Environmental regulation of cortical gene expression and circuit function

项目概要/摘要： 环境事件可以迅速改变大脑皮层中基因的表达。然而，这些变化是什么，以及它们如何改变神经元回路和动物行为的功能适应，仍然知之甚少。目前的建议旨在确定区域和细胞类型的特定变化，神经元基因表达诱导的额叶皮层的急性环境刺激，以及如何影响行为。PI实验室在前期资助期间的初步结果揭示了新的发现，即睡眠剥夺的急性环境刺激迅速上调小鼠额叶皮层中的5-羟色胺2A受体（5-HT{2A}R）水平，其方式需要立即早期基因转录因子Egr 3的功能。目前的建议的总体目标是确定细胞类型的特定转录反应的额叶皮层神经元的急性环境刺激的睡眠剥夺，并确定活动依赖的基因表达的作用，在特定的额叶皮层电路的行为。在这项应用中，研究小组汇集了一个跨学科的团队，并采取了综合的方法，结合分子，细胞和行为的方法来实现这一目标。在目的1中，将采用单细胞RNA-seq来定义由睡眠剥夺的急性环境刺激在额叶皮层神经元中诱导的基因表达的细胞类型特异性变化。在Egr 3-/-小鼠中进行的平行研究将确定需要这种活性依赖性立即早期基因转录因子的环境诱导的基因表达变化。在目标2中，将采用兴奋性和抑制性光遗传学方法来确定特定皮层回路在调节在先前资助期间鉴定的5-HT{2A} R依赖性行为和前额叶皮层依赖性空间工作记忆行为两者中的作用。影响：预计这些研究的成功完成将阐明环境刺激快速改变皮层细胞类型特异性基因表达的机制，以及这如何影响特定受体和回路，以改变额叶皮层介导的警觉状态和空间记忆形成过程。

Project Summary/Abstract: Environmental events can rapidly alter the expression of genes in the cerebral cortex. However, what those changes are, and how they may alter the functional adaptation of neuronal circuits and animal behavior, remains poorly understood. The current proposal seeks to identify the regional and cell-type specific changes in neuronal gene expression induced in the frontal cortex by an acute environmental stimulus, and how this influences behavior. Preliminary results from the PI’s laboratory during the prior funding period revealed the novel finding that the acute environmental stimulus of sleep deprivation rapidly upregulates serotonin 2A receptor (5-HT{2A}R) levels in the frontal cortex of mice, in a manner that requires function of the immediate early gene transcription factor Egr3. The overall goal of the current proposal is to define the cell-type specific transcriptional response of frontal cortex neurons to the acute environmental stimulus of sleep deprivation, and to determine the role of activity dependent gene expression in specific frontal cortex circuits on behavior. In this application, the research group brings together an interdisciplinary team and takes an integrated approach combining molecular, cellular, and behavioral approaches to accomplish the goal. In Aim 1 single cell RNA-seq will be employed to define the cell-type specific changes in gene expression induced in frontal cortex neurons by the acute environmental stimulus of sleep deprivation. Parallel studies performed in Egr3-/- mice will identify the environmentally-induced gene expression changes that require this activity-dependent immediate early gene transcription factor. In Aim 2, excitatory and inhibitory optogenetic methods will be employed to determine the role of specific cortical circuits in regulating both the 5-HT{2A}R-dependent behaviors identified during the previous funding period, and prefrontal cortex dependent spatial working memory behavior. Impact: It is anticipated that successful completion of these studies will elucidate mechanisms by which environmental stimuli rapidly alter cell-type specific gene expression in the cortex, and how this impacts specific receptors and circuits to alter frontal cortex-mediated states of alertness and processes of spatial memory formation.