DOPAMINE POSTSYNAPTIC RECEPTOR EFFECTS OF RESTRICTED SCHEDULES OF

Little work is available on the acute and time-dependant dopaminergic effects of single electroconvulsive shock (ECS) and multiple ECS despite the posited clinical utility of such schedules of electroconvulsive therapy (ECT) administration and the posited role of dopaminergic mechanisms in iieuropsychiatric disorders. In this study, using:he apomorphine-induced motility-alteration behavioural paradigm, single session multiple ECS was found to produce no significant effect while single ECS behaviourally downregulated dopamine postsynaptic receptor functioning one week after the ECS, which effect was also seen (albeit to a lesser extent) a further week later. These findings indicate a possible application of restricted schedules of ECT to dopamine postsynaptic receptor supersensitivity syndromes. Lines for future research are suggested. Historically and heuristically, the do-paminergic neurotransmitter system is considered to play a key role in the mechanisms underlying various neuro-psychiatric disorders. Studies on the dopaminergic effects of electroconvulsive shock (ECS) have largely focused on serial (administered daily or on alternate days as a 'course') schedules of administration (Gleiter and Nutt, 1989); single ECS studies have predominantly addressed dopamine (DA) autoreceptor effets (e.g. Chiodo and Antelman, 1980; Gangadhar et al., 1990), while only one study has evaluated DA post-synaptic receptor changes (Wielosz, 1983); DA effects of multiple ECS (where 2 or more convulsions are induced per session) have not been studied at all. Since both single and multiple ECT have potentially important clinical applications (Andrade, 1990), the present study sought to assess the acute and time-dependant effects of single ECS and single sesssion multiple ECS on DA postsynaptic receptors in the rat brain