FIG. 3.

Leptin-induced STAT3 signaling is reduced in POMC neurons of POMC-Socs3-OE mice. A: The 6-week-old control and POMC-Socs3-OE mice were injected with either saline or leptin (3 mg/kg), and perfused 45 min later. Double immunofluorescence analysis was carried out to examine pSTAT3 in the POMC neurons using antibodies against Tyr705-STAT3 (green) and ACTH (red). B: Number of pSTAT3-positive cells showed that leptin-induced pSTAT3 was reduced in the POMC but not other arcuate neurons in the mutant mice. C: Percentage of POMC neurons that are pSTAT3 positive upon saline or leptin treatment in control and mutant mice. n = 3–5 sections per mouse from 3–5 mice per group between bregma −1.22 and −1.58. Data represent mean ± SEM. *P < 0.05, between controls and mutants as determined by Student t test. (A high-quality digital representation of this figure is available in the online issue.)