硕螽(Deracantha onos)听觉中间神经元的声反应特征

本文报道了硕螽听通路单个听觉中间神经元的声反应特征。依据动作电位发放模式的不同,听觉中间神经元可分为两类,即紧张型与相位型。紧张型听觉中间神经元属于窄凋谐带神经元,敏感的频率范围8—18千赫,反应最佳频率在12千赫附近,与同种雄硕螽叫声的主能峰相匹配。相位型听觉中间神经元属于宽调谐带神经元,有二个敏感频率范围,分别为5—8千赫和12—18千赫。它们对声强度的编码方式也不一样:分别以动作电位的数目与反应潜伏期对声强编码。本文还讨论了不同类型听觉中间神经元的功能意义。

RESPONSE PROPERTIES OF AUDITORY INTERNEURONS IN THE BUSHCRICKET DERACANTHA ONOS (ORTHOPTERA,TETTIGONIIDAE)

The electrophysiological responses of single auditory interneurons to sound stimulation were characterized in the bushcricket Deracantha onos.In terms of characteristic pattern of spike discharge, auditory interneurons have been generally classified as tonic or phasic. According to frequency-threshold characteristics, tonic interneurons are narrowly tuned to a sound frequency of about 12 kHz, which corresponds to the dominant peak of power spectrum of conspecific stridulation songs. Phasic interneurons are broadly tuned between 5-14 kHz. For tonic interneurons, a positive relationship exists between sound intensity and spike response. For phasic interneurons, response latency decreased with increasing sound intensity up to about 60 dB above threshold. The functions of these interneurons in the processing of auditory information are discussed.