不同的声音强度对大鼠听皮层神经元特征频率可塑性的影响

Sound level of conditioned stimulus differs the plasticity of charactieristic frequency in the rat cortical neurons

目的:探讨声音强度对大鼠听皮层神经元特征频率可塑性的影响。方法:采用常规电生理学细胞外记录技术,测定不同声刺激强度下,听皮层神经元的特征频率和调谐曲线,比较条件刺激前后的变化。结果:在条件刺激声频率和神经元的特征频率相差±1.0kHz范围内,条件刺激诱导的神经元特征频率可塑性与条件刺激强度有关,较高的刺激强度比较低刺激强度诱导的特征频率可塑性概率高;特征频率可塑性的概率与神经元的频率调谐曲线类型相关,但这种相关几乎不受条件刺激声强度影响。结论:条件声刺激强度可明显影响大鼠听皮层神经元特征频率的可塑性。

Objective：Try to observe the plasticity of neuron in primary cortex of rat evoked by conditioned stimulus of different sound level.Methods：Applying conventional electrophysiological technique of extracellular recording to investigate the plasticity of characteristic frequency（CF） and frequency turning curve （FTC） of neurons in rat auditory cortex （AC） by determining CF shifts of neurons caused by sound stimulus of different sound level.Results：When the frequency difference between conditioned stimulus（CS） frequency and the CF of neuron was in 1.0 kHz,the plasticity of CF induced by CS was associated with sound level.The probability of the plasticity of CF evoked by CS of higher sound lever was more than the lower.And the probability was dependent on frequency turning curve （FTC） and almost independent on the sound level of conditioned signal.Conclusion：Sound level of conditioned stimulus differs the plasticity of characteristic frequency of neurons in rat auditory cortex.