Aversion learning in 5-day-old rats: Taste-toxicosis and texture-shock associations

• Published in: Journal of comparative & physiological psychology Vol. 94; no. 4; pp. 734 - 745
• Main Authors: Gemberling, Gail A, Domjan, Michael, Amsel, Abram
• Format: Journal Article
• Language: English
• Published: United States American Psychological Association 01-08-1980; Williams and Wilkins Co
• Subjects: Animal; Animals; Animals, Newborn; Association Learning - drug effects; Aversive Stimulation; Avoidance Learning - drug effects; Conditioned Suppression; Dose-Response Relationship, Drug; Drugs; Electroshock; Learning - drug effects; Lithium; Lithium - poisoning; Rats; Saccharin; Stimulus Intervals; Taste - drug effects; Taste Stimulation
• ISSN: 0021-9940
• DOI: 10.1037/h0077706

Five-day-old Holtzman rats that received a single pairing of a novel saccharin flavor (NF) with lithium (Li) treatment learned to suppress ingestion of saccharin on subsequent occasions (Exp I). This NF aversion (AV) learning was inversely related to the interval (IN) between the NF experience and drug administration, with significant AVs being learned with INs of 0 and 30 min but not with INs of 60 and 90 min (Exp II). Conditioning was observed when hypertonic Li served as the UCS but not with isotonic Li or hypertonic saline injections (Exp III). AV learning in infant Ss was shown to be a result of the joint action of 2 factors--pure drug effects and the somatic pain and irritation produced by the tonicity of the injected agent. Taste AV learning was specific to the drug-paired NF, and evidence is presented suggesting that 5-day-old rats display a natural hesitancy to consume novel edibles (neophobia) (Exp IV). In Exp V, 5-day-old Ss selectively associated NF stimuli with the gastrointestinal consequences of Li injection but not with cutaneous shock and selectively associated tactile stimuli with shock but not with the gastrointestinal consequences of Li. (29 ref)