Impact Of Seasonal Fluctuations In Natural Light On Cerebral Metabolism In Arctic Region Residents With Different Autonomic Tones

Abstract

Background — The study of physiological mechanisms of human acclimatization to extreme climatic conditions is an urgent task in current socioeconomic conditions of the Arctic region development. Natural cycles of seasonal adaptation based on light stimulus cause functional restructuring of the cerebral cortex and subcortical activity centers and change the activity of the autonomic nervous system. Objective — The article aims at determining the characteristics of brain energy metabolism in Arctic region residents with different autonomic tones during different seasons. Material and Methods — The first stage of our study was conducted using the computer appliance VNS-Spectrum (Neurosoft LLC, Russia) and resulted in setting up two groups: with predominance of the parasympathetic autonomic nervous system (26 subjects) and with prevailing sympathetic autonomic nervous system (23 individuals). At the second stage, the study of the seasonal dynamics in cerebral energy processes took place (in October, December, March, and June) by means of using the five-channel diagnostic complex Neuro-KM for topographic mapping of brain electrical activity via direct current potential levels (DCPL). Results — Our results did not exhibit statistically significant gender-related differences, hence they permitted to form a single group. The results were compared with the software reference values for the norm. Conclusion — Enlarged levels of natural light prompt the activation of energy metabolism in frontal and occipital lobes of the Arctic residents’ cortex, accompanied by forming an exhaustion area in the temporal lobes. In the group of sympathotonic individuals, we revealed somewhat tense adaptation processes. Adaptation process of brain energy supply in vagotonic individuals occur less stressfully during the annual cycle.