Fig. 5. The glucocorticoid receptor and the serotonin receptors 5-HT-1A and 5-HT-2A are necessary for the anxiolytic effects of MDMA: (1) Top panel: experimental protocol.
Rats were exposed for 10 min to predator-scent stress (PSS) on day 0. On day 7 rats were intraperitoneally injected with either saline, Ru486 (7.5 mg) (GR antagonist mifepristone), Ketanserin (5 mg/kg) (5-HT2A R antagonist), Pindolol (0.3 mg/kg) (5-HT1A R antagonist) or SB242084 (0.3 mg/kg) (5-HT2C R antagonist) and 30 min before MDMA (5 mg/kg|) or saline injection, administered 30 min before a brief memory reactivation session. There were 6 rats per group. During this time A LMA (distance moved; measured in cm); B Percent freezing response; C Representative patterns of locomotor activity (cumulated values) in all groups. D Urine corticosterone concentrations** (pg/ml). Behavioral measurements (EPM and ASR) were performed on day 14 and freezing behavior on day 15. E Anxiety index, which integrates the measured EPM behavioral measures; F Startle amplitude in the ASR paradigm; G Percentage of startle habituation in the ASR paradigm. H Representative accumulated movement track of the rats during a trial. Finally, the effect of trauma-cue at day 15 on LMA I (distance moved; measured in cm); and J Percent freezing response; K Representative patterns of locomotor activity (cumulated values) in all groups. The experiments described below were performed with two different cohorts of animals; 18 rats were run in one experimental design, and 18 rats in another experimental design. Bars represent group means ± SEM and percentages.