Category: Research

African fish called mormyrids communicate using pulses of electricity. To distinguish their own signal from those of neighboring fish, their brains inhibit sensory responses using a corollary discharge, which is an internal copy of their own motor command.

Carlson and Matasaburo Fukutomi, a postdoctoral fellow in his laboratory, published their new research on African mormyrid weakly electric fish in the Journal of Neuroscience.
A brief, well-defined period of inhibition keeps electric fish from missing out on other important external signals, Carlson said.

“In fish that communicate with longer pulses, sensory responses to their own pulse are delayed,” said Bruce Carlson, professor of biology in Arts & Sciences. “Thus, a delayed corollary discharge optimally blocks electrosensory responses to the fish’s own signal.”

Electric fish generate electric pulses to communicate with other fish and sense their surroundings. Some species broadcast shorter electric pulses, while others send out long ones. But all that zip-zapping in the water can get confusing. The fish need to filter out their own pulses so they can identify external messages and only respond to those signals.

African fish called mormyrids communicate using pulses of electricity. New research shows that a time-shifted signal in the brain helps the fish to ignore their own pulse. This skill has co-evolved with large and rapid changes in these signals across species.

Electric fish generate electric pulses to communicate with other fish and sense their surroundings. Some species broadcast shorter electric pulses, while others send out long ones. But all that zip-zapping in the water can get confusing. The fish need to filter out their own pulses so they can identify external messages and only respond to those signals.

African fish called mormyrids communicate using pulses of electricity. New research from biologists at Washington University in St. Louis shows that a time-shifted signal in the brain helps the fish to ignore their own pulse. This skill has co-evolved with large and rapid changes in these signals across species.

“In fish that communicate with longer pulses, sensory responses to their own pulse are delayed,” said Bruce Carlson, professor of biology in Arts & Sciences. “Thus, a delayed corollary discharge optimally blocks electrosensory responses to the fish’s own signal.”

Here, we review a history of neurophysiological studies on corollary discharge and highlight significant contributions from studies using African mormyrid weakly electric fish. Mormyrid fish generate brief electric pulses to communicate with other fish and to sense their surroundings.