[The participation of adren-, cholin- and dopaminergic mechanisms in the development of hyperbaric nitrogen narcosis in rabbits]

Abstract

Behavior and EEC responses to electrical stimulation of the frontal cortex (FC), mesencephalic reticular formation (MERF), dorsal hippocampus (DH), and nucleus caudatus (NC) were investigated in hyperbaric experiments on rabbits. As compared to the control data, the thresholds of motor reaction caused by the stimulation of FC and MERF in N2/O2 mixture at 11 ATA were increased by 41% (p < 0.05) and 10% (p < 0.05), respectively, whereas those by DH and NC stimulation showed no changes as compared to the controls. During decompression to 5 ATA, the thresholds of intracranial stimulation of FC and MERF returned to the control level. After prior injection of pharmacological agents that activated or inhibited the adren-, dopamin-, and cholinergic neurotransmitter systems, different changes in behavior, EEC, and stimulation thresholds were observed in N2-O2 under high pressure. The application of the adrenergic activator ephedrine may be promising in pharmacologically correcting nitrogen narcosis.