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 Even plants can be stressed
03.09.2015 | Max-Planck-Institut für Molekulare Pflanzenphysiologie

nachricht Research team from Münster develops innovative catalytic chemistry process
03.09.2015 | Westfälische Wilhelms-Universität Münster

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fraunhofer ISE Develops Highly Compact Inverter for Uninterruptible Power Supplies

Silicon Carbide Components Enable Efficiency of 98.7 percent

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE have developed a highly compact and efficient inverter for use in uninterruptible power...

Im Focus: How wind sculpted Earth's largest dust deposit

China's Loess Plateau was formed by wind alternately depositing dust or removing dust over the last 2.6 million years, according to a new report from University of Arizona geoscientists. The study is the first to explain how the steep-fronted plateau formed.

China's Loess Plateau was formed by wind alternately depositing dust or removing dust over the last 2.6 million years, according to a new report from...

Im Focus: An engineered surface unsticks sticky water droplets

The leaves of the lotus flower, and other natural surfaces that repel water and dirt, have been the model for many types of engineered liquid-repelling surfaces. As slippery as these surfaces are, however, tiny water droplets still stick to them. Now, Penn State researchers have developed nano/micro-textured, highly slippery surfaces able to outperform these naturally inspired coatings, particularly when the water is a vapor or tiny droplets.

Enhancing the mobility of liquid droplets on rough surfaces could improve condensation heat transfer for power-plant heat exchangers, create more efficient...

Im Focus: Increasingly severe disturbances weaken world's temperate forests

Longer, more severe, and hotter droughts and a myriad of other threats, including diseases and more extensive and severe wildfires, are threatening to transform some of the world's temperate forests, a new study published in Science has found. Without informed management, some forests could convert to shrublands or grasslands within the coming decades.

"While we have been trying to manage for resilience of 20th century conditions, we realize now that we must prepare for transformations and attempt to ease...

Im Focus: OU astrophysicist and collaborators find supermassive black holes in quasar nearest Earth

A University of Oklahoma astrophysicist and his Chinese collaborator have found two supermassive black holes in Markarian 231, the nearest quasar to Earth, using observations from NASA's Hubble Space Telescope.

The discovery of two supermassive black holes--one larger one and a second, smaller one--are evidence of a binary black hole and suggests that supermassive...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Together - Work - Experience

03.09.2015 | Event News

Networking conference in Heidelberg for outstanding mathematicians and computer scientists

20.08.2015 | Event News

Scientists meet in Münster for the world’s largest Chitin und Chitosan Conference

20.08.2015 | Event News

 
Latest News

Lighter with Laser Welding

03.09.2015 | Process Engineering

For 2-D boron, it's all about that base

03.09.2015 | Materials Sciences

Phagraphene, a 'relative' of graphene, discovered

03.09.2015 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>