How Exercise Might 'Clean' the Alzheimer's Brain

A study published in Science demonstrates that physical exercise can "clean up" the hostile environments in the brains of Alzheimer's mice, allowing new neurons in the hippocampus to enable cognitive improvements, reports Scientific American . These findings suggest pharmacological agents that augment the hippocampal environment to boost cell growth and survival might be effective to revive brain health and function in people with Alzheimer's. The investigators determined exercise enhanced memory in Alzheimer's mice compared to inactive specimens due to improved adult hippocampal neurogenesis and increased amounts of BDNF, a molecule that promotes brain cell growth. The team was able to recover brain function, specifically memory, in mice with Alzheimer's but without exercise by increasing hippocampal cell growth and BDNF levels via combined genetic and pharmacological regimens. However, blocking hippocampal neurogenesis early in Alzheimer's exacerbated nerve cell health later in stages, leading to degeneration of the hippocampus and memory function. Before human clinical trials can proceed, significant research must be conducted to establish that a medication or drug could mimic the effects of exercise by "cleaning up" the brain with BDNF and stimulating neurogenesis.