The study of social interaction in rodents is a common paradigm for research on anxiety, aggression, and phychiatric disorders. EthoVision XT allows you to accurately track multiple animals simultaneously.

• Track the paths of up to sixteen animals within one arena automatically.
• Automatically analyze social behaviors such as approach/avoidance, contact of individual body points, or interactions of two or more animals.
• Analyze velocity, heading, and distance moved of each animal, as well as individual behaviors such as immobility as measure of fear.
• Choose the size and shape of the open field, suitable to the purpose of your research.

Introduction
Social interaction tests in rodent models have been used extensively  for research on anxiety, aggression, sexual behavior, and psychiatric  disorders such as schizophrenia. Distance between animals (nosenose  or nose-tail contact) and relative movement towards or away  from each other can be important indicators of approach/avoidance  behavior, sexual behavior, or other kinds of social behavior.

EthoVision® XT provides you with the ideal tool to fully automate your  research on social interaction. You can use it to automatically track  and calculate a range of social parameters. Because you can also track  the different body points of your animals, you can even discriminate  between nose-nose or nose-tail contact, for example, allowing you to  assess anything from resident-intruder tests to sexual behavior. Combine  EthoVision XT with an open field or PhenoTyper® cage to create a  complete solution for social interaction tests.  

How it works
With EthoVision XT you can track multiple animals in one arena, allowing  you to investigate a range of social parameters. EthoVision XT can  determine which animals is which, by a simple color marker placed on  your animal. At the same time, the body contour of each one of your  rats or mice, and their nose point, center point, and tail base are still  recognized. You can also choose to track just the color marker itself.  With a range of detection methods to choose from, and EthoVision XT’s  highly advanced tracking technology, you can be sure that all of your  animals are accurately tracked. Even in difficult circumstances, such  as uneven lighting or multi-colored animals, EthoVision XT will not  let you down.

In a typical social interaction set-up, your animals are tested in an open  field or home cage environment. A camera positioned straight above  the arena sends video images to the computer running the EthoVision  XT software. To automate the test completely, you can program Etho-  Vision XT to start and stop tracking when specific conditions are met.  For example, start tracking 5 seconds after the animals have been  detected in the arena, and stop exactly 10 minutes after that.

EthoVision XT calculates a range of parameters related to the animal’s  path, location, the path shape, as well as individual and social behaviors.  You can choose to calculate the distance between two animals or  let EthoVision XT tell you when the animal is in or out of the proximity  of another animal, with user-definable thresholds. Other social  parameters are based on the position and movement between animals.  The relative movement parameter tells you whether two animals were  moving towards each other, from each other, if there was no relative  movement, or if the animals were too far away from each other for  social interaction to take place. Because the changes of position  between two animals have a smaller effect when animals are further  away from each other, EthoVision XT also calculates the net relative  movement. In this case, the absolute distance between these animals  is taken into account.

Each social parameter tells you something about the relative position  or movement from one animal to the other. To get even more out of  your data, you can combine this with the possibility to track multiple  body points. For example, nose-nose contact and nose-tail contact  can have completely different biological meaning. The first might be  more interesting when studying aggression, the second when studying  sexual behavior. EthoVision XT also offers versatile data selection possibilities,  so you can perform meaningful interpretation of your data. For  example, you can select all periods of time during which animal A was  approaching animal B, and look at the mean speed of movement of  both animals during this time. Integrated visualization plots this data  in sync with the tracks and video, so you can get an immediate feel for  your data.