Ontogenetic differences in the expression of odor-aversion learning in 4- and 8-day-old rats.
Two experiments investigated the ability of preweanling rats, 4 or 8 days of age, to form an odor-LiCl association across various CS-US delays. The results of the odor preference test indicated that 8-day-old subjects acquired an aversion to the CS+ odor when trained with either a 0 or 15 min CS-US delay, while 4-day-old subjects did not exhibit a reduction in preference for the CS+ at any of the CS-US delays tested. The absence of a reduction in preference for the CS+ by 4-day-old rats could not be attributed to their failure to acquire the odor aversion, however; they avoided a texture with which the CS+ odor was paired in a second order conditioning paradigm. The results suggest that outcomes appearing to represent age-related differences in associative learning may in some instances be more appropriately viewed as representing ontogenetic differences in the way in which acquired associations are manifested in behavior.
Miller
J S
JS
Center for Developmental Psychobiology, State University of New York, Binghamton 13901.
Molina
J C
JC
Spear
N E
NE
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn / Q000523:psychology*; D001245:Association Learning / Q000187:drug effects; D001362:Avoidance Learning / Q000187:drug effects; D002712:Chlorides / Q000633:toxicity; D003214:Conditioning, Classical / Q000187:drug effects; D005260:Female; D008094:Lithium / Q000633:toxicity; D018021:Lithium Chloride; D008297:Male; D011939:Mental Recall / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D012903:Smell / Q000187:drug effects
D002712:Chlorides; D008094:Lithium; D018021:Lithium Chloride