Mice in a 'big brother' setup develop social structures

Jun 17, 2013
This is the "Big Brother" experimental setup for observing mouse social interaction. Credit: Dr. Tali Kimchi, Weizmann Institute of Science

How does a social animal – mouse or human – gain dominance over his or her fellow creatures? A unique experiment conducted by Dr. Tali Kimchi and her team in the Weizmann Institute's Neurobiology Department provides some unusual insight into the social behavior that enables a social hierarchy, complete with a head honcho, to form.

Kimchi and her research team, Aharon Weissbrod, Genady Wasserman and Alex Shapiro, together with Dr. Ofer Feinerman of the Institute's Physics of Complex Systems Department, developed a system that enabled them to observe a large group of animals living together in semi-natural conditions. This setup was a sort of mouse version of the television show Big Brother. Different strains of were placed in the "house" – a four-meter-square pen – and allowed to go about their lives with no intervention from the human team. To automatically track the mice day and night, each mouse was implanted with an ID chip similar to those used in pet cats and dogs, and video cameras were placed strategically around the area with infrared lighting that enabled nighttime filming. With the combined chip reporting and continuous video footage, the system could automatically keep tabs on each individual mouse, knowing its precise location down to the half centimeter, in measurements that were recorded thirty times a second for days and sometimes even months on end.

Because the information they obtained was so precise, the team was able to identify dozens of individual behaviors – eating, drinking, running, sleeping, hiding, etc. – as well as social behaviors – seeking out specific companions for activities or rest, avoiding certain individuals, attacking others, and more. The researchers found that it was possible to isolate and identify typical behaviors of individuals, pairs and groups. In fact just by sorting out , the automated system was able to differentiate between the various genetic strains of the mice in the mixed groups, as well as predicting mating, with over 90% accuracy. These close observations revealed, among other social features, how one of the individuals became "king" of the group, attaining dominance over the others, both male and female.

In further experiments, the "house" inhabitants comprised one of two strains of mice, the first more "social" and the second "autistic" (exhibiting little social engagement and rigid behavior patterns). The system automatically identified the "autistic" mice by identifying their patterns of movement and public behavior.

This video is not supported by your browser at this time.
Mice in a "Big brother" setup develop social structures. Credit: Dr. Tali Kimchi, Weizmann Institute of Science

In a paper that appeared this week in Nature Communications, Kimchi and her team describe the emergence of the dominant leader and the development of a class system in a group of normal mice – just within a 24-hour period. Surprisingly, when they conducted a similar experiment with the autistic-like mice, either no leader emerged or, if one did, he was quickly overthrown.

The precise, automatic, semi-natural system the scientists have developed is enabling a deep, systematic study of the mechanisms for regulating in animal models; it may be especially useful for providing insight into the societal aspects of such disorders as schizophrenia and autism.

Explore further: Birds 'weigh' peanuts and choose heavier ones

More information: www.nature.com/ncomms/2013/130617/ncomms3018/full/ncomms3018.html

Related Stories

Autism model in mice linked with genetics

Apr 15, 2013

For the first time, researchers have linked autism in a mouse model of the disease with abnormalities in specific regions of the animals' chromosomes. The regions contain genes associated with aberrant brain development and ...

Social hierarchy prewired in the brain

Sep 30, 2011

(PhysOrg.com) -- If you find yourself more of a follower than a social leader, it may something to do with the wiring in your brain. According to a new study in Science, researchers from the Chinese Academ ...

Recommended for you

Birds 'weigh' peanuts and choose heavier ones

19 hours ago

Many animals feed on seeds, acorns or nuts. The common feature of these are that they have shells and there is no direct way to know what's inside. How do the animals know how much and what quality of food ...

Estuaries protect Dungeness crabs from deadly parasites

May 22, 2015

Parasitic worms can pose a serious threat to the Dungeness crab, a commercially important fishery species found along the west coast of North America. The worms are thought to have caused or contributed to ...

An evolutionary heads-up—the brain size advantage

May 22, 2015

A larger brain brings better cognitive performance. And so it seems only logical that a larger brain would offer a higher survival potential. In the course of evolution, large brains should therefore win ...

Our bond with dogs may go back more than 27,000 years

May 21, 2015

Dogs' special relationship to humans may go back 27,000 to 40,000 years, according to genomic analysis of an ancient Taimyr wolf bone reported in the Cell Press journal Current Biology on May 21. Earlier genome ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.