Fig. 3

A decrease in NPY expression in the ARC by Fgf11 knockdown reduces NPY projection into the PVN, increasing PVN TH expression in HFD-fed mice. A–D Neuropeptide expression in mice fed HFD for 2 weeks after ARC Fgf11 knockdown. E Representative confocal images of in situ hybridization of mRNA of Fgf11 and Npy and corresponding DAPI nuclear counterstaining in the ARC. The Fgf11 sense probe was used as a negative control. Arrowheads show Fgf11 mRNA–positive cells. Arrows indicate Npy mRNA–positive cells. Scale bar = 20 μm. F Coronal sections of the ARC and G relative immunofluorescence quantification of ARC of mice fed HFD for 2 weeks after ARC Fgf11 knockdown. H Coronal sections of the PVN and I relative immunofluorescence quantification of PVN of mice fed HFD for 2 weeks after ARC Fgf11 knockdown. Sections were immunostained for NPY; confocal microscopy acquisition settings were the same for both non-silencing shRNA control and shFgf11. Scale bars F 50 μm, H 100 μm. J Th mRNA expression in a micro-dissected sample of the PVN of ARC Fgf11 knockdown mice fed HFD for 2 weeks. K Representative confocal images of double immunostaining for NPY and TH in the PVN 2 weeks after injection of non-silencing shRNA control or Fgf11 shRNA into the ARC and L relative immunofluorescence quantification of TH. Arrows denote NPY-immunoreactive boutons. Scale bar = 5 μm. M Number of NPY-positive axon terminals adjacent to TH neuron. *p < 0.05 and **p < 0.01 (non-silencing shRNA control versus shFgf11). n = 3–10 mice/group