The main neuroendocrine pathway of immunity regulation is associated with the activation of the hypothalamic-pituitary-adrenal system, which occurs regularly under stress and is accompanied by an increase in the level of glucocorticoid hormones of the adrenal cortex. Glucocorticoids in small concentrations stimulate, and in large concentrations, they inhibit lymphocyte proliferation and other immune responses.
Negative feedback mechanisms that regulate immune activity, in which the hypothalamic-pituitary-adrenal system is involved, are described. The development of the immune response is accompanied by an increase in the activity of the noradrenergic neurons of the paraventricular nucleus of the hypothalamus. This leads to the secretion of corticotropin-releasing factor, increasing the release of ACTH by the pituitary gland, which increases the level of glucocorticoid hormones that inhibit immune responses.
With damage to the central nervous system changes the nature of neuroendocrine regulation, as well as the activity of the autonomic nervous system. Thus, the destruction of the anterior and ventromedial hypothalamus inhibits many immune functions. Opposite to the bilateral destruction of the hippocampus and tonsil enhances the proliferative response of lymphocytes to mitogens. There are numerous studies on the connections between hemispheric asymmetries and immune responses. In particular, in G. Renoux et al. (1983) found that partial removal of the left frontal parietal cerebral cortex reduces the number of T-lymphocytes and weakens their response to the T-mitogen, while the activity of B-lymphocytes does not change. Damage to the symmetric region of the right hemisphere does not affect or enhance immune responses. Of interest are the results showing a difference in the immune status of right-handed and left-handed people.In left-handers, impaired immunity occurs 2.5 times more often than in right-handers (N. Geshwind, P. Behan, 1984).
There is a relationship between the intensity of energy metabolism in certain cerebral structures and the activity of the immune system. It has been shown that in healthy people and patients with myalgia, local cerebral blood flow in the motor and somatosensory areas of the right hemisphere, in the cingulate gyrus, bilaterally and in the thalamus is associated with a negative correlation with the activity of natural killer cells of the immune system (M. Lekander et al., 2000). Electrophysiological studies have shown that high pre-frontal activation of the left hemisphere correlates with an increase in the activity of natural killers in students during exams. Conversely, sustained prefrontal activation of the right hemisphere was accompanied by a decrease in the activity of natural killers (R. Davidson, et al., 1999).
From a brief review of the properties of the immune system and its interaction with the endocrine system and the central nervous system it is clear why each adaptive response is accompanied by changes in both the immune status and cerebral energy processes. The relationship between energy processes in the brain and immunity is as follows: one of the main links that determine the interaction between cerebral energy metabolism and the immune system is the hypothalamic-pituitary adrenal axis, the activation of which under stress in some way changes the cerebral energy metabolism and the characteristics of the immune system. In the process of constant adaptation, the activity of the autonomic nervous system and the nature of interhemispheric relations also change.which largely explains the relationship between these two factors and the immune system. Activating the right and left hemisphere has a different effect on the immune system. processestherefore, hemispheric asymmetry should be considered as a special factor affecting the human immune status as well. Normally, even in the absence of stress, during the day there are certain fluctuations in the cerebral energy metabolism of the nerve centers associated with changes in the current functional state of the brain. At the same time, intercentral relations change, including the hemispheric, the state of the autonomic nervous system and, naturally, the immune activity. Therefore, neuro-immune interaction is not limited to stress, but takes place at any level of functioning of the body. This chapter will examine the relationship between cerebral energy and immune processes in the range of natural sub-stressor energy exchange fluctuations in people of different ages.
The study was conducted by us on 59 healthy subjects of both sexes aged from 22 to 80 years. Since the energy and immunological indicators have clearly pronounced age differences, the analysis of the relationship between the two processes was carried out in three groups of subjects, homogeneous by age. The subjects were divided into groups: young people (20 – 39 years), middle (40 -59 years), elderly and senile (60 – 80 years).