The elevated plus maze is often used to investigate anxiety in rats and mice. Combine EthoVision XT with the plus maze or your choice - with or without infrared backlit - to create the ideal solutions.

• Calculate a range of anxiety-related parameters automatically, such as the percentage of time spent in the
  open arms.
• Detect and analyze body elongation and immobility as measures of fear.
• Analyze behavior in relation to zones, such as the percentage of time spent elongated in a specific arm.
• No additional set-up or arena definition time in between tests; the rigid elevated stand and stable camera gantry guarantee a fixed position of camera and maze.
• Effortlessly track animals with different fur markings in sequence or track animals in darkness.

Introduction
The elevated plus maze is a well-characterized behavioral paradigm to investigate anxiety in rats and mice. The test is based upon the conflict between an innate aversion to exposed spaces and a tendency to explore new environments. The exposed places are represented by the maze’s two open arms and the two closed arms represent the safer places. Anxious animals will spend more time in the closed arms than less anxious animals. The test is typically used for the investigation of anxiety-related effects of drugs commonly prescribed for the treatment of anxiety disorders and compounds such as alcohol. In addition, the test is also used for behavioral phenotyping of rats and mice.
Combine EthoVision® XT with one of the mazes Noldus supplies, and you will have everything you need to conduct the elevated plus maze test. You can choose between a standard maze or a maze with infrared (IR) backlight. Both are available in two sizes: mice or rats. The maze creates the perfect conditions for EthoVision XT to track animals of any color and under all light conditions. 

How it works
The elevated plus maze consists of two opposing open arms and two opposing closed arms, together forming the shape of a cross and connected by a central square. When using the IR backlit maze, the combination of the infrared translucent material and IR light sources guarantee that EthoVision XT tracks the animal independent of its fur color and the surrounding light conditions. In a typical elevated plus maze set-up, a video camera is positioned above the maze. The camera sends images to the computer that is running the EthoVision XT software.

At the start of the trial, the animal is traditionally placed in the central square of the maze, facing an open arm. You can instruct EthoVision XT to automatically start and stop tracking, so there is no need to perform this manually. EthoVision XT will start tracking as soon as the animal is detected in the center square, and stop tracking as soon as the animals has spent a defined period of time in the closed arms.

EthoVision XT has several detection methods, so there is always one suited to your research. After data acquisition, you can select tracks or segments for analysis based upon independent variables or values of parameters. For instance, you can choose to only visualize those track segments belonging a specific treatment group, in which the animal was located in one of the open arms. EthoVision XT will show the different tracks in one screen. You can also choose to visualize integrated data to see the video, the track of one trial, and a plot of the values of selected parameters in one dynamic, synchronized view. 

The far most important parameters in the elevated plus maze test are the percentage of time spent in the open arms and the number of entries to these arms. With EthoVision XT, you can easily define each arm and the center square as separate zones, and combine zones to create cumulative zones. For instance, combine the two open arms into one zone and do the same for the two closed arms to make data selection and analysis even more practical, and easily compare the time spent in the open arms versus the closed arms.

Another important behavioral response in the elevated plus maze is the stretch-attend posture. This posture is characterized by the elongation of the animal’s body, and is often considered a fear response. In addition, the time spent immobile is also often used as a measure of fear. EthoVision XT can measure the time spent immobile and the elongation of the animal’s body, giving you the data you need to assess these fear responses.