Figure 2
POMC neurons from the Arc project to the VTA: Cholera toxin B (CTB)-immunoreactive (IR) neurons in the arcuate nucleus after injecting the retrograde tracer CTB into the ventral tegmental area (VTA). A few scattered CTB-IR neurons (arrowheads) appear in the arcuate nucleus as demonstrated at three rostro-caudal levels (a: Bregma −2.04 mm, b: Bregma −2.40 mm, and c: Bregma −3.84 mm). (d) Immunofluorescent detection of POMC (green) and CTB (red) in hypothalamic sections shows co-localization (yellow in color) in the arcuate nucleus. (e) The enframed area in d is further magnified to demonstrate the double-labeled cell (yellow arrow). (f) Another arcuate section showing POMC-IR neurons (green); one of these neurons also immunoreactive for CTB (in the enframed area; (g and h)).
