Facilitation of endocannabinoid effects in the ventral hippocampus modulates anxiety-like behaviors depending on previous stress experience.

摘要: Although several pieces of evidence indicate that the endocannabinoid system modulates anxiety-like behaviors and stress adaptation, few studies have investigated brain sites these effects. The ventral hippocampus (VHC) has been related to anxiety a high expression cannabinoid-1 (CB1) receptors. Moreover, signaling in is proposed regulate adaptation. In present study we role previous stressful experience on effects AM404, an anandamide uptake inhibitor, microinjected into VHC rats submitted elevated plus maze (EPM), widely used animal model anxiety. Stressed animals were forced restrained for two h 24 before test. AM404 (5-50 pmol) microinjection promoted anxiogenic-like effect non-stressed but decreased stressed animals. AM251 (0.01 1000 pmol), CB1 receptor antagonist, failed change behavior EPM over wide dose range prevented AM404. Anxiolytic-like (5 intra-VHC injection also observed Vogel conflict test (VCT), another involves exposure situations (48 water deprivation). These results suggest facilitation neurotransmission this depends experience.