The benefits of physical activity on the brain’s aging process are widely known. Evidence suggests that exerkines, a class of molecules released into the bloodstream in response to exercise, drive many of these benefits. Findings from a recent study in mice found that PF4, an exerkine derived from platelets, promotes the production of hippocampal precursor cells in the brains of older mice.

Researchers injected PF4 into mice and assessed its effects on hippocampal neurogenesis (the growth of new brain cells). Then they investigated the effects of exercise on blood platelets.

They found that systemic elevation of PF4 levels mitigated age-related declines in brain regeneration and cognitive function, an effect that was dependent upon hippocampal neurogenesis. They also found that exercise triggered platelet activation, which in turn increased the production of hippocampal precursor cells in the brains of older mice.

These findings underscore the crucial role of platelets in mediating the rejuvenating effects of exercise on the aging brain. It also sheds light on the potential mechanisms that link physical activity with improved brain health in aging, with possible implications for people who are unable to exercise due to advanced age, mobility issues, or various health conditions.

Interestingly, heat stress also promotes PF4. In a study involving endurance cyclists exercising in hot conditions, PF4 increased by as much as 150 percent. Sauna use has similar effects on PF4. Learn about other effects of heat stress from sauna use in our overview article.

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