碩士 / 國立交通大學 / 分子醫學與生物工程研究所 / 107 / Tinnitus is an anomalous acoustic perception generated without the presence of sounds, and the patients usually suffer from the distressing symptoms. An integrated hypothesis was proposed to explain tinnitus. Tinnitus and hyperacusis are considered to be the side effects of central gain elevation after cochlear insults, but the underlying mechanism is still unclear. Thus, the aim of this study is to explore the neural mechanisms of the central gain control in behaving rats.
We compared the silence activities and the sound-evoked responses by recording electrocorticography in adult Sprague-Dawley rats before and after administrating sodium salicylate (SS) which is renowned for inducing 10 to 16 kHz tinnitus. Experimental results indicated that both treatments (acute and chronic SS treatments) dramatically increased the silence activities at the anterior auditory cortex (AAC) and posterior auditory cortex (PAC), but the changes of PAC were smaller than AAC. The increased silence activities might be the potential neural marker of tinnitus. For the sound-evoked responses, SS significantly enhanced the response to high frequency tones with moderate to loud intensities at the AAC and PAC, which revealed another side effect of the central gain elevation, hyperacusis. Additionally, further analyses also depicted the association between the increases of neural synchrony and the SS-enhanced evoked-responses, especially to the mild tones, but the SS did not produce similar effects to the transient sounds. It suggested that the SS-increased neural synchrony was at least partially contribute to the central gain elevation. Furthermore, since the AAC have larger enhancement than the PAC, the AAC might be the source of the abnormal perceptions, tinnitus and hyperacusis.
| Identifer | oai:union.ndltd.org:TW/107NCTU5538011 |
| Date | January 2019 |
| Creators | Hsu, Shih-Ting, 徐士庭 |
| Contributors | Chiu, Tzai-Wen, 曲在雯 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | en_US |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 51 |
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