title: Effects of chlordiazepoxide and imipramine on maze patrolling within two different maze configurations by psychogenetically selected lines of rats.
abstract: Male rats of two lines of rats psychogenetically selected and bred for extremes in performance in shuttle box avoidance received an acute IP injection of chlordiazepoxide (CDP; 2.5, 5.0, 10.0 mg/kg), imipramine HCl (IMI: 0.33, 1.0, or 3.0 mg/kg), or vehicle. The rats were placed, 35 min after injection, in an enclosed maze with either a simple configuration with an unilluminated central arena or a complex configuration with a brightly illuminated central arena, and spontaneous maze patrolling was evaluated. Total locomotor activity during the 6-min maze test was significantly reduced by 5--10 mg/kg CDP for both RHA/Verh and RLA/Verh lines of rats in both the simple and the complex maze configurations. Treatment with 10 mg/kg CDP reduced the total explored area for both rat lines in both maze configurations. In addition, the maze area explored by RHA/Verh rats was also reduced by 5.0 mg/kg CDP for the simple configuration and by 2.5 and 5.0 mg/kg CDP for the complex configuration. Entry into the unilluminated central field of the simple maze was reduced by 5--10 mg/kg CDP only in RHA/Verh rats. In contrast, 2.5 mg/kg CDP significantly increased entry into the brightly illuminated central arena of the complex maze for the RLA/Verh rats. The doses of IMI used were without effect on the parameters of maze patrolling behavior evaluated, with the single exception that the locomotor activity of RHA/Verh rats tested in the simple maze configuration was decreased by 3.0 mg/kg IMI. The results indicate that, although the effects of CDP were generally similar for total activity and the area explored in the two psychogenetic lines investigated, there was a qualitative difference in its effect on entry into an illuminated arena.
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D002707:Chlordiazepoxide / Q000494:pharmacology*; D004193:Discrimination Learning / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005106:Exploratory Behavior / Q000187:drug effects; D007099:Imipramine / Q000494:pharmacology*; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D009949:Orientation / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D012641:Selection, Genetic
chemical_list: D002707:Chlordiazepoxide; D007099:Imipramine