Figure 1: Psilocybin reduces heroin relapse after forced abstinence but not heroin intake.
(A) Overview of experiment. Animals underwent heroin SA for 8 days. On days 9–11, animals were pretreated with 5-HT2AR agonist psilocybin 4 hr prior to SA. After 17D abstinence, animals underwent 3 relapse tests on consecutive days and were pretreated with psilocybin 4 hr prior to the test. (B-H) Shown are drug-paired active or inactive lever presses (B-D, G) and heroin infusions during SA (E, F, H). (B-F) SA behavior for each treatment group, prior to psilocybin treatment for days 1–8. Animals were split into treatment groups on day 8, with no significant differences observed in lever responses (D) or heroin infusions (F). (G-H) Heroin SA lever responses (G) and infusions (H) on days 9–11, following pretreatment with psilocybin. (I-K) Active and inactive lever presses during relapse tests on subsequent days (R1, R2, R3) for animals that were pretreated with psilocybin prior to the relapse test. (J-K) Shown are lever presses from panel I combined. Error bars indicate mean +/− standard error of the mean (S.E.M). n=5–12/group. Symbols above line indicate ANOVA: * p<0.05; Post hoc test indicated directly above individual histograms, * p<0.05 vs vehicle; # p<0.05 vs 0.1 mg/kg psilocybin; $ p<0.05 vs 1 mg/kg psilocybin.