人类的生活、工作环境中噪声无处不在,长时间或反复暴露于高强度(≥105 dB SPL)噪声环境会损伤听觉外周,引起明显的听力下降,导致噪声性聋(noise-induced hearing loss,NIHL),同时外周因暴露损伤引起的输入变化会导致听觉中枢神经活动...人类的生活、工作环境中噪声无处不在,长时间或反复暴露于高强度(≥105 dB SPL)噪声环境会损伤听觉外周,引起明显的听力下降,导致噪声性聋(noise-induced hearing loss,NIHL),同时外周因暴露损伤引起的输入变化会导致听觉中枢神经活动的代偿性变化。某些低强度噪声暴露虽然不会造成动物的听阈变化,但可对听觉中枢产生可塑性影响,并且影响阈上的听觉行为表现,这提示较低强度噪声对听觉中枢的隐匿暴露危害。为全面了解不同强度噪声对听觉系统功能的危害,本文回顾噪声暴露对听觉外周及中枢的可塑性影响研究进展,阐述不损伤听阈的噪声暴露对听觉系统的影响特点。展开更多
The precedence effect is a prerequisite for faithful sound localization in a complex auditory environment, and is a physiological phenomenon in which the auditory system selectively suppresses the directional informat...The precedence effect is a prerequisite for faithful sound localization in a complex auditory environment, and is a physiological phenomenon in which the auditory system selectively suppresses the directional information from echoes. Here we investigated how neurons in the inferior colliculus respond to the paired sounds that produce precedence-effect illusions, and whether their firing behavior can be modulated through inhibition with gamma-aminobutyric acid （GABA）. We recorded extracellularly from 36 neurons in rat inferior colliculus under three conditions： no injection, injection with saline, and injection with gamma-aminobutyric acid. The paired sounds that produced precedence effects were two identical 4-ms noise bursts, which were delivered contralaterally or ipsilaterally to the recording site. The normalized neural responses were measured as a function of different inter-stimulus delays and half-maximal interstimulus delays were acquired. Neuronal responses to the lagging sounds were weak when the inter-stimulus delay was short, but increased gradually as the delay was lengthened. Saline injection produced no changes in neural responses, but after local gamma-arninobutyric acid application, responses to the lagging stimulus were suppressed. Application of gamma-aminobutyric acid affected the normalized response to lagging sounds, independently of whether they or the paired sounds were contralateral or ipsilateral to the recording site. These observations suggest that local inhibition by gamma-aminobutyric acid in the rat inferior colliculus shapes the neural responses to lagging sounds, and modulates the precedence effect.展开更多
目的观察刺激声频率差异变化对正常人失匹配负波(mismatch negativity,MMN)的影响,探讨MMN产生机制,及其对声音辨别能力检测的应用价值。方法对12例青年健康男性行MMN检查,所有受试者均行听性脑干反应(ABR)阈值检查,确定ABR阈值,MMN检...目的观察刺激声频率差异变化对正常人失匹配负波(mismatch negativity,MMN)的影响,探讨MMN产生机制,及其对声音辨别能力检测的应用价值。方法对12例青年健康男性行MMN检查,所有受试者均行听性脑干反应(ABR)阈值检查,确定ABR阈值,MMN检查在受试者在阅读状态检测,采用odd-ball刺激方式,给予短纯音刺激,偏差刺激概率为20%,标准刺激概率为80%,刺激频率为1.1次/s,刺激声强度为ABR阈上50d B;偏差刺激声频率分别为750Hz;1000Hz;2000Hz;3000Hz,对应的标准刺激声频率分别为500Hz;500Hz;1000Hz;1000Hz,每个受试者均行4次MMN检查,每次标准刺激和偏差刺激的频率差异幅值分别为250Hz;500 Hz;1000 Hz;2000 Hz。观察各组MMN潜伏期及波幅的特点。结果所有受试者ABR阈值均≤25 d B n HL。每例受试者均可引出MMN波形,当频率差异幅度分别为250Hz,500 Hz,1000 Hz,2000 Hz时,各组MMN潜伏期分别为167.61±14.93ms,148.48±12.03ms,139.17±10.93ms,121.37±19.51ms,经方差分析,总体各组潜伏期有显著差异(F=18.81,p=0.000);波幅分别为5.62±2.68 u V,7.35±2.97 u V,6.13±1.83 u V,6.36±2.26u V,经方差分析,总体各组波幅无显著差异(F=0.956,p=0.423)。结论MMN在正常青年人可以稳定引出,而且随着刺激声频率差异的增大,其潜伏期呈现稳定而且有规律的减小,重复性良好,作为对声音辨别能力检测的有效手段,有较为广阔的临床应用价值。展开更多
Adult guinea pigs with normal Preyer’s reflexes were used in this experiment and were di-vided into 3 groups according to the intensity of noise and exposure time.Auditory brainstemevoked response was recorded before...Adult guinea pigs with normal Preyer’s reflexes were used in this experiment and were di-vided into 3 groups according to the intensity of noise and exposure time.Auditory brainstemevoked response was recorded before and after exposure to noise.Clicks were presented monaurallyat a rate of high (50Hz) as well as low (10Hz).The superior olive and inferior colliculus were ob-served under an electron microscope after the guinea pigs were exposured to 110dB noise for30min.The average shift of wave Ⅳ amplitude-intensity function curve was more than that ofwave Ⅰ after exposure to intensive noise.The difference value of wave \ latency from low(10Hz) to high (50Hz) stimulus click rate decreased and was negatively correlated with the exposuretime.Ⅰ-Ⅴ,Ⅲ-Ⅴ and Ⅳ-Ⅴ interpeak latencies were shorter after exposure to noise.Themitochondria and neurilemma swelling were found in the superior olive and inferior colliculus afterexposure,Some mechanisms of the changes of auditory center were discussed in this paper.展开更多
