A team of researchers has managed to identify the key areas of the brain where the first cellular changes related to aging appear.
- Researchers in the United States have produced a detailed cell atlas of brain aging by analyzing millions of cells in young and elderly mice.
- They discovered that certain cells, including glial cells and hypothalamus neurons, are undergoing major changes with age. Immune activity increases and myelin producing cells see their effectiveness reduced.
- These alterations affect essential functions such as metabolism and sleep. Although carried out in mice, this research offers a basis for developing therapies against human brain aging.
What if we could precisely identify the place where aging begins in the brain? It is the successful bet by researchers from the Allen Institute, in the United States, who have just produced the first detailed cellular atlas of brain aging. By studying millions of individual cells, they managed to highlight the key areas where the first age -related changes appear.
Precise cartography of brain changes
The brain can be compared to a huge metropolis, made up of thousands of “districts”, each populated by cells with specific functions. Until now, a precise census of the evolutions of these districts were lacked over time. The new study, published in the journal Naturefills this vacuum by examining cells taken from young (2 months) and elderly (18 months) mice – age groups equivalent to human brains of young adults and mature adults.
By analyzing 16 regions of the brain (representing about 35 % of its total volume) scientists identified 847 types of distinct cells. They discovered that certain populations, including support cells called glial cells, were particularly sensitive to aging. These changes appeared mainly around the third ventricle, in the hypothalamus, an area which controls essential functions such as hunger, body temperature, sleep and hormonal production.
As the brain is aging, its immune activity is intensifying, in particular in microglial cells, responsible for cleaning and brain immune defense. The macrophages associated with the borders of the brain also have increased inflammatory activity. These changes suggest that these cells must work harder to maintain brain health with age.
A roadmap for future therapies?
That’s not all: aging also affects cells that produce myelin, this essential insulating substance for communication between neurons. Like a poorly protected electric wire, these neural circuits may work less effectively.
The researchers have finally identified specific groups of neurons in the hypothalamus, responsible for the regulation of appetite, metabolism and energy consumption, which undergo drastic modifications with age. This also corroborates studies linking food factors such as intermittent fasting or caloric restriction to longevity.
“Aging is the main risk factor for devastating diseases such as Alzheimer’s, explain the researchers in a press release. These results offer a detailed card of brain cells most vulnerable to aging. “ This discovery could open the way, according to them, to new therapies to preserve brain health throughout life.
