Fig. 4.

(A) Pre-treatment of the PAG with an anti-IL-1 receptor antibody completely blocked the facilitating effects of IL-1 upon medial hypothalamically elicited defensive rage (p < 0.0001, N = 5). Note that administration of the anti-IL-1 receptor antibody alone did not alter response latencies for hissing (p = 0.91, NS, N =5); (B) Pre-treatment of the defensive rage site in the PAG with an isotype antibody (IgG_2a) did not block the potentiating effects of IL-1β upon defensive rage (p < 0.0001, N =2) and that administration of the isotype antibody alone did not alter latencies for defensive rage (p = 0.95, NS, N = 2).