SEIZURES INDUCED BY HYPERBARIC OXYGEN AND CEREBRAL γ‐AMINOBUTYRIC ACID IN CHICKS DURING DEVELOPMENT1

The susceptibility of chicks to convulsions induced by hyperbaric oxygen increased with age during the first few weeks of life. The sensitivity of the levels of cerebral GABA to change by oxygen at high pressure (OHP) also increased with age. There was correlation between the rate of decrease in concentration of cerebral GABA and the time to onset of OHP seizures. The anti‐convulsant action of intraperitoneally administered GABA was greater in 6‐9‐day‐old chicks than in 21‐23‐day‐old chicks, consistent with decreasing permeability of the blood‐brain barrier to the amino acid with increasing age.