Chinese researchers develop social anxiety conditioning model for mice

HANGZHOU, Aug. 9 (Xinhua) -- Chinese researchers have successfully developed a social anxiety disorder (SAD) conditioning model for mice, which are expected to become practical research aids for future SAD studies.

Researchers from Zhejiang University developed a four-stage standardized protocol to induce specific social fear in mice.

During the first stage, the researchers separated individual subject mice from their cage mates for five days. In the second stage, the subject mice freely explored their surrounding environments for 10 minutes, allowing them to gain a sense of safety in isolation.

During the third stage of conditioning, an unfamiliar mouse was introduced to each subject mouse's container. A mild foot shock was automatically delivered to a subject mouse each time it attempted to get close to a new mouse.

In the final stage of behavioral testing, the researchers performed a social preference-avoidance test on the mice in an open field container and a social interaction test in a three-chamber container to assess their social fear. The mice exhibited dramatic decreases in time spent in the social zone or chamber, less exploration, and lower approaching speeds in the two tests. They also exhibited a significant increase in stretching their bodies during exploration, a typical fear response.

When researchers replaced unfamiliar mice with new objects, the subject mice did not exhibit fear responses. The subject mice also did not show fear in open field tests or forced swimming tests.

The researchers said an ideal animal social fear conditioning model should demonstrate subjects' reduced social investigation of and fear responses to their conspecifics. Behavioral changes should not manifest in non-social areas.

They said that their mice conditioning model could be used for SAD studies. The research has been published in the journal Neuroscience Bulletin.