中文摘要：

应用常规电生理学技术，以神经元的特征频率和频率调谐曲线为指标，分别在生后2、3、4、5、6和8周龄SD大鼠上，研究生后发育过程中，听皮层神经元特征频率的可塑性．结果表明，在给予条件刺激频率和神经元特征频率相差1．0kHz范围内，条件刺激都可诱导各年龄组神经元特征频率向频率调谐曲线的低频端、高频端或调谐曲线的两端相应的偏移．特征频率偏移的概率与年龄相关．随着年龄的增长，特征频率偏移的比例下降，而不偏移的比例则上升．随着年龄增长，那些Q10-dB值大和频率调谐曲线对称指数大于零的神经元，特征频率偏移到频率调谐曲线高频端的比例增加更为明显（P〈0．01）．诱导特征频率完全偏移的时程和特征频率恢复的时程也与动物的年龄相关，随着年龄增长，诱导和恢复时程都明显延长（P〈0．05）．结果提示，大鼠听皮层神经元特征频率的可塑性与生后年龄相关，为深入研究中枢神经元功能活动可塑性的机制提供了重要实验资料．

英文摘要：

Using conventional electrophysiological technique, the plasticity of characteristic frequency （CF） of neurons in rat auditory cortex （AC） at postnatal age of two, three, four, five, six and eight week was investigated by determining CF and frequency tuning curve （FTC） shifts of neurons. It was found that when the frequency difference between conditioned stimulus frequency （CSF） and CF of neuron was in 1.0 kHz with conditioned stimulation, conditioned stimulus can induce CF shift toward higher frequency side （HFS）, lower frequency side （LFS） and both sides （BLH） of neuron＇s FTC. The proportion of CF shift becomes lower and the proportion of non CF shift becomes higher with the increasing of the age. Neurons with bigger Q10-dB value and symmetry index 〉0 of the FTC, increasing of the proportion of CF shift toward higher frequency side （HFS） of neuron＇s FTC is much higher. There is significant correlation between the time course and the age of rat, the older is the age, the longer is the shift time （P 〈 0.05） and the recovery time （P 〈 0.05） of neurons. The results suggest that plasticity of characteristic frequency in rat auditory cortical neurons is correlated with the postnatal age. The findings provided important data to the study of the mechanisms for the developmental plasticity of central nervous system.