Ensemble coding in olfactory cortex

描述（由申请人提供）：感觉信息的皮质处理对正常的感知、记忆和大多数高级认知功能至关重要。在许多疾病和衰老障碍中，皮质加工的中断是导致残疾的根本原因。本研究将开发和应用微电极阵列技术和新的分析工具来研究大鼠嗅（梨状）皮层的气味信息处理。具体目的是：1)确定在气味刺激过程中，梨状皮质的单个单元是否相互夹带和/或与局部场电位夹带；2)这种夹带的强度是否随气味体验而变化。这些目标是由三个特定的假设指导的：1)我们假设梨状皮质中的单个单元在气味暴露期间会相互夹带和/或与局部场电位一起，形成气味特异性皮质集合。2)我们假设单个皮质神经元会参与多个气味依赖的皮质集合。3)我们假设气味体验和/或联想气味学习将改变前梨状皮质细胞对对熟悉或习得气味的反应与对新气味的反应之间的相互关系。使用本实验室（Rennaker）制作的微电极阵列记录麻醉大鼠梨状皮质前部的多个单单元和局部场电位。气味将在刺激范例中使用流动稀释嗅觉计来传递，以最大限度地利用大数据集（Wilson）进行峰值序列和相关分析（Bastian和Rennaker）。该提案汇集了三位具有独特背景的研究人员，应用以前未在嗅觉皮层中使用的技术，但已被证明对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.