Synaptic Processing in the Olfactory System

描述（由申请人提供）：无论是早晨咖啡的香气还是情人的香味，嗅觉都是我们日常生活的重要特征。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，理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。 本实验拟采用膜片钳技术研究嗅觉神经回路在体和离体的功能特性。具体目标1提出了梨状皮质的气味表征的基本机制的特点。我们假设，气味诱发的兴奋性输入皮质锥体细胞在体内反映了直接的感觉输入从嗅球和关联（经常性）皮质锥体细胞之间的连接。具体目标2提出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管理复发性抑制和差异招聘的生理相关模式的锥体细胞活动。具体目标3提出研究从梨状皮质到嗅球的长距离反馈连接的作用。我们推测，兴奋性预测从锥体细胞调节嗅球的气味编码的初始阶段。这些实验将提供新的洞察神经回路的突触机制嗅觉在大脑中的基础。

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.