MOLECULAR FUNCTIONS OF SLEEP: EFFECTS OF AGE/ROLE OF AMP-DEPENDENT PROTEIN KINASE

老年动物的睡眠和觉醒是碎片化的，NREM睡眠较少，δ振幅降低。 睡眠时的波浪这些变化的机制及其后果尚不清楚。在这 根据这一提议，我们认为，在睡眠和清醒期间，细胞能量储存发生了变化， 个脑袋这种改变将影响AMP依赖性激酶（AMPK），其活性对细胞凋亡敏感。 ATP/AMP比率。当这种酶在低细胞能量的条件下被激活时，它会促进 释放能量储存并对抗利用能量的过程，如胆固醇合成 蛋白质翻译因此，我们认为这种酶的活性在睡眠和睡眠期间会有所不同。 清醒，AMPK活性的改变将导致胆固醇合成的改变， 蛋白质在睡眠和清醒之间的转换。我们认为， 睡眠包括增加胆固醇合成和蛋白质翻译。将对这一假设进行调查。 由于年龄较大的动物有更多的碎片睡眠，很可能这些睡眠的分子功能将被破坏。 在这个年龄段的人群中。这将导致睡眠期间大脑中胆固醇合成减少， 从而损害神经元功能，因为已知胆固醇在膜中起关键作用， 信号传导和突触可塑性。此外，在年龄较大的动物中，细胞能量电荷可能会发生更多变化 在清醒期间快速地导致更快速地抑制蛋白质翻译。由于抑制 蛋白质翻译将对许多细胞过程产生深远的影响，这可能是一个变量 它决定了清醒的持续时间。为了解决这些假设，我们建议 在年老和年轻的动物中评估以下内容：a）在年老和年轻的动物之间调节蛋白质翻译的变化， 睡眠和觉醒;B）睡眠和觉醒之间胆固醇合成调节的变化;c） AMPK磷酸化和活性在睡眠和觉醒之间的变化。此外，为了表明这些 AMPK活性的变化引起睡眠/觉醒的变化沿着伴随着胆固醇和蛋白质 合成的变化，我们将评估通过局部显微注射阻断酶活性的影响 进入一个表达显性负性酶的病毒的大脑。这个项目中的协议 开发一种协调的方法来研究睡眠的分子功能及其在睡眠中的变化。 年长的动物因此，这个项目将把我们对老年人睡眠障碍的认识带到一个新的领域。 提高认识水平，开辟新的干预途径，增强睡眠功能。

Older animals have fragmented sleep and wakefulness, less NREM sleep, and reduced amplitude of delta waves during sleep. The mechanisms for these changes and their consequences are unknown. In this proposal, we argue that during sleep and wakefulness,there is an alteration in the cellular energy stores in brain. This alteration will affect the AMP-dependent kinase (AMPK) whose activity is sensitive to cellular ATP/AMP ratios. When the enzyme is activated under conditions of low cellular energy, it promotes the liberation of energy stores and acts to antagonizeprocesses that utilize energy such as cholesterol synthesis and protein translation. We therefore propose that the activity of this enzyme will vary between sleep and wakefulness, and that alteration in activity of AMPK will lead to alterations in cholesterol synthesis and protein translation between sleep and wakefulness. We propose that restorative molecular functions of sleep include increased cholesterol synthesis and protein translation. This hypothesis will be investigated. Since older animals have more fragmented sleep, it is likely that these molecular functions of sleep will be compromised in this age group. This will lead to decreased cholesterol synthesis in brain during sleep and thereby compromised neuronal function since cholesterol is known to play a key role in membrane signaling and synaptic plasticity. Moreover, in older animals, cellular energy charge may change more rapidly during wakefulness leading to more rapid inhibition of protein translation. Since inhibition of protein translation will have profound effects on many cellular processes, this is likely to be one variable that sets the duration of wakefulness that can be sustained. To address these hypotheses, we propose to assess the following in both old and young animals: a) changes in regulation of protein translation between sleep and wakefulness;b) changes in regulation of cholesterol synthesis between sleep and wakefulness;c) changes in AMPK phosphorylation and activity between sleep and wakefulness. Further, to show that these changes in AMPK activity cause sleep/wake changes along with concomitant cholesterol and protein synthesis changes, we will assess the effects of blocking the activity of the enzyme by local microinjection into brain of a virus expressing a dominant negative form of the enzyme. The protocols in this project develop a coordinated approach to a new study of the molecular functions of sleep and their alterations in older animals. Thus, this project will take our knowledge about sleep disturbances in the elderly to a new level of understanding, opening new approaches for interveningto enhance the functions of sleep.