Olfactory aversive conditioning in the newborn (3-hr-old) rat impairs later suckling for water and milk.
An olfactory conditioning paradigm tested whether newborn rats can acquire a conditioned aversion to olfactory events associated with their first postnatal meal 3-5 hr after birth. Exposure to lemon odor (conditioned stimulus [CS]) paired with intraoral infusions of 0.1% quinine (unconditioned stimulus) resulted in explicit conditioning. Responsiveness to a surrogate nipple providing water in the presence of the CS was significantly lower than the 3 control conditions. The conditioning dramatically suppressed responsiveness to a surrogate nipple providing milk, which normally is expressed voraciously in terms of sustained nipple attachment and milk intake. These findings suggest that as early as 3-5 hr after birth newborn rats are capable of aversive conditioning to odors in the context of suckling behavior.
Department of Psychology, State University of New York at Binghamton, Box 6000, Binghamton, New York 13902-6000, USA. bh08588@binghamton.edu
Michael E
ME
Nizhnikov
Evgeniy S
ES
Petrov
Norman E
NE
Spear
D000818:Animals; D000831:Animals, Newborn; D003213:Conditioning, Psychological / Q000502:physiology*; D005260:Female; D008297:Male; D008892:Milk; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012903:Smell / Q000502:physiology*; D013391:Sucking Behavior / Q000502:physiology*; D014867:Water
D014867:Water