Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How crayfish do the locomotion

27.11.2002


Using computer models and experiments, researchers at the University of California, Davis, have identified the neurons and connections that are necessary for crayfish to swim.

"We can now pin down the essential components of the circuit," said Brian Mulloney, a professor of neurobiology, physiology and behavior at UC Davis.

The nervous system controlling locomotion is highly tuned and very stable across different groups of animals, Mulloney said. That makes crayfish a good model for much more complex nervous systems such as the human spinal cord.



New advances in the field were discussed in a session chaired by Mulloney at the Society for Neuroscience meeting in November 2002.

Crayfish swim by beating pairs of paddles called swimmerets on each body segment. The swimmerets move in sequence, starting at the back of the animal and moving forward. The movements of each segment keep a precise difference in timing, while varying in speed and force.

To keep those movements in the right sequence, the animal’s nervous system has to integrate signals from each of these different segments as well as signals from the brain.

Mulloney’s group, working with mathematicians Stephanie Jones at Harvard University and Frances Skinner at the University of Toronto, built mathematical models of the crayfish nervous system to see how they might work. They used those models to design experiments where they recorded impulses in crayfish nerves.

They showed that the swimmeret system is made up of eight modules of 70 neurons each. They found which neurons are necessary to complete the circuit, and what cells they connect to.

As the swimmerets beat, each module receives a stream of nerve impulses from the modules behind and in front of it. Signals from behind indicate a power stroke; those from the front represent a recovery stroke. Mulloney’s team has found that those different messages converge on the same target neuron, which integrates them into a graded, non-spiking signal. This combined signal tells the module when to release neurotransmitters -- chemicals which change the timing and force of limb movement.

The same basic plan is likely found in insects and other animals, Mulloney said.


###
Media contacts: Brian Mulloney, Neurobiology, Physiology and Behavior, (530) 752-1110, bcmulloney@ucdavis.edu


Andy Fell | EurekAlert!
Further information:
http://www.ucdavis.edu/

More articles from Life Sciences:

nachricht BigH1 -- The key histone for male fertility
14.12.2017 | Institute for Research in Biomedicine (IRB Barcelona)

nachricht Guardians of the Gate
14.12.2017 | Max-Planck-Institut für Biochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Plasmonic biosensors enable development of new easy-to-use health tests

14.12.2017 | Health and Medicine

New type of smart windows use liquid to switch from clear to reflective

14.12.2017 | Physics and Astronomy

BigH1 -- The key histone for male fertility

14.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>