A latent cue preference based on sodium depletion in rats.

Three experiments show latent (or incidental) learning of salt-cue relationships using a conditioned cue-preference paradigm. Rats drank a salt solution while confined in one compartment and water in an adjacent, distinct compartment on alternate days. When given access to the two compartments with no solutions present, sodium-deprived rats preferred their salt-paired compartments; normal rats preferred their water-paired compartments. Reversing the deprivation states of the two groups reversed their preferences. These results show that rats can latently acquire associations between environmental cues and the taste of salt, and can use this information flexibly to guide behavior based upon internal cues produced by sodium deprivation.