After brain injury, patients show a wide range in the degree of recovery. By a variety of mechanisms, the human brain is constantly undergoing plastic changes. Spontaneous recovery from brain injury in the chronic stage omes about because of plasticity. The brain regions are altered. resulting in functionally modified cortical network. This review cnsidered the neural plasticity from cellular and molecular mechanisms of synapse formation to behavioural recovery from brain injury in elderly humans. The stimuli required to elicit plasticity are thought to be activity-dependent elements. especially exercise and learning. Knowledge about the physiology of brain plasticity has led to the development of methods for rehabilitation.