Effects of exercise on mental health in mice with circadian rhythm disruption.

Background: Circadian rhythm disruptions are major contributors to anxiety and depression, potentially involving mechanisms like altered clock gene activity and midbrain dopamine system impairments. Exercise has been shown to play a significant role in maintaining the stability of the circadian rhythm and promoting mental health. This study aimed to investigate whether various exercise modes could alleviate mental health issues triggered by circadian rhythm disruption.

Methods: A total of 48 male C57BL/6J mice were randomly divided into four groups: control group, circadian rhythm disruption group, aerobic exercise group with circadian rhythm disruption, and resistance exercise group with circadian rhythm disruption. Circadian rhythm disruption was induced by altering the light-dark cycle every three days, followed by four weeks of exercise intervention. The behavioral rhythms of mice were evaluated through sleep recording. Behavioral assessments, including the open field test, elevated plus maze, and forced swim test, were used to evaluate anxiety- and depression-like behaviors. The expression of clock genes and dopamine levels in the prefrontal cortex were analyzed using quantitative real-time PCR and enzyme-linked immunosorbent assay.

Results: Exercise interventions significantly reduced anxiety- and depression-like behaviors in the mice. Aerobic and resistance exercise significantly maintained the circadian rhythmic expression pattern of the Bmal1 gene. Aerobic exercise increased dopamine levels in the prefrontal cortex.

Conclusion: Exercise, especially aerobic exercise, effectively alleviates mental health challenges associated with circadian rhythm disruption by influencing clock gene expression and dopamine regulation in the prefrontal cortex. These findings provide evidence for the potential use of exercise interventions as therapeutic strategies for circadian rhythm-related mental health problems.