In a novel object recognition test, you need an accurate assessment of the animal's interest in the object. EthoVision XT provides detailed tracking of not only the center point, but also the nose point and tail base of your rat or mouse.

• Measure and analyze a large number of parameters automatically, such as the time spent exploring an object.
• Analyze exploration of the object using the parameter ‘head directed to zone’, when the head is within a certain radius of the object.
• Detect and analyze body elongation as a measure of curiosity and explorative behavior.
• Analyze behavior in relation to zones, such as total time spent with nose point in any of the object zones.
• Choose the size, shape, and color of the open field that fits the need of your research.

Introduction
Testing the ability of rats and mice to recognize a novel object in an  otherwise familiar environment is a very common practice to assess  object memory. In the novel object recognition test, the interest of  an animal in a novel object versus a familiar one, is measured and  compared. If the exploration of the novel and the familiar object is  equal, this can be interpreted as a memory deficit. 

The exploration of objects by the animal is traditionally defined as  approaching the object headfirst within a short distance. To be able  to measure this parameter, you need to know the head position of  the animal. EthoVision® XT is ideally suited to identify the nose point  of a rat or mouse. Combine EthoVision XT with one of the open fields  we supply, and video and computer equipment, and you will be able  to fully automate the novel object recognition test.

How it works
The basic set-up for a novel object recognition test consists of an  open field, a video camera, and a computer running EthoVision XT.  Noldus offers various open fields, including different sizes, seamless  versions, and PhenoTyper® cages. The camera is positioned above the  open field, and sends images to the computer for accurate tracking.  In practice, the animal is first subjected to a familiarization phase  before the actual experiment takes place. During this phase, the  animal becomes acquainted with the objects, their locations, and the  testing environment. When it is time for testing, one of the objects  is replaced by an unfamiliar one, and the time the animal spends  exploring the different objects is measured. 

During the experiment EthoVision XT accurately tracks the movement  and activity of the animal. In a novel object recognition test, it  is not only important to know where the animal is in relation to the  objects, it is also crucial to know how the animal is positioned relative  to the object. Therefore, EthoVision XT allows you to track the center  point, nose point, and tail base of rats and mice. With these data, the  software is able to measure and calculate a wide range of parameters,  such as head direction and elongation. To accurately measure exploration,  the program also calculates the total time the animal spent with  its nose point in the zone belonging to a certain object, while its body  center point is situated outside this zone.   

EthoVision XT enables you to create a trial list that includes independent variables, such as age, gender, or treatment group, and you  can use these variables for data selection. This means that you can  easily compare the performance of your animals between different  groups, such as ‘treated’ and ‘non-treated’. 

Another benefit of using EthoVision XT in a novel object recognition  test, is that it enables you to automate your experiment. Some  researchers assume that an animal exhibits a strong preference for  one of the objects if it has been exploring this object for 38 seconds  or longer. If you find it practical to automatically stop tracking at the  moment the animal has developed a preference for an object, you can  instruct EthoVision XT to automatically do so as soon as an animal  has been exploring an object for 38 seconds, or any other desired  period of time. 

There are many other benefits you can gain from using EthoVision XT in this set-up. For example, you can track animals in multiple open fields simultaneously. And if you are working under Good Laboratory Practice (GLP) compliance, EthoVision XT’s GLP will help you to keep track of what happened during every step of your research.