Overview
- Researchers reporting in PNAS traced a serotonin pathway from the brain’s raphe nuclei to an auditory brainstem center tied to tinnitus.
- Stimulating the serotonin-releasing neurons increased hyperactivity in the hearing pathway and led mice to behave as if they heard a phantom sound.
- Blocking the same route lowered the abnormal firing patterns and eased tinnitus-like behavior in the animals.
- The results outline a mechanism for why SSRI antidepressants, which raise serotonin, have been reported to worsen tinnitus in some patients, prompting case-by-case medication reviews.
- The authors stress the data come from a mouse model and say human studies and region-specific drugs that avoid the ear-processing circuit are priorities.