TEMPORAL CODING IN OLFACTORY BULB CIRCUITS

这个项目的直接目标是了解 嗅球神经元的时间棘波模式与 气味编码。长期目标是将这些发现与 大脑其他区域的信息编码。假设是 这里考察的是尖峰出现的时间与 激励脉冲由不同的电路组件产生，因此 携带关于刺激计划的不同信息。这些实验是 旨在研究脊椎动物嗅球回路如何与 输出的二尖瓣和簇状细胞(MTS)的棘波模式。二 问题将被解决：1)使用受体拮抗剂作为工具，如何 NMDA和非NMDA谷氨酸受体输入是否有不同的贡献 气味引发的MT尖峰模式？假设是非- NMDA输入比NMDA输入对短延迟尖峰的贡献更大， 因此对猝发潜伏期有更大的影响；2)GABA能输入 对早期和晚期的压制都有不同的影响 在MT气味反应中？GABA和一种GABA受体拮抗剂 在细胞外记录过程中应用，以检验假设 GABA能输入对MT的尖峰潜伏期和 尖峰之后的抑制。虽然，如下所述，有 在一些研究中使用了药理工具 为了剖析电刺激引起的反应，很少有人使用 这些工具在气味刺激期间，在脊椎动物中没有 将这些响应组件与 动物。这里提出的项目将提供有关这方面的新信息 气味编码过程的重要方面，以及进一步的我们的 感官系统中的信息处理知识，学习和 记忆，以及在信息的编码和分类过程中 决策过程。像这样的研究将在 理解大脑/行为关系。

The immediate goal of this project is to understand the relationship between temporal spiking patterns in neurons in the olfactory bulb and odorant coding. The long term goal is to relate these finding to information coding in other regions of the brain. The hypothesis to be examined here is that spikes occurring at different times relative to a stimulus pulse are generated by different circuit components and thus carry different information about the stimulus. These experiments are designed to examine how vertebrate olfactory bulb circuits relate to spike patterns of the output mitral and tufted cells (MTs). Two questions will be addressed: 1)Using receptor antagonists as tools, how do NMDA and non-NMDA glutamate receptor inputs contribute differentially to odorant-elicited MT spiking patterns? The hypothesis is that non- NMDA input contributes more than NMDA input to short latency spiking, and thus has a larger effect on burst latency; 2) Do GABAergic inputs contribute differentially to both early and late periods of suppression in MT odorant responses? GABA and a GABA receptor antagonist will be applied during extracellular recording to test the hypothesis that GABAergic inputs contribute to both MT spiking latency and to suppression following spiking. Although, as described below, there have been a number of studies in which pharmacological tools have been used to dissect responses elicited by electrical stimulation, few have used these tools during odor stimulation, and in the vertebrate none have related these response components to the behavioral capabilities of the animal. The projects proposed here will provide new information on this important aspect of the odorant encoding process, and further our knowledge of information processing in sensory systems, in learning and memory, and in the coding and categorization of information during decision making processes. Studies such as these will be critical in understanding brain/behavior relationships.