Intraglomerular Lateral Inhibition in the Olfactory Bulb

描述(申请人提供)：这个项目的总体目标是确定主嗅球的输出是如何调节的，是这个结构的局部电路。特别是，这项建议侧重于研究侧抑制，这是神经回路的一种普遍特征，被认为在决定刺激诱发反应的特异性和调节包括嗅球在内的许多大脑区域的网络动力学方面发挥核心作用。更好地了解神经回路的功能特性，如侧抑制，对神经科学的许多领域具有重要意义，嗅球提供了一个有趣且易于处理的模型系统，在其中研究回路调节神经活动的基本问题。这些实验旨在解决这样一种假设，即连接嗅球内不同肾小球模块的主神经元的抑制电路的功能之一是调节功能性侧抑制。具体地说，我们使用来自二尖瓣细胞的配对记录来研究突触回路的特性，在与不同肾小球相关的二尖瓣细胞之间建立功能联系。使用这种方法，我们将测试当二尖瓣细胞活动的频率与气味刺激期间的活体记录所报告的频率相似时，是否会发生两对单独的二尖瓣细胞之间的侧向抑制。我们还将研究侧抑制连接的短期可塑性，并研究反复抑制和侧抑制的相互作用。结合这些结果，将为抑制回路在塑造感觉表征中所起的作用提供重要的见解，特别是在嗅球中，并理解抑制异常如何导致嗅球和其他大脑网络的功能缺陷。

DESCRIPTION (provided by applicant): The overall goal of this project is to determine how the output of the main olfactory bulb regulated by is the local circuitry of this structure. In particular, this proposal focuses on studying lateral inhibition, a ubiquitous feature of neuronal circuits thought to play a central role in determining the specificity of stimulus-evoked responses and in regulating network dynamics in many brain regions, including the olfactory bulb. Gaining a better understanding of functional properties of neural circuitry such as lateral inhibition is of central importance to many areas of neuroscience and the olfactory bulb presents an interesting and tractable model system in which to study fundamental questions about the regulation of neural activity by circuitry. These experiments are designed to address the hypothesis that one function of inhibitory circuitry connecting principal neurons associated with different glomerular modules in the olfactory bulb is to mediate a functional lateral inhibition. Specifically we use paired recordings from mitral cells to study the properties of synaptic circuits making functional connections between mitral cells associated with different glomeruli. Using this approach we will test whether lateral inhibition between pairs of individual mitral cells occurs when mitral cell activity is similar in frequency to what has been reported from in vivo recordings made during odor stimulation. We also will investigate short- term plasticity of lateral inhibitory connections, and study the interaction of recurrent and lateral inhibition. In conjunction these results will provide important insights into the role played by inhibitory circuits in shaping sensory representations, especially in the olfactory bulb and in understanding how abnormalities of inhibition can lead to functional deficits in the olfactory bulb and other brain networks.