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采用细胞外记录方法研究小鼠下丘中央核(the central nucleus of the inferior colliculus,ICC)听觉神经元对不同频率纯音刺激反应的延时-幅度关系.对于同一个神经元,采用基于Pieron’s法则建立的一个新方程,可对所有单一频率下延时-幅度反应曲线进行很好的拟合,提示单一频率下延时-幅度反应曲线具有相似的曲度,而仅表现为同一坐标系下所处位置的差异.经标准化消除不同频率下延时-幅度反应曲线相对于神经元特征频率(characteristic frequency,CF)下延时-幅度反应曲线的位置差异后,所有曲线高度重合.ICC神经元对声刺激延时-幅度反应曲线曲度相似并可高度重合,反映了声音信号转化为生物电信号的物理法则.以神经元CF延时-幅度反应曲线为参照,不同频率下延时-幅度反应曲线横、纵轴趋于无限大时的纵、横坐标数值的差值(ΔL及ΔA)可用来描述其位置的相对差异.声音信号处理过程中,连接于同一神经元的神经纤维和突触可功能性地简化为单个“线路”(总和纤维的长度)和单个“接头”(总和突触的强度).在线路和接头上,分别完成信号的传输(transmission)和传导(transduction).因此,ΔL及ΔA可作为衡量一条声刺激激活通路功能性相对总和纤维长度及总和突触强度的指标.实验结果显示,对于不同的频率处理通路和不同的神经元其ΔL及ΔA不同,提示神经元不同的声反应是因声刺激激活的信号处理通路不同而造成的,而用于处理不同频率声刺激的通路也是不同的.
Extracellular recording method was used to study the delay-amplitude relationship of the auditory neurons of the central nucleus of the inferior colliculus (ICC) in pure tone stimulation response at different frequencies.For the same neuron, Pieron’s law was used to establish A new equation can be fitted well to all the delay-amplitude response curves at a single frequency, suggesting that the delay-amplitude response curves at a single frequency have similar curvatures but only in the same coordinate system All curves were highly coincident with the normalized elimination of the position difference of the delay-amplitude response curve at different frequencies relative to the time-amplitude response curve at the neuron’s characteristic frequency (CF) The stimulus delay-amplitude response curve is similar in curvature and can be highly coincident, which reflects the physical principle that the sound signal is transformed into the bioelectric signal.Referring to the neuronal CF delay-amplitude response curve, the delay-amplitude response curve The horizontal and vertical axis tends to infinity when the longitudinal and abscissa values ?? of the difference (ΔL and ΔA) can be used to describe the relative differences in position. In the process, the nerve fibers and synapses that connect to the same neuron can be functionally simplified into a single “line ” (the length of the summed fiber) and a single “connector ” (sum of synaptic strength) And the linker, respectively, to complete the signal transmission and transmission (transduction). Therefore, ΔL and ΔA can be used as a measure of the acoustic activation of the activation path relative to the sum of fiber length and sum of synaptic strength indicators.Experimental results show that, for Different frequency processing pathways and different neurons have different ΔL and ΔA values, suggesting that the different acoustic responses of neurons are caused by different signal processing pathways activated by acoustic stimulation, and the pathways used to process acoustic stimulation at different frequencies are also different .