INTER-REGIONAL CODING OF ODOR VALENCE BY NEURAL ENSEMBLES

 描述(由申请者提供)：在日常生活中，感官刺激会获得习得的价值观，这些价值观会影响我们的基本行为。了解刺激情绪联系的神经基础，有时被称为价态，将对广泛的人类状况产生重要的见解。哺乳动物的嗅觉系统为理解刺激价的神经机制提供了一个简单的模型。嗅球中的二级神经元将气味信息分配到若干次级结构，包括嗅结节(OT)和梨状皮质(PCX)。气味信息在这个阶段被形成，然后被传递到与奖励、情感和学习有关的三级结构中，这反过来又 提供关于二级结构的反馈。本提案旨在解决气味价位编码在OT和PCX中的基本原则，这样做将解决有关刺激价位的区域间处理和存储的主要问题。实验将在参与可操作嗅觉任务的啮齿动物身上进行，同时进行多电极单单位记录，在某些情况下，使用化学遗传学进行神经扰动。使用这种方法，我们将确定二级结构是否专门编码气味价态(目标1)。接下来，我们将利用二级嗅觉结构的连通性来确定OT和PCX对气味价码的相互依赖(目标2)。最后，我们将确定OT和PCX中的价编码是否以及如何依赖于一个具有已知价重要性的突出的三级缔合结构(目标3)的自上而下的调制。总之，这些研究将提供气味信息处理机制的基本信息，这些编码方案的行为相关性，以及二级和三级嗅觉结构之间的关键相互作用。

 DESCRIPTION (provided by applicant): On a daily basis, sensory stimuli acquire learned values that inform our essential behaviors. Understanding the neural substrates for the emotional associations of stimuli, sometimes referred to as valence, will yield important insights into a wide range of human conditions. The mammalian olfactory system provides a simple model for understanding the neural mechanisms of stimulus valence. Second order neurons in the olfactory bulb distribute odor information into several secondary structures, including the olfactory tubercle (OT) and piriform cortex (PCX). Odor information at this stage is shaped and later transmitted into tertiary structures involved in reward, emotion, and learning, which in turn provide feedback upon the secondary structures. The present proposal seeks to address fundamental principles of odor valence coding in the OT and PCX, and in doing so will resolve major questions regarding the inter-regional processing and storage of stimulus valence. Experiments will be performed in rodents engaged in an operant olfactory task, along with simultaneous multi- electrode single-unit recordings, and in some cases, neural perturbations using chemical-genetics. Using this approach, we will determine whether secondary structures are specialized to code for odor valence (Aim 1). Next we will exploit the connectivity of secondary olfactory structures to determine the dependence of the OT and PCX upon each other for odor valence coding (Aim 2). Finally, we will determine if and how valence coding in the OT and PCX depends upon top-down modulation by a prominent tertiary association structure with known importance for valence (Aim 3). Together, these investigations will provide fundamental information on the mechanisms of odor information processing, the behavioral relevance of these coding schemes, and the critical interactions between secondary and tertiary olfactory structures.