Dopamine Release Impairments Accompany Movement Vigor Deficiency in an Exercise-Induced Fatigue Mouse Model

Fatigue is a common symptom in neurological diseases with a complex cause, involving the influence of events occurring in both the central and peripheral nervous systems. When people suffer from fatigue, a general decline in their movement performance typically occurs. The neural representation of dopamine signaling in the striatum plays a crucial role in movement regulation. Movement vigor is regulated by dopamine-dependent neuron activity in the striatum. However, whether exercise-induced fatigue alters stimulated dopamine release and further affects movement vigor has not been described. Here, for the first time, we used fast-scan cyclic voltammetry to demonstrate the effect of exercise-induced fatigue on stimulated dopamine release in the striatum in combination with a fiber photometry system to observe the excitability of striatal neurons. The movement vigor of mice was reduced, and after fatigue, the balance of excitability of striatal neurons regulated by dopamine projections was disturbed, which was induced by a reduction in dopamine release. Additionally, D2DR regulation may serve as a targeted intervention to alleviate exercise-induced fatigue and promote fatigue recovery.