Direct Current Potential of Brain as a Stress Marker on Different Stages of Adaptation in Northern Climates

Abstract

Background: The main changes in the parameters of functional systems in the process of adaptation occur in the first year of living in new conditions, and the main role in regulating human life support systems is played by the central nervous system. The brain's role in regulatory processes can be assessed by examining the levels of direct current potentials (DCP) in various brain areas by the Neuroenergy Mapping (NEM) method. The aim of this study was to assess the brain's DCP in a group of Indian students living in the Arctic region (Arkhangelsk city) for the first 6 months after arrival. Methods and Results: The study involved 106 young people aged 19–21 years. Registration, processing, and analysis of DCP were carried out in the following groups: 34 of the participants who lived in Arkhangelsk for less than 3 months at the time of the study (Group 1, short-term adaptation); 37 participants who lived in Arkhangelsk more than 6 months (Group 2, long-term adaptation); and in 35 participants who were born and are permanently residing in Arkhangelsk (Group 3, control). To study neurometabolism, the electrophysiological NEM method was used based on measuring the level of DCP. The highest functional activity among Indian students of Group 1 was found in the central (Cz) and parietal (Pz) regions. In Indian students of Group 2, on the contrary, a critically low total rate of DCP for the cerebral cortex was recorded, which indicates a decrease in the activity of the cerebral cortex. Potential values in all departments of the right hemisphere were recorded higher than the corresponding values of the left hemisphere. In Group 3, which included students living for a long time in extreme climatic and geographical conditions of the Arctic zone, there was also a stable right-hemispheric dominance with a predominance of activity in the central, parietal, and occipital regions of the cerebral cortex. The total value of DCP in the whole cortex was within the normal range, which indicates well-formed mechanisms of adaptation to extreme climatic conditions of the Arctic zone. Conclusion: Indian students, depending on the time spent in the climatic conditions of the Arctic Circle, reveal various features of cerebral metabolism. Thus, the acute stage of adaptation to a cold climate shows inadequate responses to stress caused by new environmental conditions, such as a significant increase in DCP throughout the cerebral cortex with a maximum in the central leads. After 6 months of living in a new climate, the DCP level decreases, which indicates signs of an adaptive disorder of brain function.

Keywords

• direct current potential
• brain
• arctic climate
• adaptation