Morris Water Maze Experiment

Summary

The Morris water maze is a well-accepted tool used to document the involvement of the hippocampus in a behavioral task.

Abstract

The Morris water maze is widely used to study spatial memory and learning. Animals are placed in a pool of water that is colored opaque with powdered non-fat milk or non-toxic tempera paint, where they must swim to a hidden escape platform. Because they are in opaque water, the animals cannot see the platform, and cannot rely on scent to find the escape route. Instead, they must rely on external/extra-maze cues. As the animals become more familiar with the task, they are able to find the platform more quickly. Developed by Richard G. Morris in 1984, this paradigm has become one of the "gold standards" of behavioral neuroscience.

Protocol

Setting up the water maze

1. The main component of the water maze set up should be a round pool, about 6 feet in diameter and about 3 feet deep. If you are recording the task with a video camera, make sure all sides of the maze are within the camera’s field of view.
2. Fill up the water maze with tap water, which should be close to 26°C. This may take several hours, so should be done well in advance. Periodically check the water temperature so that it is within one degree of 26°C.
3. Place the escape platform in the center of the pool. During training, it must be exposed, one inch above the water. This teaches the rat that there is a p....

Discussion

The water maze task was development by Morris ⁵. This task can be altered in numerous ways to investigate working memory, reference memory and task strategy ⁶. The procedure described here contains two critical variables which represent a deviation from other versions of the water maze: pretraining, and testing on a single day.

Pretraining - the hippocampus is involved in spatial/relational memory ^7-8. The water maze specifically tests spatial.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
SMART System	San Diego Instruments			This system is not a requirement – there are many other behavioral systems on the market.