Invited Session III: Reawakening plasticity in visual cortex: Reactivating visual plasticity in adult humans

Abstract

Neuroplasticity is a fundamental property of the nervous system that is maximal early in life, within a specific temporal window called critical period. However, it is still unclear to which extent the plastic potential of the visual cortex is retained in adulthood. We have surprisingly revealed residual ocular dominance plasticity in adult humans by showing that short-term monocular deprivation unexpectedly boosts the deprived eye (both at the perceptual and at the neural level), reflecting homeostatic plasticity. This effect is accompanied by a decrease of GABAergic inhibition in the primary visual cortex and can be modulated by non-visual factors (physical exercise, motor plasticity and energy metabolism). Finally, we have found that combining short-term reverse occlusion with physical exercise promotes the long-term improvement in visual acuity and stereopsis in adult amblyopic patients. Taken together, these results challenge the classical view of a hard-wired adult visual cortex, indicating that homeostatic plasticity can be reactivated in adult humans.