Reorganization of motor cortex and impairment of motor performance induced by hindlimb unloading are partially reversed by cortical Igf-1 administration.

•Sensorimotor restriction affects organization of motor cortex.•Sensorimotor restriction induces a degradation of motor performance.•IGF-1 partially reverses cortical shrinkage and decrease in cortical excitability.•IGF-1 prevents the degradation of spontaneous activity.•IGF-1 has only a weak effect on challenged and overground locomotion.