The Barnes maze is a popular test for assessing spatial learning and memory in rats and mice.
Basically, the animal is placed in a brightly lit environment, on the top of the Barnes maze, which consists of a large round open platform provided with a fixed number of peripheral holes. In such an open environment, rats naturally seek a dark enclosed surrounding, which is provided in the form of a dark box (goal box) under one of the round holes around the perimeter of the platform. The amount of time required for the animal to locate the goal box using visuo-spatial cues surrounding the maze periphery is measured by the researcher.
The fact that the experiment is conducted with no dietary restrictions and less stress makes of this test an interesting alternative to the radial maze and water maze test for its use in the behavioural phenotyping of genetically-modified mice.