Central serotonin (5-HT) systems have a critical role in the regulation of appetite and body weight. Central serotonin 5-HT2C receptors contribute to the leptin-independent regulation of appetite . Liraglutide, a glucagon-like peptide-1 (GLP-1) receptor agonist used clinically to treat type 2 diabetes and/or obesity, induces feeding suppression in mice 1 h after administration . We previously reported that the acute anorexic effects of liraglutide in mice do not require central 5-HT and functional leptin receptor signaling . A recent report by Anderberg et al., however, suggested that brain-derived 5-HT is critical for maintaining weight loss induced by GLP-1 receptor activation and pharmacologic blockade of central serotonin 5-HT2A receptors using R-96544 attenuates the chronic anorexic and weight loss effects of central injection of exedin-4 (EX4) or intraperitoneal injection of liraglutide in rats .