Cellular and Neurochemical Mechanisms of REM Sleep

描述(申请人提供)：本申请的长期目标是加深我们对快速眼动睡眠的细胞和神经化学机制的理解。更具体地说，我们的目标是确定桥脑被盖(PPT)细胞内信号转导通路参与受体激活介导的自由活动大鼠REM睡眠的调节。最近的证据表明，旨在改变细胞内转导通路的新化合物具有治疗内源性抑郁、癌症、低温和血小板病理性聚集的潜力，因此，识别参与REM睡眠正常调节的细胞内分子可能导致设计下一代治疗人类REM睡眠障碍(如内源性抑郁、精神分裂症、惊恐发作、双相情感障碍、发作性睡病、日间过度嗜睡)的药物。这一假设的中心假设是，PPT胆碱能细胞室中REM睡眠生成细胞的活动受特异性谷氨酸和GABA受体激活的调节。这些特殊的受体通过cAMP依赖的蛋白激酶A(PKA)传递它们的信息，以调节正常和谷氨酸诱导的REM睡眠。为了系统地检验这一假说，有四个具体的目的：1.检验PPT胆碱能细胞内cAMP-PKA信号分子参与自然和谷氨酸微量注射诱导的REM睡眠的假说。直接向PPT内微量注射cAMP和PKA抑制剂以阻断自发和谷氨酸诱导的REM睡眠将实现这一目标。2.验证PPT胆碱能细胞隔室中特定的GABA受体激活会抑制REM睡眠的假设。这一目标将通过向PPT内微量注射选择性GABA受体激动剂来阻断REM睡眠来实现。3.验证GABA受体介导的快速眼动睡眠抑制的诱导是由于cAMP-PKA信号转导通路的抑制所致的假说。在PPT内微量注射选择性cAMP-PKA激动剂阻断GABA受体激动剂对REM睡眠的抑制作用将达到这一目的。4.通过抑制PPI中REM-ON和WAKE-REM-ON细胞的活动，验证特定GABA受体的激活抑制REM睡眠的假说。这一目标将通过应用REM睡眠抑制GABA受体激动剂来识别REM-ON和Wake-REM-on PPT细胞来实现，同时记录自由活动大鼠的单细胞活动。这些研究不仅与睡眠的基本神经生物学问题有关，而且与睡眠障碍和精神疾病的问题有关。

DESCRIPTION (provided by applicant): The long-term objective of this application is to further our understanding of cellular and neurochemical mechanisms of REM sleep. More specifically, the goal is to identify Pedunculo Pontine Tegmentum (PPT) intracellular signal transduction pathways involved in the receptor activation-mediated regulation of REM sleep in the freely moving rat. Recent evidence indicates that novel compounds designed to modify intracellular transduction pathways have therapeutic potential for endogenous depression, cancer, hypothermia, and pathological aggregation of platelets, thus the identification of the intracellular molecules involved in normal regulation of REM sleep may lead to the design of the future generation of drugs to treat REM sleep disorders in humans (e.g. endogenous depression, schizophrenia, panic attacks, bipolar disorders, narcolepsy, excessive daytime sleepiness).The central hypothesis of this proposal is that the activity of REM sleep generating cells in the PPT cholinergic cell compartment is regulated by the activation of specific glutamate and GABA receptors. These particular receptors convey their message via cAMP-dependent protein kinase A (PKA) to regulate normal and glutamate-induced REM sleep. To test this hypothesis systematically, there are four specific aims: 1. Test the hypothesis that cAMP-PKA intracellular signaling molecules in the PPT cholinergic cell compartment are involved in natural and glutamate-microinjection-induced REM sleep. Microinjecting cAMP and PKA inhibitors directly into the PPT to block spontaneous and glutamate-induced REM sleep will achieve this goal. 2. Test the hypothesis that the activation of specific GABA-receptors in the PPT cholinergic cell compartment suppresses REM sleep. This goal will be achieved by microinjecting selective GABA receptor agonists into the PPT to block REM sleep. 3. Test the hypothesis that the induction of GABA-receptor-mediated suppression of REM sleep is due to the inhibition of the cAMP-PKA signal transduction pathway. Microinjecting selective cAMP-PKA activator into the PPT to block the REM sleep suppressing effect of GABA receptor agonist will achieve this goal. 4. Test the hypothesis that the activation of specific GABA receptors suppresses REM sleep by suppressing the activity of REM-on and Wake-REM-on cells in the PPI. This aim will be achieved by applying the REM sleep suppressing GABA receptor agonist to identified REM-on and Wake-REM-on PPT cells while recording single cell activity in freely moving rats. These studies are relevant not only to questions about the basic neurobiology of sleep but also to questions of sleep disorders and mental illness.