title: Sodium Taste During Sodium Appetite.
abstract: Sodium appetite appears to be an excellent model to study the neural mechanisms of motivation. In this issue of Chemical Senses, experiments by St John (2016) challenge 2 hypotheses for how a systemic sodium deficit guides an animal to find and ingest more Na ions in the environment. Both hypotheses deal with modifications of the sensory neural code produced by Na+ions on the tongue. One envisions a change in the Na+signal amplitude. A reduction could make the strong Na+signals less aversive; an increase, weak signals more noticeable. The other hypothesis requires no changes in the identity or amplitude of the Na+signal, but a shift in its hedonic tone toward sweetness or reward. The results of the 3 behavioral experiments render both explanations unlikely but fail to suggest alternatives.
authors.affiliation: Department of Neural and Behavioral Science, College of Medicine, The Pennsylvania State University, Hershey, PA, USA rxn5@psu.edu.
authors.forename: Ralph
authors.initials: R
authors.lastname: Norgren
mesh_terms: D000818:Animals; D001066:Appetite / Q000187:drug effects / Q000502:physiology*; D004435:Eating / Q000187:drug effects / Q000502:physiology; D006801:Humans; D009042:Motivation; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage* / Q000378:metabolism / Q000494:pharmacology; D013649:Taste / Q000502:physiology*
chemical_list: D017673:Sodium Chloride, Dietary
keywords: behavior; motivation; sensory coding; sodium appetite