Muscimol infusions into the IL block the induction of Fos+ cell labeling by systemic ketamine administration. (A) Location of microinfusion. (B and C) Influence of muscimol preinfusion (30 min) on ketamine induction of Fos+ labeling in the (B) IL-PFC and (C) PrL-PFC, determined 1 h after ketamine administration. Right panels show representative Fos+ immunolabeling in the IL under the indicated conditions. *P < 0.05, compared with PBS + Sal; analysis of variance (two-way ANOVA with LSD post hoc test). Ket, ketamine; Mus, muscimol; Sal, saline.