What maze has rodents find a hidden platform in a pool to test spatial learning?

The maze in which rodents find a hidden platform in a pool to test spatial learning is the Morris water maze.

Also called the Morris water navigation task, it places a rat or mouse in a circular pool of opaque water. An escape platform is submerged just below the surface, so the animal must use stable cues around the room to learn where the platform is located. Researchers track escape latency, path length, swimming speed, and search behavior.

Richard G. Morris developed the procedure in 1981 as a way to study spatial learning without relying on food deprivation or a maze filled with local odor cues. The platform’s position usually remains fixed while starting points vary, encouraging the animal to form a spatial relationship with external landmarks.

The test is often used in research on the hippocampus, memory disorders, drugs, and genetically modified rodents. It is not the same as the Barnes maze, which uses a dry circular platform with holes, or the radial arm maze, which tests choices among multiple arms.