Figure 1. Pancreatic polypeptide (PP) injection induces a Y4 receptor-dependent increase in c-Fos immunoreactivity in the brainstem and hypothalamus.
(A,B and C) Photomicrograph of brains from wild type (WT) mice showing c-Fos immunoreactivity at 30 minutes after i.p. injection of saline. (D, E and F) Brains from wild type mice showing c-Fos immunoreactivity at 30 minutes after i.p. injection of PP. (G, H and I) Brains from Y4 receptor knockout mice (Y4 −/−) showing c-Fos immunoreactivity at 30 minutes after i.p. injection of PP. Scale bar for all panels = 40 µm. NTS, nucleus tractus solitarus; AP, area postrema; ARC, arcuate nucleus of the hypothalamus; 3V, third cerebral ventricle.
