Abstract | OBJECTIVE: METHODS: The responses of IC neurons to pure tone stimuli were observed in guinea pig at Day 1 and Days 11-21 after cochlear damage induced by noise exposure. And the IC neurons of normal guinea pig were assigned as the controls. Reverse transcription-polymerase chain reaction (RT-PCR) was used to measure the concentrations of GABA(A) and GABA(B) receptors. RESULTS: (1) The types of frequency reaction area (FRA) in the experiment group were the same as those in the control group (V-shape 84.8%, W-shape 8.9%, N-shape 6.3%). But the percentages of types were markedly different at Day 1 (V-shape 63.9%, W-shape 18.1%, N-shape, 18.1%) and Days 11-21 (V-shape 84.2%, W-shape 12.3%, N-shape 3.5%) after noise exposure. (2) After noise exposure, there was a marked fault in characteristic frequency (CF) and depth function map corresponding to 4 kHz (noise frequency). The rake ratio of CF and depth linear function map in the experiment group was lower than that of the control group. The control group, Day 1 and Days 11-21 after noise exposure, the rake ratios were 6.6, 5.8, 5.2 respectively. (3) GABA(A)/ GABA(B) receptors decreased markedly at Days 1, 11 and 21 post-exposure compared to normal controls. And the values increased gradually with the prolonged time after exposure. The above findings conformed to the changes of electrophysiology of IC. CONCLUSIONS: After acoustic trauma, the responses of IC neurons to pure tone stimuli change with the elongation of time. It may be explained by the changes of IC GABA receptors after noise exposure.
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Authors | Feng Wang, Bo Hong, Dong-yi Han, Ling-yun Zhao, Ya-nan Sui, Yu-qian Liu, Wei Guo, Hui-zhan Liu, Liang-fa Liu |
Journal | Zhonghua yi xue za zhi
(Zhonghua Yi Xue Za Zhi)
Vol. 92
Issue 22
Pg. 1565-8
(Jun 12 2012)
ISSN: 0376-2491 [Print] China |
PMID | 22944065
(Publication Type: English Abstract, Journal Article, Research Support, U.S. Gov't, Non-P.H.S.)
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Chemical References |
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Topics |
- Animals
- Cochlea
(injuries)
- Electrophysiological Phenomena
- Guinea Pigs
- Hearing Loss, Noise-Induced
(metabolism)
- Inferior Colliculi
(metabolism)
- Noise
(adverse effects)
- gamma-Aminobutyric Acid
(metabolism)
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