Strain distribution of mice in discriminated Y-maze avoidance learning: Genetic and procedural differences

The current study was conducted to characterize discriminated avoidance lea rning in mice by using a Y-maze task. In Experiment 1, the task parameters were manipulated, including the amount of time spent in the start arm, the amount of time to make the avoidance response, and the intertrial interval (ITI) using C57 x SJL F1 hybrid mice. Avoidance performance was significant ly improved with longer times to avoid the shock and longer ITIs. In Experi ment 2, mice from 4 inbred strains (BALB/cByJ, DBA/2J, C57BL/6J, and SJL/J) , an F1 hybrid (C57 x SJL), and 1 outbred strain (CD1) were tested with var ious ITIs. Strain differences were observed in avoidance learning, with BAL E, DBA, C57 x Sn and CD1 mice showing significantly better avoidance learni ng than C57 mice, which were better than SJL mice. These data demonstrate t hat Y-maze performance is significantly influenced by the genetic backgroun d of the mouse and the parameters of the task.