Antipsychotic-like effect of agomelatine in a rodent model

Antipsychotic-like effect of agomelatine in a rodent model Objective: Agomelatine is a naphthalene bioisostere of melatonin. Melatonin is involved in several neurophysiological systems; nevertheless, data about the relationship between melatonin and psychosis such as schizophrenia are limited and contradictory. In this study, we examined the antipsychotic-like effects of agomelatine in a rodent model. Method: In this study, we evaluated the effect of agomelatine on novelty-induced rearing behavior and apomorphine-induced stereotypical behavior in male rats. Agomelatine (20 and 40mg/kg, i.p.), chlorpromazine (1mg/kg, i.p.), or isotonic NaCl (1mL/kg, i.p.) were administered to four groups of rats (n=6), respectively. An hour later, apomorphine (2mg/kg, s.c.) was administered to each rat. Results: Our results showed that either dose of agomelatine decreased rearing behavior in rats significantly, in a dose dependent manner. Agomelatine also decreased the stereotypical behaviour scores like chlorpromazine did. Conclusion: We conclude that agomelatine has beneficial effects on rearing and stereotypical behaviour, which were accepted to be indicators of antipsychotic effect.