Figure 3. Loss of VTA NtsR1 neurons disrupts energy balance.

A) 8 wk old male NtsR1^Cre;GFP mice received bilateral injections of AAV-DTA or AAV-GFP in the VTA. B) Images show representative NtsR1-GFP (green) and TH (purple) expression from NtsR1^GFP and NtsR1^DTA mice 2 weeks after surgery. Scale bars =200μm. Abbreviations: ml=medial lemniscus, ip=interpeduncular nucleus. C–J) Metabolic assessment of NtsR1^GFP and NtsR1^DTA mice on chow diet over 4 days (3.1 kcal/g) (NtsR1^GFP n=7, and NtsR1^DTA n=13). C) Percentage change in body weight from starting weight and D) percentage of body fat determined via NMR spectroscopy. E) Chow intake and F) total locomotor activity as measured in TSE metabolic cages. G) Weight-adjusted energy intake and H) energy expenditure at 4 wk post surgery and I) weight-adjusted energy intake and J) energy expenditure measured at 16 wk post surgery. K–R) Metabolic assessment of NtsR1^GFP and NtsR1^DTA mice on HF diet (4.7 kcal/g) (NtsR1^GFP HF n=10 and NtsR1^DTA HF n=10) over 4 days. K) Percentage change in body weight from starting weight, L) percentage of body fat, M) HF diet intake and N) total locomotor activity. O) Energy intake and P) energy expenditure at 4 wk post surgery, and Q) energy intake and R) energy expenditure at 16 wk post surgery, normalized to body mass. For C–F and K–N, graphed data represent mean ± SEM, *p < 0.05, **p < 0.01, ***p < 0.001 ****p < 0.0001 analyzed by two-way ANOVA with Bonferroni post-tests. For scatterplots in G–J and O–R, data were analyzed using ANCOVA to account for body weight as a covariate and p values are indicated on graphs. See Fig. S3 for additional metabolic data.