Neuroplasticity: an appreciation from synapse to system.

Objective: To integrate our functional knowledge in neurorehabilitation with a greater understanding of commonly held theories and current research in neuroplasticity.

Design: Literature review.

Setting: Not applicable.

Participants: Animal and human research.

Interventions: Interventions specific to application in humans: constraint-induced movement therapy, transcranial magnetic stimulation, and transcranial direct current stimulation.

Main Outcome Measures: Cortical excitability, blood oxygen level-dependent signal, and functional outcomes.

Results: There is increasing evidence elucidating the cellular and molecular mechanisms of plasticity of the nervous system including growth, modification, degradation, and even death of neurons. Some of these mechanisms directly correlate with therapy-induced behavioral changes, and all provide an understanding of the response of the nervous system to altered inputs. The understanding of neural correlates of behavior can then form the foundation for more productive, comprehensive interventions.

Conclusions: The focus of recent research surrounds translational projects aimed at enhancing clinical outcomes. Knowledge of mechanisms underlying this adaptability is the foundation for our treatments, diagnoses, and prognoses. The increasing understanding of the mechanisms underlying neuroplasticity can guide, direct, and focus the practice of current and future therapies to greater efficacy and better functional outcomes in clinical rehabilitation.