Behavioral effects of neurotrophic factor supplementation in aging

Neurotrophic factors are now recognized to play important roles in the norm al function of the mature central nervous system. This knowledge has motiva ted experiments to evaluate the potential benefits of administering neurotr ophic factors to the aged brain. This article provides a review of studies to date that have determined the behavioral effects of such treatments. Ner ve growth factor (NGF) administration appears to reliably enhance learning and memory in aged rats, while glial-derived neurotrophic factor (GDNF) cau ses some improvement in motor function. Problems associated with neurotroph ic factor administration to humans are discussed.