Swiss mice received a single i.c.v. injection of vehicle (Veh) or 10 pmol AβOs, and their brains were analyzed by Fluorojade staining of degenerating cells 7 days after the injection. Representative images of Fluorojade staining in the hypothalamus of vehicle- or AβO-injected mice (n = 4/group). Scale bar = 100 μm in left panels (top and bottom) and 20 μm in right panels (top and bottom). Positive control (bottom left panel) was the hippocampus of a mouse that received one i.c.v. injection of quinolinic acid (36.8 nmol) and was analyzed 24 h after. 