Profound and Redundant Functions of Arcuate Neurons in Obesity Development

The current obesity epidemic faces unmet mechanistic insights. It is known that the acute activity changes of a growing number of brain neurons rapidly alter feeding behaviour; however, how these changes translate to obesity development and the fundamental mechanism underlying brain neurons in controlling body weight remain elusive. Here, we show that chronic activation of hypothalamic arcuate GABAergic (GABA+), agouti-related protein (AgRP) neurons or arcuate non-AgRP GABA+ neurons all leads to obesity, which is similar the obese phenotype observed in ob/ob mice. Conversely, chronic inhibition of arcuate GABA+, but not AgRP neurons, reduces aging-related weigh gain and corrects ob/ob obesity. These results demonstrate that the modulation of Arc GABA+ neurons is a fundamental mechanism of body weight regulation and that arcuate GABA+ neurons are the major mediator of leptin action with a significant and redundant role in obesity development.