Intake and behavioral responsiveness to taste stimuli in infant rats from 1 to 15 days of age.
Infant rats from 1 to 15 days of age received oral infusions of various taste solutions, and their intake of and behavioral responses to the infusions were observed. From 1 day of age on, pups responded to strong acid and quinine solutions with certain characteristic aversive responses and suppressed intake (Experiment 1). Although even very young (1- and 3-day-old) pups suppressed their intake of strong quinine and acid solutions, and rejected them by showing certain aversive responses (gaping and forelimb flailing), other components of the adultlike aversion response sequence (chin scraping and paw treading) did not appear until approximately 12 days of age. This suggests that the failure of pups to engage in chin scraping and paw treading prior to 12 days is not due to an inability to detect aversive solutions, but rather may be due to an immaturity in pups younger than 12 days of the neural substrates subserving these aversive responses. The emergence of chin scraping and paw treading to strong acid or quinine solutions was not influenced to any marked extent by either the deprivational state of the pup (Experiment 2a) or the site of the infusion (Experiment 2b).
D000367:Age Factors; D000818:Animals; D002951:Citrates / Q000494:pharmacology; D019343:Citric Acid; D004435:Eating; D005260:Female; D005508:Food Deprivation; D005518:Food Preferences; D006851:Hydrochloric Acid / Q000494:pharmacology; D008297:Male; D009055:Mouth / Q000502:physiology; D011803:Quinine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013395:Sucrose / Q000494:pharmacology; D013649:Taste / Q000502:physiology*
D002951:Citrates; D019343:Citric Acid; D013395:Sucrose; D011803:Quinine; D006851:Hydrochloric Acid