The role of conditioned taste aversion in the suppression of food intake by estradiol.
In three experiments, ovariectomized rats were given a familiar or novel diet prior to treatment with a brain-enhanced estradiol-chemical delivery system (E2-CDS, 1 mg/kg). Experiment 1 showed that food intake was suppressed in subjects receiving either diet, but animals given a novel diet initially showed a profound anorexia which eventually recovered to the moderate suppression of animals given the familiar diet. In Experiment 2, rats showed an aversion to a novel diet paired with the E2-CDS in a two-choice preference test given on Day 2 after the injection, indicating that the initial large reduction in intake was mediated by a conditioned taste aversion. However, no aversion was observed seven days after the E2-CDS, suggesting that the residual intake suppression was mediated by unconditioned aversion or appetite suppression. Experiment 3 showed that lengthening the postovariectomy time resulted in a taste aversion that persisted for a longer duration.
Ganesan
R
R
Department of Pharmacodynamics, University of Florida, Gainesville 32610.
Simpkins
J W
JW
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D001921:Brain / Q000187:drug effects; D003214:Conditioning, Classical / Q000187:drug effects*; D004337:Drug Carriers; D004958:Estradiol / Q000494:pharmacology*; D005247:Feeding Behavior / Q000187:drug effects*; D005260:Female; D007275:Injections, Intravenous; D051381:Rats; D011919:Rats, Inbred Strains; D013649:Taste / Q000187:drug effects*
D004337:Drug Carriers; D004958:Estradiol