An alternative neural basis underlying leptin resistance.

Overconsumption of a palatable Western diet, a condition linked to central leptin resistance, contributes extensively to the current obesity epidemic. In this context, intensive efforts have focused on detailing the molecular mechanisms underlying leptin resistance. Here, we demonstrate that chronic inhibition of hypothalamic arcuate GABAergic neurons (ArcGABA) effectively reduced diet-induced obesity (DIO). Interestingly, palatable food exposure increased the activity level of ArcGABA neurons, which do not express the leptin receptor (non-LepR neurons; nonresponsive to leptin). Chronic activation of ArcGABA non-LepR neurons led to massive obesity, which was associated with normal leptin-induced pSTAT3 signaling but phenotypic leptin resistance; i.e., high leptin levels failing to reduce obesity. In contrast, chronic inhibition of ArcGABA non-LepR neurons effectively prevented and reversed DIO, suggesting a potential anti-obesity treatment strategy. These results reveal that obesogenic stimulation of ArcGABA non-LepR neurons, even with intact leptin-pSTAT3 signaling, results in obesity, identifying a novel neural basis underlying leptin resistance.