Chemosensory responses in isolated olfactory receptor neurons from Necturus maculosus.
Chemosensory responses in isolated olfactory receptor neurons from Necturus maculosus.
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DOI：
10.1085/jgp.99.3.415
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发表时间：
1992-03
期刊：
影响因子：
--
通讯作者：
Dionne VE
中科院分区：
文献类型：
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作者：
Dionne VE
在没有酶的情况下，从泥巴狗身上分离出嗅觉感受器神经元，并测试其对化疗的敏感性。这些细胞对气味的反应伴随着放电频率的变化和兴奋性的变化，这些变化是用紧密密封的贴片电极在细胞上和全细胞记录条件下检测到的。化学敏感细胞表现出两个主要的反应特征：兴奋和抑制。在混合氨基酸和单一化合物L-丙氨酸刺激的不同细胞中都观察到了这两种类型的初级反应，这表明某些气味可能有不止一种转导途径。采用常规的全细胞记录法，感受态细胞的化学敏感性迅速消失；采用阻抗式全细胞记录法，记录电流钳条件下的气味反应。作为对化学刺激的响应，兴奋性在不同的细胞中似乎以几种不同的方式被调制：气味诱导超极化或去极化的感受器电位，诱发或抑制瞬时的、节律性的产生电位，以及改变兴奋性而不改变膜电位或输入电阻。这些效应表明，嗅觉转导至少通过三种不同的途径对膜电导的四个或四个以上成分产生影响。像这样的多叉通路对于气味辨别和增强嗅觉上皮产生的“气味图像”可能是重要的。
Olfactory receptor neurons were isolated without enzymes from the mudpuppy, Necturus maculosus, and tested for chemosensitivity. The cells responded to odorants with changes in firing frequency and alterations in excitability that were detected with tight-seal patch electrodes using on-cell and whole-cell recording conditions. Chemosensitive cells exhibited two primary response characteristics: excitation and inhibition. Both types of primary response were observed in different cells stimulated by mixtures of amino acids as well as by the single compound L-alanine, suggesting that there may be more than one transduction pathway for some odorants. Using the normal whole-cell recording method, the chemosensitivity of competent cells washed out rapidly; a resistive whole-cell method was used to record odorant responses under current-clamp conditions. In response to chemical stimulation, excitability appeared to be modulated in several different ways in different cells: odorants induced hyperpolarizing or depolarizing receptor potentials, elicited or inhibited transient, rhythmic generator potentials, and altered excitability without changing the membrane potential or input resistance. These effects suggest that olfactory transduction is mediated through at least three different pathways with effects on four or more components of the membrane conductance. Polychotomous pathways such as these may be important for odor discrimination and for sharpening the "odor image" generated in the olfactory epithelium.