Adolescent swimming exercise induces systemic adaptations and molecular changes in the rat cerebral cortex

Adolescence is a critical developmental window during which physical activity can exert long-lasting effects on brain function and health. However, the molecular impact of structured exercise during this period remains poorly understood. This study investigated whether a five-week progressive swimming protocol during adolescence induces behavioral and molecular adaptations in the rat cerebral cortex MATERIALS AND METHODS: Twelve male Wistar rats were divided into Sedentary and Exercise groups. The Exercise group underwent a swimming protocol from postnatal day 41 (P41) to P73. From P76 to P79, animals underwent behavioral tests. On P80, they were euthanized for blood and cerebral cortex collection. Plasma irisin levels were measured by ELISA, and cortical proteins were analyzed by Western blotting.

Sedentary rats showed higher body weight than exercised rats. While exercise increased locomotor and exploratory tendencies, it did not affect memory. Exercised animals had elevated cortical BDNF and NRF2, with no change in irisin levels CONCLUSION: Structured swimming exercise during adolescence induces cortical molecular adaptations related to neuroplasticity and redox regulation, even in the absence of overt behavioral changes, supporting the hypothesis that early-life physical activity enhances latent brain resilience mechanisms that may be critical under future physiological or pathological challenges.