Ontogenetic differences in the association of gustatory and tactile cues with lithium chloride and footshock

Using a double dissociation design with 15% sucrose solution and exposure to a heat lamp (34 degrees C) as CSs and 0.3 M LiCl and 1-mA footshock as USs, the present study found 15-day-old rats to show selective associations similar to those found in adults. Five-day-old pups, however, expressed similar sucrose aversions when this solution was paired with either LiCl or footshock, whereas they expressed heat aversions after heat-LiCl but not heat-shock pairings. Results are discussed with respect to previous data on selective associations in pups, current theories on selective associations, and ontogenetic differences in stimulus selection.