The appearance and development of neurotransmitter sensitivity in Xenopus embryonic spinal neurones in vitro.
The appearance and development of neurotransmitter sensitivity in Xenopus embryonic spinal neurones in vitro.
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非洲爪蟾胚胎脊髓神经元神经递质敏感性的出现和体外发育。
DOI：
10.1113/jphysiol.1984.sp015328
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
Spitzer,NC
中科院分区：
文献类型：
--
作者：
Bixby,JL;Spitzer,NC
我们已经确定了发病的时间，并研究了一些在非洲爪蟾脊髓神经元的神经递质敏感性的特性，在解离的细胞培养。这些细胞最初是不敏感的，但在6小时内获得对几种激动剂的反应。近三分之一的神经元被γ-氨基丁酸（GABA）或GABA和甘氨酸去极化;这些细胞不受谷氨酸的影响。离子电泳GABA反应的逆转电位为-35 mV。这些神经元很可能是罗洪胡子神经元大约三分之二的神经元被谷氨酸去极化，被GABA和甘氨酸超极化。离子电泳GABA反应的逆转电位为-58 mV。这些神经元可能包括运动神经元。在早期和中期的发展阶段，获得了一个给定的GABA剂量的敏感性的定量测量。体外两类神经元的平均“敏感性指数”（离子电渗敏感性/输入电阻）最初与体内Rohon-Beard神经元中观察到的相同。该敏感性指数不随培养时间增加而达到体内中间阶段的值。这些培养物中Rohon-Beard样神经元的化学敏感性的发展与脊髓中Rohon-Beard神经元的化学敏感性的发展相似，这些神经元对GABA的反应开始时间，这些反应的逆转电位，药理学和脱敏，以及它们敏感的激动剂的光谱。它的不同之处在于没有对GABA敏感性的发育增加。在这些培养物中，运动神经元样神经元的化学敏感性的发展与Rohon-Beard样神经元的化学敏感性的发展在发病时间和敏感性水平以及对药理学阻断剂的敏感性方面相似。正常神经递质敏感性的几个特征，如动作电位的特征，在没有正常细胞相互作用的情况下在培养中分化。
We have determined the time of onset and examined some of the properties of neurotransmitter sensitivity in Xenopus spinal neurones developing in dissociated cell culture. These cells are initially insensitive, but acquire responses to several agonists over a period of 6 h. Nearly one‐third of the neurones were depolarized by gamma‐aminobutyric acid (GABA) or by both GABA and glycine; these cells were not affected by glutamate. The reversal potential of the ionophoretic GABA response is ‐35 mV. These neurones are likely to be Rohon‐Beard neurones. Roughly two‐thirds of the neurones were depolarized by glutamate and hyperpolarized by GABA and by glycine. The reversal potential of the ionophoretic GABA response is ‐58 mV. These neurones are likely to include motoneurones. A quantitative measure of the sensitivity to a given GABA dose was obtained at early and intermediate stages of development. The mean 'sensitivity index' (ionophoretic sensitivity/input resistance) for both classes of neurones in vitro was initially the same as that seen in Rohon‐Beard neurones in vivo. This sensitivity index did not increase with time in culture to attain the value at intermediate stages in vivo. The development of chemosensitivity in Rohon‐Beard‐like neurones in these cultures resembles that of Rohon‐Beard neurones in the spinal cord with respect to the time of onset of responses to GABA, the reversal potential, pharmacology and desensitization of these responses, and the spectrum of agonists to which they are sensitive. It differs in the absence of a developmental increase in sensitivity to GABA. The development of chemosensitivity in motoneurone‐like neurones in these cultures parallels that of Rohon‐Beard‐like neurones, with respect to the time of onset and level of sensitivity, as well as susceptibility to pharmacological blockers. Several features of normal neurotransmitter sensitivity, like features of the action potential, differentiate in culture in the absence of normal cellular interactions.