Exercise increases brain-derived neurotrophic factor level in serum of horses

• Pro-BDNF, truncated-BDNF and mature-BDNF could be detected in serum of horses.
• Exercise enhances the levels of all forms of BDNF in the serum of horses.
• Increase serum-BDNF level suggests positive response of the horse nervous system.

Serum-BDNF levels are known to reflect functions of the nervous system. It has been shown in humans that exercise increases serum-BDNF levels. However, how exercise training affects serum-BDNF in horses is unknown. Knowing how BDNF is altered in response to exercise training in horses will provide insight into the nervous system’s response to exercise and may provide a novel indicator to improve the training program for sport horses. Here we investigated the effect of exercise on the level of serum-BDNF in horses by comparing BDNF levels in serum from sedentary horses to those from active horses that are trained and participated in polo matches. The level of total serum-BDNF was significantly higher in active horses compared with that of sedentary horses. Individual forms of BDNF (pro, truncated and mature BDNF) were also significantly higher in active horses, especially the truncated-BDNF. The findings suggest that exercise increases basal levels of horse serum-BDNF, indicating the positive response of the horse nervous system to physical activities.