Neuronal and homeostatic regulation of sleep and wake by corticotropin-releasing hormone neurons in the paraventricular nucleus of the hypothalamus

项目总结 睡眠是一种进化上保守的行为，在整个动物界都被广泛观察到。它是 特点是在不同的警戒状态之间转换：唤醒、快速眼动(REM)睡眠和 非快速眼动(NREM)睡眠。这些转变是由不同神经元群体之间的相互作用控制的 受到动态平衡和昼夜节律机制的影响。因为睡眠有许多有益的和 恢复效果，良好的睡眠质量对身心健康很重要。它已经有了很好的历史 压力和睡眠是双向的关系。众所周知，压力是睡眠中断的主要原因。 慢性睡眠障碍会增加患精神障碍的风险。脑室旁 下丘脑核(PVN)含有促肾上腺皮质激素释放激素(CRHPVN)神经元，这些神经元 被证明是被压力激活的。中枢和全身应用促肾上腺皮质激素释放激素已被发现 保持清醒。更多的研究发现，中枢阻断CRH受体1(CRHR1)可降低 CRH注射的促醒作用，提示该受体在CRH介导的觉醒中起关键作用。 然而，CRH神经元调节觉醒的神经机制还不是很清楚。 追踪研究表明，CRHPVN神经元投射到下丘脑(POA)的视前区。 著名的睡眠中心，包含对睡眠调节至关重要的神经元。原位杂交研究 已经证明CRHR1在POA中表达。虽然CRH被认为是清醒的调节器， CRHPVN神经元及其向POA(CRHPVN→POA)的投射在睡眠-觉醒周期中的作用 睡眠动态平衡还没有得到充分的研究。这一提议的中心假设是CRHPVN 神经元控制觉醒，并破坏对慢性压力后睡眠压力的动态平衡反应。 为了解决这一假设，该建议将使用遗传小鼠模型CRH-CRE来专门标记CRH 神经元，体内钙成像，光遗传操作，CRISPR-Cas9基因编辑技术，以及 慢性社会挫败应激范式来操纵这些神经元及其投射。目标一号将决定 CRHPVN→POA投射在调节睡眠和觉醒中的作用。目标2将研究CRHPVN的作用 神经元和CRHPVN→POA在慢性应激后睡眠稳态中的投射。了解CRHPVN如何 神经元促进觉醒和调节睡眠稳态对慢性应激的反应将进一步阐明 控制压力的回路与调节睡眠和清醒的回路是如何相互联系的。

PROJECT SUMMARY Sleep is an evolutionarily conserved behavior that is widely observed across the animal kingdom. It is characterized by transitions between different vigilance states: wake, rapid eye movement (REM) sleep, and non-REM (NREM) sleep. These transitions are controlled by interactions between different neuronal populations and are under the influence of homeostatic and circadian mechanisms. As sleep has many beneficial and restorative effects, good quality sleep is important for mental and physical health. It has been well-established that stress and sleep have a bidirectional relationship. Stress is known to be a major cause of disrupted sleep. Chronic sleep disruption can lead to an increased risk of developing psychiatric disorders. The paraventricular nucleus of the hypothalamus (PVN) contains corticotropin-releasing hormone (CRHPVN) neurons that have been shown to be activated by stress. Central and systemic administration of CRH has been found to induce wakefulness. Additional studies have found that central blockade of the CRH receptor 1 (CRHR1) reduces the wake-promoting effects of CRH injection, suggesting this receptor plays a key role in CRH-mediated arousal. However, the neural mechanisms by which CRH neurons regulate wakefulness are not very well understood. Tracing studies have revealed that CRHPVN neurons project to the preoptic area of the hypothalamus (POA), a well-known sleep center containing neurons that are crucial for sleep regulation. In situ hybridization studies have shown that CRHR1 is expressed in the POA. While CRH has been implicated as a regulator of wakefulness, the role that CRHPVN neurons and their projections to the POA (CRHPVN→POA) play in the sleep-wake cycle and sleep homeostasis has not been fully investigated. The central hypothesis of this proposal is that CRHPVN neurons control wakefulness and impair the homeostatic response to sleep pressure following chronic stress. To address this hypothesis, this proposal will use a genetic mouse model, CRH-Cre, to specifically label CRH neurons, in vivo calcium imaging, optogenetic manipulations, CRISPR-Cas9 gene editing techniques, and a chronic social defeat stress paradigm to manipulate these neurons and their projections. Aim 1 will determine the role of CRHPVN→POA projections in regulating sleep and wakefulness. Aim 2 will investigate the role of CRHPVN neurons and CRHPVN→POA projections in sleep homeostasis following chronic stress. Understanding how CRHPVN neurons promote wakefulness and regulate sleep homeostasis in response to chronic stress will further elucidate how the circuits controlling stress are interconnected with those regulating sleep and wakefulness.