Figure 5.

Intracerebroventricular administration of leptin or interleukin (IL)‐6 induces phosphorylated signal transducer and activator of transcription‐3 (pSTAT3)‐immunoreactivity in the arcuate nucleus (ARC) after 15 minutes. Immunohistochemistry showing pSTAT3‐immunoreactivity in red, vimentin‐ (a tanycyte marker) immunoreactivity in green and 4’,6‐diamidino‐2‐phenylindole (DAPI) (nuclear staining) in blue, shown in coronal cross‐sections of parts of the third ventricle (3V) of the mouse brain. Images were obtained from mice that were killed 15 minutes after i.c.v. injection of IL‐6 (A‐C) or leptin (D‐F). White arrowheads indicate examples of pSTAT3‐immunoreactivity in the ARC. Images were obtained using the confocal microscope system described in the Materials and methods. Scale bars (overview)=100 μm, close‐up=10 μm