Characteristics of the formation of systems activity in the brain and autonomic functions in children in conditions of the European North (discussion paper)

Abstract

Results obtained from complex medical-physiological investigations performed during 10 scientific expeditions in the Arkhangel'sk Region in 2003-2005 are presented. The effects of climatological-geographic, biogeochemical, and social conditions of the conditions obtaining in the Far North region of Russia on sexual maturation, formation of the structural-functional organization of the brain, autonomic functions, and immunological and biochemical status of schoolchildren were studied using state-of-the-art neurophysiological methods (computerized electroencephalography, computerized rheoencephalography, computerized electric dipole origin tomography, etc.), psychophysiological and psychometric methods (assessment of the state of cognitive and memory functions, Wechsler intellectual scale), along with biochemical assay of monoamine oxidase (MAO, the key enzyme in adrenergic neurotransmitter metabolism) and the liver enzyme butyrylcholinesterase (BuChE) and physicochemical analysis of the levels of macroelements and trace elements in the body.

Age and gender features of the content of macro and trace elements in the organisms of children from the European North

“…Natural factors are supplemented with the socioeconomic ones, such as significant social and informational isolation (especially of rural residents), uncomfortable living conditions, monotonic diet with deficiency of essential vitamins and minerals, etc. This complex set of factors of the North has an adverse impact on the state of health of the population in gen eral and children in particular [2][3][4][5][6].…”

“…Physicochemical studies of the content of macro and trace elements in the blood and hair of children showed that "microelementoses" and an increased content of ecotoxicants in the body may cause not only various anatomical and physiological abnormali ties in the development of children and specific dis eases but also the disturbance of the age related devel opment of mental functions [ 6] and a decrease in the total body resistance and adaptability [6,13]. In addi tion to studying the role of macro and trace elements in metabolism, the study of the interaction between macro and trace elements in various biosubstrates in various diseases and biological processes is currently of great importance [14,15].…”

“…However, the described features and age delay in the development of the hormonal [4], immune [23], and nervous [6,24] systems in northern children may, to a certain extent, be related to the excess or defi ciency of various chemical elements in the body. Deviations from the biologically acceptable level of chemical elements in the hair should be considered as an indication of failure of adaptive mechanisms and a risk of increased morbidity [13,15].…”

EEG Correlates of Genophenotypic Characteristics of Brain Development in Children of the Aboriginal and Settler Populations in Northeast Russia

“…The effects of complex natural-climatic and social-domestic conditions imposing increased requirements on physiological systems induce not only functional deviations due to the state of pressure on the regulatory systems in children's bodies ("critical states of development"), but also slowing of the rate of "maturation" of the neurophysiological mechanisms of the brain [19,31]. Some 42% of schoolchildren in the Archangel Region showed signs of immaturity (compared with age norms) of the main EEG rhythm, while 23% showed delays in the formation of brain bioelectrical activity by 1.5-2 years [18], which is consistent with slower hormonal and physical (morphometric parameters) development [22]. Adaptation to school pressure presents an increased demand on the CNS, so children with signs of functional immaturity of the brain (EEG data) show complex learning difficulties [6,8,31,32].…”

“…Despite the stringency of the genetic program for individual development in children, constant exposure to particular environmental factors on the body during pre-and postnatal development induces adaptive mechanisms (population adaptation [14]), which may be linked with morphofunctional changes in a number of body systems [7,10,18]. Population genetic studies of the functional asymmetry of the brain in the root and settler populations of north-east Russia have shown that ecological factors mediated by people's lifestyles may influence the phenotype frequency distributions of interhemisphere functional interactions [15].…”