Utilizing a Reconfigurable Maze System to Enhance the Reproducibility of Spatial Navigation Tests in Rodents

This protocol provides a flexible maze experiment environment and allows the experimenter to perform multiple maze tasks in a single space. The main advantage of this technique is that the desired maze shape can be instantly configured by combining standardized parts. In addition, that system can be easily disassembled and reproduced for and This method contributes to the study of behavioral and physiological mechanisms of navigation.

It is also useful in a test body to screen for behavioral abnormalities in transgenic and knockout animals. To begin, insert towers with baseplates into the punching board to form a T-shaped framework of the maze. Attach pathways to the upper part of the towers, and replace the pathway in the delayed area with a treadmill.

Attach feeders to each edge of the maze, and then attach movable walls to the left and right branches. For the task execution, start up and connect the control box, the microcontroller, and the PC.Write a program to set up the task schedule and receive the parameters needed for the experiment on the microcontroller, and then execute a task. Construct the desired maze shape, move the rats from the home cages, and place them in the arbitrary position of the maze.

Allow the rats to freely explore the constructed maze for 10 minutes to become habituated. Set up a program to perform the delayed alternation task with the treadmill and change the shape of the maze if necessary. Place the rats at an arbitrary position in the maze and execute the training or test of the delayed alternation task.

Return the rats to the home cage after each task and wipe the maze thoroughly with 70%ethanol after each rat. Wait for at least 5 minutes before using the maze again. For the animal trajectory, record the animal behavior during the delayed alternation task with a ceiling-mounted digital video camera.

Finally, track the running trajectories using markerless pose estimation software based on images captured at 50 frames per second. The images of the reconfigurable maze test for rats are shown in this figure. The pathway parts were reconfigured into several shapes in a single environment.

The images shown here represent the reconfigurable maze test for mice. These mazes were placed with feeders and movable walls at any location. The maze shape changes gradually during the train and test phases of the delayed alternation task.

The type of feeder used in the task is indicated by a colored box. The running trajectories of a representative rat are shown here. These graphical images represent the behavioral performance of the rats for 4 days, from the start of the training to the end of the test.

The task completion time for each training phase and the first day of the test phase are shown here. The percentages of correct choice responses in the delayed alternation test are presented in this figure. The dotted lines indicate the chance levels.

The reconfigurable maze assembly time is presented in this figure. The linear track was modified into a T-shaped maze with the addition of pathways, feeders, and a treadmill. Five experimenters performed three trials each, and all trials were performed on the same day.

It is important to place the maze parts correctly on the floor with holes. By using the baseplate to determine the layout, maze experiment can be performed with high reproducibility.