To a hungry fish on the prowl, the split-second neural processing required to see, track, and gobble up a darting flash of prey is a matter of survival.
To scientists, it's a window into how our brain coordinates the eye motions that enable us to hit a baseball, sidestep an errant skateboarder, and otherwise make our way in a world full of danger and opportunity.
This process is now better understood, thanks to a team of scientists that imaged the activity of individual neurons in a part of a zebrafish's brain called the optic tectum. The optic tectum receives signals from the retina, filters them, then sends the signals to other parts of the brain that control motion.
They found that when the fish saw something that resembles prey zipping by, the output neurons in the optic tectum are strongly activated. These output neurons send signals to the rest of the brain a jolt to spark the fish into action and give chase.
But when the fish saw large flashes of light and dark, the equivalent of a bland world devoid of potential prey, the output neurons in the optic tectum are weakly activated.
"We can see, for the first time, how neurons in the fish's optic tectum take visual information and convert it into an output that drives action," says Ehud Isacoff, a biophysicist who holds joint appointments with Lawrence Berkeley National Laboratory's Physical Biosciences and Materials Sciences Divisions and UC Berkeley's Department of Molecular and Cell Biology.
Isacoff conducted the research with a team of scientists that includes Claire Wyart, a scientist in his UC Berkeley lab; Filippo Del Bene of Herwig Baier's University of California at San Francisco lab; and Loren Looger of the Janelia Farm Research Institute in Virginia.
They report their research in the October 29 issue of the journal Science.
Their work could shed light on how we process visual information. The optic tectum in fish is re
|Contact: Dan Krotz|
DOE/Lawrence Berkeley National Laboratory