Latent learning about calcium and sodium.
We used the latent-learning paradigm to examine whether replete rats can recognize sodium and calcium and whether they use that knowledge to guide consumption when subsequently mineral deprived. Rats fed a nutritionally complete diet received four pairs of 17-h training trials. During one trial of each pair, the rats drank grape- or cherry-flavored water; during the other, they drank the other flavor mixed with 100 mM CaCl2 (experiment 1), 750 mM NaCl (experiment 2), or 584 mM (20% wt/vol) sucrose (experiment 3). The rats were then fed nutritionally complete, calcium-deficient, or sodium-deficient diet for 3 wk and were given a two-bottle preference test between the two flavors. Relative to rats fed complete diet, calcium-deprived rats had elevated preferences for calcium- and sodium-paired flavors but not sucrose-paired flavors. Sodium-deprived rats had elevated preferences only for sodium-paired flavors. These results provide evidence for the existence of innate calcium and sodium appetites in calcium-deprived rats. They indicate that these distinct appetites are centrally generated behaviors and are not simply due to peripheral alterations in taste perception.
Coldwell
S E
SE
Department of Psychology, University of Pennsylvania, Philadelphia 19104-6196.
Tordoff
M G
MG
D000818:Animals; D002118:Calcium; D002122:Calcium Chloride; D005518:Food Preferences; D007858:Learning / Q000502:physiology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time; D012964:Sodium; D012965:Sodium Chloride; D013395:Sucrose; D013649:Taste
D012965:Sodium Chloride; D013395:Sucrose; D012964:Sodium; D002122:Calcium Chloride; D002118:Calcium