The effect of hypoxia on isonicotinic acid hydrazide-induced seizures in chicks during ontogenesis

Abstract

Abstract : The concentration of gamma-aminobutyric acid (GABA) in the brain of various species is elevated by hypobaric hpoxia, or by hypoxia caused by the breathing at ambient pressure of a gas mixture of low oxygen content. Hypobaric hypoxia also delays the onset of semi-carbazide- and methionine sulphoximine-induced seizures and it has been suggested that the elevation in brain GABA level may be responsible for the anticonvulsant action. Although the above studies clearly indicate that both an elevation in brain GABA concentration and an anticonvulsant actio are associated with hypoxic conditions, the results do not necessarily indicate a causal relation between the first two phenomena. The present investigation was therefore initiated to obtain additional information about this.