This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Social behavior is found across the tree of life, with animals of all types benefiting from living in a group environment. Large bird flocks and fish schools coordinate their actions by sharing information among individuals.
This is especially important when groups are attacked by predators, since information about a threat must promptly pass between members of the group to enable effective escape. Yet, how this information is passed between individuals has remained a mystery. In a paper published in Nature, scientists in the Neurobiology Department at the University of California San Diego report their discovery of a neural signature of social action detection in an ancient visual midbrain circuit that exists across fish, birds and primates.
The authors found this circuit by recording the brain activity of schooling fish that were observing the escape behaviors of their social partners. This study was led by Jo-Hsien Yu, a recent graduate of UC San Diego's Biological Sciences Ph.D. Program, in the lab of Assistant Professor of Neurobiology Matthew Lovett-Barron.
The authors studied the glassfish Danionella cerebrum, whose tiny, transparent body (approximately 12 millimeters long [0.5 inch], less than the width of your pinky finger) allows researchers to noninvasively measure brain activity using optical microscopes. The Lovett-Barron lab has previously shown that glassfish use their sense of vision to school and interact by copying their neighbors' actions. In this new study, they examined how groups of glassfish respond to danger—a rapidly approaching visual object simulating a predator attack.
They found that groups of fish were more effective at escaping from danger than individual fish and used their sense of vision to rapidly scatter away from each other. When a predator approached the group, fish farthest from danger were still able to escape if they could see their neighbors closer to the threat fleeing the visible danger. "Each fish in the group sees their neighbors move, and moves in response—an interaction that produces schooling," said Lovett-Barron.
"The ability to pay attention to each other helps these fish detect danger as well." But would fish escape from danger if they only saw their neighbors escape, even without directly experiencing the threat? To test this, postdoctoral fellow Geoff Meyerhof used video game software to design schools of virtual Danionella fish, whose realistic appearance, posture and movements attracted real fish to swim with them along a screen. If these virtual fish suddenly escaped, the real fish scattered from the screen as if a real threat were present.
Extract — continue reading at the source.
