Although liraglutide reportedly increases brain 5-HT levels in rats  and both liraglutide and serotonergic receptor agonists, like lorcaserin, reduced body weight and food intake in rats, the increase in brain 5-HT levels does not always induce reductions of food intake and body weight, especially in mice. Despite increased brain 5-HT levels, ob/ob mice display hyperphagia and obesity . The genetic inhibition of 5-HT synthesis in the brainstem decreases food intake and body weight in ob/ob mice and the wild-type mice . In addition, the pharmacologic inhibition of 5-HT synthesis in the brainstem induced by treatment with a high dose PCPA (500 mg/kg) or trans-2 PCPA decreases body weight and food intake in C57BL6J mice, db/db mice , and high-fat diet-induced obesity . Thus, the decrease in central 5-HT leads to the decrease in body weight and food intake in mice.