The gustatory electrophysiological responses of medial sensillum of the polyphagous caterpillar, Helicoverpa armigera, to 7 kinds of sugars, inositol and their mixtures were measured by top recording technology. The responding cells in medial sensillum corresponding different stimulus and the interactions of different compounds in mixtures during the process of electrophysiological responses were analyzed. The results showed that: (1) the electrophysiological responses of medial sensillum to D-inositol, D-fructose, xylose, D-arabinose, D-glucose, maltose, D-trehalose and L-rhamnose were obvious, but the responding patterns between sugars and innositol were different trom a concentration-dependent responses in inositol and non-concentration-dependent responseses in sugars; (2) the differences of responding patterns between the pure sugar compounds and the mixture of fructose, arabinose and trehalose were not significant, indicating the same cell responding the 3 kinds of sugars; (3) Responses of the mixtures of fructose and inositol indicated that inositol-sensitive cell responded to fructose. The firing rate of mixture of fructose and inositol were higher than that of the two pure compounds, suggesting the synergistic interaction of responses of the two stimulus. All the results suggested that the inisitol-sensitive cell in medial sensillum of the polyphagous species of H. armigera may be one of “broad-spectrum” taste cells.%利用电生理学技术,以多食性的棉铃虫为研究对象,测定幼虫下颚中栓锥感器对7种糖和肌醇及其混合物的味觉电生理反应,分析不同物质诱导中栓锥感器内对应的味觉感受细胞及不同物质之间诱导昆虫电生理反应的交互作用.结果表明:(1)棉铃虫幼虫下颚中栓锥感器对肌醇、果糖、木糖、阿拉伯糖,葡萄糖、麦芽糖、海藻糖和鼠李糖的单一物质都有明显的电生理反应,但是对肌醇和糖类的反应模式不同,肌醇诱导的反应呈典型的浓度梯度反应,而糖诱导的反应不呈浓度梯度反应;(2)对果糖、阿拉伯糖和海藻糖混合物的反应模式与单一糖没有显著差异,表明不同糖均诱导了一个味觉细胞的反应;(3)对果糖和肌醇混合物的反应表明,果糖诱导了中栓锥感器内肌醇细胞的反应.果糖和肌醇的混合物的反应频率显著高于单一物质的反应,表明这两种物质对肌醇细胞的诱导反应有"叠加作用".以上结果表明中栓锥感器内的肌醇细胞可能为多食性昆虫棉铃虫的一个"广谱性"的味觉细胞.
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