Rebooting the brain helps stop the ring of tinnitus in rats

Jan 12, 2011

(PhysOrg.com) -- Researchers were able to eliminate tinnitus in a group of rats by stimulating a nerve in the neck while simultaneously playing a variety of sound tones over an extended period of time, says a study published today in the advance online publication of the journal Nature. The hallmark of tinnitus is often a persistent ringing in the ears that is annoying for some, debilitating for others, and currently incurable. Similar to pressing a reset button in the brain, this new therapy was found to help retrain the part of the brain that interprets sound so that errant neurons reverted back to their original state and the ringing disappeared. The research was conducted by scientists from the University of Texas at Dallas and MicroTransponder Inc., in Dallas.

"Current treatments for generally involve masking the sound or learning to ignore it," said James F. Battey, Jr., M.D., Ph.D., director of the National Institute on and Other Communication Disorders (NIDCD), which funded a large part of the research. "If we can find a way to turn off the noise, we'll be able to improve life substantially for the nearly 23 million American adults who suffer from this disorder."

Tinnitus is a symptom some people experience as a result of hearing loss. When in the inner ear are damaged, such as from , the resulting hearing loss changes some of the signals sent from the ear to the brain. For reasons that are not fully understood, some people will develop tinnitus as a result.

"We believe the part of the brain that processes sounds—the auditory cortex—delegates too many to some frequencies, and things begin to go awry," said Michael Kilgard, Ph.D., associate professor of behavior and brain sciences at UT-Dallas, and a co-principal investigator on the study. "Because there are too many neurons processing the same frequencies, they are firing much stronger than they should be."

In addition, the neurons fire in sync with one another and they also fire more frequently when it is quiet. According to Dr. Kilgard, it's these changing brain patterns that produce tinnitus, which is usually a high-pitched tone in one or both ears, but it may also be heard as clicking, roaring, or a whooshing sound.

Dr. Kilgard, along with co-principal investigator Navzer Engineer, M.D., Ph.D., of MicroTransponder, Inc., and others on the research team first sought to induce changes in the auditory cortex of a group of by pairing stimulation of the vagus , a large nerve that runs from the head and neck to the abdomen, with the playing of a single tone. When the vagus nerve is stimulated, it releases acetylcholine, norepinephrine, and other chemicals that help encourage changes in the brain. They wanted to find out if they could induce more brain cells to become responsive to that tone over a period of time.

For 20 days, 300 times a day, researchers played a high-pitched tone, at 9 kilohertz (kHz), to eight rats. At the same time that the tone was played, an electrode delivered a very small electrical pulse to the vagus nerve. The researchers found that the number of neurons tuned to the 9 kHz frequency had jumped by 79 percent in comparison to the control rats.

In a second group of rats, they randomly played two different tones—one at 4 kHz and the other at 19 kHz—but stimulated the vagus nerve only for the higher tone. Neurons tuned to the higher frequency increased by 70 percent while neurons tuned to the 4 kHz tone actually decreased in number, indicating that the tone alone was not enough to initiate the change. It had to be accompanied by vagus nerve stimulation (VNS).

Next, the researchers tested whether tinnitus could be reversed in noise-exposed rats by increasing the numbers of neurons tuned to frequencies other than the tinnitus frequency. A group of the noise-exposed rats with tinnitus received VNS that was paired with different tones surrounding the tinnitus frequency 300 times a day for about three weeks. Rats in the control group received VNS with no tones, tones with no VNS, or no therapy. For both groups, measurements were taken four weeks after noise exposure, then 10 days after therapy began, and one day, one week, and three weeks after therapy ended.

Rats that received the VNS paired with tones showed promising results for each time point after therapy began, including midway through therapy, indicating that the ringing had stopped for the treated rats. Conversely, the data from control rats indicated their tinnitus had continued throughout the testing period. What's more, the researchers followed two treated and two control rats for an additional two months and found that the treated rats maintained this benefit for 3.5 months after noise exposure, while the controls continued to be impaired.

The researchers also evaluated neural responses in the auditory cortex in these same rats and found that neurons in the treated rats had returned to their normal levels, where they remained. This indicated that the tinnitus had disappeared. However, the control group levels continued to be distorted, indicating that the tinnitus persisted. Overall, the researchers found that the VNS treatment paired with tones had not only reorganized the neurons to respond to their original frequencies, but it also made the brain responses sharper, decreased excitability, and decreased synchronization of auditory cortex neurons.

"The key is that, unlike previous treatments, we're not masking the tinnitus, we're not hiding the tinnitus. We are retuning the brain from a state where it generates tinnitus to a state that does not generate tinnitus. We are eliminating the source of the tinnitus," said Dr. Kilgard.

