How does brain aging occur?

Aging of the brain to a certain extent is inevitable, but not monotonous. It affects everyone, but it happens differently for different people. Slowing down the aging of the brain or its complete cessation is the ultimate goal in the search for eternal youth. Is brain aging a "slippery slope" that we have to walk? Or can we do something that will slow down the rate of extinction?

Weighing about 1.5 kg, the human brain is an amazing engineering structure consisting of about 100 billion neurons connected by trillions of synapses.

Throughout life, the human brain changes more than any other part of the body. From the beginning of brain development in the third week of pregnancy to old age, its complex structures and functions are continuously changing, and neural networks and signaling pathways are formed and destroyed.

During the first few years of life, the child's brain forms more than a million new interneuronal contacts every second. During the preschool period, the size of the brain increases fourfold and by the age of 6 reaches about 90% of the adult brain volume.

The frontal lobes, regions of the brain responsible for organizational functions such as planning, working memory and self–control, are among the last to mature and may not be fully formed until the age of 35.

Normal aging of the brain

As we age, all the systems of the body gradually fade away, the same thing happens with the brain. Forgetfulness is associated with aging. Similar "memory lapses" are often experienced by people aged 20-30 years, but they do not attach any importance to this at all.

Older people often begin to worry about forgetfulness because of the relationship between memory disorders and Alzheimer's disease. However, Alzheimer's disease and other types of dementia (dementia) are not part of the normal aging process.

Common memory disorders associated with normal aging:

• difficulties with learning something new: it may take more time to memorize new information;

• multitasking: slow processing of information can complicate the processing and scheduling of tasks performed simultaneously;

• memorizing names and numbers: strategic memory, which helps to remember names and numbers, begins to fade at the age of 20:

• Memorizing appointments: without reminders, information about appointments can be "stored" and not used.

While the results of a number of studies indicate that a third of older people experience violations of declarative memory (information about facts or events that has been stored and may be in demand), according to other studies, about 20% of 70-year-olds perform cognitive function tests as well as 20-year-olds.

Currently, researchers are working on combining fragments of a giant puzzle from the results of studies devoted to the study of the brain in order to identify the smallest changes that occur over time, eventually leading to the described changes.

General changes considered to be manifestations of brain aging:

• Brain mass: a decrease in the volume of the frontal lobe and hippocampus – regions involved in higher cognitive functions and the formation of new memories – begins at the age of 60-70 years.

• Density of the cerebral cortex: thinning of the outer surface of the brain covered with convolutions due to the destruction of synaptic contacts. Fewer contacts can contribute to slowing down cognitive processes.

• White matter: White matter consists of nerve fibers coated with myelin, united in bundles and transmitting nerve signals between nerve cells. It is believed that myelin also thinns with age, which leads to a slowdown in processing and information and the extinction of cognitive function.

• Neurotransmitter systems: researchers suggest that with age, the brain synthesizes fewer chemical signaling compounds and a decrease in the activity of dopamine, acetylcholine, serotonin and norepinephrine may contribute to the extinction of cognitive function and memory, as well as the development of depression.

Understanding the neural foundations of cognitive decline can help in the search for treatments or strategies that help slow down or prevent physical exhaustion of the brain.

Recent discoveries in the field of brain aging

Currently, a number of studies are being conducted on solving the puzzle of brain aging, and new discoveries are a frequent occurrence.

Stem cells

Recently, researchers at the Albert Einstein College of Medicine in New York in experiments on mice found that, apparently, hypothalamic stem cells regulate the rate of aging of the body.

According to Professor Dongsheng Cai, according to the observations, the number of hypothalamic nerve stem cells naturally decreases throughout the animal's life, and this decrease accelerates the aging process. However, it was also found that the effects of this reduction are reversible. Restoring the population size of these cells or the concentration of molecules produced by them allows you to slow down or even reverse various aspects of aging of the whole organism.

The introduction of hypothalamic stem cells into the brains of ordinary old mice and middle-aged mice whose stem cells were deliberately destroyed slowed down or reversed the signs of aging. The researchers claim that this work is the first step towards slowing down the aging process and curing age-related diseases.

