Morphine improved stress-induced amnesia and anxiety through interacting with the ventral hippocampal endocannabinoid system in rats.

Morphine improved stress-induced amnesia and anxiety through interacting with the ventral hippocampal endocannabinoid system in rats. Brain Res Bull. 2020 Sep 13;: Authors: Abbasi-Habashi S, Ghasemzadeh Z, Rezayof A Abstract The present study aimed to investigate the possible role of the ventral hippocampal (VH) cannabinoid CB1 receptors in the improving effect of morphine on stress-induced memory formation impairment and anxiety. A step-through type passive avoidance task and a hole-board test were used to measure memory formation and anxiety-like exploratory behavior, respectively. The results showed that the exposure to 10-min stress immediately after the successful training phase impaired memory formation and also produced anxiogenic-like exploratory behaviour in adult male Wistar rats. Moreover, morphine administration before stress exposure improved the adverse effects of stress on memory formation and exploratory behaviour. After training, intra-VH microinjection of cannabinoid CB1/CB2 receptor agonist, WIN 55,212-2 (0.01-0.05 μg/rat) enhanced the response of an ineffective dose of morphine (0.5 mg/kg for memory; 5 mg/kg for anxiety, i.p.) on memory impairment and anxiogenic-like exploratory behaviour induced by acute stress. Intra-VH microinjection of the higher dose of WIN 55,212-2 alone impaired memory formation. Post-training microinjection of a cannabinoid CB1 receptor antagonist/inverse agonist, AM-251 (100-150 ...
Source: Brain Research Bulletin - Category: Neurology Authors: Tags: Brain Res Bull Source Type: research