When we exercise vigorously, our brains release large amounts of feel-good hormones called endorphins. In addition to the feel-good hormones released by exercise, exercise also produces a hormone that boosts memory and helps prevent alzheimer's disease, a new study suggests. The study was led by professor Arancio at Columbia University in the United States
A few years ago, exercise experts discovered a hormone called irisin that is released into the circulatory system during exercise. Initial studies showed that irisin mainly plays a role in energy metabolism. But the new study found that the hormone also promotes the growth of neurons in the hippocampus, an area of the brain important for learning and memory.
Arancio said: "this finding may explain why exercise improves memory and the potential for a protective effect in brain diseases such as alzheimer's."
In the new study, Arancio led an international team of researchers that first looked for a link between irisin and alzheimer's disease in the population. Using tissue samples from brain Banks, they found irisin in the hippocampus, where levels of the hormone are reduced in alzheimer's patients. However, electrophysiological and behavioral analysis showed that the increase of FNDC5/ irisin in the brain of alzheimer's mouse model can significantly improve the plasticity and memory of synapses.
What is the mechanism behind this? The researchers concluded that FNDC5 / irisin reduces the expression of synaptic related genes induced by amyloid beta oligomers and also activates transcriptional inhibition in hippocampal neurons associated with alzheimer's disease.
In these models, irisin also prevents loss of dendritic spines from exposure to amyloid beta oligomers, possibly by reducing the binding of amyloid beta oligomers to neurons and reducing the level of soluble Aβ42. Finally, irisin also stimulates the CAMP-PKA-CREB signaling pathway, which is responsible for memory formation.
The team also found reduced levels of FNDC5/ irisin in normal elderly people with brain and lewy body dementia, suggesting that the hormone has a broader impact on brain disorders and aging. Secondly, FNDC5/ irisin, as a key mediator of maintaining synaptic function and memory through exercise, may be an alternative treatment for elderly alzheimer's patients.
The researchers said this was only the result of animal studies, and that it would take at least three to four years of research before irisin could be used for clinical treatment in humans.