Scientists identify role of brain activity in lifespan

According to a study, brain activity would have an impact on human aging and lifespan, in addition to known factors such as genetics, lifestyle or environment. The study, based on data from human brains and mice (among others…) is the first showing that the nervous system influences longevity.

The brain is made up of billions of nerve cells: neurons. These form the network of the nervous system, which extends to nerves, muscles or glands. Startling new research, from the Blavatnik Institute at Harvard Medical School, explains that the secret to living longer may lie in this neural activity, which speeds up and slows down with age.

The impact of excessive neural activity

The study published last Wednesday in the journal Nature suggests that excessive neural activity in the brain is linked to a shorter lifespan, while suppressing this overactivity increases a human’s longevity. This discovery is still too recent and requires more research before implying concrete recommendations.

The link between nervous system activity and longevity is not entirely surprising. The mechanism that controls brain arousal is closely linked to the mechanism that controls metabolism, which has long been linked to lifespan, says study co-author Dr. Bruce Yanker, professor of genetics and neurology at Harvard. Medical School.

But the fact that less brain activity was associated with longevity seemed at first “illogical” to Bruce Yanker, who assumed that an active brain would be linked to better health and vitality.

Neural excitation affects lifespan

Bruce Yankner and his colleagues began their research by analyzing gene expression patterns: the extent to which various genes are turned on and off in brain tissue. This information was collected by researchers at Harvard Medical School who examined hundreds of healthy brains of deceased elderly people between the ages of 60 and 100 who were “cognitively intact”, i.e. without dementia. The research revealed some striking differences: “People between the ages of 85 and 100 had significantly less expression of genes linked to neural overactivity than those who died between the ages of 60 and 80,” said Bruce Yankner.

Then the scientists wondered if this was a correlation or causation effect. Indeed, does this disparity in neural arousal simply occur because of factors more determining lifespan, or do arousal levels directly affect longevity? And if so, how?

To go further, the team conducted a series of experiments, including genetic, cellular and molecular biology tests, in the model organism, Caenorhabditis elegans (a small, transparent, non-parasitic worm), and on genetically modified mice. Additional analyzes of brain tissue from people who have lived for more than a century have also been performed. Results revealed that altering neural excitation did indeed affect lifespan

The power of REST protein

The key to this true signaling cascade appears to be a protein called REST, previously shown by Bruce Yankner’s work to be able to protect aging brains from dementia and other stressors. According to the authors, such excessive activity could manifest itself in many ways, ranging from muscle twitching to a change in mood or even thought.

This protein, also known to regulate genes, also inhibits neuronal excitation. Indeed, blocking the REST protein, or its equivalent in animal models, resulted in higher neuronal activity and earlier deaths, while boosting the REST protein had the opposite effect. Additionally, scientists found that human centenarians had significantly more REST proteins in the nuclei of their brain cells than people who died between the ages of 70 and 80. “It appears that the REST protein and metabolism could work in tandem to prevent premature death,” said Bruce Yankner.

“It was extremely exciting to see how all these data sources converged,” said Monica Colaiácovo, study co-author and professor of genetics at HMS.

The impact of habits and behaviors on neural activity

The new study does not yet specify whether and how a person’s thoughts, personality or behavior can affect an individual’s longevity. “An exciting future area of ​​research will be to determine the link between these findings and higher brain functions of such order,” Yankner said.

In any case, according to the researchers, these results raise the possibility that certain drug treatments, such as those targeting rest, can prolong lifespan by modulating neuronal activity and could well help in the design of new treatments against diseases. diseases involving neuronal overactivity: Alzheimer’s or bipolar disorders. In addition to promising research, behavioral treatments like meditation also have a future!

According to Bruce Yanker, this study is a promising step in understanding how “a person’s thoughts, personality, and behavior affect their overall health and longevity.”