The relative contribution of pre- and neonatal ethanol administration to changes in mice behavior.

Parent C57BL/10Bg and DBA/1Bg inbred mice were fed 10% ethanol in their drinking solution during mating and pregnancy and/or early post parturition period. The susceptibility to audiogenic seizures and the open field behavior of their offspring were tested at age 29--33 days. Our previous experiments have indicated that continuous exposure to ethanol during pre- and neonatal periods enhanced the susceptibility to audiogenic seizures in both strains and decreased open field activity only in the strain C57. The present study, while confirming previous findings, assessed the relative contribution of the prenatal and the neonatal administration of ethanol to the behavioral changes. Among C57 mice, the neonatal period was most important for the induction of changes in seizures, but prenatal exposure which alone had no effect, enhanced the outcome of neonatal administration. Among DBA mice either period induced seizures, but the contribution of the neonatal period was the most significant. Early ethanol administration affected open field behavior only in C57 mice. There was an additive interaction between the two periods (latency), no effect by any period alone but together they produced a full effect (ambulation), or that either period alone was sufficent to produce a full effect (defecation).