The Elevated Plus Maze (EPM) is currently one of the most frequently used tests to study anxiety in small rodents.
The test is based on the aversion of rodents to open spaces and height. The EPM apparatus is elevated from the floor. The equipment is a four arm maze with two opposing open arms (lighted arms, without walls) and two opposing closed arms (sheltered arms, with walls). On the test day, the animal is placed in the center area facing the open arm. The behavior during the test session is recorded, and behavioral parameters such as time spent in the open and in the closed arms, number of visits in the open and closed arms as well as latency to enter the open arm are measured automatically.