Browsing by Author "Immonen, Johanna"

Aims Sleep is needed to maintain brain homeostasis. Chronic insufficient sleep has been associated with elevated levels of inflammatory markers. Microglia are the resident immune cells of the brain. As microglial morphology correlates with their functional state, the current study aimed to characterize microglial morphology after insufficient sleep and recovery sleep. We hypothesised that microglia adopt an activated state after insufficient sleep, indicated by a deramification of the branches and an enlargement of cell bodies compared with the controls. Methods We caused insufficient sleep with acute sleep deprivation by 9 h of gentle handling, and conducted sleep fragmentation for 14 days in mice. The tissue was collected after perfusing the animals with PFA. The brain tissue from ventral hippocampus was immunostained for microglia and imaged with a confocal microscope. Ramification and soma size were quantified by tracing the branches and segmenting the somas. Results Neither the acute sleep deprivation nor the chronic fragmented sleep did result in any differences in morphology compared with their control groups. Surprisingly, the soma size was significantly smaller following the recovery sleep after fragmented sleep compared with the controls. Conclusions Microglial morphology and thus function may not be affected by acute sleep deprivation and chronic fragmented sleep in ventral hippocampus. Microglial soma size was significantly smaller after recovery sleep following chronic fragmented sleep compared with the control. This could have been due to larger soma sizes in this control group compared with other controls. Further studies are needed.