[The function of the brain structures in rabbits under the action of hyperbaric helium and nitrogen-oxygen mixtures]

Behaviour of rabbits as well as excitability thresholds of certain brain areas were determined by intracranial electrostimulation under high pressure in the heliox and nitrox media. Excitability of the mesencephalic reticular formation and of the frontal cortex in particular, decreased under 11 ata in the nitrox medium. On the contrary, measurements of the thresholds and EEG data have shown an increase in excitability in all brain regions under 41 ata of the heliox medium. Excitability increased most of all in the dorsal hippocampus and nucleus caudatus. The role of different brain structures in the symptomatics of nitrogen narcosis and high-pressure nervous syndrome is discussed.