Antioxidants Prevent the Effects of Physical Exercise on Visual Cortical Plasticity

Physical activity has been recently shown to enhance adult visual cortical plasticity, both in human subjects and animal models. While physical activity activates mitochondrial oxidative metabolism leading to a transient production of reactive oxygen species, it remains unknown whether this process is involved in the plasticizing effects elicited at the visual cortical level. Here, we investigated whether counteracting oxidative stress through a dietary intervention with antioxidants (vitamins E and C) interferes with the impact of physical exercise on visual cortex plasticity in adult rats. Antioxidant supplementation beyond the closure of the critical period blocked ocular dominance plasticity in response to eye deprivation induced by physical activity in adult rats. Antioxidants exerted their action through a mithormetic effect that involved dampening of oxidative stress and insulin-like growth factor 1 (IGF-1) signaling in the brain.