Featured Research

from universities, journals, and other organizations

Tinnitus is the result of the brain trying, but failing, to repair itself

Date:
January 15, 2011
Source:
Georgetown University Medical Center
Summary:
Tinnitus appears to be produced by an unfortunate confluence of structural and functional changes in the brain, say neuroscientists.

Tinnitus appears to be produced by an unfortunate confluence of structural and functional changes in the brain, say neuroscientists at Georgetown University Medical Center (GUMC).

The phantom ringing sounds heard by about 40 million people in the U.S. today are caused by brains that try, but fail to protect their human hosts against overwhelming auditory stimuli, the researchers say in the January 13th issue of Neuron. They add that the same process may be responsible for chronic pain and other perceptual disorders.

The researchers say that the absence of sound caused by hearing loss in certain frequencies, due to normal aging, loud-noise exposure, or to an accident, forces the brain to produce sounds to replace what is now missing. But when the brain's limbic system, which is involved in processing emotions and other functions, fails to stop these sounds from reaching conscious auditory processing, tinnitus results.

"We believe that a dysregulation of the limbic and auditory networks may be at the heart of chronic tinnitus," says the study's lead investigator, Josef P. Rauschecker, PhD, a neuroscientist. "A complete understanding and ultimate cure of tinnitus may depend on a detailed understanding of the nature and basis of this dysregulation."

Tinnitus isn't curable, although antidepressants appear to help some patients, as does the use of masking noise to diminish focus on the ringing sensations.

Using functional Magnetic Resonance Imaging (fMRI), the Georgetown researchers tested 22 volunteers, half of whom had been diagnosed with chronic tinnitus. They found that moderate hyperactivity was present in the primary and posterior auditory cortices of tinnitus patients, but that the nucleus accumbens exhibited the greatest degree of hyperactivity, specifically to sounds that were matched to frequencies lost in patients.

The nucleus accumbens is part of the corticostriatal circuit, which is involved in evaluation of reward, emotion, and aversiveness, says Rauschecker. "This suggests that the corticostriatal circuit is part of a general 'appraisal network' determining which sensations are important, and ultimately affecting how or whether those sensations are experienced," he says. "In this study, we provide evidence that these limbic structures, specifically the nucleus accumbens and the ventromedial prefrontal cortex, do indeed differ in the brains of individuals with tinnitus."

Functional lapses in these same areas have also been implicated to altered mood states and to chronic pain. "Both of these conditions may also involve the inability to suppress unwanted sensory signals," Rauschecker says.

Based on their findings, the researchers argue that the key to understanding tinnitus lies in understanding how the auditory and limbic systems interact to influence perception -- be it sound, emotions, pain, etc.

Grant support was provided by the National Institute on Deafness and Other Communication Disorders, the Tinnitus Research Consortium, the Tinnitus Research Initiative, and the Skirball Foundation.


Story Source:

The above story is based on materials provided by Georgetown University Medical Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. Amber M. Leaver, Laurent Renier, Mark A. Chevillet, Susan Morgan, Hung J. Kim and Josef P. Rauschecker. Dysregulation of Limbic and Auditory Networks in Tinnitus. Neuron, Volume 69, Issue 1, 13 January 2011, Pages 33-43 DOI: 10.1016/j.neuron.2010.12.002

Cite This Page:

Georgetown University Medical Center. "Tinnitus is the result of the brain trying, but failing, to repair itself." ScienceDaily. ScienceDaily, 15 January 2011. <www.sciencedaily.com/releases/2011/01/110112122504.htm>.
Georgetown University Medical Center. (2011, January 15). Tinnitus is the result of the brain trying, but failing, to repair itself. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2011/01/110112122504.htm
Georgetown University Medical Center. "Tinnitus is the result of the brain trying, but failing, to repair itself." ScienceDaily. www.sciencedaily.com/releases/2011/01/110112122504.htm (accessed July 25, 2014).

Share This




More Mind & Brain News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

University Quiz Implies Atheists Are Smarter Than Christians

University Quiz Implies Atheists Are Smarter Than Christians

Newsy (July 25, 2014) An online quiz from a required course at Ohio State is making waves for suggesting atheists are inherently smarter than Christians. Video provided by Newsy
Powered by NewsLook.com
Beatings and Addiction: Pakistan Drug 'clinic' Tortures Patients

Beatings and Addiction: Pakistan Drug 'clinic' Tortures Patients

AFP (July 24, 2014) A so-called drugs rehab 'clinic' is closed down in Pakistan after police find scores of ‘patients’ chained up alleging serial abuse. Duration 03:05 Video provided by AFP
Powered by NewsLook.com
New Painkiller Designed To Discourage Abuse: Will It Work?

New Painkiller Designed To Discourage Abuse: Will It Work?

Newsy (July 24, 2014) The FDA approved Targiniq ER on Wednesday, a painkiller designed to keep users from abusing it. Like any new medication, however, it has doubters. Video provided by Newsy
Powered by NewsLook.com
Can Watching TV Make You Feel Like A Failure?

Can Watching TV Make You Feel Like A Failure?

Newsy (July 24, 2014) A study by German researchers claims watching TV while you're stressed out can make you feel guilty and like a failure. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins