Cerebral restorative plasticity from normal ageing to brain diseases: a "never ending story".

Brain plasticity can be considered the main result of brain communication with the 'external' and 'internal' environment. Learning new skills as well as endogenous brain function recovery following a lesion are based on neural plasticity, a dynamic phenomenon occurring in response to modification of conscious and pre- or sub-conscious experiences as they progressively stabilize at the synaptic and neural networks level. In spite of previously accepted theory, brain plasticity occurs throughout lifespan being an inner property of the system. Different models of brain plasticity are examined in relation with different modifications of the CNS: healthy brain ageing, neurodegenerative disorders, ischemic stroke and multiple sclerosis. A clarification of advantageous as well as of aberrant brain plasticity mechanisms in pathological conditions may help to improve the development of rehabilitation methods to better address and facilitate such processes.