Neural connections in the brain cause complex behavior. Neurons are small computing machines that can only exert influence by networking.
Control of the simplest elements of behavior (for example, reflexes) does not require a large number of neurons, but even reflexes are often accompanied by a person's awareness of the triggering of a reflex. Conscious perception of sensory stimuli (and all higher functions of the nervous system) depends on a huge number of connections between neurons.
Neural connections make us who we are. Their quality affects the functioning of internal organs, intellectual abilities and emotional stability.
Wiring
Neural connections of the brain - the wiring of the nervous system. The work of the nervous system is based on the ability of a neuron to perceive, process and transmit information to other cells.
Information is transmitted through a nerve impulse. The behavior of a person and the functioning of his body is completelydepends on the transmission and receipt of impulses by neurons through processes.
A neuron has two types of processes: an axon and a dendrite. The axon of a neuron is always one, it is along it that the neuron transmits impulses to other cells. It receives an impulse through dendrites, of which there may be several.
Many (sometimes tens of thousands) axons of other neurons are "connected" to the dendrites. Dendrite and axon contact via synapse.
Neurons and synapses
The gap between the dendrite and the axon is the synapse. Because the axon is the "source" of the impulse, the dendrite is the "receiver", and the synaptic cleft is the place of interaction: the neuron from which the axon comes is called presynaptic; the neuron from which the dendrite comes is postsynaptic.
Synapses can form between an axon and a neuron body, and between two axons or two dendrites. Many synaptic connections are formed by the dendritic spine and the axon. Spines are very plastic, have many shapes, can quickly disappear and form. They are sensitive to chemical and physical influences (injuries, infectious diseases).
In synapses, information is most often transmitted through mediators (chemical substances). The mediator molecules are released on the presynaptic cell, cross the synaptic cleft, and bind to the membrane receptors of the postsynaptic cell. Mediators can transmit an excitatory or inhibitory (inhibitory) signal.
Neural connections of the brain are the connection of neurons throughsynaptic connections. Synapses are the functional and structural unit of the nervous system. The number of synaptic connections is a key indicator for brain function.
Receptors
Receptors remember every time they talk about drug or alcohol addiction. Why should a person be guided by the principle of moderation?
The receptor on the postsynaptic membrane is a protein tuned to mediator molecules. When a person artificially (with drugs, for example) stimulates the release of mediators into the synaptic cleft, the synapse tries to restore balance: it reduces the number of receptors or their sensitivity. Because of this, the natural concentration levels of neurotransmitters in the synapse cease to have an effect on neural structures.
For example, people who smoke nicotine change the susceptibility of receptors to acetylcholine, desensitization (decrease in sensitivity) of receptors occurs. The natural level of acetylcholine is insufficient for receptors with reduced sensitivity. Because acetylcholine is involved in many processes, including those associated with concentration and comfort, a smoker cannot get the beneficial effects of the nervous system without nicotine.
However, the sensitivity of receptors is gradually restored. Although this may take a long time, the synapse returns to normal and the person no longer needs third-party stimulants.
Development of neural networks
Long-term changes in neuralconnections occur in various diseases (mental and neurological - schizophrenia, autism, epilepsy, Huntington's, Alzheimer's and Parkinson's diseases). Synaptic connections and internal properties of neurons change, which leads to disruption of the nervous system.
The activity of neurons is responsible for the development of synaptic connections. "Use it or lose it" is the principle behind the brain's neural networks. The more often neurons "act", the more connections between them, the less often, the less connections. When a neuron loses all of its connections, it dies.
Some authors express other ideas that are responsible for regulating the development of neural networks. M. Butz links the formation of new synapses with the brain's tendency to maintain a "usual" level of activity.
When the average level of activity of neurons falls (for example, due to injury), neurons build new contacts, with the number of synapses, the activity of neurons increases. The reverse is also true: as soon as the level of activity becomes more than the usual level, the number of synaptic connections decreases. Similar forms of homeostasis are often found in nature, for example, in the regulation of body temperature and blood sugar levels.
M. Boots M. Butz noted:
…the formation of new synapses is due to the desire of neurons to maintain a given level of electrical activity…
Henry Markram, who is involved in a project to create a neural simulation of the brain, highlights the prospects for the development of an industry to study the disruption, repair and development of neuralconnections. The research team has already digitized 31,000 rat neurons. The neural connections of the rat brain are presented in the video below.
