Win-Shift Radial Maze Training Procedures

During radial maze training, the rats are placed in the center of the maze with the entrance to 4 baited arms open. The remaining four non-baited arms are blocked by removable clear Plexiglass doors.After entering the open arms and consuming all of the pellets in the maze, the rats are returned to their home cage for a brief delay. They are then returned to the maze for a retention test.During the "win-shift" retention test, each of the 8 arms are open, however, pellets are now placed only in the arms that were previously blocked. Entries into the new baited arms are recorded as correct responses while visits to unbaited arms are scored as errors. Repeated entry into any arm is also considered an error. All subjects begin training with a 5 min delay between training and the "win-shift" retention test. After reaching a criterion of 80% correct (4 out of 5 correct responses) for two consecutive days, the animals are moved to a 15 min training retention interval. After achieving the 80% criterion for two consecutive days with the 15 min interval, subjects are moved to the testing phase of the study on the following day. On the test day, subjects are placed on the maze with the 4 arms blocked and 4 arms open and baited. After consuming the pellets in the 4 baited arms, subjects are removed from the maze and given a drug treatment and retained in the testing room for 18 hours before being administered the retention test. The procedures for the 18 hour retention test are identical to those used with the 5 and 15 min delay with all arms open but with food found only in the previously blocked arms. The number of errors or the mean percentage of correct responses the animals make in locating the pellets in the 4 new baited arms serve as  indices of retention.