Figure 3.

Fasting induces pS6-IR in LepRb- and AgRP-expressing neurons in the MB-ARC. A, LepRb^EGFP mice were allowed to feed ad libitum (Ad Lib Fed) or were fasted for 24 h before treatment with leptin (Lep; 5 mg/kg, ip) or vehicle (Veh) for 1 h before the animals were killed and processing for the immunofluorescent detection of LepRb/EGFP (green) expression and pS6-IR (red). Top panels show representative images of pS6-IR alone (left) and merged pS6-IR and EGFP-IR images (right). LepRb/EGFP neurons that contain pS6-IR are plotted as mean ± sem (n ≥ 3 per condition; bars with different letters were significantly different by ANOVA, P < 0.05). B, Animals heterozygous for Agrp^LacZ were allowed to feed ad libitum or were fasted for 24 h before treatment with leptin (Lep; 5 mg/kg, ip) or vehicle (Veh) for 1 h before the animals were killed and processing for the immunofluorescent detection of AgRP/LacZ (red)-expression and pS6-IR (green). Top panels show representative images of AgRP (β-gal) alone (top), pS6-IR alone (middle), and merged β-gal and pS6-IR images (bottom). AgRP (β-gal) neurons that contain pS6-IR are plotted as mean ± sem (n ≥ 3 per condition; bars with different letters were significantly different by ANOVA, P < 0.05). 3V, Third ventricle.