Paddlefish sensors tuned to detect signals from zooplankton prey

January 5, 2012

Neurons fire in a synchronized bursting pattern in response to robust signals indicating nearby food.

In 1997, scientists at the Center for Neurodynamics at the University of Missouri - St. Louis demonstrated that special sensors covering the elongated snout of paddlefish are electroreceptors that help the fish detect by responding to the weak voltage gradients that swimming zooplankton create in the surrounding water. Now some of the same researchers have found that the electroreceptors contain oscillators, which generate rhythmical firing of electrosensory neurons. The oscillators allow the electroreceptors to create a dynamical code to most effectively respond to emitted naturally by zooplankton.

The results are presented in a paper appearing in the AIP's journal Chaos.

To test the response of paddlefish electroreceptors to different , the researchers recorded signals from electrosensory neurons of live fish, while applying weak electric fields to the water in the form of computer-generated artificial stimuli or signals obtained previously from swimming zooplankton.

The team then analyzed the power contained in different frequency ranges for the noisy input signals and the corresponding electroreceptor responses, and compared the two. In addition to finding that the paddlefish best encode the signals emitted by zooplankton, the team also found that as the strength of the was raised, the firing of the fish's sensory neurons transitioned from a steady beat to a noisy pattern of intermittent bursts.

This bursting pattern became synchronized across different groups of electroreceptors, increasing the likelihood of the signal reaching higher-order neurons. This provides a plausible mechanism to explain how reliable information about the nearness of prey is transferred to the fish's brain, the researchers write.

Explore further: Scientists trace origin of shark’s electric sense

More information: "Sensory Coding in Oscillatory Electroreceptors of Paddlefish" is published in Chaos: An Interdisciplinary Journal of Nonlinear Science.

Related Stories

Scientists trace origin of shark’s electric sense

February 6, 2006

Sharks are known for their almost uncanny ability to detect electrical signals while hunting and navigating. Now researchers have traced the origin of those electrosensory powers to the same type of embryonic cells that gives ...

Bursting neurons follow the same beat, sometimes

September 12, 2011

A simplified mathematical model of the brain's neural circuitry shows that repetitious, overlapped firing of neurons can lead to the waves of overly synchronized brain activity that may cause the halting movements that are ...

Recommended for you

French teen finds 560,000 year-old tooth (Update)

July 28, 2015

A 16-year-old French volunteer archaeologist has found an adult tooth dating back around 560,000 years in southwestern France, in what researchers hailed as a "major discovery" Tuesday.

The couple who Facebooks together, stays together

July 27, 2015

Becoming "Facebook official" is a milestone in modern romance, and new research suggests that activities on the popular social networking site are connected to whether those relationships last.

0 comments

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.