Neuroprotection and Cognitive Enhancing Training Strategies

Environmental enrichment (EE) provides many neurological benefits including increased cortical weight, neuronal density, dendritic branching, and angiogenesis. These changes manifest as improved cognitive performance. In a rodent model, EE is used successfully as a therapy following traumatic brain injury (TBI) to reduce functional deficits in motor function, spatial memory, and learning. The objective of this work is to exploit the benefits of EE to identify training mechanisms that can be applied to healthy adults to enhance cognitive performance and provide neuroprotection. Two experiments were conducted. The first experiment explored EE as a neuroprotective strategy against cognitive deficits induced by traumatic neurological insults. Adult male rats were placed in an enriched environment for 15 days before medial prefrontal cortex injury via controlled cortical impact. Animals were behaviorally tested to assess memory, anxiety, and sensory neglect. Lesion-induced deficits in spatial memory were significantly attenuated in EE rats. In addition, sensory neglect was reduced in EE rats relative to non-enriched animals. The second experiment was aimed at identifying a specific mode of EE that could be realistically applied to healthy human adults to improve cognitive performance. Motor skills training (MST) is a specific form of exercise that offers neurological benefits including synaptogenesis, cerebellar angiogenesis, motor cortex strengthening and reorganization, and hippocampal neurogenesis. Adult male rats were trained for four weeks then behaviorally tested to assess memory, anxiety, and exploratory behavior. MST significantly improved subsequent performance on tasks of spatial memory. MST also reduced anxiety-like behavior. Both EE and MST experiments provide behavioral data to support non-invasive, non-pharmaceutical training techniques that provide numerous functional benefits. Various biomarkers of stress, plasticity and inflammation were explored as potential mechanisms of neuroprotection and cognitive enhancement; however no candidate proteins were identified. Future work is necessary to identify and understand target mechanisms that can lead to functional improvements. This work provides simple, inexpensive training solutions to both military and civilian populations that can be used to lessen the severity of TBI in populations at increased risk of injury due to occupational hazards.