Modular organization of excitatory circuits between neurons of the spinal superficial dorsal horn (laminae I and II)
Modular organization of excitatory circuits between neurons of the spinal superficial dorsal horn (laminae I and II)
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DOI：
10.1523/jneurosci.0102-05.2005
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发表时间：
2005-04-13
影响因子：
5.3
通讯作者：
Perl, ER
中科院分区：
文献类型：
--
作者：
Lu, Y;Perl, ER
脊髓浅背角（SDH）（Ⅰ层和Ⅱ层）的神经回路及其与疼痛和其他躯体感觉现象的关系仍知之甚少。为了获取有关这一问题的信息，通过对成对细胞进行同步全细胞记录，在大鼠脊髓切片中研究了已识别的SDH神经元之间的突触连接。观察到了兴奋性和抑制性连接。本报告重点关注所观察到的兴奋性联系。SDH神经元之间的突触兴奋性连接具有高度选择性，且始终是单向的。反复出现两种模式（神经元分类见材料与方法）（格鲁特和珀尔，2002年）。具有背根（DR）C纤维输入的Ⅱ层中央神经元单突触地兴奋具有DR Aδ输入的Ⅱ层垂直神经元。具有DR Aδ输入的Ⅱ层外侧垂直神经元单突触地兴奋Ⅰ层神经元。一些突触后的Ⅰ层细胞被证明向头端投射。与通常相连的神经元情况相反，在未相连的神经元对中，同一类型神经元的初级传入输入被证明非常相似。总之，这些观察结果表明，SDH中的神经回路，包括其胶状质（Ⅱ层），具有一种明确的组织形式，其中特定的神经元组合构成模块，用于修饰和传递来自Aδ和C初级传入纤维的感觉信息。
Neural circuitry of the spinal superficial dorsal horn (SDH) (laminae I and II) and its relationship to pain and other somatosensory phenomena remain poorly understood. To gain information on this issue, synaptic connections between identified SDH neurons were studied in rat spinal cord slices by simultaneous whole-cell recordings from pairs of cells. Both excitatory and inhibitory connections were noted. This report focuses on the observed excitatory linkages. Synaptic excitatory connections between SDH neurons proved highly selective and consistently were unidirectional. Two patterns repeatedly appeared (for neuron classification, see Materials and Methods) (Grudt and Perl, 2002). Lamina II central neurons, with dorsal root (DR) C-fiber input, monosynaptically excited lamina II vertical neurons with DR A delta input. Lamina II outer vertical neurons with DR A delta input monosynaptically excited lamina I neurons. Some of the postsynaptic lamina I cells were shown to project rostrally. In contrast to the usual case for connected neurons, in unconnected pairs, primary afferent input to the same type of neuron proved closely similar. Together, these observations indicate that the neural circuitry in the SDH, including its substantia gelatinosa (lamina II), has an explicit organization in which particular combinations of neurons comprise modules arranged to modify and transmit sensory information arriving from A delta and C primary afferent fibers.