Nuclear phosphorylated-STAT3 expression in the area postrema induced by CIA onset on PID 35. (A) Representative images for phosphorylated-STAT3 (pSTAT3) immunostaining with nuclear staining (DAPI) in the area postrema on PID 35 in the CIA (left panels) and FA group (right panels). Yellow dashed lines reflect the boundaries of the area postrema. Boxed areas are shown at higher magnification on the lower (a) to (f). (B–D) Results of quantitative analysis for pSTAT3 intensity in the intranuclear area (B) and extranuclear area (C) of the area postrema (FA, n = 6 mice; CIA, n = 8 mice). Normalized intranuclear pSTAT3 intensity to extranuclear pSTAT3 intensity (D) is significantly higher in the CIA group. DAPI: 4′,6-diamidino-2-phenylindole; FA: Freund’s adjuvant; PID: post-immunization day; STAT3: signal transducers and activators of transcription