Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

'Electric' fish shed light on ways the brain directs movement

01.02.2007
Research could lead to improvements in prosthetic limbs and robots

Scientists have long struggled to figure out how the brain guides the complex movement of our limbs, from the graceful leaps of ballerinas to the simple everyday act of picking up a cup of coffee. Using tools from robotics and neuroscience, two Johns Hopkins University researchers have found some tantalizing clues in an unlikely mode of motion: the undulations of tropical fish.

Their findings, published in the January 31 issue of the Journal of Neuroscience, shed new light on the communication that takes place between the brain and body. The fish research may contribute to important medical advances in humans, including better prosthetic limbs and improved rehabilitative techniques for people suffering from strokes, cerebral palsy and other debilitating conditions.

"All animals, including humans, must continually make adjustments as they walk, run, fly or swim through the environment. These adjustments are based on feedback from thousands of sense organs all over the body, providing vision, touch, hearing and so on. Understanding how the brain processes this overwhelming amount of information is crucial if we want to help people overcome pathologies," said Noah Cowan, an assistant professor of mechanical engineering in Johns Hopkins' Whiting School of Engineering. In studying the fish and preparing the Neuroscience paper, Cowan teamed up with Eric Fortune, assistant professor of psychological and brain sciences in the Krieger School of Arts and Sciences, also at Johns Hopkins.

... more about:
»Cowan »Engineering »Fortune »Tube »nervous system

Cowan and Fortune focused on the movements of a small, nocturnal South American fish called the "glass knifefish" because of its almost transparent, blade-shaped body. This type of fish does something remarkable: it emits weak electrical signals which it uses to "see" in the dark. According to Fortune, several characteristics, including this electric sense, make this fish a superb subject for the study of how the brain uses sensory information to control locomotion.

"These fish are ideal both because we can easily monitor the sensing signals that their brains use and because the task we asked the fish to do -- swim forward and backward inside a small tube -- is very simple and straightforward," said Fortune, who also uses the fish to study the neural basis and evolution of behavior.

The fish prefer to "hide" inside these tubes, which are immersed in larger water tanks. In their research, Cowan and Fortune challenged the fish's ability to remain hidden by shifting the tubes forward and backward at varying frequencies. This required the fish to swim back and forth more and more rapidly in order to remain inside the tubes. But as the frequency became higher, the fish gradually failed to keep up with the movement of the tubes.

The team's detailed engineering analysis of the fish's adjustments under these conditions suggested that the animal's sensors and brains are "tuned" to consider Newton's laws of motion, Cowan said. In other words, the team found that the fish's nervous systems measured velocity, so the fish could accelerate or "brake" at just the right rate to remain within the moving tube.

"The fish were able to accelerate, brake and reverse direction based on a cascade of adjustments made through their sensory and nervous systems, in the same way that a driver approaching a red light knows he has to apply the brakes ahead of time to avoid overshooting and ending up in the middle of a busy intersection," Fortune said. "Your brain has to do this all the time when controlling movement because your body and limbs, like a car, have mass. This is true for large motions that require planning, such as driving a car, but also for unconscious control of all movements, such as reaching for a cup of coffee. Without this sort of predictive control, your hand would knock the cup off the table every time."

The researchers' understanding of the complex relationship between the glass knifefish's movements and the cascade of information coming into their brains and bodies via their senses could eventually spark developments in areas as far reaching as medicine and robotics.

"That animals unconsciously know that they have mass seems obvious enough, but it took a complex analysis of a very specialized fish to demonstrate this," Fortune said. "With this basic knowledge, we hope one day to be able to ‘tune' artificial systems, such as prosthetics, so that they don't have the jerky and rough movements that most robots have, which is critical for medical applications."

The team's use of both neuroscience and engineering principles and tools also make it an important project for other reasons.

"So far, we have used a series of engineering analyses to tease apart some important information about how the nervous system works," Cowan said. "As we move forward, we expect to discover other exciting aspects of brain function that suggest new ways to design sensory control systems for autonomous robots."

Lisa De Nike | EurekAlert!
Further information:
http://limbs.me.jhu.edu/
http://www.psy.jhu.edu/~fortune/

Further reports about: Cowan Engineering Fortune Tube nervous system

More articles from Life Sciences:

nachricht A novel socio-ecological approach helps identifying suitable wolf habitats
17.02.2017 | Universität Zürich

nachricht New, ultra-flexible probes form reliable, scar-free integration with the brain
16.02.2017 | University of Texas at Austin

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Switched-on DNA

20.02.2017 | Materials Sciences

Second cause of hidden hearing loss identified

20.02.2017 | Health and Medicine

Prospect for more effective treatment of nerve pain

20.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>