Influence of intranasal oxytocin on fear consolidation in healthy humans

BACKGROUND: Although recent data in healthy humans suggestthat treatment with intranasal oxytocin (OT) may facilitate extinction recall,to date, little is known about the effects of OT on memory consolidationprocesses. AIM: To examine the effect of intranasal administration of OT compared with placebo on memory consolidation blockade of a de novo fear memory in a classical 2-day fear conditioning procedure. RESULTS: There were no significant differences between the OT and the placebo groups on the first two extinction trials (mean (SD)=0.01 (0.39) vs 0.15 (0.31), t=−1.092, p=0.28). Similarly, during early extinction, analysis of variance for repeated measures failed to show significant main effects of extinction trials: trials (F(4, 112)=1.58, p=0.18), drug (F(1, 112)=0.13, p=0.72) or drug × trials interaction (F(4, 112)=0.76, p=0.56). CONCLUSION: Our results suggest that OT administered in a double-blind fashion immediately after fear conditioning does not significantly reduce consolidation of fear learning as measured by a differential skin conductance response tested at the beginning of extinction.