Learned preference for the limiting amino acid in rats fed a threonine-deficient diet.
Preference for an odor associated with protein is only seen in protein-deprived rats. We hypothesized that rats depleted of the amino acid threonine (THR) would prefer a flavored solution paired with a THR replete diet. Rats were given a flavored drink paired with THR-deficient (DEV) diet followed by a second flavor paired with a corrected (COR) diet. In choice testing, the animals clearly selected the COR-paired flavor, while control rats preferred the other flavor. This did not, however, differentiate between aversion to the DEV-paired flavor and learned preference for the COR-paired flavor. In subsequent tests, an unpaired flavor was given rather than the DEV-paired flavor. The COR-paired flavor was included in the test as before. In the second and third trials, using either DEV or a less profoundly deficient diet, animals depleted of THR selected the COR-paired flavor to a greater extent than control rats. We conclude that animals deficient in the essential amino acid, THR, show a learned preference for the flavor paired with repletion.
Gietzen
D W
DW
Department of Physiological Sciences, School of Veterinary Medicine, University of California, Davis 95616.
McArthur
L H
LH
Theisen
J C
JC
Rogers
Q R
QR
D000601:Amino Acids, Essential / Q000008:administration & dosage*; D000818:Animals; D001066:Appetite / Q000502:physiology; D001245:Association Learning / Q000502:physiology; D001362:Avoidance Learning / Q000502:physiology*; D003214:Conditioning, Classical / Q000502:physiology*; D005518:Food Preferences / Q000502:physiology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013649:Taste / Q000502:physiology*; D013912:Threonine / Q000172:deficiency*
D000601:Amino Acids, Essential; D013912:Threonine