Microglia are involved in the protection of memories formed during sleep deprivation

Nicholas W. Gentry; Thomas McMahon; Maya Yamazaki; John Webb; Thomas D. Arnold; Susanna Rosi; Louis J. Ptáček; Ying-Hui Fu

Neurobiology of Sleep and Circadian Rhythms (May 2022)

Microglia are involved in the protection of memories formed during sleep deprivation

Nicholas W. Gentry,
Thomas McMahon,
Maya Yamazaki,
John Webb,
Thomas D. Arnold,
Susanna Rosi,
Louis J. Ptáček,
Ying-Hui Fu

Affiliations

Nicholas W. Gentry: Department of Neurology, University of California, San Francisco, San Francisco, CA, 94143, USA
Thomas McMahon: Department of Neurology, University of California, San Francisco, San Francisco, CA, 94143, USA
Maya Yamazaki: Department of Neurology, University of California, San Francisco, San Francisco, CA, 94143, USA
John Webb: Department of Neurology, University of California, San Francisco, San Francisco, CA, 94143, USA
Thomas D. Arnold: Department of Pediatrics, University of California, San Francisco, San Francisco, CA, 94143, USA; Department of Physical Rehabilitation Science, University of California, San Francisco, San Francisco, CA, 94143, USA; Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, 94143, USA
Susanna Rosi: Department of Physical Rehabilitation Science, University of California, San Francisco, San Francisco, CA, 94143, USA; Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, 94143, USA; Weill Institute for Neuroscience, University of California, San Francisco, San Francisco, CA, 94143, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, 94143, USA
Louis J. Ptáček: Department of Neurology, University of California, San Francisco, San Francisco, CA, 94143, USA; Institute for Human Genetics, University of California, San Francisco, San Francisco, CA, 94143, USA; Weill Institute for Neuroscience, University of California, San Francisco, San Francisco, CA, 94143, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, 94143, USA; Corresponding author. Department of Neurology, University of California, San Francisco, San Francisco, CA, 94143, USA.
Ying-Hui Fu: Department of Neurology, University of California, San Francisco, San Francisco, CA, 94143, USA; Institute for Human Genetics, University of California, San Francisco, San Francisco, CA, 94143, USA; Weill Institute for Neuroscience, University of California, San Francisco, San Francisco, CA, 94143, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, 94143, USA; Corresponding author. Department of Neurology, University of California, San Francisco, San Francisco, CA, 94143, USA.

Journal volume & issue: Vol. 12
p. 100073

Abstract

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Sleep deprivation can generate inflammatory responses in the central nervous system. In turn, this inflammation increases sleep drive, leading to a rebound in sleep duration. Microglia, the innate immune cells found exclusively in the CNS, have previously been found to release inflammatory signals and exhibit altered characteristics in response to sleep deprivation. Together, this suggests that microglia may be partially responsible for the brain's response to sleep deprivation through their inflammatory activity. In this study, we ablated microglia from the mouse brain and assessed resulting sleep, circadian, and sleep deprivation phenotypes. We find that microglia are dispensable for both homeostatic sleep and circadian function and the sleep rebound response to sleep deprivation. However, we uncover a phenomenon by which microglia appear to be essential for the protection of fear-conditioning memories formed during the recovery sleep period following a period of sleep deprivation. This phenomenon occurs potentially through the upregulation of synaptic-homeostasis related genes to protect nascent dendritic spines that may be otherwise removed or downscaled during recovery sleep. These findings further expand the list of known functions for microglia in synaptic modulation.

Published in Neurobiology of Sleep and Circadian Rhythms

ISSN: 2451-9944 (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Medicine: Internal medicine: Neurosciences. Biological psychiatry. Neuropsychiatry; Science: Biology (General)
Website: https://www.journals.elsevier.com/neurobiology-of-sleep-and-circadian-rhythms

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