Seniors are forever told to keep their minds active by tackling Sudoku or Wordle, taking up knitting or playing chess.
However, scientists believe that those people aged over 80 who remain alert have bigger brain cells – and perhaps more importantly, those cells do not contain “tau tangles”, abnormal protein formations which are a key feature of Alzheimer’s disease.
A new study led by researcher Tamar Gefen, an assistant professor of psychiatry and behavioural sciences at Northwestern University‘s Feinberg School of Medicine, Chicago, looked at “super-agers”: a select group of seniors who have the memory skills of people decades younger.
The study, published in the Journal of Neuroscience, found that super-agers have larger neurons in one memory-related region of the brain, the entorhinal cortex, than other older adults with average brains – and these neurons were even bigger than those of people 20 to 30 years younger than them.
“The remarkable observation that Super-Agers showed larger neurons than their younger peers may imply that large cells were present from birth and are maintained structurally throughout their lives,” said Prof Gefen.
“We conclude that larger neurons are a biological signature of the Super-Aging trajectory.”
Cells in the entorhinal cortex are thought to be particularly vulnerable to tau tangles, both in the normal aging process and in the early stages of Alzheimer’s. According to Prof. Gefen, shrinking of neurons in this region is a “characteristic marker” of the disease.
“We suspect this process is a function of tau tangle formation in the affected cells leading to poor memory abilities in older age.
“Identifying this contributing factor (and every contributing factor) is crucial to the early identification of Alzheimer’s, monitoring its course and guiding treatment,” she said.
