Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Decoding the secrets of balance

27.07.2012
New understanding of how the brain processes information from inner ear offers hope for sufferers of vertigo

If you have ever looked over the edge of a cliff and felt dizzy, you understand the challenges faced by people who suffer from symptoms of vestibular dysfunction such as vertigo and dizziness.

There are over 70 million of them in North America. For people with vestibular loss, performing basic daily living activities that we take for granted (e.g. dressing, eating, getting in and out of bed, getting around inside as well as outside the home) becomes difficult since even small head movements are accompanied by dizziness and the risk of falling.

We’ve known for a while that a sensory system in the inner ear (the vestibular system) is responsible for helping us keep our balance by giving us a stable visual field as we move around. And while researchers have already developed a basic understanding of how the brain constructs our perceptions of ourselves in motion, until now no one has understood the crucial step by which the neurons in the brain select the information needed to keep us in balance.

The way that the brain takes in and decodes information sent by neurons in the inner ear is complex. The peripheral vestibular sensory neurons in the inner ear take in the time varying acceleration and velocity stimuli caused by our movement in the outside world (such as those experienced while riding in a car that moves from a stationary position to 50 km per hour). These neurons transmit detailed information about these stimuli to the brain (i.e. information that allows one to reconstruct how these stimuli vary over time) in the form of nerve impulses.

Scientists had previously believed that the brain decoded this information linearly and therefore actually attempted to reconstruct the time course of velocity and acceleration stimuli. But by combining electrophysiological and computational approaches, Kathleen Cullen and Maurice Chacron, two professors in McGill University’s Department of Physiology, have been able to show for the first time that the neurons in the vestibular nuclei in the brain instead decode incoming information nonlinearly as they respond preferentially to unexpected, sudden changes in stimuli.

It is known that representations of the outside world change at each stage in this sensory pathway. For example, in the visual system neurons located closer to the periphery of the sensory system (e.g. ganglion cells in the retina) tend to respond to a wide range of sensory stimuli (a “dense” code), whereas central neurons (e.g. in the primary visual cortex at the back of the head tend to respond much more selectively (a “sparse” code). Chacron and Cullen have discovered that the selective transmission of vestibular information they were able to document for the first time occurs as early as the first synapse in the brain. “We were able to show that the brain has developed this very sophisticated computational strategy to represent sudden changes in movement in order to generate quick accurate responses and maintain balance,” explained Prof. Cullen. “I keep describing it as elegant, because that’s really how it strikes me.”

This kind of selectivity in response is important for everyday life, since it enhances the brain’s perception of sudden changes in body posture. So that if you step off an unseen curb, within milliseconds, your brain has both received the essential information and performed the sophisticated computation needed to help you readjust your position. This discovery is expected to apply to other sensory systems and eventually to the development of better treatments for patients who suffer from vertigo, dizziness, and disorientation during their daily activities. It should also lead to treatments that will help alleviate the symptoms that accompany motion and/or space sickness produced in more challenging environments.

The research was conducted by Corentin Massot a Postdoctoral fellow in the Department of Physiology, and Adam Schneider a Ph.D. Student in the Department of Physics.

To read an abstract of the paper

The research was funded by: The Canadian Institutes of Health Research (CIHR) and the Fonds de recherche du Québec - Nature et technologies (FQRNT)

Katherine Gombay | EurekAlert!
Further information:
http://www.mcgill.ca

More articles from Health and Medicine:

nachricht New discoveries predict ability to forecast dementia from single molecule
12.12.2018 | UT Southwestern Medical Center

nachricht Pain: Perception and motor impulses arise in the brain independently of one another
12.12.2018 | Technische Universität München

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

Im Focus: Researchers develop method to transfer entire 2D circuits to any smooth surface

What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.

Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...

Im Focus: Three components on one chip

Scientists at the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) succeed in important further development on the way to quantum Computers.

Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

New discoveries predict ability to forecast dementia from single molecule

12.12.2018 | Health and Medicine

CCNY-Yale researchers make shape shifting cell breakthrough

12.12.2018 | Physics and Astronomy

Pain: Perception and motor impulses arise in the brain independently of one another

12.12.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>