Characteristics and consequences of free-feeding ethanol ingestion during the first two postnatal weeks of the rat.

The present experiment used a free-feeding technique devised by Hall to compare ingestion of ethanol and water during postnatal days 3 to 12. More intake of ethanol than water was observed, subject to reasonably consistent individual differences in ethanol intake unrelated to body weight or general fluid intake. Relative to Low ethanol consumers, pups that ingested higher quantities of ethanol showed less "place" aversion for stimuli associated with ethanol ingestion. High ethanol consumers did not, however, show an absolute conditioned place preference relative to water-only controls, and they exhibited a conditioned aversion to the odor of ethanol. These results indicate that ethanol intake during the first two postnatal weeks is modulated by the early occurrence of individual differences and a disposition to drink more ethanol than water, but the reinforcement effects of ethanol at this age are unclear.