Ensemble coding in olfactory cortex

描述（由申请人提供）：感觉信息的皮层处理对于正常感知、记忆和大多数高阶认知功能至关重要。皮质处理的中断是许多疾病和衰老障碍中残疾的根本原因。本计画将发展并应用微电极阵列技术及新颖的分析工具，以探讨大鼠嗅觉（梨状）皮质对气味资讯的处理。具体的目的是1）确定在气味刺激期间梨状皮质中的单个单元是否相互夹带和/或与局部场电位夹带，以及2）这种夹带的幅度是否随气味体验而变化。这些目标是由三个具体的假设指导：1）我们假设，在梨状皮质的单个单位将夹带到彼此和/或与局部场电位在气味暴露，形成气味特异性的皮质合奏。2)我们假设，单个皮质神经元将参与一个以上的气味依赖的皮质合奏。3)我们假设，气味的经验和/或联想气味学习将修改前梨状皮质细胞对熟悉或学习的气味相比，新的气味的活动之间的交叉相关性。本研究采用本实验室制作的微电极阵列，在麻醉大鼠的梨状皮质前部记录多个单位电位和局部场电位。气味将使用流动稀释嗅觉仪在刺激范例中提供，以最大化尖峰序列和相关性分析（Bastian和Rennaker）所需的大型数据集（Wilson）。这项提议汇集了三位具有独特背景的研究人员，他们应用了以前在嗅觉皮层中没有使用过的技术，但已被证明对于理解其他系统非常强大。这种组合非常适合R21机制。

DESCRIPTION (provided by applicant): Cortical processing of sensory information is critical for normal perception, memory and most higher order cognitive functions. Disruption of cortical processing is a fundamental cause of disability in many disease and aging disorders. This proposal will develop and apply micro-electrode array technology and novel analytical tools to examine odor information processing in the olfactory (piriform) cortex of rats. The specific aims are to 1) determine whether single-units in piriform cortex entrain to each other and/or with local field potentials during odor stimulation, and 2) whether the magnitude of this entrainment changes with odor experience. These aims are guided by three specific hypotheses: 1) We hypothesize that single-units in piriform cortex will entrain to each other and/or with local field potentials during odor exposure, forming odor-specific cortical ensembles. 2) We hypothesize that single cortical neurons will participate in more than one odor-dependent cortical ensemble. 3) We hypothesize that odor experience and/or associative odor learning will modify cross-correlation's between activity of anterior piriform cortex cell pairs responding to familiar or learned odor compared to novel odors. Multiple single-units and local field potentials will be recorded in anterior piriform cortex of anesthetized rats using micro-electrode arrays fabricated in our lab (Rennaker). Odors will be delivered using flow-dilution olfactometers in stimulation paradigms developed to maximize large datasets (Wilson) necessary for spike train and correlation analyses (Bastian and Rennaker). This proposal brings together three researchers with unique backgrounds to apply techniques not previously utilized in olfactory cortex, yet proven to be extremely powerful for understanding other systems. This combination is ideally suited for the R21 mechanism.