Sex Differences in Reaction to Chronic Unpredictable Stress in the House Mouse of Wild Origin

The study on wild-derived house mice (Mus musculus musculus) examined sex-specific responses to chronic unpredictable stress (CUS) over 5 weeks, involving 52 mice (26 males and 26 females). It found that stressed females gained significantly less weight compared to controls, while both sexes showed increased weights in stress-related organs like the adrenal and thymus. Behavioral differences were noted, with stressed females exhibiting prolonged grooming and fewer immobility episodes, whereas stressed males showed increased activity and shorter immobility in stress tests. Additionally, stressed males had higher levels of hair corticosterone. These findings underscore distinct biological and behavioral stress coping strategies between male and female mice, suggesting the need for sex-specific approaches in stress research and treatment.