Ontogeny of brain catecholamine turnover and susceptibility to audiogenic seizures in DBA/2J mice

We have investigated the relationship between catecholamine turnover and susceptibility to audiogenic seizures (AGS) in the developing DBA/2J mouse. Turnover of dopamine and norepinephrine was determined after administration of alphamethylparatyrosine at 3 weeks of age when nearly all mice (94%) exhibited AGS, at 6 weeks when only 30% were susceptible, and at 12 weeks when none developed seizures. Turnover of brain dopamine increased progressively from 236 ng/g/hr at 3 weeks to 389 ng/g/hr by 12 weeks of age. Norepinephrine turnover increased significantly between 3 and 6 weeks of age, then remained stable thereafter. Turnover times for each catecholamine did not change appreciably with maturation. Our results support the notion that susceptibility to AGS may be mediated in part by brain catecholaminergic mechanisms.