Materials and Methods

First, four mice were introduced to a simple double T-maze. Two different entrances to the reward area were placed at different ends. These entrances gave the mice access to a playground. The playground consisted of toys, food, a wheel, tunnels, cotton bedding and different objects the mice could climb on. Each mouse was designated a specific entrance with the other entrance closed off. A green mat was placed at their designated entrance, so the mice would learn to associate entrance to the maze with this object. When optimal performance time was reached completing this simple T-maze, the mice were introduced to a more complex maze.

Figure 1: The setup of the initial T-maze used. Two mice were designated exit 1 and two mice were designated exit 2. Only their designated exit allowed them access to the reward, with the other exit closed off.



For the second maze, the mice were placed in an enclosed intermediate area where an entrance to the maze was located. At the maze entrance, a wooden block was placed so the mice would associate the maze entrance with this object. The mice were then conditioned to complete the maze. The same reward was given with the associated green mat placed at the playground entrance. The mice were again designated a specific playground entrance. This designation would prevent the mice from completing the maze by following the scent left by the previous mouse. Instead, they would have to complete the maze by remembering their designated path.

Figure 2: Design of the second maze used. The four experimental mice were placed in the intermediated area located at the maze entrance. A wooden block was placed in front of the maze entrance and a green place mat was placed in their designated exit. Only their designated exit gave them access to the playground, with the other exit closed off. Only their designated exit contained the place mat.

After 35 trials of completing the maze, the last part of the experiment was performed. The mice were placed in the intermediate area and both of the associated objects were placed at different ends. They were given access to the reward using this new entrance located in the intermediate area. The four mice were then allowed to complete the maze twice, but with no reward given. After these two maze runs, the mice were again placed in the intermediate area. A line was drawn to divide the intermediate area in half, with one end having the wooden block and the other end having the green mat. The time spent in each section was recorded for a minute. This process was repeated five times over a five day period.

Figure 3: Mice were placed in the intermediate area and allowed access to the reward through this new entrance. They were then allowed to run the maze but with both exits closed off and no access to the reward (playground). For the last part of the experiment, the mice were placed in the enclosed intermediate area and their time spent near each entrance was timed for one minute.

As a control, four mice that had no previous exposure to the maze or the associated objects were also placed in the intermediate area over this five day period. Their time spent in each section was recorded for a minute. This would test whether there was any significance or other variable present to account for the results of the experimental mice