Response properties of isolated mouse olfactory receptor cells
Response properties of isolated mouse olfactory receptor cells
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DOI：
10.1111/j.1469-7793.2001.0113m.x
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发表时间：
2001-01-01
影响因子：
5.5
通讯作者：
Matthews, HR
中科院分区：
文献类型：
--
作者：
Reisert, J;Matthews, HR
1.采用吸管法研究了小鼠嗅感受器细胞的反应特性。细胞暴露于气味桉叶素或修改离子含量的解决方案，通过快速改变溶液灌注纤毛。所有实验均在37 ℃下进行。小鼠嗅觉感受器细胞表现出对刺激浓度的动作电位频率的陡峭依赖性，刺激浓度增加3倍时，放电频率通常在200-300 Hz达到饱和。受体电流随着桉叶素浓度的增加而逐渐增加，并且在桉叶素浓度的100倍范围内不饱和.当用低浓度气味刺激30秒时，细胞以零星的尖峰放电响应。较高的浓度导致在刺激开始时产生大的受体电流，其在几秒钟内返回到基线水平，在其上升阶段伴随着动作电位的短暂爆发。此后，在刺激的其余部分观察到振荡反应模式，包括持续约1 s的受体电流的重复增加，伴随着动作电位的短暂爆发。嗅觉适应研究通过比较两个紧密间隔的气味刺激的反应。当细胞在气味暴露之间的5秒间隔期间用林格溶液灌注时，对第二气味刺激的响应恢复到其原始幅度的80%。相比之下，暴露于胆碱取代的低Na+溶液之间的气味刺激有两个影响。首先，受体电流响应的第一个气味刺激没有终止一样快，在NaF的存在下，这表明存在的Na+-Ca 2+交换。第二，对第二刺激的反应仅恢复到其原始幅度的55%，表明Na+-Ca 2+交换参与刺激后小鼠嗅觉受体细胞敏感性的恢复。
1. Response properties of isolated mouse olfactory receptor cells were investigated using the suction pipette technique. Cells were exposed to the odour cineole or to solutions of modified ionic content by rapidly changing the solution superfusing the cilia. All experiments were performed at 37 degreesC.2. Mouse olfactory receptor cells displayed a steep dependence of action potential frequency on stimulus concentration, a 3-fold increase in stimulus concentration often saturating the firing frequency at 200-300 Hz. The receptor current increased more gradually with increasing cineole concentration and did not saturate within the 100-fold range of cineole concentrations applied.3. When stimulated for 30 s with a low odour concentration, cells responded with sporadic spike firing. Higher concentrations led to the generation of a large receptor current at the onset of stimulation which returned to baseline levels within a few seconds, accompanied during its rising phase by a short burst of action potentials. Thereafter an oscillating response pattern was observed during the remainder of the stimulus, consisting of repetitive increases in receptor current of around 1 s duration accompanied by short bursts of action potentials.4. Olfactory adaptation was studied by comparing the responses to two closely spaced odour stimuli. The response to the second odour stimulus recovered to 80% of its original magnitude when the cell was superfused with Ringer solution during the 5 s interval between odour exposures. In contrast, exposure to a choline-substituted low Na+ solution between odour stimuli had two effects. First, the receptor current response to the first odour stimulus did not terminate as quickly as in the presence of Naf, suggesting the presence of a Na+-Ca2+ exchanger. Second, the response to the second stimulus only recovered to 55% of its original magnitude, demonstrating the involvement of Na+-Ca2+ exchange in the recovery of sensitivity in mouse olfactory receptor cells following stimulation.