Alcohol exposure during development alters social recognition and social communication in rats

The present study examined the effects of postnatal alcohol exposure via gastric intubation on social communication of diet preference and social recognition. Rats were placed in one of three treatment groups. All treatments occurred from postnatal day (PD) 2 through 10 and Experiments 1 and 2 were conducted when the rats reached 60 and 100 days of age, respectively. Alcohol-exposed pups received a 3.0 g/kg dose of ethanol in milk solution that was delivered by insertion of PE-10 tubing down the esophagus daily from PD 2 through 10. Intubated control animals underwent intubation without ethanol or milk. Nontreated control pups were weighed daily. In Experiment 1, a nonexperimental rat was initially given access to lab chow mixed with a spice and then housed with an experimental rat for 30 min. The experimental rat was subsequently given access to two diets—one that the nonexperimental rat had consumed and a novel diet. It was found that the alcohol-exposed females consumed a greater percent of the communicated diet than the control females. In Experiment 2, the experimental rats were first exposed to a juvenile for 5 min and then exposed to the same juvenile after a delay of 30 or 90 min. Investigation time was recorded in both sessions and a reduction of investigation time in the second session is an indicator of social recognition memory. Alcohol-exposed rats of both sexes had poorer memory of a juvenile than both control groups after a 90-min delay. Together, these data indicate that basic components of social behavior may be altered by alcohol exposure during development.