A recent study showed that the AGRP neuron-specific knockout of the vesicular GABA transporter (Vgat) caused reduced synaptic release of GABA; these knockout mice were lean, resistant to obesity, had increased locomotor activity, and had an attenuated hyperphagic response to ghrelin [41]. The gene discussed is SLC32A1; the disease is obesity due to melanocortin 4 receptor deficiency.