Title: Neural Mechanisms of Tinnitus

Speaker: Dr. Jinsheng Zhang (Wayne State University)

Time: September 28 2016 (Wed) 13:00-15:00

Venue: R1113, Wangkezhen Building, PKU

Tinnitus is a condition and type of neurological disorder whereby individuals may perceive relentless phantom sounds in the absence of overt acoustic stimulation. Patients with chronic tinnitus can suffer from depression, anxiety, and sleep disturbance, which significantly impair their quality of daily life. Tinnitus-related disability compensation also creates a significant economic burden on society. With the goal of developing effective drugs and device treatments for tinnitus, my lab has been investigating the underlying neural mechanisms of tinnitus by taking a multidisciplinary approach, which includes behavioral assays, multi-channel and multi-structural electrophysiology, MRI/MEMRI, immunocytochemistry, as well as neuromodulatory and pharmacological interventions. In addition to neural mechanisms such as hyperactivity, hypersynchrony and plastic reorganization within brain structures, we investigate neural interactions between centers and identify information flow that contributes to the development and maintenance of tinnitus. We have found that, compared to tinnitus(-) animals, there was increased coherence and synchrony at certain frequency bands in auditory structures, especially the auditory cortex of tinnitus(+) animals. We have also investigated how tinnitus suppression is achieved by auditory cortex stimulation (top-down neuromodulation) and cochlear stimulation (bottom-up neuromodulation) through cochlear implants. We found that increased coherence and hypersynchrony in the auditory cortex were suppressed by auditory cortex electrical stimulation, and hyperactivity and hypersynchrony were down-regulated by cochlear electrical stimulation. Taken together, our findings indicate that chronic tinnitus perception is of both cortical and subcortical origin and that suppression of tinnitus may involve neuromodulation and gating adjustment at both cortical and subcortical levels.

Host: Liang Li