Exercise, antidepressant medications, and enhanced brain derived neurotrophic factor expression

Physical activity and antidepressant treatment have each separately been of significant interest for the management of Alzheimer's disease (AD); parti cularly the behavioral problems associated with this dementing disorder. We have found that combined antidepressant treatment and physical activity ha ve an additive, potentiating effect on BDNF mRNA expression within several areas of the rat hippocampus. During the 20-day experimental period, animal s were treated daily with imipramine (15 mg/kg) or tranylcypromine (7.5 mg/ kg) by intraperitoneal injection. Exercising rat groups were given access t o running wheels for the duration of the experiment. BDNF mRNA levels were assessed in several cell groups of the hippocampus by in situ hybridization , using a [S-35] labelled riboprobe complementary to the full-length BDNF s equence, and computer-assisted densitometry. The combination of physical ac tivity and antidepressant treatment for the 20-day period led to a signific ant potentiation of full-length BDNF mRNA levels within the dentate gyrus a nd CA 1, CA 3, and CA 4 cellular fields, above the levels obtained with eac h intervention alone. These results provide impetus for the study of physic al exercise as a potential enhancer of treatment response to antidepressant s. [Neuropsychopharmacology 21:679-682, 1999] (C) 1999 American College of Neuropsychopharmacology. Published by Elsevier Science Inc.