People who live longer have a reduced level of neural activity – involved in everything from twitching to moving your arms and thinking – compared with those who have shorter lives. A protein known to protect the ageing brain from dementia appears to be responsible for the difference, a discovery that might pave the way for drugs to increase lifespan.
Bruce Yankner at Harvard University and his colleagues wanted to understand how gene expression in the brain – the way genes are turned on or off – affects lifespan in humans.
They studied brain tissue from hundreds of cognitively healthy humans who had died between the ages of 60 and 100. When they compared the samples from those who died before the age of 80 with those who were at least 85 when they died, the team found that those who lived the longest had fewer genes related to neural excitation switched on.
To find out if this might be a factor in lifespan, Yankner and his colleagues then used drugs to suppress neural excitation in nematode worms. The more they suppressed neural excitation, the longer the worms lived on average.
