The AudioNotch Tinnitus Treatment Blog

Cool Paper: “Homeostatic plasticity drives tinnitus perception in an animal model.”

Written by AudioNotch Team on March 22, 2013

Categories: Hearing Tinnitus

Another cool paper has come out presenting animal research on the patho-physiology (abnormal physiology) that produces tinnitus. The abstract reads fairly easily:

Hearing loss often results in tinnitus and auditory cortical map changes, leading to the prevailing view that the phantom perception is associated with cortical reorganization.However, we show here that tinnitus is mediated by a cortical area lacking map reorganization.

High-frequency hearing loss results in two distinct cortical regions: a sensory-deprived region characterized by a decrease in inhibitory synaptic transmission and a normal hearing region showing increases in inhibitory and excitatory transmission and map reorganization.

The region deprived of sensory input (corresponding to the hearing loss region) displayed a lack of neuronal inhibition. Thus restoring normal inhibition (the hypothesized mechanism of Tailor-Made Notched Sound Therapy) should reduce tinnitus.

Hearing-lesioned animals displayed tinnitus with a pitch in the hearing loss range. Furthermore, drugs that enhance inhibition, but not those that reduce excitation, reversibly eliminated the tinnitus behavior.

The tinnitus tone corresponded to the frequency range of the hearing loss, and drugs were used to restore normal inhibition and suppress tinnitus.

These results suggest that sensory deprivation-induced homeostatic down-regulation of inhibitory synapses may contribute to tinnitus perception. Enhancing sensory input through map reorganization may plausibly alleviate phantom sensation.

A free link to the full paper is available here.