O-34: Study the Effects of Endogenous Cannabinoid Breakdown Inhibitor on Learning and Memory in Rat (Pages: 33-34)

Rasuli B *, Rasuli S , Komaki A ,


Objective: Hippocampus has a key role in the learning and memory processing. Hippocampus-dependent memory is mediated, at least in part, by hippocampal synaptic plasticity. Endocannabinoids are one of the endogenous systems that modulate this plasticity event. There is currently debate over the interaction between L-type voltage dependent Ca2+ channels and endocannabinoid system on the synaptic plasticity. In this study we examined the effects of acute administration of URB597, as endocannabinoid breakdown inhibitor, following chronic administration of Verapamil, as Ca2+ channels blocker, on passive avoidance (PA) test in male Wistar rats. Materials and Methods: Rats were treated i.p. with Verapamil hydrochloride (10,25,50 mg/kg) (n=8) and saline (n=10) as solvent of Verapamil for 13 days (once daily). Before PA test, single i.p injection of saline, Verapamil or URB597 (0.3 mg/kg) (n=9) was done. Then PA training was started. Retrieval test was done 24 hours after training. The statistical analysis of data was performed by analysis of variance (ANOVA) followed by Tukey post hoc analysis. In all cases differences were considered significant if p< 0.05. Results: The results show that there is significant difference on the PA learning and memory between groups. URB597 has decreased the acquisition and retrieval of PA task. Also, Verapamil decreased the acquisition and retrieval of PA task. On the other hands decrease in PA task during chronic administration of Verapamil + acute URB597, is greater than other groups. Conclusion: The results of the present experiment indicate that acute administration of endocannabinoid breakdown inhibitor, URB597, decrease the cognitive performance of PA task in normal rats. Also, there is an interaction between Ca2+ channels blocker and endocannabinoid system. It seems this result is due to endocannabinoid changing in the neural structures related to learning and memory processing