Homeostatic plasticity drives tinnitus perception in an animal model

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 108; no. 36; pp. 14974 - 14979
• Main Authors: Yang, Sungchil, Weiner, Benjamin D, Zhang, Li S, Cho, Sung-Jin, Bao, Shaowen
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 06-09-2011; National Acad Sciences
• Subjects: Animal behavior; Animal cognition; animal models; Animals; Auditory cortex; Auditory Cortex - physiopathology; Auditory Perception; Behavior, Animal; Biological Sciences; Brain; Deafness; Disease Models, Animal; drugs; hearing; hearing disorders; Hearing loss; Homeostasis; Homeostasis - drug effects; Lesions; Neuronal Plasticity; Neurons; Rats; Rats, Sprague-Dawley; Sound; Synapses; Synaptic transmission; Tinnitus; Tinnitus - drug therapy; Tinnitus - physiopathology
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1107998108

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. 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. 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.