南方医科大学学报

南方医科大学学报 ›› 2021, Vol. 41 ›› Issue (11): 1712-1718.doi: 10.12122/j.issn.1673-4254.2021.11.17

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听觉响应信噪比在上行听觉通路中的演变

王敬敬，宋长宝，梁妃学   

  1. 南方医科大学生物医学工程学院，广东 广州 510515
  • 出版日期:2021-11-20 发布日期:2021-12-10

Evolution of auditory response signal-to-noise ratio in ascending auditory pathways

WANG Jingjing, SONG Changbao, LIANG Feixue   

  1. School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, China
  • Online:2021-11-20 Published:2021-12-10

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摘要： 目的 探究上行听觉通路各级脑区听觉响应信噪比的特征演变规律、不同大脑状态对各级脑区听觉响应信噪比的调节，以及编码声音特征的有效指标。方法 以SPF级C57BL/6J清醒小鼠的下丘、内侧膝状体、初级听皮层的神经元为研究对象，以能够表征3个脑区群体响应为目的记录大量神经元信号，实验结束后统计共使用小鼠80只，其中下丘和内侧膝状体各20只，初级听皮层40只。采用玻璃微电极贴附式方法分别记录3个脑区神经元的最佳频率听觉响应，通过计算神经元的自发与诱发建立分布模型，并对听觉响应信噪比的演变规律进行统计分析；通过监测小鼠跑动速度判断小鼠的运动状态，分析在安静和跑动状态下不同脑区神经元的自发与诱发的变化以及听觉响应信噪比变化的情况。结果 上行听觉通路中不同脑区自发均符合泊松分布，诱发均符合对数正态分布；听觉响应信噪比在下丘脑区显著比内侧膝状体和听皮层大，3个脑区两两之间具有显著差异（IC与MGB：P<0.001，IC与A1：P<0.001，MGB与A1：P<0.001）；多个脑区的听觉响应信噪比在不同运动状态下都维持稳定，即IC、MGB、A1听觉响应信噪比在安静状态下和跑动状态下均没有显著性差异（IC：P=0.537，MGB：P=0.383，A1：P=0.126）。结论 听觉响应信噪比可能是编码声音特征的更有效指标。

关键词: 听觉响应信噪比；上行听觉神经通路；大脑状态；听皮层

Abstract: Objective To explore the characteristics of the evolution of auditory response signal-to-noise ratio at all levels of the ascending auditory pathway, its modulation by different brain states in different brain regions, and its potential value as an effective indicator for encoding sound characteristics. Methods Eighty C57BL/6J awake mice were used for recording the best frequency auditory response of the neurons in the inferior colliculus (n=20), medial geniculate body (n=20), and primary auditory cortex using a glass microelectrode. The probability density of spontaneous and evoked firing of the neurons was calculated to establish a distribution model of spontaneous and evoked firing, and the evolution of the auditory response signal-to-noise ratio was statistically analyzed. The changes in spontaneous and evoked firing of the neurons and the auditory response signal- to-noise ratio in different brain regions were analyzed at rest and during running. Results In different brain regions in the ascending auditory pathway, the spontaneous firing of the neurons all showed a Poisson distribution, and the evoked firing showed a lognormal distribution. The auditory response signal- to-noise ratio was significantly greater in the inferior colliculus than in the medial geniculate body and auditory cortex (P<0.001). The auditory response signal-to-noise ratio in the 3 brain regions remained stable irrespective of the states of motion (P>0.05). Conclusion Auditory response signal-to-noise ratio may serve as an effective indicator of encoding sound characteristics.

Key words: auditory response signal-to-noise ratio; ascending auditory neural pathway; brain states; auditory cortex