Neuroplasticity
The development of neural connections in the brain is associated with the creation of new synapses and the modification of existing ones. The possibility of modifications is due to synaptic plasticity - a change in the "power" of the synapse in response to the activation of receptors on the postsynaptic cell.
A person can remember information and learn thanks to the plasticity of the brain. Violation of the neural connections of the brain due to traumatic brain injuries and neurodegenerative diseases due to neuroplasticity does not become fatal.
Neuroplasticity is driven by the need to change in response to new living conditions, but it can both solve a person's problems and create them. A change in synapse power, for example, when smoking, is also a reflection of brain plasticity. Drugs and obsessive-compulsive disorder are so difficult to get rid of precisely because of the maladaptive change in synapses in neural networks.
Neuroplasticity is greatly influenced by neurotrophic factors. N. V. Gulyaeva emphasizes that various disorders of neural connections occur against the background of a decrease in the levels of neurotrophins. Normalization of the level of neurotrophins leads to the restoration of neural connections in the brain.
All effective drugs used to treat diseases of the brain, regardless of their structure, if they are effective, they are one way or anothermechanism normalize local levels of neurotrophic factors.
Optimization of neurotrophin levels cannot yet be achieved by direct delivery to the brain. But a person can indirectly influence the levels of neurotrophins through physical and cognitive loads.
Physical activity
Reviews of studies show that exercise improves mood and cognition. Evidence suggests that these effects are due to altered levels of neurotrophic factor (BDNF) and improved cardiovascular he alth.
High levels of BDNF have been associated with better measures of spatial ability, episodic and verbal memory. Low levels of BDNF, especially in the elderly, have been correlated with hippocampal atrophy and memory impairment, which may be related to cognitive problems associated with Alzheimer's disease.
Studying the possibilities for the treatment and prevention of Alzheimer's, researchers often talk about the indispensability of exercise for people. So, studies show that regular walking affects the size of the hippocampus and improves memory.
Physical activity increases the rate of neurogenesis. The appearance of new neurons is an important condition for relearning (gaining new experience and erasing the old one).
Cognitive loads
Neural connections in the brain develop when a person is in a stimulus-enriched environment. New experiences are the key to increasing neural connections.
New experience- this is a conflict when the problem is not solved by the means that the brain already has. Therefore, he has to create new connections, new patterns of behavior, which is associated with an increase in the density of spines, the number of dendrites and synapses.
Learning new skills leads to the formation of new spines and the destabilization of old connections between spines and axons. A person develops new habits, and old ones disappear. Some studies link cognitive disorders (ADHD, autism, mental retardation) with spinal abnormalities.
Spines are very flexible. The number, shape and size of spines are associated with motivation, learning and memory.
The time it takes to change their shape and size is literally measured in hours. But it also means that new connections can disappear just as quickly. Therefore, it is best to prioritize brief but frequent cognitive loads over long and infrequent ones.
Lifestyle
Diet can enhance cognition and protect the brain's neural connections from damage, aid in their recovery from illness, and counteract the effects of aging. Brain he alth appears to be positively affected:
- omega-3 (fish, flax seeds, kiwi, nuts);
- curcumin (curry);
- flavonoids (cocoa, green tea, citrus fruits, dark chocolate);
- B vitamins;
- vitamin E (avocado, nuts, peanuts, spinach, wheat flour);
- choline (chicken, veal, eggyolks).
Most of the listed products indirectly affect neurotrophins. The positive impact of diet is enhanced by the presence of exercise. In addition, moderate caloric restriction stimulates the expression of neurotrophins.
For the restoration and development of neural connections, it is useful to exclude saturated fats and refined sugars. Foods with added sugars reduce neurotrophin levels, which negatively affects neuroplasticity. And the high content of saturated fats in food even slows down the recovery of the brain after traumatic brain injuries.
Among the negative factors affecting neural connections: smoking and stress. Smoking and prolonged stress have recently been associated with neurodegenerative changes. Although short-term stress can be a catalyst for neuroplasticity.
The functioning of neural connections also depends on sleep. Perhaps even more than all the other factors listed. Because sleep itself is the price we pay for brain plasticity. Ch. Cirelli
CV
How to improve neural connections in the brain? Positive impact:
- exercise;
- tasks and difficulties;
- good sleep;
- balanced diet.
Negative impact:
- fatty food and sugar;
- smoking;
- prolonged stress.
The brain is extremelyplastic, but it is very difficult to "sculpt" something out of it. He does not like to waste energy on useless things. The fastest development of new connections occurs in a situation of conflict, when a person is not able to solve the problem using known methods.
