Stengl M
Institut für Zoologie, Universität Regensburg, Germany.
J Comp Physiol A. 1994 Feb;174(2):187-94. doi: 10.1007/BF00193785.
Specialized olfactory receptor neurons in insects respond to species-specific sex pheromones with transient rises in inositol trisphosphate and by opening pheromone-dependent cation channels. These channels resemble cation channels which are directly or indirectly Ca(2+)-dependent. But there appear to be no internal Ca2+ stores in the outer dendrite where the olfactory transduction cascade is thought to start. Hence, it remains to be determined whether an influx of external Ca2+ precedes pheromone-dependent cation currents. Patch clamp measurements in cultured olfactory receptor neurons from Manduca sexta reveal that a transient inward current precedes pheromone-dependent cation currents. A transient inositol trisphosphate-dependent Ca2+ current, also preceding cation currents with the characteristics of pheromone-dependent cation currents, shares properties with the transient pheromone-dependent current. These results match the biochemical measurements with the electrophysiological data obtained in insect olfactory receptor neurons.
昆虫体内的特殊嗅觉受体神经元会对物种特异性性信息素做出反应，导致肌醇三磷酸短暂升高，并通过打开信息素依赖性阳离子通道来实现。这些通道类似于直接或间接依赖Ca(2+)的阳离子通道。但是，在嗅觉转导级联反应被认为起始的外树突中，似乎不存在内部Ca2+储存库。因此，外部Ca2+的流入是否先于信息素依赖性阳离子电流，仍有待确定。对烟草天蛾培养的嗅觉受体神经元进行膜片钳测量发现，在信息素依赖性阳离子电流之前会出现一个短暂的内向电流。一种短暂的肌醇三磷酸依赖性Ca2+电流，同样先于具有信息素依赖性阳离子电流特征的阳离子电流，它与短暂的信息素依赖性电流具有共同特性。这些结果将生化测量与在昆虫嗅觉受体神经元中获得的电生理数据相匹配。
