Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Every Bite You Take, Every Move You Make, Astrocytes Will Be Watching You

19.05.2015

Research reveals a previously unknown role for non-neuron cells in the brain

Chewing, breathing, and other regular bodily functions that we undertake “without thinking” actually do require the involvement of our brain, but the question of how the brain programs such regular functions intrigues scientists.


Courtesy Jeff Lichtman/Harvard University. Licence : CC BY NC ND 2.0. Source : https://flic.kr/p/5sEdqj

Chewing, breathing, and other regular bodily functions that we undertake “without thinking” actually do require the involvement of our brain, but the question of how the brain programs such regular functions intrigues scientists. Arlette Kolta, a professor at the University of Montreal’s Faculty of Dentistry, has shown that astrocytes play a key role. Astrocytes are star-shaped glial cells in our brain. Glial cells are not neurons – they play a supporting role. Kolta’s finding in fact challenges some of the beliefs scientists have about the way our brain works. Here, brain neurons are illustrated in a “brainbow.” The astrocytes are not shown.

A team lead by Arlette Kolta, a professor at the University of Montreal’s Faculty of Dentistry, has shown that astrocytes play a key role. Astrocytes are star-shaped glial cells in our brain. Glial cells are not neurons – they play a supporting role. The team’s finding in fact challenges some of the beliefs scientists have about the way our brain works.

The brain contains billions of cells and every brain function depends on the ability of neurons to communicate with each other. Neurons use an electrical language to communicate and the pattern of their electrical activity encodes the essence of the message that they convey to the next neuron.

“In the neuron-centric vision that dominates at the moment, changes in the pattern of neuronal electrical activity depend solely on the intrinsic properties of neurons and on the information they transmit to one another. Our results demonstrate that glial cells play a crucial role controlling the pattern of neuronal electrical activity and thereby neuronal functions,” Kolta said.

By using different methods to measure the electrical activity of neurons in the trigeminal system which enables sensation in the face and facial motor functions, the researchers were able to look at how the brain processes chewing.

“We discovered a mechanism by which astrocytes regulate the extracellular concentration of calcium in this sensory-motor circuit, and by doing this, determine the pattern of electrical activity of surrounding neurons. We think that the trigeminal neurons that we investigate have a dual function depending on the pattern of their electrical activity which can be either tonic or bursting,” explained Philippe Morquette, first author of the study. Tonic is like the hum when you pick up the phone, a continuous and permanent connection to the different parts of the system, while bursting is like the ringing you hear when you finish dialing. .

When neurons are in the tonic mode, they faithfully relay to other neurons information that they receive from sensory afferents. Sensory afferents are the means by which the brain and nervous system receive signals from the bodily senses. When they are in the rhythmic bursting mode they generate a rhythmic motor command, like the one needed to produce a repetitive movement such as chewing.

“The rhythmic bursting mode depends on activation of a current that is modulated by the extracellular concentration of calcium. We show that astrocytes are responsible for the switch from one mode to the other, and thus presumably from one function to the other. The switch cannot occur when astrocytes are ‘inactivated’ or when the described astrocytic mechanism is blocked. This mechanism relies on release of a specific calcium binding protein released by glial cells,” Morquette added.

Published in Nature Neuroscience on May 4, the study is the first to show the role that astrocytes play in regulating the concentration of calcium outside of neurons, bolstering the idea that these cells play an important role in neural processing. “The mechanism for regulating calcium that we described may have far reaching implications given the number of neuronal functions that may be altered by changes in extracellular calcium concentration and by the ubiquitous distribution of S100-beta, the calcium binding protein involved,” Morquette explained.

The importance of the findings is far greater than a better understanding of how we chew. “The mechanisms involved contribute to a wide variety of brain functions: they’re at the basis of other vital and repetitive movements like locomotion and respiration, they’re widespread in the cortex, hippocampus and other areas, and have been associated to many important functions such as attention and learning and memory. Finally, it is well known that astrocytes are over-activated in pathological situations associated with increased burst firing, like during seizures, and we believe that the mechanism described here is of particular relevance to those situations,” Kolta said.

About this study:
Philippe Morquette, Dorly Verdier, Aklesso Kadala, James Féthière, Antony G Philippe, Richard Robitaille and Arlette Kolta published “An astrocyte-dependent mechanism for neuronal rhythmogenesis” in Nature Neuroscience on May 4, 2015. Kolta and Morquette are affiliated with the Department of Neurosciences and Groupe de Recherche sur le Système Nerveux Central at University of Montreal’s Faculty of Medicine. Kolta is also affiliated with the university’s Faculty of Dentistry, and with the Réseau de Recherche en Santé Buccodentaire et Osseuse du Fonds de Recherche Québec-Santé. The study was financed by Canadian Institutes for Health Research (grant 14392). The University of Montreal is officially known as Université de Montréal.

Contact Information
William Raillant-Clark
International Press Attache
w.raillant-clark@umontreal.ca
Phone: 514-343-7593
Mobile: 514-566-3813

William Raillant-Clark | newswise
Further information:
http://www.umontreal.ca

More articles from Life Sciences:

nachricht Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University

nachricht How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>