Long-lasting consequences of early ethanol on network activity during sleep

摘要/摘要 胎儿酒精谱系障碍(FASD)是西方国家智力残疾的主要原因之一， 有神经行为特征，如学习、记忆和情绪方面的缺陷。我们建议，发展性 乙醇(Etoh)暴露可能会导致睡眠期间神经活动模式的长期中断，这是 已知对巩固记忆和突触动态平衡很重要。如果是这样的话，这将造成一种情况 其中神经系统在睡眠期间自我修复和重新调整的正常能力将受到损害， 导致在酒精暴露结束很长时间后每天都会对神经系统功能造成侮辱。为了支持这一点 假设，在过去的资金周期中，我们已经证明了发育的乙醇干扰和 成人非快速眼动睡眠的碎片，2)成年人睡眠中断的程度预测认知障碍，3) 睡眠障碍与小白蛋白(PV)和生长抑素(SST)表达严重缺失有关 已知参与睡眠-觉醒结构的GABA能中间神经元，4)PV细胞的破坏 通过神经五肽基因敲除的功能复制了发育酒精的某些方面，但不是睡眠，并且 5)用氯化锂预防由发育性乙醇引起的细胞丢失可防止睡眠、解剖学和认知 减损。在这次更新中，我们计划进一步探索发育中的乙醇对睡眠的影响机制 醒来时带着细胞特有的分析。目标1将检验这样一个假设，即选择性光遗传激活 备用GABA能神经元将修复发育中乙醇所致的睡眠和认知障碍 转基因小鼠(例如，SST-CRE；目标1.1)。在同样的动物身上，我们会把睡眠和觉醒联系起来 与几个已识别的GABA能回路(例如，SST，Reelin， 与睡眠相关区域的血管活性肠肽(VIP)，包括前脑基底核、海马区和 大脑皮层。数据将包括使用共聚焦和电子显微镜识别的细胞类型的突触相互作用 以及高尔基分析(目标1.2)。对我们化验过的动物进行解剖分析 睡眠/觉醒和认知功能将允许我们将结构(例如，突触密度)与 神经行为功能/功能障碍/修复(例如，慢波活动、兴奋性/抑制性[E/I]平衡)。目标2.1 检查PV/SST细胞在多大程度上被发育中的乙醇杀死，或者下调 追踪荧光标记的PV/SST神经元祖细胞在Nkx2.1-Cre；Ai9中的表型表达 暴露于乙醇的小鼠。这将提供必要的信息来指导恢复GABA能功能的尝试 在接触了乙醇之后。Aim 2.2将PV/SST神经间祖细胞移植到无水乙醇处理的小鼠体内，以检测 如果在已确定的大脑区域重新填充GABA能神经元将恢复睡眠和/或皮质活动(例如，缓慢- 波活动、E/I平衡)，以及与睡眠相关的认知功能和电路结构。如果成功，则结果 这一提议可能为理解和修复早期乙醇诱导的神经打开了一扇新的窗口 和认知障碍。

ABSTRACT/SUMMARY Fetal alcohol spectrum disorder (FASD) is one of the primary causes of intellectual disability in western nations, with neurobehavioral hallmarks such as deficits in learning, memory and mood. We propose that developmental ethanol (EtOH) exposure may induce long-lasting disruption of neural activity patterns during sleep which are known to be important for memory consolidation and synaptic homeostasis. If so, this would create a situation wherein the normal ability of the nervous system to repair and readjust itself during sleep would be impaired, resulting in a daily insult to nervous system function long after the EtOH exposure ended. In support of this hypothesis, during the past funding cycle we have demonstrated that developmental EtOH 1) disrupts and fragments adult non-REM sleep, 2) the extent of sleep disruption in adults predicts cognitive impairment, 3) the sleep impairment is associated with severe loss of parvalbumin (PV) and somatostatin (SST) expressing GABAergic interneurons which are known to contribute to sleep-wake architecture, 4) disruption of PV cell function through neuropentraxin knock-out replicates some aspects of developmental ethanol but not sleep, and 5) preventing cell loss induced by developmental EtOH with LiCl prevents sleep, anatomical, and cognitive impairments. In this renewal, we plan to further explore the mechanisms of developmental EtOH effects on sleep and waking with cell specific analyses. Aim 1 will test the hypothesis that selective optogenetic activation of spared GABAergic neurons will restore the deficits in sleep and cognition induced by developmental EtOH in transgenic mice (e.g., SST-Cre; Aim 1.1). In the same animals, we will correlate sleep-wake function/dysfunction/repair with anatomical structure of several identified GABAergic circuits (e.g., SST, reelin, vasoactive intestinal peptide (VIP)) in sleep-related regions including basal forebrain nuclei, hippocampus and neocortex. Data will include synaptic interactions of identified cell types using confocal and electron microscopy as well as Golgi analyses (Aim 1.2). Performing the anatomical analyses on animals that we have assayed for sleep/wake and cognitive function will allow us to directly relate structure (e.g., synaptic density) with neurobehavioral function/dysfunction/repair (e.g., slow-wave activity, excitatory/inhibitory [E/I] balance). Aim 2.1 examines to what extent PV/SST cells are killed by developmental EtOH, or alternatively have down-regulated phenotypic expression by tracking the fate of fluorescently labeled PV/SST neuron progenitors in Nkx2.1-Cre;Ai9 mice exposed to EtOH. This will provide information needed to guide attempts to restore GABAergic function after EtOH exposure. Aim 2.2 will transplant PV/SST interneuron progenitors into EtOH treated mice, to examine if re-populating GABAergic neurons in identified brain regions will restore sleep and/or cortical activity (e.g., slow- wave activity, E/I balance), as well as sleep-related cognitive function and circuit structure. If successful, results from this proposal could open a new window into both understanding and repair of early ethanol-induced neural and cognitive impairment.