碩士 / 國立成功大學 / 生理學研究所 / 100 / In estimating the presence of tinnitus in animals, a conditioned behavior (polydipsia avoidance) and a reflexive behavior (pre-pulse inhibition acoustic startle reflex) are commonly used. Both of them have strength and weakness: polydipsia avoidance is more accurate, but requires long period of training; acoustic startle reflex requires no training but it only occurs at high sound intensity levels (〉90 dB SPL), way above that of tinnitus percept (〈 35 dB SPL). Hence, the use of other kinds of acoustic reflexes that can be elicited at low intensities would be very beneficial. However, the characterization of other acoustic reflexes (head orienting reflex, pinna reflex, freezing reflex) has not been done especially at low intensity levels where tinnitus is typically perceived. Here an imaging system is developed to study three acoustic reflexes. To minimize habituation, a host of acoustic signals are presented (including a set of pre-recorded environmental sounds with broad spectra). In the control adult rats: (a) head orienting reflex was often observed at a longer latency (~150 ms); (b) concurrent with this, pinna movements that are ipsi-lateral to sound source with response latency ~50 ms; (c) vibrissa freezing response that appeared with much shorter latency (~80 ms). The different response latencies are consistent with the different central neural pathways underlying these reflexes. Most importantly, all of these reflexes could be induced by sounds at levels below 40 dB SPL. Preliminary study on a putative tinnitus animal model (early sound exposure) indicated a trend of threshold elevation suggesting the presence of masking likely due to tinnitus or hearing loss. Results strongly suggested that these acoustic reflexes could be potentially useful as a simple and objective means of probing the tinnitus.
| Identifer | oai:union.ndltd.org:TW/100NCKU5116125 |
| Date | January 2012 |
| Creators | Szu-NingYeh, 葉斯寧 |
| Contributors | Wai-Fung Poon, 潘偉豐 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | en_US |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 97 |
Page generated in 0.0019 seconds