CA-2+-DEPENDENT ADAPTIVE PROPERTIES IN THE SOLITARY OLFACTORY RECEPTOR CELL OF THE NEWT
CA-2+-DEPENDENT ADAPTIVE PROPERTIES IN THE SOLITARY OLFACTORY RECEPTOR CELL OF THE NEWT
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DOI：
10.1016/0006-8993(90)90605-b
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发表时间：
1990-05-07
期刊：
影响因子：
2.9
通讯作者：
SHIBUYA, T
中科院分区：
文献类型：
--
作者：
KURAHASHI, T;SHIBUYA, T
采用全细胞膜片钳技术，用单细胞标本分析嗅觉感受器电位的时间依赖性衰减。在标准条件下用10 mM N-戊基乙酸酯长时间刺激时，63个分离的嗅觉细胞中有17个出现缓慢去极化反应。在这17个细胞中，有14个细胞的反应幅度(“相/强”反应)在9个S内逐渐衰减，半衰变时间为1.71±-。1.10 S(平均值+-)S.D.)。相对波幅(张力成分与峰值波幅之比，Vonic/Vmax)为0.29。0.10。响应衰减归因于气味激活的电导失活。失活后的恢复率由双脉冲实验确定，与静息间隔有关。只有当外部介质中含有钙离子时，才能观察到气味激活电导的失活。此外，还发现气味激活的电导能够渗透钙离子(PCA/PNA=6.5)，而内部EGTA浓度的增加(至50 mM)抑制了失活。这些观察表明，对长时间刺激的嗅觉反应的衰退是由钙离子内流介导的。
The time-dependent decay of the olfactory receptor potential was analyzed with a solitary cell preparation by using the whole-cell patch clamp technique. During prolonged stimulation by 10 mM N-amylacetate under standard conditions, 17 out of 63 isolated olfactory cells responded with slow depolarization. Of these 17 cells, response amplitudes in 14 cells (''phasic/tonic'' response) gradually decayed within 9 s, with a half-decay time of 1.71 .+-. 1.10 s (mean .+-. S.D.). The relative amplitude (ratio of tonic component to peak amplitude, Vtonic/Vmax) was 0.29 .+-. 0.10. The response decay was attributed to the inactivation of the odorant-activated conductance. The recovery after inactivation, which was determined with double pulse experiments, was dependent on the resting interval. The inactivation of the odorant-activated conductance was found to be observed only when the external medium contained Ca2+. In addition, it was found that the odorant-activated conductance was capable of permeating Ca2+ (PCa/PNa = 6.5), and a rise in the internal EGTA concentration (to 50 mM) inhibited the inactivation. These observations suggest that the decay of the olfactory response to prolonged stimulation is mediated by Ca2+ influx.