Figure 10.

Infusion of the NPY Y1 receptor antagonist BIBO 3304 in the basolateral amygdala blocks the extinction of fear-potentiated startle. A, Animals were implanted with bilateral cannulae in the basolateral or medial amygdala 7–10 d before behavioral training. Immediately before extinction training, animals were infused with either vehicle (n = 20) or 200 pmol/side BIBO 3304 into either the basolateral (n = 15) or medial (n = 7) amygdala. Animals were tested off drug 48 h later to assess extinction retention (Post-Ext). B, Animals who received BIBO 3304 into the basolateral amygdala had significantly greater fear-potentiated startle during Post-Ext than vehicle controls. No difference was found for animals who received intra-medial amygdala BIBO 3304 [significant main effect of treatment (F _(2,40) = 3.281, p < 0.05); error bars indicate ±SEM; *p < 0.05 compared with vehicle].