Knowledge Base

Introduction

The Radial Arm Maze Test

The radial arm maze was designed to measure spatial learning and memory in rats (Olton and Samuelson, 1976; Olton, 1978, 1985). The original apparatus consists of eight arms, each about 4 feet long, and all radiating from a small circular central platform. At the end of each arm there is a food site, the contents of which are not visible from the central platform.

The design ensures that, after checking for food at the end of each arm, the rat is always forced to return to the central platform before making another choice. For example, when investigating working memory, all arms are provided with a food reward and the animal should visit each arm only once.

Correct performance of the radial maze task requires intact spatial memory abilities. Performance is affected by hippocampal impairment and a variety of pharmacological agents (e.g., Janitzky et al. 2011).

References

• Janitzky, K, Schwegler, H., Kröber, A., Roskoden, T., Yanagawa, Y. & Linke, R. (2011). Species-relevant inescapable stress differently influences memory consolidation and retrieval of mice in a spatial radial arm maze. Behavioural Brain Research, (1), 142-148.
• Olton, D.S. (1978). Characteristics of spatial memory. In: Hulse S.H., Fowler H, Honig W.K. (Eds.), Cognitive processes in animal behavior, Hillsdale, NJ: Lawrence Erlbaum Associates, 341-373.
• Olton, D.S. (1985). The radial arm maze as a tool in behavioral pharmacology. Physiol. & Behav., 793-797.
• Olton, D.S., & Samuelson, R.J. (1976). Remembrance of places passed: Spatial memory in rats. Journal of Experimental Psychology: Animal Behavior Processes, 97-116.
• Wenk, G.L. (2004). Unit 8.5A Assessment of Spatial Memory Using the Radial Arm Maze and Morris Water Maze, in: Current Protocols in Neuroscience, John Wiley and Sons, Inc.

Physical Setup

The following suggestions are specifically to optimize video tracking:

• The camera should have a good view of the entire region the animal can be in. The arena should fill the field of view.
• There must be maximum contrast between the background and the animal. If you use white animals in the maze, make sure the floors of the arms are dark and vice versa. Preferably, the floor of the room should be the same color (and matted) as the maze, contrasting with the animal.
• Lighting should be uniform and even with no shadows.
• If you have reflections in your image, EthoVision XT may confuse those reflections with your subject, and track the reflections rather than your animal. To prevent reflections, place indirect lighting above or around the maze. 'Globe' type bulbs twice the diameter as standard light bulbs are ideal. They should be close enough to the maze so that there is no direct line of sight between the bulbs and the camera lens. The light should reflect off the walls and ceiling, so that it only reaches both the lens and radial maze indirectly.

Source: EthoVision XT 18 - Application Manual, Noldus Information Technology