Morphology and axonal arborization of rat spinal inner lamina II neurons hyperpolarized by μ-opioid-selective agonists
Morphology and axonal arborization of rat spinal inner lamina II neurons hyperpolarized by μ-opioid-selective agonists
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DOI：
10.1002/cne.10587
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发表时间：
2003-04-07
影响因子：
2.5
通讯作者：
Light, AR
中科院分区：
文献类型：
--
作者：
Eckert, WA;McNaughton, KK;Light, AR
脊髓胶状质（SG;板III）的腹侧或内部区域是重要的产生和维持痛觉过敏和神经病理性疼痛的异质亚板。为了测试Hi神经元是否可以被μ-阿片激动剂[D-Ala（2），N-Me-Phe（4），Gly（5）-ol]-脑啡肽（DAMGO; 500 nM）超极化，并解决μ-阿片诱发的III神经元抑制的可能下游后果，我们将体外全细胞、紧密密封记录方法与细胞内示踪剂生物胞素的荧光标记和共聚焦显微镜相结合。研究的23个神经元中有21个具有可识别的轴突。9个拥有轴突腹侧投射到板III-V;其中6个被DAMGO超极化。四个神经元与可识别的轴突，投射到板层我被DAMGO超极化。大多数神经元可分为胰岛细胞和柄细胞。9个标记的胰岛细胞中有5个和7个柄细胞中只有2个被DAMGO超极化。三个是星状细胞：一个类似于多刺细胞，三个无法分类。DAMGO使每个星状细胞、棘状细胞和1个未分类细胞超极化。我们的数据支持的假设，L-阿片受体激动剂的作用的一部分涉及抑制的interneurons的多突触兴奋通路的一部分，从初级传入神经元在深和/或浅背角。(C)2003 Wiley-Liss，Inc.
The ventral or inner region of spinal substantia gelatinosa (SG; lamina IIi) is a heterogeneous sublamina important for the generation and maintenance of hyperalgesia and neuropathic pain. To test whether Hi neurons can be hyperpolarized by the mu-opioid agonist [D-Ala(2), N-Me-Phe(4), Gly(5)-ol]-enkephalin (DAMGO; 500 nM) and to address possible downstream consequences of mu-opioid-evoked inhibition of IIi neurons, we combined in vitro whole-cell, tight-seal recording methods with fluorescent labeling of the intracellular tracer biocytin and confocal microscopy. Twenty-one of 23 neurons studied had identifiable axons. Nine possessed axons that projected ventrally into laminae III-V; six of these were hyperpolarized by DAMGO. Three of four neurons with identifiable axons that projected to lamina I were hyperpolarized by DAMGO. Most neurons could be classified as either islet cells or stalked cells. Five of nine labeled islet cells and only two of seven stalked cells were hyperpolarized by DAMGO. Three were stellate cells: one resembled a spiny cell and three could not be classified. DAMGO hyperpolarized each of the stellate cells, the spiny cell, and 1 of the unclassified cells. Our data support the hypothesis that part of the action of L-opioid agonists involves the inhibition of interneurons that are part of a polysynaptic excitatory pathway from primary afferents to neurons in the deep and/or superficial dorsal horn. (C) 2003 Wiley-Liss, Inc.