In this test the animal is required to swim in a tank of opaque water until it finds a submerged platform that it can mount to escape the water. Presumably, the animal uses specific visual cues placed around the outside of the tank to learn where the platform is located. An animal that is able to remember the cues will find the platform more quickly each time it completes a trial swim. Animals are initially given a series of “learning trials” in which they are allowed to swim in the tank until they find the platform. Each learning trial lasts a specific amount of time and the time between trials must also be specified. Following this, a “probe trial” is run in which the submerged platform is removed and the time the animal spends swimming in the quadrant of the tank where the platform was previously located is measured. Animals that have learned the position of the platform will spend most of their time in the quadrant where the platform was previously located. Animals that are poor learners will spend time searching other areas of the tank.

Morris water maze was originally developed for rats because of their fondness of water, but this characteristic may sometimes be of concern because sometimes rats are reported to continue swimming even after finding the platform. In mice, performance in this test is highly dependent on genetic background. Special consideration must be given to the use of this test in mouse strains or genotypes with reduced ability to navigate using spatial cues or to swim, (e.g. blind mice may perform poorly for reasons other than bad memory). In addition, mice with other physiological or behavioural traits such as impaired thermogenesis or high anxiety levels may also perform poorly in this test1.


1. Terry AV Jr. Spatial Navigation (Water Maze) Tasks. In: Buccafusco JJ, editor. Methods of Behavior Analysis in Neuroscience. 2nd edition. Boca Raton (FL): CRC Press; 2009. Chapter 13. Available from: