Acute CNTF treatment activates hypothalamic neurons.

<p>Immunohistochemistry was performed to assess neuronal activation by c-Fos-immunoreactivity (ir) in wild-type mice treated with intracerebroventricular (i.c.v.) saline or CNTF (0.5 µg/ml). A–F: Representative photomicrographs showing expression of c-Fos-ir in the hypothalamic ARC, VMH, LH, dDMH, vDMH, PeV, and PVN regions in coronal sections of mouse hypothalami (as indicated on the images). Scale bar: 1 mm. Inset in each image represents a higher magnification of the boxed area. Scale bar: 100 µm. A and D represent negative control images for the anti-c-Fos antibody. DAB staining: nuclear brown (c-Fos). 3V, third ventricle. G: Bar graph showing the number of c-Fos-ir neurons in the hypothalamic regions at 2 h post-treatment. Data in the bar graph are expressed as mean ± SEM (n = 4 animals/group; *<i>P</i><0.05; **<i>P</i><0.01).