VNS is currently being used to treat roughly 50,000 people with epilepsy or depression, and MicroTransponder hopes to conduct clinical studies using VNS with paired tones in tinnitus patients.

"The clinical protocol is being finalized now and a pilot study in tinnitus patients will be conducted in Europe in the near future," said Dr. Engineer, vice president of preclinical affairs at MicroTransponder. "The support of the NIDCD has been essential to allow our research team to continue our work in this important area of tinnitus research." MicroTransponder is a neuroscience-based medical device company that is working to develop treatments for a variety of neurological diseases, including tinnitus, chronic pain, and anxiety.

In the meantime, the researchers are currently working to fine-tune the procedure to better understand such details as the most effective number of paired frequencies to use for treatment; how long the treatment should last; and whether the treatment would work equally well for new tinnitus cases in comparison to long-term cases.

Explore further: Imaging study reveals white-matter deficits in users of codeine-containing cough syrups

Provided by National Institutes of Health

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gwrede
1.9 / 5 (7) Jan 12, 2011
"Rebooting the brain"... This article is like those about Invisibility Cloaks in the lab, Black Holes in acoustics, and other pathetically titled articles.
Kingsix
5 / 5 (7) Jan 12, 2011
As a person suffering from Tinnitus myself I am very glad to hear that progress is being made in this area.
For those wondering about what tinnitus may be like, I have ringing in both ears constantly, the ringing in my left ear has 2 or 3 tones, its difficult to tell. My right ear has one tone, but changes in air pressure, blood pressure, sinus problems cause this to get louder or quieter. The blood pressure issue, which I am experiencing right now, makes the noise get loud with ear pump of blood through the ear.
Its really very irritating. I have had tinnitus for 12 years now, 24-7.
Aliensarethere
5 / 5 (2) Jan 12, 2011
I can only imagine how it must be for you Kingsix. My mother has tinnitus, and she is really bothered by it, so much she is saying it's not worth living.
Ulg
5 / 5 (2) Jan 12, 2011
I had Tinnitus for 11 consecutive days and it disappeared over night while sleeping luckily, it is nice to hear a bit of news on this though as I am sure many people suffer from this and it can be quite a nuisance.
anoopc
5 / 5 (2) Jan 12, 2011
I have had Tinnitus almost for ever... Can't remember when it started. Its not a buzzing or clicking one though (thank God). The only thing I have noticed is it gets agitated with drinks. I have just learned to tune it out/make friends with it. I use ear plugs to sleep (yes seems opposite of what we would want) but it helps my brain get used to the ringing and not be bothered by it.

If you train your brain enough you can actually hear a pin drop on a carpet.
KingDWS
5 / 5 (1) Jan 12, 2011
I wonder if this is just a variant on the pink noise therapy. I'll second the ear plugs for sleeping. It does seem to cut down on excess noise at times. Also noticed using or even just wearing noise cancelling headphones for a while takes the edge off the high pitched tones for a few hours afterwards.
maxcypher
5 / 5 (1) Jan 12, 2011
I have tinnitus from playing loud music in my 20's and 30's. I found out that East Indians consider the ringing to be a sort of chanting of "OM", so that is how I've treated it during the last decade. Being a musician and having tinnitus really sucks! I hope this research pans out. BTW, one can get on the email announcement list for tinnitus developments at the MicroTransponder site, if you're interested.
Thex1138
5 / 5 (1) Jan 12, 2011
Another cause of Tinnitus is pressure in the neck on the nerve root that goes to the ear... C1/C2...
After chiropractic adjustments my Tinnitus had gone. So there are a number of causes and solutions.
Mira_Musiclab
not rated yet Jan 12, 2011
I feel for you guys. Really glad they seem to be making some progress with it though.

I'd go completely insane if I had to deal with that day in and day out.. (well, more than I am already)
fixer
5 / 5 (1) Jan 12, 2011
Certainly it looks good, but how do you tell if a rat has tinnitus?
Mira_Musiclab
not rated yet Jan 12, 2011
Lol Fixer, was wondering the same thing..

