Synaptic Processing in the Olfactory System

描述(申请人提供)：无论是我们早晨咖啡的香味，还是情人的气味，嗅觉都是我们日常生活中的一个重要特征。我们研究的长期目标是了解嗅觉信息在哺乳动物大脑中是如何处理的。为了解决这个问题，我们研究了嗅球和嗅皮层中神经元回路和突触的特性，这是大脑中处理嗅觉信息的第一个部位。我们的统一假设是，了解嗅觉回路的突触机制对于揭示大脑如何编码我们的嗅觉至关重要。本实验采用膜片钳记录技术研究体内和体外嗅觉回路的功能特性。具体目标1建议描述梨状皮质气味表征的基本机制。我们假设，气味诱发的兴奋性传入体内的皮质锥体细胞既反映了来自嗅球的直接感觉输入，也反映了皮质锥体细胞之间的联合(反复)联系。特定目的2建议研究梨状皮质中形成活动的局部抑制回路的作用。我们假设，不同类型的动态反馈电路控制着反复的抑制，并被与生理相关的锥体细胞活动模式差异化地招募。具体目标3建议研究梨状皮质到嗅球的远程反馈联系的作用。我们假设来自锥体细胞的兴奋性投射调节嗅球气味编码的初始阶段。这些实验将为了解大脑嗅觉背后的神经回路的突触机制提供新的见解。 与公共健康相关：嗅觉是影响我们生活质量的一个重要因素。这项研究试图了解控制嗅觉如何在大脑中处理的基本特征。

DESCRIPTION (provided by applicant): Whether it be the aroma of our morning coffee or the scent of a lover, the sense of smell is a critical feature of our daily life. The long-term objective of our research is to understand how olfactory information is processed in the mammalian brain. To address this question, we study the properties of neuronal circuits and synapses in the olfactory bulb and olfactory cortex, which are the first sites in the brain where olfactory information is processed. Our unifying hypothesis is that understanding the synaptic mechanisms of olfactory circuits is critical for revealing how the brain encodes our sense of smell. The experiments proposed employ patch-clamp recording techniques to study the functional properties of olfactory circuits in vivo and in vitro. Specific Aim 1 proposes to characterize the fundamental mechanisms governing odor representations in the piriform cortex. We hypothesize that odor-evoked excitatory input to cortical pyramidal cells in vivo reflects both direct sensory input from the olfactory bulb and associational (recurrent) connections between cortical pyramidal cells. Specific Aim 2 proposes to investigate the role of local inhibitory circuits that shape activity in piriform cortex. We hypothesize that distinct types of dynamic feedback circuits govern recurrent inhibition and are differentially recruited by physiologically relevant patterns of pyramidal cell activity. Specific Aim 3 proposes to investigate the role of long-range feedback connections from piriform cortex to the olfactory bulb. We hypothesize that excitatory projections from pyramidal cells regulate the initial stages of odor coding in the olfactory bulb. These experiments will provide new insight into the synaptic mechanisms of neural circuits underlying olfaction in the brain. PUBLIC HEALTH RELEVANCE: The sense of smell is an important factor that contributes to our quality of life. This research seeks to understand the fundamental features governing how the sense of smell is processed in the brain.