Dr. Bruce Spiegelman of the Dana-Farber Cancer Institute and Harvard Medical School has identified the exercise induced brain chemical and the pathway the chemical functions in to improve cognition and reduce neurological diseases according to an article in the Oct. 10, 2013, edition of the journal Cell Metabolism.
A molecule called irisin is produced in the brain during endurance exercise. Irisin was shown to activate genes involved in learning and memory and to minimize the symptoms of neurological diseases like depression, stroke, and Alzheimer's disease in mice.
The scientists found that a molecule called FNDC5 and its cleavage product, irisin, are elevated in the brain by endurance exercise. The increase in irisin levels produced by endurance exercise increases the levels of a growth factor named brain-derived neurotrophic factor (BDNF).
Mice genetically altered to produce low levels of irisin demonstrated low blood levels of BDNF.
Increased levels of irisin sped up the transport of BDNF across the blood brain barrier and activated genes involved in cognition.
The researchers are attempting to synthesize a stable form of the irisin protein that can be given to people as an injection or in a pill form. This development could prevent the growth of neurological diseases in older people and young people who refuse to exercise.