Exercise Can 'Clean Up' Alzheimer's Environment

A study by Massachusetts General Hospital (MGH) researchers published in Science found neurogenesis in the brain structure in which memories are stored can improve cognitive function in a mouse model of Alzheimer's, reports the Harvard Gazette . They determined cognition can be impeded by the hostile inflammatory environment in the brains of persons with Alzheimer's, and physical exercise can "clean up" that environment, aiding the survival of new neurons and improving cognition. Experiments revealed that adult hippocampal neurogenesis (AHN) could be induced in the mouse model either via exercise or treatment with drugs and gene therapy. Specimens in which AHN was induced by exercise exhibited improved cognitive performance and lower levels of beta-amyloid. "Newly born neurons, induced by drugs and gene therapy, were not able to survive in brain regions already ravaged by Alzheimer's pathology, particularly neuroinflammation," notes MGH's Rudolph Tanzi. According to MGH Professor Se Hoon Choi, "exercise also turned on the production of brain-derived neurotrophic factor, or BDNF — known to be important for the growth and survival of neurons — which created a more hospitable brain environment for the new neurons to survive. By combining drugs and gene therapy that both induced neurogenesis and increased BDNF production, we were able to successfully mimic the effects of exercise on cognitive function."