Published in 'Nature' magazine, the study was conducted by researchers at Harvard Medical School. Researchers compared donated brain tissue of those who lived unusually long lives to those who died in their 60s and 70s. Between the two groups, researchers found a difference in the levels of a protein called REST. REST is involved in obstructing genes that ignite activity in the brain. Those who lived longer lives had a higher level of REST than those who died before their mid 80s. There's the idea that you want to keep your brain active in later life. [According to the study,] the thing that is super unexpected is ... limiting neural activity is a good thing in healthy aging. , Michael McConnell, Lieber Institute for Brain Development, via 'Greenwich Time'. The lead study author said that aging seems to somehow make "the brain less efficient." This seems to be "harmful ... reduc[ing] lifespan as a result.". The study researchers are in the beginning stages of testing the implications of targeting REST with drugs.