Nociceptin-like immunoreactivity in the rat dorsal horn and inhibition of substantia gelatinosa neurons
Nociceptin-like immunoreactivity in the rat dorsal horn and inhibition of substantia gelatinosa neurons
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DOI：
10.1016/s0306-4522(97)00251-0
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发表时间：
1997-12-01
期刊：
影响因子：
3.3
通讯作者：
Dun, NJ
中科院分区：
文献类型：
--
作者：
Lai, CC;Wu, SY;Dun, NJ
孤啡肽，也称为孤啡肽FQ，被认为是ORL 1的内源性配体。（8，9，12）当向小鼠脑室内注射孤啡肽时，在行为测试中产生痛觉过敏。（8，12）最近的研究已经证明了ORL（脊髓中的转录物）的存在，并且ORL 1样免疫反应性已经定位于整个脊髓的神经纤维和胞体。（1，16）在此，我报告了通过免疫组织化学技术将痛敏素样免疫反应定位于大鼠背角浅层的纤维样成分，22-26日龄大鼠腰髓横切片胶状质神经元的全细胞记录显示，低浓度的外源性痛敏素（100-300 nM）抑制刺激背根诱发的兴奋性突触后电位，而不引起静息膜电位和谷氨酸诱发的去极化的明显变化。在1 μ M的浓度下，痛敏素使胶状质神经元超极化并抑制锋电位放电。已知的阿片受体拮抗剂纳洛酮（1 μ M）不能逆转痛敏素的超极化和突触抑制作用。我们的研究结果提供了证据表明，痛敏肽样肽是集中在大鼠背角的神经纤维，它可能作为一种抑制性递质内的胶状质。(C)1997年IBRO。出版社：Elsevier Science Ltd
Nociceptin, also referred to as orphanin FQ, is believed to be the endogenous ligand for the ORL1.(8,9,12) Nociceptin, when injected intracerebroventricularly to mice, produced hyperalgesia in behavioral tests.(8,12) Recent studies have demonstrated the presence of ORL, transcript in the spinal cord, and ORL1-like immunoreactivity has been localized to nerve fibers and somata throughout the spinal cord.(1,16) Here, me report the localization of nociceptin-like immunoreactivity to fiber-like elements of the superficial layers of the rat dorsal horn by immunohistochemical techniques, Whole-cell recordings from substantia gelatinosa neurons in transverse lumbar spinal cord slices of 22-26-day-old rats showed that exogenous nociceptin at low concentrations (100-300 nM) depressed excitatory postsynaptic potentials evoked by stimulation of dorsal rootlets without causing an appreciable change of resting membrane potentials and glutamate-evoked depolarizations. At a concentration of 1 mu M, nociceptin hyperpolarized substantia gelatinosa neurons and suppressed spike discharges, The hyperpolarizing and synaptic depressant action of nociceptin was not reversed by the known opioid receptor antagonist naloxone (1 mu M). Our result provides evidence that nociceptin-like peptide is concentrated in nerve fibers of the rat dorsal horn and that it may serve as an inhibitory transmitter within the substantia gelatinosa. (C) 1997 IBRO. Published by Elsevier Science Ltd.