To Study of the Effect of Melatoninon Noradrenaline Mediated Behavioural Responses after Electroconvulsive Shock (ECS) Administration

Objectives: To look for possible data regarding the effects of melatonin on noradrenaline mediated behavioral responses after Electroconvulsive Shock (ECS) administration in rats. Methods: Forty rats were divided in four groups with ten rats in each group and treatment duration was kept for ten days in all the groups. 1. Control group- distilled water (2ml daily). 2. ECS pretreated group- Single ECS daily. 3. Melatonin group- melatonin suspension (10 mg/kg/day, p.o.) daily. 4. Test group- Single ECS daily + melatonin suspension one hour after ECS (10mg/kg/day, p.o). Clonidine induced sedation was used as a model to assess noradrenaline mediated behavioral changes. Clonidine induced sedation score was assessed 30 min after giving intraperitoneal injection of clonidine hydrochloride (100 μg/kg) in each group on day 11.Data was analysed by Mann-Whitney U test. Results: Findings show that administration of single ECS daily for consecutive 10 days results in enhancement of clonidine induced sedation. Melatonin administration decreases clonidine induced sedation which may be due to modulation at noradrenergic neurotransmission. Also, melatonin significantly retarded the ECS-induced enhancement of clonidine induced sedation. Conclusion: ECS administration leads to enhancement in clonidine induced sedation. Melatonin administration could prevent enhancement in clonidine induced sedation which may be due to modulation at the level of noradrenergic transmission. This modulation in noradrenergic transmission might be of some value in attenuation of disruption of memory following ECS administration. As ECT in humans is known to produce memory disruption, a possible potential therapeutic utility of melatonin to prevent memory disruption in such patient is worth considering.