Synaptic Processing in the Olfactory System

描述：(申请人提供) 我们研究的长期目标是了解嗅觉是如何 信息是在哺乳动物的大脑中处理的。为了解决这个问题，我们 第一例大鼠嗅球脑片神经元特性的研究 大脑中处理嗅觉信息的地方。而快速突触 大脑中的传递通常是由释放的神经递质介导的 从轴突神经末梢，树突状递质的释放被认为发挥了 在嗅球中起着重要作用。二尖瓣主瓣释放谷氨酸 细胞树突兴奋局部中间神经元树突、颗粒细胞、 继而将γ-氨基丁酸(GABA)释放回二尖瓣 树枝状结构。这种树枝状环路是自我和侧向抑制的基础。 二尖瓣细胞，并被认为在气味中起关键作用 嗅球的辨别和分辨。这一行动的主要目标是 研究建议是阐明突触机制 嗅觉中二尖瓣细胞和颗粒细胞间的树突抑制 灯泡。具体目标侧重于描述的基本属性 两种细胞类型之间的传递以及GABAB受体的作用 以及调节树突信号的活性依赖的可塑性。二尖瓣和二尖瓣 用红外微分干涉光学技术观察颗粒神经元 (Ir-DIC)，并用膜片钳记录技术进行研究。具体目标一 建议建立治理经济实力的基本量化机制 二尖瓣和颗粒突触偶联对之间的树突传递 细胞。特异性目标2建议研究GABAB受体在 树突状抑制。我们假设代谢性GABAB受体 在调节二尖瓣和二尖瓣之间的树突相互作用中起重要作用 颗粒细胞。特定目标3建议研究突触可塑性在 树-树突触。我们假设兴奋性树突状细胞的输入 颗粒细胞表达活性依赖的长时程增强和抑制。 这些实验将为突触机制提供新的见解。 潜在的树-树传递，这在 在大脑中处理嗅觉信息。

DESCRIPTION: (provided by applicant) 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 neurons in slices of the rat olfactory bulb-the first site in the brain where olfactory information is processed. While fast synaptic transmission in the brain is typically mediated by neurotransmitters released from axon nerve endings, dendritic transmitter release is thought to play an important role in the olfactory bulb. Glutamate released from principal mitral cell dendrites excites the dendrites of local interneurons, granule cells, which in turn release gamma-aminobutyric acid (GABA) back onto mitral dendrites. This dendrodendritic circuit underlies self- and lateral inhibition of mitral cells and has been suggested to play a critical role in odor discrimination and resolution in the olfactory bulb. The major goal of this research proposal is to elucidate the synaptic mechanisms governing dendrodendritic inhibition between mitral and granule cells in the olfactory bulb. The specific aims focus on characterizing the fundamental properties of transmission between the two cell types, as well as the role of GABAB receptors and activity-dependent plasticity in modulating dendritic signaling. Mitral and granule neurons are visualized with infrared differential interference optics (IR-DIC) and studied using patch-clamp recording techniques. Specific Aim I proposes to establish the basic quantal mechanisms governing the strength of dendritic transmission between synaptically coupled pairs of mitral and granule cells. Specific Aim 2 proposes to investigate the role of GABAB receptors in dendrodendritic inhibition. We hypothesize that metabotropic GABAB receptors play an important role in modulating dendritic interactions between mitral and granule cells. Specific Aim 3 proposes to investigate synaptic plasticity at dendrodendritic synapses. We hypothesize that excitatory dendritic inputs to granule cells express activity-dependent long-term potentiation and depression. These experiments will provide new insight into the synaptic mechanisms underlying dendrodendritic transmission, which is of critical importance in the processing of olfactory information in the brain.