COTMAN, C.W., and C. ENGESSER-CESAR. Exercise enhances and protects brain function. Exerc. Sport Sci. Rev., Vol. 30, No. 2, pp. 75-79, 2002. Physical activity, in the form of voluntary wheel running, induces gene expression changes in the brain. Animals that exercise show an increase in brain-derived neurotrophic factor, a molecule that increases neuronal survival, enhances learning, and protects against cognitive decline. Microarray analysis of gene expression provides further support that exercise enhances and supports brain function.