Convulsant and anticonvulsant effects of gamma-hydroxybutyrate (GHB) have been studied in chicks.2. When administered alone, GHB produced weak myoclonic seizures accompanied by electrocortical synchrony and spikes.3. GHB was found to protect chicks against leptazol- and picrotoxin-induced seizures. A slight potentiation of strychnine-induced seizures was evident.