Synaptic Processing in the Olfactory System

无论是我们早晨咖啡的香味，还是情人的气味，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 在哺乳动物的大脑中进行处理。为了解决这个问题，我们研究了神经元回路的性质。 以及嗅球和嗅皮层中的突触，这是大脑中嗅觉最早的部位 对信息进行处理。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很重要。 本实验拟采用大鼠梨状皮质前叶的体外脑片制备方法。 我们还使用了一种新的切片制备方法，其中嗅球仍然附着在皮质上。梨状肌 皮质锥体细胞和中间神经元将使用红外微分干涉光学技术进行可视化。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 集中精神。具体目标1建议描述管理转让的基本机制 从嗅球到大脑皮层的感觉信息。我们假设单个二尖瓣细胞可以 与梨状锥体细胞有很强的联系，而突触整合的相对较少 在梨状皮质，二尖瓣细胞的输入是特征检测的基础。具体目标2建议调查 在梨状皮质形成突触整合中的局部抑制回路。我们假设前馈 反馈抑制中间神经元在生理过程中调节突触整合和棘波输出 嗅球输入的相关模式。具体目标3研究群体编码使用 嗅球梨状皮质脑片细胞活动的成像。我们假设时间和空间 锥体细胞活动的模式可以编码有关嗅觉的时间和定位的信息 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.