Source of cognitive decline in aging brains

January 7, 2009

(PhysOrg.com) -- As people age, memory and the ability to carry out tasks often decline. Scientists looking for ways to lessen that decline often have focused on the "gray matter" -- the cortical regions where high-level functions such as memory are located.

But there are signs that the search may need to be expanded: A new study by MIT neuroscientists has found that memory and cognitive impairments were more associated with loss of brain "white matter," which forms connections within and between brain regions.

"Historically a lot of people have put their eggs in the gray matter basket. This study suggests that what might really be important are the connections and the integrity of the connections," said David Ziegler, a graduate student in the Department of Brain and Cognitive Sciences and lead author of a paper on the work that appeared in the online edition of Neurobiology of Aging in December.

Enhancing white matter in older people through drug intervention or changes in diet or cardiovascular fitness could offer a new approach to countering some of the cognitive declines that are typical of advanced age, said Ziegler, who works in the laboratory of Suzanne Corkin, professor of behavioral neuroscience.

The study is the first to examine changes in both white and gray matter and correlate those changes with declines in memory and cognition, said Ziegler.

White matter consists of bundles of neuronal axons that form connections between neurons, allowing brain regions to communicate with each other. Gray matter, or cortex, is where the bodies of neurons are located.

The researchers used a new MRI brain scanning technique, known as diffusion tensor imaging, to study the white and gray matter of two groups of healthy adults -- one group aged 18 to 30, and the other aged 60 to 85.

They also measured subjects' performances in three categories -- memory for specific events; memory for vocabulary; and ability to plan and carry out everyday tasks.

In the older subjects, the researchers found a correlation between decline in cognitive performance and deterioration in the white matter of the frontal brain regions, where planning and executive functions are located. Similarly, deterioration of white matter in the parietal and temporal lobes, which are involved in memory, was associated with memory impairment.

"Thus, age-related impairments in specific cognitive capacities may arise from degenerative processes that affect the underlying connections of their respective neural networks," the researchers wrote in their paper.

Other authors of the paper are former MIT postdoctoral associates Olivier Piguet, who is now at the Prince of Wales Medical Research Institute, Sydney, Australia; David Salat, now at the Athinoula A. Martinos Center for Biomedical Imaging; and former MIT laboratory technicians Keyma Price and Emily Connally.

Provided by MIT

Explore further: Music training strengthens children's brains, decision-making network

Related Stories

Music training strengthens children's brains, decision-making network

November 14, 2017
If the brain is a muscle, then learning to play an instrument and read music is the ultimate exercise.

Elementary neural processing units that tile the mouse brain

November 6, 2017
A hexagonal lattice organizes major cell types in the cerebral cortex, researchers in Japan have discovered. The pattern repeats across the brain, with similar cells synchronizing their activity in 'microcolumns', which could ...

Anesthesia and surgery during infancy may impact white matter during childhood

August 24, 2017
General anesthesia and surgery in otherwise healthy infants under the age of 1 year old could be associated with decreases in the amount of white matter in the brain, as well as reductions in the remaining white matter's ...

Menopause triggers metabolic changes in brain that may promote Alzheimer's

October 10, 2017
Menopause causes metabolic changes in the brain that may increase the risk of Alzheimer's disease, a team from Weill Cornell Medicine and the University of Arizona Health Sciences has shown in new research.

When making decisions, monkeys use different brain areas to weigh value and availability

August 30, 2017
There are many calculations at play in our minds when we make a decision, whether we are aware of them or not. Seventeenth-century mathematician Blaise Pascal first introduced the idea of expected value, which is reached ...

MRI shows gray matter myelin loss strongly related to MS disability

September 10, 2014
People with multiple sclerosis (MS) lose myelin in the gray matter of their brains and the loss is closely correlated with the severity of the disease, according to a new magnetic resonance imaging (MRI) study. Researchers ...

Recommended for you

Age and gut bacteria contribute to multiple sclerosis disease progression

November 17, 2017
Researchers at Rutgers Robert Wood Johnson Medical School published a study suggesting that gut bacteria at young age can contribute to multiple sclerosis (MS) disease onset and progression.

Molecular guardian defends cells, organs against excess cholesterol

November 16, 2017
A team of researchers at the Harvard T. H. Chan School of Public Health has illuminated a critical player in cholesterol metabolism that acts as a molecular guardian in cells to help maintain cholesterol levels within a safe, ...

Ancient enzyme could boost power of liquid biopsies to detect and profile cancers

November 16, 2017
Scientists are developing a set of medical tests called liquid biopsies that can rapidly detect the presence of cancers, infectious diseases and other conditions from only a small blood sample. Researchers at The University ...

Prototype ear plug sensor could improve monitoring of vital signs

November 16, 2017
Scientists have developed a sensor that fits in the ear, with the aim of monitoring the heart, brain and lungs functions for health and fitness.

FDA to crack down on risky stem cell offerings

November 16, 2017
U.S. health authorities announced plans Thursday to crack down on doctors pushing stem cell procedures that pose the gravest risks to patients amid an effort to police a burgeoning medical field that previously has received ...

Strain of intestinal bacteria can stop high-salt diet from inducing inflammatory response linked to hypertension

November 15, 2017
Microbes living in your gut may help protect against the effects of a high-salt diet, according to a new study from MIT.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.