Hypercapnia-induced brain acidosis: Effects and putative mechanisms on acute kainate induced seizures

Abstract Aims This study investigated the mechanism of the anticonvulsant effects of carbogen containing 5% CO 2 in a kainic acid (KA) rat model. Main methods Four-week-old Sprague–Dawley rats were divided into four groups: control, carbogen, KA + air, and KA + carbogen. Carbogen containing 5% CO 2 was applied immediately after KA injection, and cortical pH was recorded. High-performance liquid chromatography was used to detect the release of γ-aminobutyric acid (GABA) and glutamate. We used electrophysiology to measure cortical and hippocampal activities. Key findings Carbogen increased the onset latency of seizure (KA + air group, 26.12 ± 2.11 min; KA + carbogen group 43.65 ± 2.78 min, P P P P P P P Significance Carbogen containing 5% CO 2 decreased seizures by reducing cortical pH, by increasing GABA release, and by affecting electrical activity of the brain.