大鼠皮层AⅠ区神经元对纯音频率的反应特征

The Characteristics of the Acoustic Response of A ⅠNeurons to the Frequency of Pure Tone

使用微电极在体胞外记录方法研究了SD大鼠AⅠ区神经元对纯音频率的反应特征.实验结果显示,AⅠ区神经元调谐曲线分为"V"、"W"和"U"型,神经元的Q10和Q30值均随着神经元特征频率(CF)的增大而增加,不同CF神经元在A Ⅰ区具有分域特性,对高频敏感的神经元位于A Ⅰ区嘴侧,对低频敏感的神经元位于A Ⅰ区尾侧.结果还表明,随着A Ⅰ区神经元CF变大,神经元对特定的频率选择性能越强,频率响应范围变窄.CF的分域特性明显,反映了大鼠初级听皮层对声音频率信息编码遵循有规律的部位原则.

The characteristics of the acoustic response of AⅠ neurons to the frequency of pure tone were investigated with extracellularly recording. The experimental results showed that the tuning curves of A Ⅰ neurons could be classified into 'V', 'W', and 'U' types. Q10 values and Q30 values of A Ⅰ neurons increased with increasing of the characteristic frequencies (CFs) of these neurons. The results also showed the topographical distribution of the CFs of neurons in AⅠ cortex. Generally the neurons with high CFs laid in the rostral part of A Ⅰ , and the neurons with low CFs laid in its caudal part. These results indicated that A Ⅰ neurons with high CFs had more powerful frequency selectivity ability than that with low CFs, and that the frequency range of acoustic response of A Ⅰ neurons widened with increasing of CFs of these neurons. The topographical distribution of the CFs in A Ⅰ indicated that the coding on frequency of sound stimulation accorded with the rule of place coding.