Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cc to the brain: how neurons control fine motor behavior of the arm

31.01.2014
Motor commands issued by the brain to activate arm muscles take two different routes.

As the research group led by Professor Silvia Arber at the University of Basel's Biozentrum and the Friedrich Miescher Institute for Biomedical Research has now discovered, many neurons in the spinal cord send their instructions not only towards the musculature, but at the same time also back to the brain via an exquisitely organized network.


Synaptic terminals of premotor neurons in the studied brainstem nucleus (blue). Axons of a marked spinal interneuron subpopulation terminating in a specific domain of this brainstem nucleus (pink).

This dual information stream provides the neural basis for accurate control of arm and hand movements. These findings have now been published in Cell.

Movement is a fundamental capability of humans and animals, involving the highly complex interplay of brain, nerves and muscles. Movements of our arms and hands, in particular, call for extremely precise coordination. The brain sends a constant stream of commands via the spinal cord to our muscles to execute a wide variety of movements.

This stream of information from the brain reaches interneurons in the spinal cord, which then transmit the commands via further circuits to motor neurons innervating muscles. The research group led by Silvia Arber at the Biozentrum of the University of Basel and the Friedrich Miescher Institute for Biomedical Research has now elucidated the organization of a second information pathway taken by these commands.

Cc to the brain: one command – two directions
The scientists showed that many interneurons in the mouse spinal cord not only transmit their signals via motor neurons to the target muscle, but also simultaneously send a copy of this information back to the brain. Chiara Pivetta, first author of the publication, explains: “The motor command to the muscle is sent in two different directions – in one direction, to trigger the desired muscular contraction and in the other, to inform the brain that the command has actually been passed on to the musculature.” In analogy to e mail transmission, the information is thus not only sent to the recipient but also to the original requester.
Information to brainstem nucleus segregated by function
What happens to the information sent by spinal interneurons to the brain? As Arber’s group discovered, this input is segregated by function and spatially organized within a brainstem nucleus. Information from different types of interneurons thus flows to different areas of the nucleus. For example, spinal information that will influence left-right coordination of a movement is collected at a different site than information affecting the speed of a movement.
Fine motor skills supported by dual information stream
Arber comments: “From one millisecond to the next, this extremely precise feedback ensures that commands are correctly transmitted and that – via the signals sent back to the brain from the spinal cord – the resulting movement is immediately coordinated with the brain and adjusted.” Interestingly, the scientists only observed this kind of information flow to the brain for arm, but not for leg control. “What this shows,” says Arber, “is that this information pathway is most likely important for fine motor skills. Compared to the leg, movements of our arm and especially our hands have to be far more precise. Evidently, our body can only ensure this level of accuracy in motor control with constant feedback of information.”

In further studies, Silvia Arber’s group now plans to investigate what happens if the flow of information back to the brain is disrupted in specific ways. Since some interneurons facilitate and others inhibit movement, such studies could provide additional insights into the functionality of circuits controlling movement.

Original Citation
Chiara Pivetta, Maria Soledad Esposito, Markus Sigrist, and Silvia Arber
Motor-Circuit Communication Matrix from Spinal Cord to Brainstem Neurons Revealed by Developmental Origin

Cell, Volume 156, Issue 3, 537-548, 30 January 2014 | doi: 10.1016/j.cell.2013.12.014

Heike Sacher | Universität Basel
Further information:
http://www.unibas.ch

More articles from Life Sciences:

nachricht Rapid adaptation to a changing environment
28.04.2016 | Christian-Albrechts-Universität zu Kiel

nachricht Tiny microscopes reveal hidden role of nervous system cells
28.04.2016 | Salk Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: ORNL researchers discover new state of water molecule

Neutron scattering and computational modeling have revealed unique and unexpected behavior of water molecules under extreme confinement that is unmatched by any known gas, liquid or solid states.

In a paper published in Physical Review Letters, researchers at the Department of Energy's Oak Ridge National Laboratory describe a new tunneling state of...

Im Focus: Bionic Lightweight Design researchers of the Alfred Wegener Institute at Hannover Messe 2016

Honeycomb structures as the basic building block for industrial applications presented using holo pyramid

Researchers of the Alfred Wegener Institute (AWI) will introduce their latest developments in the field of bionic lightweight design at Hannover Messe from 25...

Im Focus: New world record for fullerene-free polymer solar cells

Polymer solar cells can be even cheaper and more reliable thanks to a breakthrough by scientists at Linköping University and the Chinese Academy of Sciences (CAS). This work is about avoiding costly and unstable fullerenes.

Polymer solar cells can be even cheaper and more reliable thanks to a breakthrough by scientists at Linköping University and the Chinese Academy of Sciences...

Im Focus: Ultra-thin glass is up and coming

As one of the leading R&D partners in the development of surface technologies and organic electronics, the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP will be exhibiting its recent achievements in vacuum coating of ultra-thin glass at SVC TechCon 2016 (Booth 846), taking place in Indianapolis / USA from May 9 – 13.

Fraunhofer FEP is an experienced partner for technological developments, known for testing the limits of new materials and for optimization of those materials...

Im Focus: Measuring the heat capacity of condensed light

Liquid water is a very good heat storage medium – anyone with a Thermos bottle knows that. However, as soon as water boils or freezes, its storage capacity drops precipitously. Physicists at the University of Bonn have now observed very similar behavior in a gas of light particles. Their findings can be used, for example, to produce ultra-precise thermometers. The work appears in the prestigious technical journal "Nature Communications".

Water vapor becomes liquid under 100 degrees Celsius – it condenses. Physicists speak of a phase transition. In this process, certain thermodynamic...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

The “AC21 International Forum 2016” is About to Begin

27.04.2016 | Event News

Soft switching combines efficiency and improved electro-magnetic compatibility

15.04.2016 | Event News

Grid-Supportive Buildings Give Boost to Renewable Energy Integration

12.04.2016 | Event News

 
Latest News

Possible Extragalactic Source of High-Energy Neutrinos

28.04.2016 | Physics and Astronomy

University of Illinois researchers create 1-step graphene patterning method

28.04.2016 | Materials Sciences

Rapid adaptation to a changing environment

28.04.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>