文摘人类的生活、工作环境中噪声无处不在,长时间或反复暴露于高强度(≥105 dB SPL)噪声环境会损伤听觉外周,引起明显的听力下降,导致噪声性聋(noise-induced hearing loss,NIHL),同时外周因暴露损伤引起的输入变化会导致听觉中枢神经活动的代偿性变化。某些低强度噪声暴露虽然不会造成动物的听阈变化,但可对听觉中枢产生可塑性影响,并且影响阈上的听觉行为表现,这提示较低强度噪声对听觉中枢的隐匿暴露危害。为全面了解不同强度噪声对听觉系统功能的危害,本文回顾噪声暴露对听觉外周及中枢的可塑性影响研究进展,阐述不损伤听阈的噪声暴露对听觉系统的影响特点。
基金supported by the National Natural Science Foundation of China,No.81271090 and the Beijing Natural Science Foundation,No.7112055
文摘The precedence effect is a prerequisite for faithful sound localization in a complex auditory environment, and is a physiological phenomenon in which the auditory system selectively suppresses the directional information from echoes. Here we investigated how neurons in the inferior colliculus respond to the paired sounds that produce precedence-effect illusions, and whether their firing behavior can be modulated through inhibition with gamma-aminobutyric acid （GABA）. We recorded extracellularly from 36 neurons in rat inferior colliculus under three conditions： no injection, injection with saline, and injection with gamma-aminobutyric acid. The paired sounds that produced precedence effects were two identical 4-ms noise bursts, which were delivered contralaterally or ipsilaterally to the recording site. The normalized neural responses were measured as a function of different inter-stimulus delays and half-maximal interstimulus delays were acquired. Neuronal responses to the lagging sounds were weak when the inter-stimulus delay was short, but increased gradually as the delay was lengthened. Saline injection produced no changes in neural responses, but after local gamma-arninobutyric acid application, responses to the lagging stimulus were suppressed. Application of gamma-aminobutyric acid affected the normalized response to lagging sounds, independently of whether they or the paired sounds were contralateral or ipsilateral to the recording site. These observations suggest that local inhibition by gamma-aminobutyric acid in the rat inferior colliculus shapes the neural responses to lagging sounds, and modulates the precedence effect.
文摘目的观察刺激声频率差异变化对正常人失匹配负波(mismatch negativity,MMN)的影响,探讨MMN产生机制,及其对声音辨别能力检测的应用价值。方法对12例青年健康男性行MMN检查,所有受试者均行听性脑干反应(ABR)阈值检查,确定ABR阈值,MMN检查在受试者在阅读状态检测,采用odd-ball刺激方式,给予短纯音刺激,偏差刺激概率为20%,标准刺激概率为80%,刺激频率为1.1次/s,刺激声强度为ABR阈上50d B;偏差刺激声频率分别为750Hz;1000Hz;2000Hz;3000Hz,对应的标准刺激声频率分别为500Hz;500Hz;1000Hz;1000Hz,每个受试者均行4次MMN检查,每次标准刺激和偏差刺激的频率差异幅值分别为250Hz;500 Hz;1000 Hz;2000 Hz。观察各组MMN潜伏期及波幅的特点。结果所有受试者ABR阈值均≤25 d B n HL。每例受试者均可引出MMN波形,当频率差异幅度分别为250Hz,500 Hz,1000 Hz,2000 Hz时,各组MMN潜伏期分别为167.61±14.93ms,148.48±12.03ms,139.17±10.93ms,121.37±19.51ms,经方差分析,总体各组潜伏期有显著差异(F=18.81,p=0.000);波幅分别为5.62±2.68 u V,7.35±2.97 u V,6.13±1.83 u V,6.36±2.26u V,经方差分析,总体各组波幅无显著差异(F=0.956,p=0.423)。结论MMN在正常青年人可以稳定引出,而且随着刺激声频率差异的增大,其潜伏期呈现稳定而且有规律的减小,重复性良好,作为对声音辨别能力检测的有效手段,有较为广阔的临床应用价值。
文摘Adult guinea pigs with normal Preyer’s reflexes were used in this experiment and were di-vided into 3 groups according to the intensity of noise and exposure time.Auditory brainstemevoked response was recorded before and after exposure to noise.Clicks were presented monaurallyat a rate of high (50Hz) as well as low (10Hz).The superior olive and inferior colliculus were ob-served under an electron microscope after the guinea pigs were exposured to 110dB noise for30min.The average shift of wave Ⅳ amplitude-intensity function curve was more than that ofwave Ⅰ after exposure to intensive noise.The difference value of wave \ latency from low(10Hz) to high (50Hz) stimulus click rate decreased and was negatively correlated with the exposuretime.Ⅰ-Ⅴ,Ⅲ-Ⅴ and Ⅳ-Ⅴ interpeak latencies were shorter after exposure to noise.Themitochondria and neurilemma swelling were found in the superior olive and inferior colliculus afterexposure,Some mechanisms of the changes of auditory center were discussed in this paper.
