Sleep Neurobiology and Circuitry

7000万美国人患有某种睡眠障碍。行为、情绪和 记忆力随着睡眠的减少而恶化，随着持续的睡眠剥夺而变得更糟。缺乏 睡眠与阿尔茨海默氏症有关。有相当数量的数据关于 唤醒我们的神经元(唤醒活性神经元)和启动NREM的神经元(NREM-max) 和快速眼动睡眠(REM-max)。然而，大脑中也有胶质细胞，它们的数量超过了 神经元。一个星形细胞接触数百个树突和数万个突触 (Bushong等人，2002，Halassa等人，2007)。因此，星形胶质细胞可以主动控制神经元 活动和突触传递。越来越多的证据表明，星形胶质细胞的活动可能 调节睡眠的兴衰。睡眠通过激活星形胶质细胞来增加(我们的数据， Pelluru等人，2016)，最近的证据表明，大脑皮层星形胶质细胞在觉醒时很活跃 相对于NREM和REM睡眠。清醒时，其他脑区的神经胶质细胞也活跃吗？或, 神经胶质细胞是否有类似于神经元的不同活动模式？有没有REM-max胶质细胞？它是 考虑到胶质细胞现在被认为可以清除大脑中的 废物。我们将使用显微内窥镜成像小带内神经胶质细胞和局部神经元的活动。 Incerta，70%的GABA神经元在NREM和REM睡眠中最活跃的区域。 四个特定的目标将检验存在神经胶质细胞动态激活的总体假设 在清醒时，NREM和REM睡眠。在睡眠期间，将对不明地带的神经胶质细胞进行成像，并 对睡眠丧失6小时的反应，以检验睡眠后神经胶质细胞荧光增加的假设 损失。在目标3中，将用药物遗传学来操纵局部神经胶质细胞的活性，以测试 激活神经胶质细胞也激活局部兴奋性(囊泡性谷氨酸转运体)假说 类型2；vGLUT2)和抑制性(Lhx6-cre，共定位于GABA的转录因子 神经元)神经元。在目标4中，兴奋性神经元和抑制性神经元在小脑皮质的活动 Incerta将被操纵(光遗传学和Dredd)，胶质细胞中的荧光将被成像 以检验神经元活动改变局部神经胶质细胞活动的假设。 提出的目标是利用尖端方法在男性身上测试特定的假设 和雌性老鼠。在资助期内实现这些目标是可行的，因为我们有 在收集和分析显微内窥镜数据方面拥有成熟的专业知识。总体影响： 这个项目是，它机械地识别本地电路中位于 睡眠的出现。将星形胶质细胞包含在电路模型中将有助于更好地理解 睡眠的动态平衡和单半球睡眠，这是目前的“神经元-- “以人为本”的模特未能做到这一点。

70 million Americans suffer from some sort of sleep disorder. Behavior, mood and memory deteriorate with sleep loss and it gets worse with continuing sleep deprivation. Lack of sleep has been linked to Alzheimer's disease. There is considerable amount of data on the neurons that wake us up (wake-active neurons) and neurons that initiate NREM (NREM-max) and REM sleep (REM-max). However, there are also glia in the brain and they outnumber neurons. A single astrocyte contacts hundreds of dendrites, and tens of thousands of synapses (Bushong et al., 2002, Halassa et al., 2007). As such, astrocytes can actively control neuronal activity and synaptic transmission. Converging evidence shows that astrocyte activity may regulate the waxing and waning of sleep. Sleep is increased by activating astrocytes (our data, Pelluru et al., 2016), and recent evidence shows that cortical astrocytes are active in waking relative to NREM and REM sleep. Are glia also active during waking in other brain regions? Or, do glia have a varied pattern of activity similar to neurons? Are there REM-max glia? It is important to answer these questions considering that glia are now believed to clear the brain of waste. We will use microendoscopy to image the activity of glia and local neurons in the zona incerta, a region where 70% of the GABA neurons are most active in NREM and REM sleep. Four specific aims will test the overall hypothesis that there is a dynamic activation of glia during waking, NREM and REM sleep. Glia in the zona incerta will be imaged during sleep, and in response to 6h sleep loss to test the hypothesis that fluorescence in glia increases after sleep loss. In aim 3, the activity of local glia will be manipulated with pharmacogenetics to test the hypothesis that activating glia also activates local excitatory (vesicular glutamate transporter type 2; vGLUT2) and inhibitory (Lhx6-cre, a transcription factor that colocalizes in GABA neurons) neurons. In aim 4, the activity of the excitatory and inhibitory neurons in the zona incerta will be manipulated (optogenetics and DREDD) and fluorescence in glia will be imaged to test the hypothesis that activity of neurons changes activity of the local glia. The proposed aims utilize cutting-edge methodologies to test specific hypotheses in male and female mice. It is feasible to achieve the aims during the funding period because we have established expertise in collecting and analyzing microendoscopy data. The overall impact of this project is that it mechanistically identifies activity in local circuits that precedes the emergence of sleep. Inclusion of astrocytes in circuit models will lead to a better understanding of sleep homeostasis and unihemispheric sleep, which is something that current “neuron- centric” models have failed to do.