Figure 6. Arc GABA+ but not AgRP neurons are necessary for ageing-related body weight gain.
a, Diagram showing injections of Kir2.1 vectors to bilateral Arc of 7-8 week old Vgat-Cre mice. b, Representative traces showing spontaneous activity of control (top) and Kir2.1-expressing Arc GABA+ neurons (bottom). c, Comparison in percentage of Arc GABA+ neurons that express c-Fos in response to overnight fasting between control and Kir2.1 mice, n=3/group with 2-sided unpaired Student’s t tests, t=12.17, df=4, **p=0.0003. d-i, Weekly body weight (d, two-way ANOVA tests, F(1, 120)=226.8, **p<0.0001 Kir2.1 vs mCherry, body composition in fat (e, t=6.816, df=11, **p<0.0001) and lean mass (f, t=5.015, df=11, **p=0.0004) measured at the 11th week after viral injection; food intake (g, t=4.923, df=8, **p=0.0012), O2 consumption (h, t=2.428, df=8, *p=0.0413) and locomotion (i, t=6.649, df=8, **p=0.0002) measured during the first week after viral injection when the body weight difference between groups was minimal, n=5/groups, all with 2-sided unpaired Student’s t tests in e-i. j-l, Body weight effects of Kir2.1 expression in AgRP neurons. (j) Diagram showing injections of Kir2.1 vectors to bilateral Arc of 7-8 week old AgRP-Cre mice. k, Comparison in percentage of AgRP neurons expressing c-Fos in response to fasting, n=3/group, 2-sided unpaired Student’s t tests (t=9.289, df=4, **p=0.0007). l, Comparison in weekly body weight between groups after viral injection, 2-way ANOVA, F(1, 120)=1.926, p=0.1645 Kir2.1 vs mCherry. All data presented at mean +/− sem.