Do single neurons need to sleep and why? Investigating the cellular signatures o

单个神经元需要睡眠吗？为什么？

• 批准号: 8794553
• 负责人: Chiara Cirelli
• 金额: $ 37.68万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8794553
• 关键词: Address; Behavior; Brain; Brain Part; Calcium; Cell Count; Cells; Chemosensitization; Cognition; Complement; Complex; Cortical Column; Data; Drosophila genus; Electrodes; Environment; Exposure to; Fatigue; Human; Image; Individual; Lead; Learning; Left; Mammals; Mediating; Methods; Monitor; Motor Cortex; Mus; Mushroom Bodies; Neuronal Plasticity; Neurons; Organism; Performance; Qualifying; Rattus; Relative (related person); Rest; Rodent; Scalp structure; Sleep; Slow-Wave Sleep; Stimulus; Synapses; Synaptic plasticity; System; Testing; Time; Training; Tube; awake; fly; in vivo; mutant; relating to nervous system; research study; response; sensory stimulus; sleep regulation

ABSTRACT Sleep is thought to be essential to restore brain functions, and converging evidence suggests that a key function may be to rebalance cellular changes triggered by plasticity during wake. This evidence is consistent with the hypothesis that sleep and wake may occur, be regulated, and perform their functions at the level of individual neurons. Recently, using multi-array recordings in freely moving rats, we obtained direct evidence that sleep can occur locally within a group of cortical neurons, while the rest of the brain remains awake, and that such "local sleep" increases with the duration of wake. If so, many questions arise: does local sleep also occur in species very different from mammals, such as flies? Are the mechanisms underlying the occurrence of local sleep similar to those that are known to regulate sleep need, specifically intense neural plasticity leading to tiredness, which requires sleep to enforce synaptic renormalization? Or does local sleep reflect temporary neuronal fatigue due to intense neural activity and short-lasting depletion of energy or calcium stores, and thus not qualify properly as sleep? Finally, it is unknown whether there are cellular/ultrastructural signatures that sleep has occurred and presumably performed its functions. In this proposal, we will test whether local sleep exists in flies by using in vivo calcium imaging to monitor simultaneously the activity of dozens of neurons in specific neuronal circuits. We will then test whether local sleep, like sleep proper, is regulated by intense synaptic plasticity ("tiredness") or instead by mere activity ("fatigue"). To do so we will first establish if local sleep increases during extended wake in a complex enriched environment (fly mall), expected to lead to tiredness in the mushroom bodies, relative to extended wake in an impoverished environment (single tube). Next, we will induce local dTrpA1-mediated activation during extended wake in single tubes, as well as during sleep. These 2 conditions of intense activity with little plasticity are expected to lead to fatigue, and their effects on local sleep will again be compared with those of extended wake in single tubes. To further decouple the effects of plasticity from those of activity we will repeat the experiments in learning mutants, in which exposure to the fly mall should not lead to plasticity/tiredness. Finally, we will use SBF-SEM to test whether there are ultrastructural signatures that can distinguish neurons of flies that have been awake from those of flies that slept, and compare the effects of wake with plasticity leading to tiredness with those of wake associated with dTrpA1-mediated intense firing leading to fatigue. Altogether, these studies in flies will complement those in mice in Project II, which use similar or the very same methods. Together, they will establish if sleep and wake are regulated homeostatically at the single neuron level, and if they leave ultrastructural signatures that reflect their consequences and functions for individual cells.

抽象的 睡眠被认为对于恢复大脑功能至关重要，综合证据表明，睡眠是恢复大脑功能的关键 功能可能是重新平衡唤醒期间由可塑性引发的细胞变化。这个证据是一致的 假设睡眠和觉醒可能发生、受到调节并在 单个神经元。最近，通过对自由活动的大鼠进行多阵列记录，我们获得了直接证据 睡眠可以在一组皮质神经元内局部发生，而大脑的其余部分保持清醒，并且 这种“局部睡眠”随着清醒时间的延长而增加。如果是这样，就会出现许多问题：局部睡眠也可以吗？ 发生在与哺乳动物非常不同的物种中，例如苍蝇？其发生的机制是否是 局部睡眠类似于已知的调节睡眠需求的睡眠，特别是强烈的神经可塑性导致 疲劳，这需要睡眠来强制突触重新正常化？或者局部睡眠反映的是暂时的 由于剧烈的神经活动和能量或钙储存的短暂消耗而导致的神经元疲劳，因此 不符合睡眠标准？最后，尚不清楚是否存在细胞/超微结构特征 睡眠已经发生并且大概发挥了它的功能。在这个提案中，我们将测试局部睡眠是否 通过使用体内钙成像同时监测果蝇中数十个神经元的活动， 特定的神经元回路。然后我们将测试局部睡眠是否像正常睡眠一样受到强烈的调节 突触可塑性（“疲劳”）或单纯的活动（“疲劳”）。为此，我们将首先确定本地是否 在复杂丰富的环境（飞行购物中心）中，长时间醒来时睡眠会增加，预计会导致 蘑菇体内的疲劳，相对于贫困环境中的长时间唤醒（单管）。 接下来，我们将在单管中长时间唤醒期间以及在 睡觉。这两种可塑性很小的剧烈活动条件预计会导致疲劳，及其影响 局部睡眠的结果将再次与单管中长时间唤醒的结果进行比较。为了进一步解耦 可塑性的影响与活动的影响我们将在学习突变体中重复实验，其中暴露 去飞翔购物中心不应导致可塑性/疲劳。最后，我们将使用SBF-SEM来测试是否存在 超微结构特征可以区分已醒来的果蝇的神经元和未清醒的果蝇的神经元 睡眠，并比较具有可塑性导致疲劳的觉醒的影响与与可塑性相关的觉醒的影响 dTrpA1 介导的强烈放电导致疲劳。总而言之，这些针对果蝇的研究将补充那些针对果蝇的研究。 项目 II 中的小鼠使用相似或完全相同的方法。他们将一起确定是否睡眠和醒来 在单个神经元水平上进行稳态调节，如果它们留下反映的超微结构特征 它们对单个细胞的影响和功能。