"Super-old men" (SuperAgers)

"Super-old people" are a group of rare individuals over the age of 80 who have retained the sharpness of memory of healthy young people

Researchers at the Feinberg School of Medicine, part of Northwestern University in Chicago, compared super-old people with a control group that included ordinary people of the same age. As a result, they found that the brain of super-old people decreases in size more slowly than the brain of ordinary people, which provides a higher resistance to the deterioration of memory characteristic of old age. This indicates that the age-related extinction of cognitive functions is not inevitable.

According to associate Professor Emily Rogalski, she and her colleagues have found that super-old people are resistant to the normal rate of extinction and somehow they manage to shift the balance between life expectancy and healthy life expectancy, which allows them to enjoy the last years of their lives.

Scientists hope that studying the uniqueness of superagers will allow them to identify biological factors that contribute to the preservation and maintenance of good memory in old age.

Therapeutic approaches that help slow down brain aging

We already know the factors that accelerate the aging process of the brain. For example, obesity in middle age can accelerate brain aging by about 10 years, and the use of both conventional and dietary versions of sugary carbonated drinks correlates with rapid aging of the brain, a decrease in its total volume, deterioration of episodic (event) memory, as well as a decrease in the size of the hippocampus.

An increasing amount of scientific data testifies in favor of the fact that the lifestyle of people with the lowest rate of extinction of cognitive function and memory includes the following points:

• regular physical activity;

• engaging in intellectually stimulating activities;

• preservation of social activity;

• ability to cope with stress;

• healthy diet;

• a good dream.

The results of recent studies indicate the existence of many methods that allow a person to actively influence the state of their health and, possibly, slow down the rate of aging of the brain.

Physical exercises

One of the constantly surfacing interventions aimed at preventing age-related decline of mental abilities is physical activity.

Combining aerobic exercise and moderate-intensity weight training during 45-minute workouts, conducted as often as possible, significantly increases the intellectual brain power of people aged 50 years and older.

Also, researchers from the University of Miami found that in people over the age of 50 with low or virtually no physical activity, the deterioration of memory and thinking abilities occurred twice as fast as in people of the same age, whose physical activity can be described as moderate or high-intensity.

It has also been found that dancing has a rejuvenating effect on the brain of elderly people. According to the results of a study conducted by the German Center for the Study of Neurodegenerative Diseases in Magdeburg, while regular physical activity can reverse the manifestations of brain aging, the most pronounced effects were observed in elderly people who regularly dance.

Playing musical instruments

Specialists of the Baycrest Health Sciences Research Center at the University of Toronto have established why playing musical instruments can help older people in the fight against age-related cognitive decline and preserve the ability to listen.

They found that learning to make sounds on a musical instrument in a special way changes the electrical activity of the brain, improving a person's ability to listen and hear. Changes in brain activity indicate the formation of new neural connections to compensate for damage caused by diseases or injuries and disrupting a person's ability to perform various tasks.

According to Dr. Bernhard Ros, a hypothesis has been proposed that playing a musical instrument requires the collaboration of many brain systems, including systems that ensure a person's ability to hear, move and perceive various signals. During this study, scientists for the first time registered direct changes in brain activity after one session, which confirms the ability of the act of extracting musical sounds to have a strong effect on the brain.

Diet

The key to maintaining brain health is the diet. Recent studies have revealed a relationship between the content of omega-3 and omega-6 fatty acids in the blood with healthy aging of the brain. Another study found that the use of foods included in the Mediterranean diet and the MIND diet is associated with a reduced risk of memory impairment in older people.

Researchers from the University of Illinois have shown that the nervous reactions of middle–aged people with the highest content of lutein in the body – a compound found in green leafy vegetables such as cabbage and spinach, as well as eggs and avocados - are similar to the reactions of people much younger.

The number of people over the age of 65 is rapidly increasing all over the world and, according to statistical forecasts, in a number of countries, including the USA, over the next 40 years their number will increase by more than 2 times. Given the trend of rapid aging of the population, the study of changes in cognitive function accompanying aging, as well as the development of methods for its preservation to improve the quality of life in old age is an extremely important task.

Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on Medical News Today: What happens to the brain as we age?