(a) Immunochemical staining for GFP of a mouse infused with AAV in the LH; Scale bar correspond to 400 μm in the top panel and 200 μm in the bottom ones; (b) Left panel: Intra-LH infusions of AAV-Snd3 downward-shifted the dose-response curve in syndecan-3 KO mice (FR5). Dose F(6,102)=10.55, P<0.0001; AAV-Snd3 F(1,102)=4.596, P=0.047. Right panel: The dose-intake curve was shifted downward in AAV-Snd3-infused syndecan-3 KO mice (same mice as in left panel). Dose F(5,85)=148.4, P<0.0001; AAV-Snd3 F(1,85)=9.135, P=0.008; Interaction F(5,85)=5.443, P<0.001. n=9–10. (c) Left panel: Wild-type mice receiving intra-LH AAV-Snd3 reached lower breakpoints than AAV-GFP mice under a PR schedule. Dose F(6,90)=3.55, P=0.003; AAV-Snd3 F(1,90)=10.51, P=0.006; Interaction F(6,90)=2.311, P=0.04. Middle panel: the dose-response curve of wild-type mice was shifted downward by AAV-Snd3. Dose F(6,90)=3.415, P=0.004; AAV-Snd3 F(1,90)=9.075, P=0.009. Right: dose-intake curve was reduced by AAV-Snd3 in wild-type mice. Dose F(5,75)=60.09, P<0.0001; AAV-Snd3 F(5,75)=7.638, P=0.015; Interaction F(5,75)=2.915, P=0.019. n=8–9. Data are presented as mean±s.e.m. *P<0.05 and **P<0.01, AAV-GFP-infused versus AAV-Snd3-infused mice (LSD post-hoc test).