Limbic system (human Nervous system)
The limbic system consists of various anatomically and functionally related formations of the brain. Some of them belong to the subcortex, others — to the cortex, but not to the new one, which covers the surface of the large hemispheres, and to the old, ancient, which took place in the process of evolutionary development in the depths of the brain. Thus, both subcortical and cortical formations of the limbic system are located in the depth of the brain, and they are paired, since there are both in the right and in the left hemisphere.
The most important of them — the hippocampus, whose name is determined by its form (in Greek hippocampus — seahorse), almond-shaped complex — subcortical formation in the temporal lobe and transparent septum — also sub – cortical formation, located at the point of contact of the two hemispheres. Some scientists to the limbic system also include the frontal, temporal and limbic areas of the cerebral cortex and the hypothalamus.
The functions of the limbic system are extremely complex and diverse. It plays an important role in the formation of behavior, emotions, memory, participates in the regulation of internal organs and processing of impulses. coming from the organ of taste. With the activities of the limbic system, scientists associate the emergence of the basic biological needs of man — in food, drink. the desire for self-preservation, procreation. The level of these needs depends on a number of external and internal factors. For example, the need for food occurs when the Central nervous system impulses signaling the state of the stomach, the level of glucose in the blood, and a number of other signals.
In the limbic system, impulses or biological motivations are formed, which — and this also involves the limbic system — cause complex complexes of actions aimed at meeting vital needs. Unlike simple unconditioned reflexes, such as sneezing, coughing, blinking, physiologists call them complex unconditioned reflexes, or instinctive behavior. An example is the behavior of a newborn baby during breastfeeding, which is a set of coordinated actions. As the child grows and develops, his instinctive behavior is more and more subordinated to the consciousness formed in the process of training and education.
According to scientists, the limbic system is responsible for emotions: positive — joy, pleasure and negative — fear, anger, rage. Based on numerous studies, experts have concluded that most likely emotions are formed mainly in the amygdala, hypothalamus, transparent septum, as well as in the frontal areas of the cerebral cortex.
Some idea of that. what formations of the limbic system are in charge of these or other emotions, give experimental data. In certain areas of the animal’s brain implanted electrodes. Clicking on them connected to the pedal, the animal delivers the electrical impulses to one or another education in the limbic system. If the “pleasure centers” are irritated, the animal presses the pedal up to 8000 times per hour, forgetting about food and drink. The irritation of the other parts of the brain appearance of the animal, his posture reflected that fear or as aggression, and re-press the pedal, it refuses.
Interestingly, experience has shown that “pleasure centers” and “fear centers” are located in the limbic system only a few millimeters apart.
Experts suggest that depending on the degree of development of this or that structure in the limbic system of the animal and is dominated by certain emotions. This conclusion can be made based on the following facts: damage to the amygdala complex makes aggressive animals manual, and the destruction of the transparent partition manual—for some time aggressive, furious.
The limbic system, mainly the hippocampus and amygdala complex, takes part in the most complex processes underlying memory. However, they are not a long-term storage of information coming to the brain. This role is likely performing a new bark of the big hemispheres. Limbic system due to the peculiarities of its anatomical structure as if specially designed for short-term storage of information.
Due to the interweaving of axon beams (processes of the nerve cell), connecting the various formations of the limbic system, a number of large and small closed circles are formed within it, adapted for the re-plying of nerve impulses and co – storage of excitation for a certain time.
It is no accident with the predominant defeat of the hippocampus. for example, alcohol, a person’s memory is impaired on recent events. According to the observations of doctors, alcoholics who are on treatment in the hospital, find it difficult to answer questions about whether they had lunch today or not. when they took the medicine, whether they worked in the workshop. And at the same time they remember the old events of their lives well.
The participation of the limbic system is proved. especially almond-shaped complex and transparent partition. in the processing of information from the olfactory organs. Moreover, initially, the limbic system was attributed only to olfactory function. But later the idea of the limbic system expanded. It turned out that it is well developed in animals devoid of smell.
It is known what an important role is played in the maintenance of normal life biogenic amines: dopamine, noradrenaline, serotonin. which is so rich limbic system. With the violation of their balance is associated, for example, the occurrence of nervous and mental diseases.
In recent decades, the limbic system discovered new biologically active substances — neuropeptides: enkefalin, endorphin and others. Neurons secreting neuropeptides and perception, located in the hypothalamus, the amygdaloid complex, a transparent partition.
Much of the work of the limbic system is not yet fully understood. Fundamental research will help to determine the true place of the limbic system among other parts of the brain, will equip practitioners with new methods of treatment of diseases of the Central nervous system.