Periadolescent alcohol alters adult behavioral characteristics in the rat.

Long-Evans hooded rats were given 5% alcohol (EtOH), 10% EtOH or tap water as sole fluid from postnatal day 21 (P21) to P70. The 10% EtOH group drank 26% less and 10% EtOH males gained 7.6% less weight than the tap water control group. There were no significant consumption or weight differences between 5% EtOH and control subjects. At P105, 35 days after the conclusion of alcohol dosing, we conducted several behavioral tests. Males in the 10% group drank 67.8% more alcohol than controls in a two-bottle preference test. On a DRL-20-s operant reinforcement schedule, a difficult timing task dependent upon limbic structures, subjects in the 10% group had higher barpress rates, while those in the 5% group had lower barpress rates than controls. On this task, 10% females received fewer reinforcements, while both 5% and 10% males earned more reinforcements than controls. Efficiency ratios were lowest for 10% females and highest for 5% males. Males in the 5% group had shorter latencies than controls to find the platform in a Morris water maze and were significantly more likely than controls to initially find the platform. These data suggest that EtOH consumption during periadolescent development may have long-lasting neurobehavioral effects.