚未在GC回路水平上进行探索。味觉和嗅觉是紧密相连的。解剖学和神经影像学研究已经开始描述这两种模式的协同整合，并表明GC是主要的一体化化学感觉淋巴结。尽管取得了很大的进展，但关于GC中单个神经元是否以及如何整合多模态化学感觉整合的信息很少。本研究采用三步法，均依赖于多电极技术，在大鼠口内取样味觉和气味时记录GC中单个神经元的集合。第一个实验旨在确定味觉和气味是如何由GC的单个神经元表示的。在更好地理解GC的化学感觉反应后，第二个实验将验证气味-味觉体验调节GC化学感觉活动的假设。第三个实验沿着这个轨迹继续探索不一致的气味-味觉混合物如何抑制GC的化学感觉活动。总之，本R03提案中概述的实验将为深入理解警觉啮齿动物GC中多模态化学感觉信息的电路级整合奠定基础。如果成功，这项研究将阐明GC中的单个神经元如何处理生态协同的化学感觉信息，并将建立GC作为与食物相关的刺激的多感觉整合的主要区域。

DESCRIPTION (provided by applicant): Integration of sensory information from multiple modalities is believed to enhance the detection of convergent stimuli. This multimodal integration was originally theorized to occur only in higher order cortical areas, such as prefrontal cortex. However, recent research has shown multimodal sensory responses in every primary sensory cortex, including gustatory cortex (GC). GC is the primary cortex responsible for processing information related to taste and is known to code multisensory information related to taste, such as temperature, touch and anticipatory cues. However, the most conspicuous sensory interaction, that of taste and olfaction, has not been explored at the GC circuit-level. Taste and olfaction are intimately linked. Anatomical and neuroimaging studies have begun to describe the synergistic integration of these two modalities and suggest GC as a primary integrative chemosensory node. Despite this great progress, very little information is available on whether and how single neurons in GC integrate multimodal chemosensory integration. The proposed research is a three step approach, all of which rely upon multielectrode techniques to record ensembles of single neurons in GC while rats intraorally sample tastes and odors. The first experiment is designed to determine how taste and odor are represented by single neurons in GC. After a better understanding of GC chemosensory response, the second experiment will test the hypothesis that odor-taste experience modulates chemosensory activity in GC. The third experiment continues along this trajectory to explore how incongruent odor-taste mixtures suppress chemosensory activity in GC. Altogether, the experiments outlined in this R03 proposal will lay a foundation for an in depth understanding of the circuit-level integration of multimodal chemosensory information in GC of alert rodents. If successful, this research will elucidate how single neurons in GC process ecologically synergistic chemosensory information and will establish GC as a primary area of multisensory integration of stimuli related to food.