A Preventive Effect of Exercise in a Mouse Model of Essential Tremor

Essential tremor (ET) has seen limited research exploring the benefits of exercise, unlike other neurodegenerative disorders. This study investigates how two forms of exercise - high-intensity interval training (HIIT) and resistance training (RT) - affect mice with ET-like symptoms caused by harmaline injections. The researchers used a repeated-measures design, dividing the mice into three groups: one underwent HIIT, another engaged in RT, and the third served as a sedentary control.

Throughout the study, each group received injections before and after the intervention period. The team measured tremor kinetics using accelerometry, analyzing power within the 8-14 and 14-29 Hz frequency bands. Additionally, they conducted high-speed video analysis to assess tremor kinematics, providing further validation.

The researchers also examined potential signaling molecules released during exercise, specifically focusing on blood lactate and Brain-Derived Neurotrophic Factor (BDNF) levels in each group. The results revealed a significant decrease in power within the 8-14 Hz band for the HIIT group, alongside an increase in the 14-29 Hz band. These changes were not observed in the RT or SED groups. Furthermore, the HIIT group experienced a shift in BDNF concentration.

The findings suggest that the HIIT protocol may have helped the mice shift tremor frequency to higher bands, offering functional resistance against harmaline-induced tremor. This study supports high-intensity aerobic physical exercise as a potential therapeutic or preventive intervention for ET, with implications for future human studies.