Effect of central IL-6 immunoneutralization on reversal learning and downstream signaling pathways in the OFC. a, Both CIC stress and treatment with an anti-IL-6 antibody (200 ng/d, i.c.v.) increased trials to meet criterion on the reversal learning stage of the attentional set-shifting test. *p < 0.05, main effect compared with IgG control groups. +p < 0.05, main effect compared with nonstress control groups. b–e, Treatment with the IL-6 antibody decreased STAT3 and ERK1/2 phosphorylation in the OFC without affecting AKT phosphorylation. Fold change relative to No Stress, IgG Antibody control group. *p < 0.05, main effect compared with IgG control groups. f, Representative Western blot images. n = 9–11 per group.