Healthy and extraordinary brains reveal clues to aging well

By Paige Bartlett

AAAS cognitive aging session

Video games may be a useful tool to improve cognition in older individuals. Photo: University of California, San Francisco, Neuroscape Center.

AUSTIN, Texas — People are living longer than ever, but are these added years good ones? Research has provided drugs and lifestyle recommendations about diet and exercise that let us live longer, yet many people spend those extra years suffering from dementia.

“We’ve gotten quite good as a medical community at increasing the lifespan, but this is coming at a cost,” said Emily Rogalski, a neuroscientist from Northwestern University’s Feinberg School of Medicine, during a Feb. 18 session at the American Association for the Advancement of Science (AAAS) annual meeting.

Much of the research on quality of life in old age focuses on what’s going wrong in the brains of people with dementia and Alzheimer’s disease. However, new research examining the brains and lives of people who age well illuminates possible reasons some people experience dementia and cognitive decline, while others don’t.

Rogalski’s work with “SuperAgers” — rare individuals over 80 who have a memory equivalent to people in their 50s and 60s — uncovers some of the biological and psychosocial factors that make them exceptional.

“SuperAgers represent a group where there’s more of a balance, where they’re living long and living well,” Rogalski said. Her team found several differences between SuperAgers and typical, healthy agers.

While most aging individuals have thinning of the outer layer of the brain, SuperAgers don’t. This layer, called the cortex, underlies many brain functions including higher processes, such as language and logical thinking, although the implications of its thinning aren’t yet clear.

The SuperAgers also tend to have stronger social ties, reporting more positive relationships on scales of psychological well-being. This echoes other research demonstrating that strong, beneficial social connections lead to longer and healthier lives.

Understanding why SuperAgers differ from their peers might lead to drug, lifestyle or technological interventions to slow or even stop cognitive decline in the elderly.

A video game designed to improve cognitive abilities by forcing players to multitask is one example, developed by University of California San Francisco neuroscientist Adam Gazzaley and his team. In the game, players simultaneously steer a car and react to different shapes that appear on screen. Depending on how it fares in clinical trials, the game could treat a number of disorders associated with aging, including mild cognitive impairment and geriatric depression.

And in the 90+ healthy aging study among nonagenarians, University of California, Irvine neuroscientist Claudia Kawas’ team discovered a protein associated with pathological aging in healthy brains at relatively high rates.

Known as beta-amyloid, the protein forms clusters in the brain known as plaques. These plaques are one of the characteristic features of Alzheimer’s, and one of the suspected causes. When looking at donated brains from deceased study participants, about 60% of individuals with dementia had these plaques. However, in participants without any signs of dementia almost 40% also had these plaques.

Perhaps protective factors are at work, Kawas said. For example, the APOE gene influences the development of Alzheimer’s disease. One version of the gene increases the likelihood of developing the disease, while another version seems to protect against it.

More recently, the 90+ study observed amyloid plaques in participants who were still alive, via brain scans. Results have been mixed, but the most recent analysis suggested that healthy individuals with high levels of amyloid plaques showed no difference in cognitive decline compared to healthy individuals with little to no amyloid plaques.

“I think that we really need to change our thinking, ” Kawas said, and should start looking more closely at other causes of dementia beyond the amyloid plaques.

Unlocking the process of how to age well will boost quality of life in the golden years. Not only will this research expand our knowledge of dementia and Alzheimer’s, but it could also hint at new therapies to limit or even stop cognitive decline.

“When we forget where our car keys are, and we can’t remember a name, we get kind of used to that and say ‘Oh, I’m just getting older’,” Rogalski said. “But perhaps we’re setting our expectations a bit too low.”

Paige Bartlett is a senior at the University of Washington majoring in neurobiology and minoring in English. A staff writer at UW’s student newspaper, The Daily, Bartlett is also the editor-in-chief of Grey Matters, a UW undergraduate journal covering neuroscience for a general audience. Reach her at paige@bartletts.net.

Feb. 22, 2018

Comments

Awesome article from one UW undergrad to another!

Amplify the signal