[An electrophysiological study of the brain of rats with different resistances to oxygen deficiency in acute hypoxia].

The Fourier spectre of power (SP) and bioelectrical activity of the cortex, hippocampus and hypothalamus were studied in unrestrained rats with high (HR) and low (LR) resistance to oxygen deficiency before and after their stay at the "altitude" of about 11,000 m. After acute hypobaric hypoxia there were the EEG changes in LR rats: displacement of the SP peak in low-frequency activity and decreasing of absolute power of all the ranges of SP. In one hour after the "altitude", these EEG parameters were restored. The EEG of the HR rats was not altered. The cortex of the brain seems to be the most susceptible to hypoxia.