International Union for Circumpolar Health Ministry of Public Health and Social Development of RF Russian Academy of Medical Sciences Siberian Branch of Russian Academy of Medical Sciences Siberian Branch of Russian Academy of Sciences Medical Polar Fund “Science” The Northern Forum

Abstracts

Ecology and adaptation (medical ecology)

In recent years, our attention has been drawn to the problem of incomplete adaptation. Medvedev was the first to formulate the notion of compromise forms of adaptive responses to a set of environmental factors under the conditions of contradictory physiological requirements. Afterwards, this notion gave rise to the concept of incomplete adaptation. Incomplete adaptation is formed in a specific informational environment, e.g., in the case of a short-term exposure to a factor to which it is impossible to adapt and a subsequent return to a usual environment. It may be assumed that adequate adaptation does not take place even when the combination of extreme and normal conditions is repeated many times because the exposure is too short and the factor is extreme. The psychophysiological mechanisms of incomplete adaptation have not been studied sufficiently. One of the main obstacles to the progress of research in this field is the absence of a suitable experimental model of incomplete adaptation that would allow analysis of its patterns and mechanisms under laboratory conditions with the use of various electrophysiological and computer techniques. Short-term extreme hypoxia followed by a return to normobaric, normoxic conditions constitutes, in effect, the intermittent normobaric hypoxia procedure. We used this method to model incomplete adaptation. The Neirokartograf software was used to calculate the correlations between EEG, external respiration, and gas exchange parameters recorded in the initial state, after 10 or 20 sessions of intermittent normobaric hypoxia, and after its cessation. It is reasonable to assume that the reversal of hemispheric predominance as well as the involvement of the fronto-parietal lobes with their in-terhemispheric integration is the determining electrophysiological pattern under INH. The character of alterations in the respiratory center sensitivity and EEG indices indicate that INH sessions are unable to produce self-adaptation to hypoxia. It seems INH promotes the organism to meet unexpected hypoxic conditions that may result in stable reconstruction of respiration regulation.

Note. Abstracts are published in author's edition

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