Lepr^flox/flox Syn-cre mice have disrupted neuronal leptin signaling outside the ARH and VMH. A, Representative images of EGFP immunoreactivity in coronal sections from R26^mTmG/+Syn-cre mice (right panels) and R26^mTmG/+ controls (left panels) demonstrate widespread Syn-cre-induced recombination in anatomically matched sections at the level of the arcuate nucleus (upper panels) and the NTS (lower panels). Representative images of recombination of Lepr^flox allele in indicated CNS regions (B) and peripheral tissues (C; with hypothalamus included for comparison), assessed by PCR of genomic DNA from male Lepr^flox/flox Syn-cre and Lepr^flox/flox male littermates, using primers mLepr101 and mLepr102. D, Abundance of wild-type (wt) Lepr-b cDNA in CNS regions of 8-week-old Lepr^flox/flox Syn-cre (n = 5) and Lepr^flox/flox (n = 4) male mice, assessed by quantitative RT-PCR with LeprE17 primers and expressed relative to Lepr^flox/flox hypothalamus. E, Representative images of p-STAT3 staining in hypothalamic nuclei (ARH, VMH, DMH, and LHA, top panels; ARH and PMV, middle panels; NTS lower panels) in brain sections from 10-week-old Lepr^flox/flox Syn-cre (n = 4) male mice and Lepr^flox/flox littermate (n = 3) controls, 45 minutes after injection of 2 μg/g leptin or vehicle, quantified in panel F. *, P < .05 between genotypes via Student's t test corrected for repeated measures.