Neurobiological bases of rehabilitation

The adult brain maintains the ability to reorganise throughout life. Motor cortical representations can reorganise rapidly in response to different stimuli. Important mechanisms for mediating reorganisation in the cerebral cortex involve the unmasking of existing, but latent, horizontal connections and modulation of GABAergic inhibition and synaptic efficacy. Interfering with these mechanisms can either block or enhance reorganisational processes. Following injury to the motor cortex alterations of the neurotransmitter system regulation, recruitment of additional undamaged brain areas even remote from the injury, and anatomical alterations such as axonal sprouting and synaptogenesis in the brain tissue surrounding the lesion or in the homotopic motor area of the non-affected hemisphere occur. The understanding of cortical reorganisation may enable us to apply principles of plasticity to the rehabilitation of patients after brain injury.