Environmental regulation of cortical gene expression and circuit function

项目摘要/摘要： 环境事件可以迅速改变大脑皮层基因的表达。然而，这些变化是什么，以及它们可能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。目前的建议试图确定急性环境刺激诱导的额叶皮质神经元基因表达的区域和细胞类型的特定变化，以及这种变化如何影响行为。PI的实验室在之前的资助期间的初步结果显示，这一新的发现是，睡眠剥夺的急性环境刺激迅速上调了小鼠额叶皮质中5-羟色胺2A受体(5-HT2AR)的水平，这种方式需要立即早期基因转录因子Egr3的功能。本研究的总体目标是确定额叶皮质神经元对睡眠剥夺的急性环境刺激的细胞类型特异性转录反应，并确定额叶皮质特定回路中活动依赖基因表达对行为的作用。在这一应用中，研究小组汇集了一个跨学科的团队，并采取了结合分子、细胞和行为方法的综合方法来实现这一目标。在目标1中，将使用单细胞RNA-SEQ来确定睡眠剥夺的急性环境刺激诱导的额叶皮质神经元基因表达的细胞类型特异性变化。在Egr3-/-小鼠身上进行的平行研究将确定环境诱导的基因表达变化，这些变化需要这种活性依赖的即刻早期基因转录因子。在目标2中，兴奋性和抑制性光发生方法将被用来确定特定的皮层回路在调节前一资金时期发现的5-HT2AR依赖行为和前额叶皮质依赖的空间工作记忆行为中的作用。影响：预计这些研究的成功完成将阐明环境刺激迅速改变大脑皮层细胞类型特定基因表达的机制，以及这如何影响特定受体和回路以改变额叶皮质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.