Microglial surveillance: No clock is better than a bad clock
Microglia-specific knock-down of Bmal1 improves memory and protects mice from high fat diet-induced obesity. https://doi.org/10.1038/s41380-021-01169-z
Disrupted biological clock rhythms are assumed to have negative health consequences, our recent finding indicates that this might be not the case in every situation. We found that when we deleted the core clock gene Bmal1 from the brain microglial cells in mice, their learning and memory improved, and they were protected from high fat diet-induced obesity. We believe the enhanced flexibility in surveillance and phagocytosis in the clockless microglia played a major role in this. Without the strict control of the intrinsic biological clock, microglia can perform their surveillance and phagocytosis tasks on demand, i.e. at any time of the day when there is a metabolic stressor or cognitive challenge. Thus, for microglial cells, no clock is better than a bad clock.