Synaptic Processing in the Olfactory System

无论是早晨咖啡的香气，还是爱人的香气，嗅觉都是至关重要的 日常生活的特点。我们研究的长期目标是了解嗅觉信息是如何产生的 在哺乳动物大脑中进行处理。为了解决这个问题，我们研究神经元回路的特性 嗅球和嗅皮层中的突触，它们是大脑中嗅觉的第一个部位 信息被处理。我们的统一假设是，了解嗅觉的突触机制 电路对于揭示大脑如何编码我们的嗅觉非常重要。 建议的实验采用大鼠前梨状皮层的体外脑切片制备。 我们还使用了一种新颖的切片制剂，其中嗅球仍然附着在皮质上。梨状体 皮层锥体细胞和中间神经元将使用红外微分干涉光学进行可视化。我们 将使用全细胞膜片钳记录和细胞内钙成像来研究这些细胞 浓度。具体目标 1 建议描述控制转移的基本机制 从嗅球到皮层的感觉信息。我们假设单个二尖瓣细胞可以 与梨状锥体细胞建立牢固的连接，并且相对较少的突触整合 二尖瓣细胞输入是梨状皮层特征检测的基础。具体目标 2 建议调查该角色 局部抑制电路在塑造梨状皮层突触整合中的作用。我们假设前馈 和反馈抑制中间神经元在生理过程中调节突触整合和尖峰输出 嗅球输入的相关模式。具体目标 3 建议使用以下方法研究群体编码 嗅球梨状皮层切片中细胞活动的成像。我们假设时间和空间 锥体细胞活动模式可以编码有关嗅觉时间和定位的信息 嗅球的输入。这些实验将为突触机制提供新的见解 大脑中潜在的嗅觉。

Whether it be the aroma of our morning coffee or the scent of a lover, the sense of smell is a critical feature of 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 important for revealing how the brain encodes our sense of smell. The experiments proposed employ an in vitro brain slice preparation of the rat anterior piriform cortex. We also use a novel slice preparation in which the olfactory bulb remains attached to the cortex. Piriform cortex pyramidal cells and interneurons will be visualized using infrared differential interference optics. We will study these cells using whole-cell patch clamp recording and imaging of intracellular calcium concentration. Specific Aim 1 proposes to characterize the fundamental mechanisms governing the transfer of sensory information from the olfactory bulb to the cortex. We hypothesize that individual mitral cells can make strong connections onto piriform pyramidal cells and that the synaptic integration of relatively few mitral cell inputs underlies feature detection in piriform cortex. Specific Aim 2 proposes to investigate the role of local inhibitory circuits in shaping synaptic integration in piriform cortex. We hypothesize that feedforward and feedback inhibitory interneurons regulate synaptic integration and spike output during physiologically relevant patterns of olfactory bulb input. Specific Aim 3 proposesto investigate population coding using imaging of cell activity in olfactory bulb-piriform cortex slices. We hypothesize that temporal and spatial patterns of pyramidal cell activity can encode information regarding the timing and localization of olfactory input in the olfactory bulb.These experiments will provide new insight into the synaptic mechanisms underlying olfaction in the brain.