The Morris water maze is used for measuring spatial learning and memory in laboratory rodents. Subjects swim in a large pool to find an escape platform submerged just below the surface of the water. Spatial cues around the maze help subjects learn the location of the platform. After several training trials, rodents typically learn to swim straight to the escape platform. Training consists of a several trials per day over a period of approximately 4-5 days. Investigators can measure latency to escape, distance taken to reach the escape platform, time spent in the correct quadrant of the maze, and velocity to measure how well a subject has learned the task. Optionally, a probe trial can be performed after training is complete where the escape platform is relocated or removed altogether and time spent searching the correct quadrant of the maze is measured during a brief trial. After the time limit is up, the subject is removed from the pool and placed back in its cage.
- Water maze
- Mobile device (iOS or Android) with the BehaviorCloud Camera app installed
- Tripod or mobile device mount
- Laptop or second mobile device
- Calibration pattern from app.behaviorcloud.com
Setting up the testing room
Environment: The testing room should be a quiet space with WiFi access. The room should be illuminated and spatial cues should be placed around the maze. For example, different shapes cut out of colored paper can be taped to the walls of the room. The maze should be set up several feet from where the experimenter sits.
Streaming: Log in to the BehaviorCloud Camera app and begin streaming. Mount the mobile device running the BehaviorCloud Camera app above the maze so the entire area is in full view. It is important for the mobile device and the maze to remain in the same positions throughout testing.
Controls: A laptop or a second mobile device should be set up where the experimenter plans to sit during trials. Log in to app.behaviorcloud.com to reach the experiment dashboard and create a new experiment.
Running a trial
Preparation: Animals should be brought into the testing room approximately 30 minutes before testing to acclimate to the environment.
Calibration: To get an accurate measure of distance traveled by each rodent, it is important to calibrate the system at the beginning of an experiment. From the laptop or second mobile device, click calibration and hold the checkerboard calibration pattern just above water level. A preview window will show the system automatically recognize the pattern and calculate a distance measurement. Click the arrow to continue to the next step.
Starting a trial: Click Experiment Video and then the plus icon to add a new subject. Select the mobile device that is being used for streaming, enter the subject ID, and enter the duration of the test in seconds. On the next screen, you will be prompted to clear the arena, which means to remove any animals, people, or other moving objects from the view. Then you will be prompted to insert the subject and begin the trial.
Finishing a trial: When the scheduled duration has elapsed, the test will automatically end and you will be prompted to enter the next subject ID. Repeat running subjects until you are finished.
BehaviorCloud makes your raw video data and analysis tools accessible from anywhere using your online account. At your desk in the lab (or at your favorite coffee shop), log in to your account and run your analysis.
Setting the boundary: Draw a circle to set a tracking boundary to specify the area to be analyzed. Click save.
Generate position data: Next generate XY position data for all of the subjects.
Set zones: Draw and label zones to specify the escape platform and the four quadrants of the maze. Click save.
Generate data files: Generate zoned activity data for all of the subjects and download the .csv file.
BehaviorCloud will provide data including latency to escape, distance taken to reach the escape platform, time spent in the correct quadrant, and velocity for each subject. These measures reflect the subject’s spatial memory of the escape platform. Analyzing how these values change over the course of training can describe how quickly a subject is learning the location. Subjects that take less time and distance to navigate to the platform are thought to have better memory of its location.
BehaviorCloud automatically tracks movement in the water maze so you can easily generate all the relevant variables you need to analyze spatial learning and memory. While you’re testing behavior in the water maze, don’t forget that BehaviorCloud also makes it easy to upload and analyze videos you’ve already recorded and even invite collaborators to contribute. Happy testing!