Barnes Maze: A Method for Assessing Spatial Learning and Memory in Lab Animals

Before beginning the Barnes Maze testing procedure, clean all of the maze components with water and 70% ethanol. When the components are dry, assemble the maze and randomly assign each mouse to a target hole to use throughout the testing period.

The holes can be labeled 1 to 20 on the bottom of the maze or on the outside of the maze perimeter where they are not visible from within the maze. To start a training test, replace the assigned hole disk with a 23 by 11 centimeter black box and use rubber bands and hooks to firmly attach the box to the maze.

Then, place a mouse onto the center of the Barnes Maze beneath a cup and allow the mouse to acclimate for 30 seconds. At the end of the acclimation period, begin the video recording and turn on the light and ultrasonic noisemaker.

Lift the cup via a string mechanism to avoid biasing the initial heading of the animal and start a timer behind an observation curtain. Track the animal's movements on a piece of paper with a diagram of the maze and use the diagram to analyze the mouse's search strategies as well as to determine the number of holes that were explored in the quadrant opposite the target.

When the mouse enters the target hole, cover the hole with a heavy opaque binder and turn off the ultrasonic noisemaker. If the mouse has not entered the target after 5 minutes, corral the animal into the target hole. Then, allow the mouse to remain in the target box for 1 minute undisturbed, making sure to turn off the ultrasonic noise. Then, return the animal to its cage.

When all of the mice have been tested, manually review their recording to track the overall movement of the mouse to determine the number of incorrect holes explored before and after the target is found, as well as the number of holes from the target hole to the first hole explored and any notable grooming behavior.