Microglia are the brain's resident innate immune cells and also have a role in synaptic plasticity. Microglial processes continuously survey the brain parenchyma, interact with synaptic elements and maintain tissue homeostasis. However, the mechanisms that control surveillance and its role in synaptic plasticity are poorly understood. Microglial dynamics in vivo have been primarily studied in anesthetized animals. Here we report that microglial surveillance and injury response are reduced in awake mice compared to anesthetized mice, suggesting that arousal state modulates microglial function. Pharmacological stimulation of β2-adrenergic receptors recapitulated these observations and disrupted experience-dependent plasticity, and these effects required the presence Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use:
Microglia are the innate immune cells of the brain with roles in neuroimmunology and synaptic plasticity. Microglial processes continuously survey the brain parenchyma interacting with synaptic elements and maintaining tissue homeostasis. However, the mechanisms that control surveillance and its role in synaptic plasticity are poorly understood. Microglial dynamics in vivo have been primarily studied in anesthetized animals, where slow-wave neural activity resembles sleep-like states. We report that microglial surveillance and injury response in awake animals are reduced compared to when animals are anesthetized, suggesting that arousal state profoundly modulates microglial roles in the physiological brain. Stimulating β2-adrenergic receptors recapitulated these observations and also disrupted experience-dependent plasticity only when intact β2-adrenergic receptors were present in microglia specifically. These results indicate that microglial roles in surveillance and synaptic plasticity in the healthy brain are modulated by noradrenergic fluctuations between arousal states and raises new considerations for sleep/wake disruption in neurodevelopment and neuropathology.
Cover: The cover, by Rianne D. Stowell et al., is based on the Research Article Cerebellar microglia are dynamically unique and survey Purkinje neurons in vivo, DOI: . Acrylic painting by Rianne D. Stowell.
In the version of this article initially published, bars indicating the means in Fig. 1j were drawn incorrectly, although the individual data points and P value were correct. The error has been corrected in the HTML and PDF versions of the article.
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