Astrocytic calcium signals modulate exercise-induced fatigue in mice.

Exercise-induced fatigue (EF) is characterized by a decline in maximal voluntary muscle force following prolonged physical activity, influenced by both peripheral and central factors. Central fatigue involves complex interactions within the central nervous system (CNS), where astrocytes play a crucial role. This study explores the impact of astrocytic calcium signals on EF. We used adeno-associated viruses to express GCaMP7b in astrocytes of the dorsal striatum in mice, allowing us to monitor calcium dynamics. Our findings reveal that EF significantly increases the frequency of spontaneous astrocytic calcium signals. Utilizing genetic tools to either enhance or reduce astrocytic calcium signaling, we observed corresponding decreases and increases in exercise-induced fatigue time, respectively. Furthermore, modulation of astrocytic calcium signals influenced corticostriatal synaptic plasticity, with increased signals impairing and decreased signals ameliorating long-term depression (LTD). These results highlight the pivotal role of astrocytic calcium signaling in the regulation of exercise-induced fatigue and synaptic plasticity in the striatum.