Social interaction tests in mice and rats are extremely useful for research involving animal models of psychiatric disorders including Schizophrenia and neurodevelopmental disorders like Autism.
A defining hallmark of many psychiatric disorders is abnormal social interaction or withdrawal from social contact. There are several different types of tests used to measure social interaction in rodents, but the most common is called the Three-chambered Social Interaction Test, originally developed by Dr. Jacqueline Crawley. This test measures time spent by the experimental animal in social investigation of other animals within the experimental arena.
Testing occurs in three phases inside of a three-chambered box.
First, the experimental animal is habituated to the 3-chambered arena. Next, the rodent is placed in the middle chamber and encounters a never-before-met intruder in either the left or right chamber. This phase can be used to examine the experimental animal’s general sociability.
Rodents generally prefer to spend more time in groups and will investigate a novel intruder more than a familiar one.
In the final phase, the experimental subject animal encounters the now-familiar animal and a new never-before-met intruder in the previously vacant chamber. This phase can be used to examine the experimental animal’s interest in social novelty since rodents will generally prefer the novel social interaction.
To measure sociability and preference for social novelty you can quantify both the total time spent in each chamber as well as total entries into either chamber.
Crawley, J. N. (2007). Whats wrong with my mouse?: behavioral phenotyping of transgenic and knockout mice. Hoboken, NJ: Wiley-Interscience.