Figure 1.

Phosphorylation of S6 in response to fasting and leptin in the MB-ARC and VMH. A, Wild-type (+/+) animals under ad libitum-fed (Ad Lib Fed) or 24-h-fasted conditions treated with leptin (Lep; 5 mg/kg, ip) or vehicle (Veh) for 1 h before the animals were killed. B, Ad libitum-fed Lep^ob/ob mice. C, Overnight (∼16-h) fasted +/+ mice (treated with leptin or vehicle, as indicated) that were processed for immunohistochemical analysis of pS6-IR. Top panels show representative images of immunofluorescent detection of pS6-IR, whereas the graphs below show the fold induction (or total counts) of the number of pS6 cells in the MB-ARC and VMH. Data were quantified and plotted as mean ± sem (n ≥ 3 per condition; bars with different letters were significantly different by ANOVA, P < 0.05). *, P < 0.01; **, P < 0.001 by Student’s t test; P value of trend as indicated in B. 3V, Third ventricle.