Keynote: Microglia modulate stable wakefulness via thalamic reticular nucleus

Speaker: Qiaojie Xiong, Stony Brook
Title: Microglia modulate stable wakefulness via thalamic reticular nucleus
Emcee: Robert Froemke
Backend host: Gowri Somasekhar
Presented during Neuromatch Conference 3.0, Oct 26-30, 2020.

Summary: Microglia are involved with brain homeostasis and immunity, but their role in regulating vigilance remains unclear. We employed genetic, physiological, and metabolomic methods to examine microglial involvement in the regulation of wakefulness and sleep. Microglial depletion decreased stable nighttime wakefulness in mice by increasing transitions between wakefulness and non-rapid eye movement (NREM) sleep. Metabolomic analysis revealed that the diurnal variation of the brain ceramide disappeared in microglia-depleted mice. Ceramide preferentially influenced microglia in the thalamic reticular nucleus (TRN), and local depletion of TRN microglia produced similar impaired wakefulness. Chemogenetic manipulations of anterior TRN neurons showed that they regulated transitions between wakefulness and NREM sleep. Their firing capacity was suppressed by both microglial depletion and added ceramide. In microglia-depleted mice, activating anterior TRN neurons or inhibiting ceramide production both restored stable wakefulness. These findings demonstrate that microglia can modulate stable wakefulness through anterior TRN neurons via ceramide signaling