Effects of acute hypoxia on the EEG and impulse activity of the neurons of various brain structures in rats

Abstract

The EEG and impulse activity of the neurons of the cerebral cortex and other structures of the brain were studied in the dynamics of hypoxic influence. In the initial phase of hypoxia (2000-6000 m), activation of the EEG and impulse discharge of neurons set in; in this case EEG activation arose earlier and was more pronounced. In the second phase of hypoxia (7500-10,000 m), the EEG changed in the direction of a reorganization of the frequency spectrum from one rhythm to another - from fast to slow activity of the type of delta waves. At this time the impulse activity was gradually suppressed, and the cortical neurons exhibited higher sensitivity to hypoxia and were inhibited earlier than the cells of the hypothalamus and medulla oblongata.

Low Atmospheric Oxygen Attenuates Alpha Oscillations in the Primary Motor Cortex of Awake Rats

“…4,5) To bridge the gap between cellular and cognitive functions, another physiological study monitored electroencephalograms of rats under high-altitude conditions to investigate the effects of hypobaric hypoxia on neural activity and revealed that neural activity was shifted from fast to slow oscillations. 6) However, the possibility that this reorganization of oscillatory frequencies in neural activity is caused by the change in total air pressure cannot be excluded and is yet to be addressed. To evaluate a net effect of oxygen concentration in air on neural and peripheral activity, we devised an experimental configuration in which oxygen concentration levels were exclusively manipulated while the total atmospheric pressure was maintained at the standard 1 atm, which we call 'experimental hypoxia,' hereafter.…”

Προγνωστικός Δείκτης Αποκατάστασης Ασθενών Με Οξεία Αναπνευστική Ανεπάρκεια Σε Μονάδα Εντατικής Θεραπείας Με Τη Χρήση Γραμμικών Και Μη Γραμμικών Τεχνικών Επεξεργασίας Ηλεκτροεγκεφαλογραφικών Καταγραφών

“…Οι επιπτώσεις της υποξίας στο ηλεκτροεγκεφαλογράφηµα Η προοδευτική ελάττωση της παροχής οξυγόνου στον εγκέφαλο προκαλεί ΗΕΓραφικές µεταβολές, οι οποίες αρχικά χαρακτηρίζονται από ελάττωση της συχνότητας και του ύψους του ρυθµού άλφα (Sieker et al, 1960;Gurvitch and Ginsburg, 1977;Schellart and Reits, 2001) (σπάνια παρατηρείται αρχικά παροδική αύξηση του ύψους του ρυθµού άλφα). Στη συνέχεια οι βραδείες δραστηριότητες θήτα και δέλτα κυριαρχούν και το ύψος των εγκεφαλικών ρυθµών αυξάνει (Akopyan et al, 1984;Van der Worp et al, 1991).…”