Guidelines > Morris Water Maze Guideline
The Morris Water Maze Task is a behavioral test used to assess the spatial learning capacity of animals. In this test, the animal is placed in a round tank filled with opaque water containing an escape platform, which can be hidden (submerged) or not. Visual cues, such as colored shapes, are placed around the pool in plain sight of the rat. Various parameters are recorded, including the time spent in each quadrant of the pool, the time taken to reach the platform (latency), and total distance traveled.
In cue discrimination trials, the platform is randomly placed in the tank above the water surface. The animal is given a series of trials with different starting points. The time it takes for the rat to get on the platform is recorded.
In spatial discrimination trials, the platform is placed in the tank below the water surface. The platform remains in the same location relative to the visual cues in the room. The animal is given a limited amount of time to find the platform.
In probe trials, the animal is placed in the tank for a defined period of time without the platform. The time and path-length the animal spends in each quadrant is recorded.
The following materials are needed to perform the Morris Water Maze:
- A 1.2-2 meters in diameter round tank
- An adjustable (escape)platform of approximately 8-10 cm diameter
- Water.
- Spatial cues
- Towel, hair drier, heating pads, etc. These are used to dry the animals after they have finished their testing and to prevent hypothermia
The tank is placed in a well lit room and filled with clean water (can be made opaque with non-toxic dyes) the day of use at a level of approximately 8 cm below the rim of the tank. The water temperature is maintained between 26-28oC.
The platform is placed in a random location either 1 cm above or below the water level. The platform should not be placed close to the tank wall as they may be able to find it by swimming close to the wall.
The tank is divided in four quadrants and spatial cues are placed on specific areas on the room designating the four quadrants. Make sure that the animals can see the cues from their point of view.
The animal is placed in the tank and is given 60 seconds to find the platform. Animals that are unable to find the platform in 60 seconds are assisted to find the platform.
Animals are given time to rest in between trials.
The training schedule, number of trials per animal, rest time between trials will vary according to testing paradigm and should be approved by the IACUC prior to performing the test.
At the end of each training session, the rats are dried with disposable towels and placed in a warm cage until completely dry before moving them back to their permanent housing.
The tank is drained, sanitized with a quaternary ammonium solution, rinsed and let dry in preparation for the next session.
