Microcomputer-assisted open field measures of rats given ethanol on postnatal days 1-8

This study examined direct effects of postnatally administered ethanol upon growth and adult open field behaviors in male rats. Charles Rivers CD albino rats (13 litters) were used in 5 groups; ethanol, Sustagen, pair-fed, handled, or unhandled. Experimental animals were intragastrically fed ethanol (Sustagen [Mead Johnson] vehicle) twice daily, comparable volumes isocaloric Sustagen, handled or left unhandled. Ethanol doses on postnatal days 1-8, respectively, were: 1, 2, 3, 4, 4, 3, 2, 1 g/kg. Ethanol-pups ceased weight gains at 4 g/kg; a handled pup, kept with a nonlactating female until its body weight matched its ethanol littermate, became a pair-fed control. Group body weights did not differ from day 21 throughout the experiment, day 154. Open field testing (day 120-124) used microcomputer programs to record event times and frequencies. Ethanol-treated rats had lower activity and longer start latencies (p less than 0.05) but did not differ on other computer-timed measures. Unhandled animals displayed some differences. When underfeeding effects are eliminated, ethanol (up to 4 g/kg) given on postnatal days 1-8 produced open field activity changes that persisted until day 120.