[Cortical-subcortical interactions and the brain functional state regulation under acute hypoxia in man]

Regulation mechanisms of the brain functional state (FS) were studied in man during acute hypoxic conditions (inhalation of 8% O2 hypoxic air for 15-25 minutes). Changes in balance of the brain regulatory structures activities caused by hypoxia determine FS dynamics that is reflected in the reorganization of the EEG spatial interrelations (by data of factor and cluster analysis of EEG cross-correlation matrices), as well as translocation of intracerebral position of electrical equivalent dipole sources (EEDS) coupled with EEDS density rising in medial and basal regions of the cerebral hemisphere temporal lobes (by EEDS-tomography data). Alterations of the cortical-sub-cortical interactions show a decline in the brain activating system tone, a decrease in the neocortical inhibitory control of subcortical processes, and activation of structures of limbic and hypothalamic regions. Switching of integrative regulatory control mechanism from "cortical-thalamic" system level to "limbic-dyencephalic" one could ensure both removal of powerful unspecific components of hypoxic stress and a greater stability of essential physiological parameters of the main vital functions regulation during oxygen deficiency accumulation.