Preclinical Studies of Neuroplasticity Following Experimental Brain Injury

A significant challenge in the care of stroke survivors is chronic functional deficits that limit activities of daily living. Despite substantial functional recovery that can occur in the initial weeks following a stroke, over 50% of stroke survivors exhibit hemiparesis 6 months after stroke, which is particularly significant because motor recovery plateaus after 3–6 months. Because of the compelling need to reduce the burden of these chronic deficits, there is great interest in understanding the specific relationships between neuroplasticity and functional recovery. While fully understanding that these mechanisms will necessarily require clinical research in human cohorts, studies utilizing experimental animal models of brain injury are valuable because preclinical studies provide the ability to induce repeatable lesions, to control the specific environmental exposures that animals receive including the amount of rehabilitative training, to test novel therapies or medications, and to examine the structural and functional changes in cortical organization at different time points. Here we review recent advances that have informed our understanding of neuroplasticity following experimental models of brain injury. Initially, we will review the impact of rehabilitation on functional recovery. Next, we will describe the functional and structural reorganization that is associated with rehabilitation and discuss the functional relevance of specific patterns of reorganization. Finally, we will conclude by describing preclinical evidence for several novel therapies designed to enhance neuroplasticity that span various stages of development towards clinical trials.