Amygdalar Activation Following Sleep Deprivation in Female Mice

Coordinated activity across multiple brain regions regulate sleep-wake activity. Sleep deprivation alters this brain activity pattern to increase sleep pressure or sustain arousal, but it may also impair cognitive or mood-related processes. We recently showed prominent neuronal activation following sleep deprivation in the amygdala of male mice, which is involved in fear, stress and emotional regulation. However, as the amygdala is a sexually dimorphic brain region, it is not clear whether sleep deprivation similarly impacts the female amygdala. We compared neuronal activation in the amygdala of rested and sleep-deprived (SD) female mice and determined if amygdalar subregions are similarly impacted by sleep deprivation in male and female mice. We optimized a dual stain for c-Fos immunoreactivity and Nissl bodies to map neuronal activation within parcellated amygdalar regions. There was greater expression of the neuronal activation marker c-Fos in the SD than rested female amygdala overall, and c-Fos distribution in the SD amygdala spanned its entire anteroposterior axis while that in the rested amygdala was restricted to the middle of the amygdala only. The greatest increase in c-Fos expression following SD were at the basolateral, basomedial, and medial amygdala, and this expression pattern was similar to the male amygdala. However, some regions like the anterior amygdalar area and posterior amygdalar nucleus comprised lower c-Fos expression in SD female amygdala. Taken together, these results indicated that the female amygdala was similarly activated by sleep deprivation and may mediate similar functions in male and female mice.