It's a common experience when it takes a little while for our hearing to be restored after listening to our iPods too loud or attending a raucous concert.But new research at the University of Michigan Health System suggests over-exposure to noise can actually cause more lasting changes to our auditory circuitry - changes that may lead to tinnitus, commonly known as ringing in the ears.
U-M researchers previously demonstrated that after hearing damage, touch-sensing "somatosensory" nerves in the face and neck can become overactive, seeming to overcompensate for the loss of auditory input in a way the brain interprets - or "hears" - as noise that isn't really there.
Tinnitus
Tinnitus is the perception of ringing, hissing, or other sound within the ears when no corresponding external sound is present.
Advertisement
The new study, which appears in the Feb. 1 issue of The Journal of Neuroscience, found that somatosensory neurons maintain a high level of activity following exposure to loud noise, even after hearing itself returns to normal.
The findings were made in guinea pigs, but mark an important step toward potential relief for people plagued by tinnitus, says lead investigator Susan E. Shore, Ph.D., of U-M's Kresge Hearing Research Institute and a professor of otolaryngology and molecular and integrative physiology at the U-M Medical School.
![Tinnitus Symptom Evaluation]( "Tinnitus Symptom Evaluation")
Tinnitus is a ringing or a swishing noise that emanates from the ear or head. It is not a life-threatening condition and usually resolves with time.
"The animals that developed tinnitus after a temporary loss in their hearing after loud noise exposure were the ones who had sustained increases in activity in these neural pathways," Shore says. "In the future it may be possible to treat tinnitus patients by dampening the hyperactivity by reprogramming these auditory-touch circuits in the brain."
In normal hearing, a part of the brain called the dorsal cochlear nucleus is the first stop for signals arriving from the ear via the auditory nerve. But it's also a hub where "multitasking" neurons process other sensory signals, such as touch, together with hearing information.
During hearing loss, the other sensory signals entering the dorsal cochlear nucleus are amplified, Shore's earlier research found. This overcompensation by the somatosensory neurons, which carry information about touch, vibration, skin temperature and pain, is believed to fuel tinnitus in many cases.
Tinnitus affects up to 50 million people in the United States and millions more worldwide, according to the American Tinnitus Association. It can range from intermittent and mildly annoying to chronic, severe and debilitating. There is no cure.
Source: Eurekalert
Tinnitus Symptom Evaluation
Tinnitus is a ringing or a swishing noise that emanates from the ear or head. It is not a life-threatening condition and usually resolves with time.
Advertisement
"The animals that developed tinnitus after a temporary loss in their hearing after loud noise exposure were the ones who had sustained increases in activity in these neural pathways," Shore says. "In the future it may be possible to treat tinnitus patients by dampening the hyperactivity by reprogramming these auditory-touch circuits in the brain."
In normal hearing, a part of the brain called the dorsal cochlear nucleus is the first stop for signals arriving from the ear via the auditory nerve. But it's also a hub where "multitasking" neurons process other sensory signals, such as touch, together with hearing information.
During hearing loss, the other sensory signals entering the dorsal cochlear nucleus are amplified, Shore's earlier research found. This overcompensation by the somatosensory neurons, which carry information about touch, vibration, skin temperature and pain, is believed to fuel tinnitus in many cases.
Tinnitus affects up to 50 million people in the United States and millions more worldwide, according to the American Tinnitus Association. It can range from intermittent and mildly annoying to chronic, severe and debilitating. There is no cure.
Source: Eurekalert
Tinnitus in Elderly Patients as an Indicator of Prognosis of Mild-To-Moderate Congestive Heart Failure -Study
Prevalence of tinnitus in a large group of elderly patients with CHF and to define the relationship between the occurrence of tinnitus and the severity and prognosis of CHF.
Advertisement
 Pine Bark Naturally Improves Tinnitus: StudyMore than 50 million Americans will experience some degree of tinnitus in their lifetime, according to the American Tinnitus Association. Tinnitus | Advertisement
|
Advertisement
Recommended Reading
Latest Research News
Brain plasticity following blindness leads to superior ability in sensing signals from the heart, which has implications for bodily awareness and emotional processing.
A group of scientists were awarded £1.3 million to create a new “point of care testing” kit that detects Alzheimer's disease biomarkers.
Is there a connection between Osteoporosis and dementia? Yes, loss in bone density may be linked to an increased risk of dementia in older age.
Link between chromosome length and biological aging marker discovered. The finding helps explain why people with longer telomeres have a lower dementia risk.
Integrated structural biology helps discover how the cystic fibrosis transmembrane conductance regulator (CFTR) works.