AGRP and Insulin resistance: As expected, stimulation of AgRP neurons in control ChR2AgRP; NPYwt/wt animals expressing mCherry in the ARC resulted in the induction of insulin resistance during an ITT while ChR2AgRP; NPYΔ/Δ mice expressing mCherry in AgRP neurons exhibited a profound protection from the induction of insulin resistance during the ITT (Fig. 5d, e, Supplementary Fig. 5a–f).