I'm guessing there's voltages present that can be picked up on EEG-type detectors. What I'm really curious about, is if there's actually tones being generated in the cochlea because of this..
ketanco
not rated yet Jan 13, 2011
I have tinnitus since 18 years now... It happened overnight after going to a night club and standing near the speaker for a while... There is no silence for me since then, all these years. Either the surrounding is louder than my ringing, or if I am at a silent place, then I hear the ringing of my ears... I really hope they find a cure for us... I tested several times over the years about my level of hearing and it is normal. however I am also sure that it was better before the incident happened...
GuruShabu
1 / 5 (2) Jan 13, 2011
I have tinnitus since I falled down on the floor on my back and hit the ground hard with my head.
Since that day I have continuous tinnitus.
It is about 2 years now.
Bob_Kob
2.3 / 5 (3) Jan 13, 2011
I've got minor tinnitus, i can only really hear it when it is very silent like nighttime. However I've noticed by concentrating I can actually reduce the noise so that is almost completely disappears. Obviously once the concentration ends it comes back but its amazing to think that its all controllable deep down in the brain. We just have to find the keys to unlock it.
jjoensuu
not rated yet Jan 13, 2011
I have had tinnitus for some years now, it is only a bit annoying however. A couple of years ago I was told that it was caused by some damage in the inner ear. Lately I noticed that the sound that I hear goes lower when I have to unscrew a bottle cap, although only for the short moment that I am tensing a muscle in my arm. So since the sound can go lower it probably is some sort of a nerve issue rather than an actual physical injury.
Rikk
not rated yet Jan 13, 2011
Some good news. I have had tinnitus for about 12 years (since age 55). I did the TRT therapy (using the Jastroboff device) 6 years ago - which helped a bit - but over time I grew accustomed. Then a year ago I had sudden deafness in one ear (total and permanent). Now not only am I deaf in that ear - but I have extreme tinnitus in it(tones, birds chriping, buzzing) constantly and still have tinnitus in the other ear as well (with 70% loss in that ear). The specialists say with more time I will adjust to it too. Although it is very much still there - I don't notice it unless I think about it. Perhaps it is because of the deafness. I have to really focus to hear what is said that I don't notice the tinnitus as much. Time can be a great healer.
Modernmystic
1 / 5 (1) Jan 13, 2011
As a person suffering from Tinnitus myself I am very glad to hear that progress is being made in this area.
For those wondering about what tinnitus may be like, I have ringing in both ears constantly, the ringing in my left ear has 2 or 3 tones, its difficult to tell. My right ear has one tone, but changes in air pressure, blood pressure, sinus problems cause this to get louder or quieter. The blood pressure issue, which I am experiencing right now, makes the noise get loud with ear pump of blood through the ear.
Its really very irritating. I have had tinnitus for 12 years now, 24-7.


Had mine about the same amount of time. The only time it USUALLY bothers me is at night, a fan will usually mask it enough. If not I have to turn on the TV. I won't say it's "debilitating" but it can be as ANNOYING AS HELL sometimes.

Glad to hear there's some progress on this!
racchole
not rated yet Jan 13, 2011
I feel for you guys. Really glad they seem to be making some progress with it though.

I'd go completely insane if I had to deal with that day in and day out.. (well, more than I am already)


You'd be surprised how capable we are of dealing with problems that don't go away. I have a distinct memory of the one of the first few nights after my tinnitus started - it was god awful, and now today I've managed to completely block out the conscious awareness of it.
KapeKelly
1 / 5 (1) Jan 13, 2011
SO this 'rebooting of the brain', is this an alternative use for electric shock therapy? I understand that reboots the entire brain, clears the memory banks too and solves most major depression. Seem like overkill and using elephant tranq to treat a mouse. I have tinnitus but will live with it over rebooting my whole brain to fix it.
Plus, wasnt there some debate that perhaps some humans hearing is able to hear outside of the normal human range and that tinnitus may just be a reflection of that, like kids can hear sounds that grown ups no longer can.
djfl
not rated yet Jan 15, 2011
I have had tinnitus since 1987. It started when I was taking antibiotics for a strep throat infection, and it drove me nuts for many years until it finally died down to where I only noticed it when it was very quiet, but I had to sleep with one of those machines that makes different sounds like the ocean, rainfall, etc. Last August, I had to take Zantac for a heartburn problem that was caused by another antibiotic, and I woke up one morning with a screeching noise in my right ear. Then a few days later, I woke up with the same noise in my left ear. The tinnitus was back with a vengeance. When I looked up Zantac side effects, tinnitus was listed, so I stopped taking the Zantac and hoped that the tinnitus would go away, but it didn't. It has been five months now, and it seems to be getting worse. I sleep on my side, but I alternate from side to side during the night, and it gets very loud in whichever ear is on the pillow.
SkyAbove
5 / 5 (1) Jan 15, 2011
I’ve tried many treatments and even experimented on my own tinnitus. I’ve discovered that about 100 mg of magnesium aspartate per meal will reduce my tinnitus by over 50%. And about 10 micrograms of melatonin at night reduces it 90% for half the next day. I’ve been tested by Kaiser after a few years on these and I regained some hearing loss in both ears. From this experience I believe tinnitus comes from the NMDA receptors, which are excitatory.
1. Takumida et al. Pharmacological models for inner ear therapy with emphasis on nitric oxide. Acta Otolaryngol 121:16-20 (2001).
2. Pall and Bedient. The NO/ONOO– cycle as the etiological mechanism of tinnitus. Int Tinnitus J 13(2):99-104 (2007).
SkyAbove
not rated yet Jan 15, 2011
I have tried many treatments and experimented on my own tinnitus. I’ve discovered that about 100 mg of magnesium aspartate per meal will reduce my tinnitus by over 50%. And about 10 micrograms of melatonin at night reduces it 100% for half the next day. I’ve been tested by Kaiser after a few years on these and I regained some hearing loss in both ears. For this experience I believe tinnitus comes from the NMDA receptors, which are excitatory.
1) Takumida et al. Pharmacological models for inner ear therapy with emphasis on nitric oxide. Acta Otolaryngol 121:16-20 (2001).
2) Pall and Bedient. The NO/ONOO– cycle as the etiological mechanism of tinnitus. Int Tinnitus J 13(2):99-104 (2007).
Nyloc
not rated yet Jan 16, 2011
I've experienced tinnitus off-and-on for many years. At one point, I became very anxious, fearing that it would never go away. This anxiety seemed to aggravate the constant high-pitched squeal.

