Neural Control and Modulation of Thirst, Sodium Appetite, and Hunger

The function of central appetite neurons is instructing animals to ingest specific nutrient factors that the body needs. Emerging evidence suggests that individual appetite circuits for major nutrients—water, sodium, and food—operate on unique driving and quenching mechanisms. This review focuses on two aspects of appetite regulation. First, we describe the temporal relationship between appetite neuron activity and consumption behaviors. Second, we summarize ingestion-related satiation signals that differentially quench individual appetite circuits. We further discuss how distinct appetite and satiation systems for each factor may contribute to nutrient homeostasis from the functional and evolutional perspectives. Oka and colleagues describe the distinct neural mechanisms that suppress sodium, water, and food appetites in response to the sight, smell, taste, and ingestion of these nutrients.