Correlations between neuronal morphology and electrophysiological features in the rodent superficial dorsal horn
Correlations between neuronal morphology and electrophysiological features in the rodent superficial dorsal horn
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DOI：
10.1113/jphysiol.2001.012890
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发表时间：
2002-04-01
影响因子：
5.5
通讯作者：
Perl, ER
中科院分区：
文献类型：
--
作者：
Grudt, TJ;Perl, ER
在从麻醉的自由活动的仓鼠制备的脊髓切片中，研究了脊髓浅背角（SDH）、Ⅰ层和Ⅱ层单个神经元的形态与其电生理特性之间的关系。用填充有生物素的微电极进行紧密封接的全细胞记录，以确定电生理特征并标记所研究的神经元。根据胞体的位置和大小、树突和轴突的分支模式、自发突触电位、诱发的突触后电流、对去极化脉冲的放电模式以及电流 - 电压关系对神经元进行分类。获得了170个神经元的数据；其中13个胞体在Ⅰ层，157个在Ⅱ层。刺激节段性背根在几乎每个取样的神经元（161/166）中都引起了迅速的兴奋性反应，其中近3/4显示出假定的单突触兴奋性突触后电流（EPSCs）。大多数神经元（133/170）符合几种独特的形态类别之一。在很大程度上，具有共同形态结构和神经突分布的神经元具有共同的电生理特征。13个Ⅰ层神经元中有5个相对较大，在水平方向有广泛的树突分支，并且有一个明显的轴突指向腹侧和对侧。这些假定的腹外侧投射神经元在结构和电生理上与其他Ⅰ层神经元不同，其他Ⅰ层神经元具有同侧、局部分支的轴突和/或进入背外侧索的分支。120个Ⅱ层神经元符合五种形态类别之一：胰岛样、中央型、内侧 - 外侧型、放射状或垂直型。根据功能特征，中央细胞进一步分为三组。我们得出结论，脊髓浅背角包含许多类型的神经元，其形态特征与特定的功能特征相关，这意味着浅背角在功能组织及其作为细的初级传入纤维的主要突触终末的作用方面具有多样性。
Relationships between the morphology of individual neurones of the spinal superficial dorsal horn (SDH), laminae I and II, and their electrophysiological properties were studied in spinal cord slices prepared from anaesthetized, free-ranging hamsters. Tight-seal, whole-cell recordings were made with pipette microelectrodes filled with biocytin to establish electrophysiological characteristics and to label the studied neurones. Neurones were categorized according to location and size of the somata, the dendritic and axonal pattern of arborization, spontaneous synaptic potentials, evoked postsynaptic currents, pattern of discharge to depolarizing pulses and current-voltage relationships. Data were obtained for 170 neurones; 13 of these had somata in lamina I and 157 in lamina II. Stimulation of the segmental dorsal root evoked a prompt excitatory response in almost every neurone sampled (161/166) with nearly 3/4 displaying putative monosynaptic EPSCs. The majority of neurones (133/170) fitted one of several distinctive morphological categories. To a considerable extent, neurones with a common morphological configuration and neurite disposition shared electrophysiological characteristics. Five of the 13 lamina I neurones were relatively large with extensive dendritic arborization in the horizontal dimension and a prominent axon directed ventrally and contralaterally. These presumptive ventrolateral projection neurones differed structurally and electrophysiologically from the other lamina I neurones, which had ipsilateral, locally arborizing axons and/or branches entering the dorsal lateral funiculus. One hundred and twenty lamina II neurones fitted one of five morphological categories: islet, central, medial-lateral, radial or vertical. Central cells were further divided into three groups on functional features. We conclude that the spinal SDH comprises many types of neurones whose morphological characteristics are associated with specific functional features implying diversity in functional organization of the SDH and in its role as a major synaptic termination for thin primary afferent fibres.