Then I noticed, by chance, that the intensity of the sound correlated to the amount of sleep I had the night before. Paying close attention to my sleep habit's, I discovered that after a good night's sleep, it almost disappears the next day.

I know that its difficult in this hectic world to get enough sleep. Having to wake up to go to work rather than waking up naturally is reality for many, but I suggest that sufferers experiment with this, even on weekends.

Knowing that there is a way to diminish tinnitus is a relief in itself. And one can always go to bed earlier.
gmurphy
not rated yet Jan 16, 2011
Several years ago, a wheel-barrow tire I was inflating using a heavy duty compressor exploded next to my head. I was deaf for nearly a day afterwards but eventually recovered my hearing almost completely. I am occasionally susceptible to tinnitus. I associate it with stress. I can usualy "turn it off" within a few minutes by through meditation. I don't know if this could help anybody else but it's worth a shot.
johnwbales
not rated yet Jan 17, 2011
So far as I know I have had tinnitus my entire life. I first noticed it at the age of four years when someone asked me jokingly if my ears were ringing. I thought for a second and said yes. I have to think about it to notice it, but it is always with me and is fairly loud compared to external noises. Each ear has a constant major tone with constantly wavering tones around that tone. It doesn't bother me. I am 67 years old. It was only about 10 years ago that I learned that this was not normal. I though everyones ears rang all the time.
KellyB
not rated yet Jan 19, 2011
I have suffered from extremely bad tinnitus for several decades now. Imagine the hissing sound you hear from the water refilling the toilet bowl so loud that it can still be heard when standing near a jet taking off at the airport. 24/7. Imagine a life where any background noise makes normal conversations unintelligible. I for one will welcome any advance that gives me an important part of my life back. I just wish I lived in Europe so I could volunteer for the trial.
ketanco
not rated yet Jan 23, 2011
Several years ago, a wheel-barrow tire I was inflating using a heavy duty compressor exploded next to my head. I was deaf for nearly a day afterwards but eventually recovered my hearing almost completely. I am occasionally susceptible to tinnitus. I associate it with stress. I can usualy "turn it off" within a few minutes by through meditation. I don't know if this could help anybody else but it's worth a shot.

by meditating, do you mean focusing on making the sound disappear or how is your medidation exactly? Thanks for advice
ana344
not rated yet Jan 25, 2011
I have had Tinnitus for more than two months after I underwent an operation named Transtympanic drainage which supposedly was going to free some pressure in my ears.I was wrongly diagnosed ototubaritis, since otherENT told me that the only thing I needed was some anti-inflammatories. My Tinnitus is rated 98% severe and I also have very severe hyperacusy.This has completely ruined my life.I have no life since I have Tinnitus, some days I wish I wouldn't get up because is really hard to cope with it.I have insomnia and this is deriving me in a depression, I can't hardly concentrate in anything and not being able to sleep during the nights because the horrible noise wakes me up and tortures me is something hard to cope with.I just keep praying everyday that God delivers me from this horrible nightmare and I can get my life back.These news about a cure for T brings some hope for those who like me have "lost their life" with the it.How long will it take to be reallity in our lives?