[Comparative reactivity of the neo-, paleo- and archicortex of the brain under conditions of ether and hexanal anesthesia].

In acute experiments on dogs subject to investigation under ether- and hexobarbital sodium-induced anesthesia was comparative reactivity of the neo-(sensomotor region), paleo-(hippocampus) and archicortex (olfactory lobe) of the brain. It was found that following administration of low and medium doses of general anesthetics more marked EEG changes, with but an insignificant inhibition of respirations and a slight fall in arterial pressure, were observed to occur in the hippocampus and in the olfactory lobe, as against the biocurrents in the sensomotor region. Such a regularity continued for as long as the oxygen tension in the neocortex was maintained at a level higher than in the paleo-and archicortex. Upon introduction of toxic ether and hexobarbital doses the oxygen tension in the neocortex dropped earlier and the inhibition of its bioelectric activity would set in concurrently or sooner than in the olfactory lobe and in the hippocampus.