Ghrelin mediates GLP-1R localization on VANs. (A) In a fasted state, ghrelin restricts GLP-1Rs on VANs to the cytoplasm; therefore, exogenous GLP-1 cannot access its receptors and has no effect on food intake. (B) In a refed state, when ghrelin concentrations are low, GLP-1Rs are present in the plasma membrane; therefore, exogenous GLP-1 can bind to its receptor and induce satiation. FI, food intake; GLP-1, glucagon-like peptide 1; GLP-1R, glucagon-like peptide 1 receptor; VAN, vagal afferent neuron.