Effects of physostigmine on shuttle avoidance in rats exposed prenatally to ethanol.

Shuttle avoidance performance following pretreatment with physostigmine was assessed in 85- to 100-day-old rats whose mothers consumed a liquid diet consisting of 35% ethanol-derived calories (EDC) during pregnancy. Offspring of pair-fed (0% EDC) and ad lib lab chow (LC) dams served as controls. Animals received either 0, 0.1 or 0.2 mg/kg physostigmine sulfate prior to acquisition training in a shuttle avoidance apparatus. Training consisted of 50 trials/day for 4 days. Thirty-five percent EDC rats made fewer avoidances than controls during acquisition training. Treatment with physostigmine reduced the number of avoidances made, and did so similarly for all prenatal treatment groups. Escape latencies were not affected by prenatal treatment, although they were increased by physostigmine administration prior to training. Neither prenatal treatment nor physostigmine treatment affected activity as measured by the number of intertrial crossings while in the apparatus. These data indicate that alcohol-exposed animals did not respond differentially to physostigmine relative to controls, suggesting that cholinergic dysfunction may not underlie the prenatal alcohol-induced deficit in active avoidance.