Fig. 6: Photostimulation of VTAglutamate-only neurons decreases feeding behavior, while photostimulation of VTAGABA-only neurons does not modify feeding behavior.
A Timeline for feeding experiment. B VTA injection of Con/Foff viral vectors in vglut2-Cre/vgat-Flp mice and VTA photostimulation. C–D Photostimulation of VTAglutamate-only neurons increased feeding initiation latency (C; group × phase: F(1,18) = 15.93; p = 0.0009) and decreased the amount of food eaten (D; group × phase: F(1,18) = 5.91; p = 0.03) in Glu-only-ChR2-eYFP mice (n = 10) but not in Glu-only-eYFP control mice (n = 10). E VTA injection of Coff/Fon viral vectors in vglut2-Cre/vgat-Flp mice and VTA photostimulation. F–G Photostimulation of VTAGABA-only neurons decreased the feeding initiation latency after termination of photostimulation (F; group × phase: F(1,17) = 9.07; p = 0.008) without modifying the amount of food eaten (G; group × phase: F(1,17) = 3.78; p = 0.07) in GABA-only-ChR2-eYFP mice (n = 10) but not in GABA-only-eYFP control mice (n = 9). Light-blue rectangles indicate VTA photostimulation. Differences in the amount eaten or the latency to start eating were calculated as the values obtained the 5th day of the experiment minus the values obtained the 4th day of the experiment, and are presented as mean ± SEM. Two-way ANOVA with Tukey HSD post hoc test. *p < 0.05, ***p < 0.001, against eYFP mice; ++p < 0.01, +++p < 0.001, against the laser phase. Source data are provided as a Source Data file.
