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是必不可少的，而融合的证据表明这是关键 功能可能是在唤醒过程中由可塑性触发的重新平衡。这个证据是一致的 假设可能发生睡眠和唤醒，并受到调节并执行其功能 个体神经元。最近，使用自由移动大鼠中的多阵列记录，我们获得了直接证据 这种睡眠可以在一组皮质神经元内发生，而大脑的其余部分保持清醒，并且 这种“局部睡眠”随着唤醒的持续时间而增加。如果是这样，就会出现许多问题：当地的睡眠也会吗 发生在与诸如苍蝇之类的哺乳动物不同的物种中？是出现的基础机制 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。 疲倦，需要睡眠才能执行突触重新归一化？还是当地的睡眠反映了暂时的 由于强烈的神经活动和能量或钙存储的短暂耗尽而引起的神经元疲劳，因此 睡眠不正确？最后，尚不清楚是否有蜂窝/超微结构特征 睡眠发生了，大概是执行了其功能。在此提案中，我们将测试当地的睡眠 通过使用体内钙成像同时监测数十个神经元的活性，存在于果蝇中 特定的神经元电路。然后，我们将测试当地睡眠（例如适当的睡眠）是否受到强烈调节 突触可塑性（“疲倦”）或仅通过活动（“疲劳”）。为此，我们将首先确定是否本地 在复杂的富集环境（Fly Mall）的延长唤醒期间，睡眠会增加，预计会导致 蘑菇体的疲倦，相对于在贫困环境中延长的唤醒（单管）。 接下来，我们将在单管延长唤醒期间以及在 睡觉。这2种激烈活动的条件预计几乎没有可塑性会导致疲劳，它们的影响 在局部睡眠中，将再次将其与单管中的唤醒延伸。进一步将 可塑性从活动中的影响，我们将在学习突变体中重复实验，其中暴露 到苍蝇购物中心不应导致可塑性/疲倦。最后，我们将使用SBF-SEM测试是否存在 超微结构的特征可以区分苍蝇的神经元与苍蝇的神经元 睡觉，并将唤醒的影响与可塑性进行比较，从而导致疲倦与与之相关的唤醒的影响 DTRPA1介导的强烈发射导致疲劳。总共，这些苍蝇研究将补充 项目II中使用类似或相同方法的小鼠。他们一起确定是否睡觉并醒来 在单个神经元水平上受到调节的调节，如果它们留下反映的超微结构签名 它们对单个细胞的后果和功能。