Some Brain Cells Change with Age, Some Don’t: Study

Some brain cells are more susceptible to the ravages of aging than others, a new mouse study has found.

These results could shed new light on why people’s risk for dementia, Alzheimer’s disease and other brain disorders increase with age, researchers said in a study published Jan. 1 in the journal Nature.

“Aging is the most important risk factor for Alzheimer’s disease and many other devastating brain disorders. These results provide a highly detailed map for which brain cells may be most affected by aging,” Dr. Richard Hodes, director of the National Institute on Aging, said in an NIA news release.

“This new map may fundamentally alter the way scientists think about how aging affects the brain and also provide a guide for developing new treatments for aging-related brain diseases,” Hodes added.

Using advanced genetic analysis, researchers compared individual cells in the brains of 2-month-old “young” and 18-month-old “senior” mice.

Specifically, they looked at the genetic activity of cell types located in 16 different regions constituting 35% of the total volume of the mouse brains.

Researchers found that aging tends to decrease activity in genes associated with brain cells.

For example, aging reduced development of newborn neurons in at least three different parts of the brain — including neurons associated with learning and memory.

On the other hand, aging also increased the activity of genes associated with immune and inflammatory function.

Cells most sensitive to aging appeared to surround the third ventricle, a major pipeline enabling spinal fluid to pass through a brain region called the hypothalamus. The hypothalamus produces hormones that control basic body functions like temperature, heart rate, sleep, thirst and hunger.

These observations jibe with previous studies showing links between aging and metabolism, researchers said.

For example, intermittent fasting and other calorie-restrictive diets have been shown to increase life span.

That could be explained by the age-sensitive neurons found in the hypothalamus, which produces hormones that control hunger and energy production, researchers argue.

“This study shows that examining the brain more globally can provide scientists with fresh insights on how the brain ages and how neurodegenerative diseases may disrupt normal aging activity,” John Ngai, director of the National Institutes of Health’s Brain Research Through Advancing Innovative Neurotechnologies initiative, said in a news release.

More information

The Cleveland Clinic has more on the hypothalamus.

SOURCE: National Institutes of Health, news release, Jan. 1, 2025

Source: HealthDay