Sleep has an essential role for optimal brain function, but the cellular substrates for sleep regulation are not fully understood. Microglia, the immune cells of the brain, have gained increasingly more attention over the last two decades for their important roles in various brain functions that extend beyond their well-known immune function, including brain development, neuronal protection, and synaptic plasticity. Here we review recent advances in understanding: i) morphological and phenotypic dynamics of microglia including process motility/growth and gene/protein expression, and ii) microglia-neuron interactions including phagocytosis and contact at synapses which alters neuronal circuit activity, both under physiological state in the adult brain. We discuss how the microglia-neuron interactions particularly at synapses could influence microglia and neuronal activities across circadian cycles and sleep/wake states. We also review recent findings on how microglia respond to sleep loss. We conclude by pointing out key questions and proposing suggestions for future research to better understand the role of microglia in sleep regulation, sleep homeostasis, and the function of sleep.

睡眠对最佳大脑功能起着至关重要的作用，但睡眠调节的细胞基质尚不完全清楚。小胶质细胞是大脑的免疫细胞，在过去的 20 年里，因其在各种大脑功能中的重要作用而受到越来越多的关注，这些功能超出了其众所周知的免疫功能，包括大脑发育、神经元保护和突触可塑性。在这里，我们回顾了在理解方面的最新进展：i) 小胶质细胞的形态学和表型动力学，包括过程运动/生长和基因/蛋白质表达，以及 ii) 小胶质细胞 - 神经元相互作用，包括吞噬作用和突触处的接触，这会在生理状态下改变神经元回路活动在成年人的大脑中。我们讨论了小胶质细胞 - 神经元相互作用，特别是在突触处如何影响小胶质细胞和神经元活动，跨越昼夜节律周期和睡眠/觉醒状态。我们还回顾了最近关于小胶质细胞如何应对睡眠不足的发现。最后，我们指出关键问题并为未来的研究提出建议，以更好地了解小胶质细胞在睡眠调节、睡眠稳态和睡眠功能中的作用。