“Common side effects of antidepressant medications “
Tinnitus is a physical condition, it’s not a disease, usually caused by a fault in the hearing system. A common cause of tinnitus is inner ear cell damage. Tiny hairs in our inner ear move to the pressure of sound waves. This triggers ear cells to release an electrical signal through a nerve from ear to brain. The brain illuminates these signals as sound. If the hairs in the inner ear bent or broken, they can “leak” random electrical impulses to the brain, causing tinnitus.
Scientists at Oregon Health & Science University shows why a common antidepressant medication may heighten the condition.
Researchers focused on the action of serotonin, an important neuromodulator in the brain. They investigate brain tissue in mice, mainly the dorsal cochlear nucleus where sensory integration and tinnitus occurs. According to researchers, the discovered neurons in the brain known as fusiform cells 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. The study could suggest a common class of antidepressants noted as selective serotonin reuptake inhibitors (SSRIs). SSRIs can reduce the symptoms of depression and anxiety by increasing the level of serotonin in the brain.
However, SSRIs advised to treat anxiety or depression, sometimes worsen the patient’s tinnitus. Tinnitus defined as the chronic perception of sound when there is no internal or external acoustic source.
Lead author Zheng-Quan Tang, noted a review of existing scientific literature indicate many patients reported an increase in tinnitus, after they began taking SSRIs. At least 10 percent of the U.S. population affected by tinnitus.
Scientists interested in exploring another area of research focused on a type of ion channel in the membrane of neurons activated by serotonin. If the scientists determine a way to deactivate those channels, they allow the beneficial effects of antidepressants while limiting the seriousness of tinnitus.
More information: [Cell Reports]