"AMPing up" our understanding of the hypothalamic control of energy balance.

AMP-activated protein kinase (AMPK) has emerged as a metabolic "fuel gauge," which oscillates between anabolic and catabolic processes that ultimately influence energy balance. A study in this issue of the JCI by Claret et al. now extends the role of AMPK in medial basal hypothalamic neurons (see the related article beginning on page 2325). These findings maintain AMPK signaling as a common cellular mechanism in proopiomelanocortin and neuropeptide Y/agouti-related protein neurons and links hypothalamic AMPK to coordinated energy and glucose homeostasis.