Only neurons will survive: How to repair nerve cells
It used to be said that nerve cells do not regenerate.- However, new research confirms that we can not only “waste” nerves. Neurogenesis - or the process of formation of nerve cells - has recently been discovered, so scientists have no complete picture of it, and the data often diverge. The difficulty lies in the fact that studying the human brain is not easy for obvious reasons - medical and ethical - and research is still being conducted mainly in rodents. Nevertheless, we tried to figure out what is known about neurons today.
Hard way to the brain
Unlike cells of other tissues, neurons are not able to divide, so scientists have long thought that we are limited to the stock inherited at birth. Later it turned out that new neurons still appear during life - they arise from stem cells that can turn into almost any. The brain also has its stock of such universal assistants. So far, the scientific community has not determined the exact number of departments in which new neurons are formed. It is known that they are formed in the subventicular zone (a thin layer of cells along the ventricles of the brain) and in the dentate gyrus of the hippocampus, a part of the brain that is responsible for emotions and memory.
A significant part of fresh nerve cells quickly dies - due to the microenvironment, the work of neurotransmitters, the activity of certain proteins and other brain chemistry. In addition, for the newborn nerve cell to exist, it is necessary to form connections (synapses) with others: solitary floating neurons are not needed by the brain. On average, about 700 new surviving neurons are embedded into the brain structure every day.
Neurons are dying - and that's fine.
The brain of an adult consists of about 86 billion neurons - but at birth they are much more. According to an employee of the laboratory of age-related psychogenetics at the Psychological Institute of Radioactive Waste, a psychophysiologist Ilya Zakharov, by the end of the first year of life, the number of surviving neurons is two times less than at birth. The development of the brain most actively occurs in the first three years of life — at this time, neural connections are formed, in which all intellectual and emotional experience, skills formed and fixed remain. Everything that a child sees, touches, smells, tastes, or learns something else, is recorded as a new synaptic connection. In the same way, the brain will develop all its life, but it makes the main leap in early childhood.
At the same time, the brain tries to restore order and destroys part of the nerve cells that did not have time to enter into relations with others, considering them to be useless. The so-called apoptosis occurs - programmed cell death. This is a normal process, in which there is nothing scary.
One for all
According to Zakharov, although stress can contribute to cell death due to the toxic effect of certain hormones and neurotransmitters, such a loss is also not critical. "Nerve-disrupting" stress is generally a very vague concept. “Everyone knows what stress is, and no one knows what it is,” wrote Hans Selye, the founder of the theory of stress.
Alexey Payevsky, the editor-in-chief of the Neuronews website, notes that a neuron is a strong cell itself, and when it comes to death, it is not a single emotional shock that is meant, but the so-called oxidative stress - a shift of chemical reactions in the body towards oxidation. Chronic fatigue syndrome, prolonged depression, neurodegenerative diseases (for example, Parkinson’s disease or Alzheimer's disease), injuries and other factors can lead to it.
It’s not worth worrying about the stressful loss of nerve cells because there are ways to compensate for it - first of all, it is plasticity of the brain. A single neuron can form a multitude of synaptic connections — usually about ten thousand of them — and, if necessary, take on the functions of a lost comrade. For example, signs of Parkinson's disease will begin to appear only when more than 90% of the nerve cells of the brain die. It turns out that one cell can work for nine.
Learning and enjoyment
Scientists agree that the brain is harmed by the same processes that do not benefit the rest of the body: depression, chronic fatigue, lack of sleep, unbalanced diet, too much alcohol. These factors, most likely, prevent the formation of new ones. It is logical that the opposite effect should be carried out by classes that are useful in general - and, ideally, also pleasant.
The formation of new neurons and their integration is highly dependent on the microenvironment, including neurotransmitters — special substances that help cells transmit signals to each other; These signals can be both exciting and inhibiting. There are many neuromediators, and they include, for example, the well-known dopamine and serotonin - they have a positive effect on the formation of neural connections. Activities that promote the release of dopamine or serotonin, can contribute to neurogenesis; it includes all that is pleasant or useful for the survival and procreation of the race: food, laughter, love, sex, and also the acquisition of new knowledge.
Zakharov specifies that it is still difficult to select a specific neurotransmitter that is guaranteed to influence neurogenesis, but it can be said for sure that obtaining fresh information plays a positive role. Cognitive processes and experience not only contribute to the emergence of new neurons, but also "help" them to survive - learning involves cells in the creation of new chains.
In addition, the so-called enriched environment has a good effect on neurogenesis. The mice that lived in cells with their fellows, as well as a variety of interesting objects - from a running wheel, toys and labyrinths to the most diverse food, had more neurons than rodents who lived alone in empty cages. In the world of people, a rich environment implies a “human” version of all that was in mice: we need social contacts, entertainment, solving various problems, physical activity, a rich diet and making discoveries.
Sport
In studies conducted again in mice, it turned out that the more the animal "goes in for sports" (runs around the wheel) in childhood and adolescence, the longer it maintains mental clarity in old age. It was also noted that the combination of physical activity with mental contributes to a better memorization and assimilation of knowledge. These effects are associated with cognitive reserve, which theoretically affects neurogenesis in adults - although the mechanisms of these processes are not yet clear.
It was after these experiments that they began to say that to maintain the health of the brain, you need to run - but, probably, the physical activity itself is of fundamental importance, and not its specific form. Another thing is that it is impossible to get the mouse to do yoga or dancing in order to study their effect on the brain. Ilya Zakharov says that for people who lead an active lifestyle, brain aging slows down, because sport is also experience, the constant acquisition and development of skills. And it also affects the health of the brain physically - improves blood circulation, promotes the delivery of nutrients to the nervous system.
Sleep and food
It is believed that in a dream the connections between neurons become stronger, and all the information accumulated during the day is being ordered - something like a hard disk defragmenting occurs. Lack of sleep (chronic sleep deprivation and stable insomnia) not only interferes with neurogenesis, but also reduces the positive effect of learning processes - the brain simply does not have time to bring the knowledge gained in order.
Recommendations for a balanced and varied diet relevant to the nervous system. Omega-3 fatty acids are one of the main substances that enhance the formation of new nerve cells; they also have a positive effect on spatial memory and performance, not to mention heart health. These compounds must be sought in fatty fish and seafood - from shrimp to algae. The beneficial effect is attributed to substances such as flavonoids (they are rich in green tea, citrus fruits, cocoa, blueberries) and resveratrol (found in grapes, red wine).
Antidepressants
This option is not recommended for prophylactic purposes - that is, simply to stimulate neurogenesis. But it has long been proven that depression affects both existing nerve cells and the formation of new ones. Antidepressants, in addition to the obvious effect of mood correction, have a beneficial effect for neurogenesis. Among other things, they contribute to the development of neurotransmitters - and they, in turn, improve the formation of neurons and psychological well-being.
Photo:Ioannis Pantzi - stock.adobe.com, goir - stock.adobe.com, Ozon
