'Sharp' older brains are not the same as younger brains

Nov 13, 2005
Brain

Researchers working with rats have found the first solid evidence that still "sharp" older brains store and encode memories differently than younger brains.

This discovery is reported by a Johns Hopkins team in the issue of Nature Neuroscience released online Nov. 13. Should it prove to apply as well to human brains, it could lead eventually to the development of new preventive treatments and therapies based on what healthy older brains are doing, rather than on the less relevant, younger brain model, according to study co-author Michela Gallagher, chair of the Department of Psychological and Brain Sciences at Johns Hopkins' Zanvyl Krieger School of Arts and Sciences.

"We found that aged rats with preserved cognitive abilities are not biologically equivalent to young rats in some of the basic machinery that neurons use to encode and store information in the brain," said Gallagher, who collaborated with Alfredo Kirkwood and Sun Seek Min of Johns Hopkins' Krieger Mind/Brain Institute and Hey-Kyoung Lee, now of the University of Maryland College Park. Lee was a research associate at the Mind/Brain Institute when the research was done.

The Gallagher-Kirkwood team compared the brains of 6-month-old rats with those of 2-year-old (considered "aged") rodents that had performed in the "young" range on various learning tasks. The aged rats' brains also were compared with those of older rats which showed declines in their abilities to learn new things. The researchers were looking at a key set of nerve cell connections that store information by modifying the strength of chemical communications at their synapses. (Synapses are the tiny gaps between nerve cells, where chemicals released by one cell act upon another.) Synaptic communication is the way brains register and preserve information to form memories.

The team found that while the older rats with compromised cognition had brains that had lost the ability to adjust the force of those synaptic communications, the older rats whose memories remained sharp still had that capacity. Interestingly enough, the successful older rats also relied far less than did younger rats on a synaptic receptor that is linked to a common mechanism for storing memories, the team learned.

"Instead, successful agers relied more than young rats on a different mechanism for bringing about synaptic change," Gallagher said. "This 'switch' could serve the same purpose – storing memories – but through a different neurochemical device."

Source: Johns Hopkins University

Explore further: Physicists create tool to foresee language destruction impact and thus prevent it

add to favorites email to friend print save as pdf

Related Stories

Google eyes Chrome on Windows laptop battery drain

18 minutes ago

Google Chrome on Microsoft Windows has been said to have a problem for some time but this week comes news that Google will give it the attention others think the problem quite deserves. Namely, Google is to ...

Security contest techies say they hacked Tesla Model S

2 hours ago

The good news: Tomorrow's cars are computers on wheels. The bad news: Tomorrow's cars are computers on wheels. Ma Jie, writing in Bloomberg News, reported this week that the Tesla Model S sedan was the target ...

Water problems lead to riots, deaths in South Africa

3 hours ago

Three babies who died from drinking tap water contaminated by sewage have become a tragic symbol of South Africa's struggle to cope with a flood of people into cities designed under apartheid to cater to ...

Recommended for you

Affirmative action elicits bias in pro-equality Caucasians

18 hours ago

New research from Simon Fraser University's Beedie School of Business indicates that bias towards the effects of affirmative action exists in not only people opposed to it, but also in those who strongly endorse equality.

Narcissistic CEOs and financial performance

Jul 24, 2014

Narcissism, considered by some as the "dark side of the executive personality," may actually be a good thing when it comes to certain financial measures, with companies led by narcissistic CEOs outperforming those helmed ...

Election surprises tend to erode trust in government

Jul 24, 2014

When asked who is going to win an election, people tend to predict their own candidate will come out on top. When that doesn't happen, according to a new study from the University of Georgia, these "surprised losers" often ...

User comments : 0