Study suggests serotonin may worsen tinnitus

August 22, 2017, Oregon Health & Science University
Credit: CC0 Public Domain

Millions of people suffer from the constant sensation of ringing or buzzing in the ears known as tinnitus, creating constant irritation for some and severe anxiety for others. Research by scientists at OHSU shows why a common antidepressant medication may worsen the condition.

The study, to be published Aug. 22 in the journal Cell Reports, focused on the action of serotonin, an important neuromodulator in the brain. Researchers examined brain tissue in mice, specifically the where sensory integration and occurs. Researchers discovered that neurons known as fusiform cells within this portion of the brain become hyperactive and hypersensitive to stimuli when exposed to serotonin.

"We saw that the activity of those neurons went through the roof," said senior author Laurence Trussell, Ph.D., a professor of otolaryngology in the OHSU School of Medicine and scientist in the OHSU Vollum Institute.

If the findings bear up to additional research, the study could have implications for a common class of antidepressants known as selective serotonin reuptake inhibitors (SSRI). SSRIs can alleviate symptoms of moderate to severe depression and anxiety by increasing the level of serotonin in the brain. Serotonin is a chemical compound that acts as a neurotransmitter thought to be responsible for maintaining mood balance.

However, the research suggests that SSRIs prescribed to treat anxiety or depression may sometimes worsen patients' tinnitus. Tinnitus is defined as the chronic perception of sound when there is no internal or external acoustic source.

"If you're a physician treating a patient for depression who also has hearing loss or tinnitus, you may want to be careful about prescribing a drug that compounds their feelings of anxiety," said Trussell, who also suffers from tinnitus and, in addition to his other roles, has an appointment in the Oregon Hearing Research Center at OHSU. "The SSRI may be enhancing the thing you're trying to fix."

Lead author Zheng-Quan Tang, Ph.D., a senior postdoctoral fellow in Trussell's lab, noted that a review of existing scientific literature indicated that many patients reported an increase in tinnitus soon after they began taking SSRIs.

"Estimates vary, but at least 10 percent of the U.S. population is affected by tinnitus," Tang said.

The OHSU scientists are interested in exploring another area of research focused on a type of ion channel in the membrane of neurons that is activated by . If the scientists can determine a way to deactivate those channels, they may be able to allow the beneficial effects of antidepressants while limiting the severity of tinnitus.

Explore further: Compound enhances SSRI antidepressant's effects in mice

Related Stories

Compound enhances SSRI antidepressant's effects in mice

June 21, 2013
A synthetic compound is able to turn off "secondary" vacuum cleaners in the brain that take up serotonin, resulting in the "happy" chemical being more plentiful, scientists from the School of Medicine at The University of ...

Bilateral tinnitus is hereditary

March 9, 2017
Researchers have been able to demonstrate the hereditary nature of certain forms of tinnitus. Bilateral tinnitus - that is, tinnitus in both ears - has been shown to depend on genetic factors, particularly in men. The twin ...

Researchers visualize brain's serotonin pump, provide blueprint for new, more effective SSRIs

April 6, 2016
Researchers at Oregon Health & Science University's Vollum Institute have uncovered remarkably detailed 3-D views of one of the most important transporters in the brain - the serotonin transporter. Their study, published ...

In search of tinnitus, that phantom ringing in the ears

April 23, 2015
About one in five people experience tinnitus, the perception of a sound—often described as ringing—that isn't really there. Now, researchers reporting in the Cell Press journal Current Biology on April 23 have taken advantage ...

Why some antidepressants may initially worsen symptoms

December 17, 2014
New research helps explain a paradoxical effect of certain antidepressants—that they may actually worsen symptoms before helping patients feel better. The findings, highlighted in a paper publishing online December 17 in ...

Computer-based cognitive training program may help patients with severe tinnitus

January 19, 2017
In a study published online by JAMA Otolaryngology-Head & Neck Surgery, researchers evaluated the effect of a cognitive training program on tinnitus.

Recommended for you

Research shows signalling mechanism in the brain shapes social aggression

October 19, 2018
Duke-NUS researchers have discovered that a growth factor protein, called brain-derived neurotrophic factor (BDNF), and its receptor, tropomyosin receptor kinase B (TrkB) affects social dominance in mice. The research has ...

Good spatial memory? You're likely to be good at identifying smells too

October 19, 2018
People who have better spatial memory are also better at identifying odors, according to a study published this week in Nature Communications. The study builds on a recent theory that the main reason that a sense of smell ...

Scientists discover the region of the brain that registers excitement over a preferred food option

October 19, 2018
At holiday buffets and potlucks, people make quick calculations about which dishes to try and how much to take of each. Johns Hopkins University neuroscientists have found a brain region that appears to be strongly connected ...

How clutch molecules enable neuron migration

October 19, 2018
The brain can discriminate over 1 trillion odors. Once entering the nose, odor-related molecules activate olfactory neurons. Neuron signals first accumulate at the olfactory bulb before being passed on to activate the appropriate ...

Gene plays critical role in noise-induced deafness

October 19, 2018
In experiments using mice, a team of UC San Francisco researchers has discovered a gene that plays an essential role in noise-induced deafness. Remarkably, by administering an experimental chemical—identified in a separate ...

Weight loss success linked with active self-control regions of the brain

October 18, 2018
New research suggests that higher-level brain functions have a major role in losing weight. In a study among 24 participants at a weight-loss clinic, those who achieved greatest success in terms of weight loss demonstrated ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.