Exercise may slow development of Alzheimer's
In a recent study, where non-exercising mice were given a protein produced by exercising mice, researchers discovered that doing so activated genes that help preserve brain health, while also boosting the growth of new nerves in areas of the brain linked to learning and memory.
As a result, these findings could help lead to the development of a drug that improves cognitive function in the aging brains of older adults. Such a drug could also help slow down the advancement of brain declining diseases, such as Alzheimer's and Parkinson's.
It has long been known that endurance exercise can help improve brain function, particularly in older people. However, until this latest study, the underlying molecular mechanisms remained unknown.
In an earlier study, Dr. Bruce Spiegelman, from Dana-Farber Cancer Institute and Harvard Medical School in Boston, and his research team had already discovered that the protein, called FNDC5, is released into the bloodstream (as a variant called irisin) as a result of muscular exertion.
For this new study, published in the latest online issue of the journal Cell Metabolism, Dr. Bruce Spiegelman and his team monitored the effect of endurance exercise on mice that voluntarily ran on an exercise wheel for 30 days.
As a result, they discovered that endurance exercise increased production of FNDC5, which effectively activated genes that boosted a brain-protective protein (BDNP) in the hippocampus, a region of the brain linked to learning and memory that is also just one of two regions in the adult brain that can grow new nerve cells.
Because exercise increases the effect of BDNF in the hippocampus, where brain cells are preserved and growth of new nerves are promoted, it can therefore give learning and memory a boost.
Until now, however, it wasn’t fully understood what actually tied exercise to BDNF at the molecular level, which is important to know if you’re going to develop new drugs that have the same effect.
Accordingly, this is the first study to discover that there is a molecular pathway linking exercise to increased BDNF activity and FNDC5, but the researchers reveal that there may also be other pathways to discover as well.
For part of the study, the research team demonstrated that synthetically boosting FNDC5 without the help of exercise had the same effect.
“What is exciting is that a natural substance can be given in the bloodstream that can mimic some of the effects of endurance exercise on the brain,” Spiegelman explained. But he also warns that more studies are needed to find out whether giving mice FNDC5 actually leads to improved brain function.
Source: Exercise Induces Hippocampal BDNF through a PGC-1[alpha]/FNDC5 Pathway; Christiane D. Wrann, James P. White, John Salogiannnis, Dina Laznik-Bogoslavski, Jun Wu, Di Ma, Jiandie D. Lin, Michael E. Greenberg, Bruce M. Spiegelman; Cell Metabolism (published online October 10, 2013)