Postnatal high-peak blood ethanol concentration and external cue-based discrimination learning and reversal in the preweanling rat: comparison with memory-based discrimination learning.

Postnatal exposure to ethanol that produces high-peak blood ethanol concentrations (HP-BEC) in artificially reared infant rats affects hippocampal neuroanatomy and discrimination learning based on memorial cues from a patterned (single) alternation (PA) schedule in preweanling rats (P. L. Greene, J. L. Diaz-Granados, & A. Amsel, 1992). In the present experiments, discrimination by preweanling rats exposed to ethanol in the same way was tested with nonmemorial, external cues. In this external cue-based discrimination and in its reversal, ethanol-exposed rats were not different from normal or artificially reared controls whether the cues were presented in a PA or random manner, although there was some evidence that the memorial cues from the PA schedule contributed to learning a discrimination based on external cues, suggesting that the deficit reported earlier in ethanol-exposed rats is a memorial deficit and not a general discrimination deficit.