Loud sounds damages hearing Noise-Induced Hearing Loss and Tinnitus
A team of researchers from the Massachusetts Eye and Ear and Harvard Medical School have designed a new mouse model. They expressed genes in the inner ear hair cells that aid in the protection of age-related hearing loss (ARHL) and noise-induced hearing loss (NIHL). In their project, they proposed new mechanisms for hearing loss as well as other therapies including gene therapy or medicine. The researchers set forth investigating the different mechanisms in both types of hearing losses which may have a common pathway. They examined the overexpression of Islet1 (precursor gene located in the inner ear that assists with differentiation and development). Results showed that Islet1 expression aided in the protection of the hair cells and support hair cell survival. When mice were exposed to acoustic trauma, their hearing was more intact compared to their kin who did not have the gene.
We know that prolonged exposure to loud sounds damages hearing, by killing the sensory hair cells in the inner ear. We also know that it leaves a lasting impression on how the brain processes sound.
These researchers have discovered that sound trauma leaves a lasting impression on the brain circuitry. This suggests that the brain can mitigate or exaggerate the damage sustained by the inner ear and its sensory apparatus after exposure to the sound.
The researchers will employ state-of-the-art electrophysiology and imaging methods to explore to explore the changes happening in the auditory neurons of the brain following sound trauma in a mouse model.