Effects of electroconvulsive shock on monoaminergic systems in the rat brain. Thesis

The effects of single or repeated electroconvulsive shock (ECS) (once daily for 7 days) on rat behavior and on the level, utilization and uptake of biogenic amines in rat brain were studied between one and ten days after the last ECS. It has been found that a single ECS caused catalepsy and analgesia, depressed locomotor activity and locomotor hypermotility produced by amphetamine and nomifensine (but not by apomorphine) and decreased the frequency of head twitch response evoked by LiCl. Repeated ECS also induced catalepsy and analgesia but enhanced both the spontaneous locomotor activity and amphetamine, nomifensine and apomorphine-induced hypermotility, and increased the frequency of head twitch response produced by LiCl, 5-HTP and 5-methoksytryptamine. Single and repeated ECS did not change exploratory motility or stereotyped behavior induced by apomorphine, but enhanced haloperidol-induced catalepsy and altered dopamine and serotonin levels in the rat brain. The utilization of NA and DA was not changed by repeated ECS, whereas the uptake of these amines was slightly reduced. The present results provide evidence that a single ECS depresses but repeated ECS augments some behavioral responses to dopaminergic and serotonergic agonists. The possible biochemical mechanisms involved in these effects of ECS are discussed.