Effects of morphine on the distribution of Fos protein in the trigeminal subnucleus caudalis neurons during experimental tooth movement of the rat molar
Effects of morphine on the distribution of Fos protein in the trigeminal subnucleus caudalis neurons during experimental tooth movement of the rat molar
复制标题
吗啡对大鼠磨牙实验性牙齿移动过程中三叉神经尾亚核神经元Fos蛋白分布的影响
DOI：
10.1016/s0006-8993(98)01323-7
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发表时间：
1999
期刊：
影响因子：
2.9
通讯作者：
S. Wakisaka
中科院分区：
文献类型：
--
作者：
Y. Aihara;T. Maeda;K. Hanada;S. Wakisaka
本研究旨在揭示大鼠上磨牙实验性牙齿移动诱导后三叉神经尾侧亚核（SpVc）Fos样免疫反应（-IR）神经元分布的时间变化。进一步观察吗啡和纳洛酮对SpVc内Fos阳性神经元的影响。实验性牙齿移动是通过在第一和第二上磨牙之间插入弹性橡胶来诱导的。正常动物SpVc内Fos阳性神经元较少。紧接着插入的弹性带后，Fos-IR神经元的分布是在正常动物中观察到的。诱导实验性牙齿移动后1 ~ 4 h，Fos阳性神经元数量显著增加，2 h达高峰，随后逐渐减少。大多数神经元位于同侧SpVc浅层的背内侧部，靠近奥贝，但少数位于SpVc的腹侧部。对侧SpVc浅层和腹侧也有Fos样免疫反应阳性神经元，但数量明显少于同侧。用吗啡（3和10 mg/kg，i. p.）（2）在同侧SpVc浅层，Naloxone（2 mg/kg，i. p.）可明显抑制Fos阳性神经元的诱导，且呈剂量依赖性，其作用可被Naloxone（2 mg/kg，i. p.）拮抗。纳洛酮预处理可增强同侧SpVc Fos阳性神经元的表达。吗啡预处理可使Fos阳性神经元减少，提示Fos阳性神经元的诱导可能是由于诱导实验性牙齿移动所引起的伤害性刺激所致。
The present study was undertaken to disclose temporal changes in the distribution of Fos-like immunoreactive (-IR) neurons in the trigeminal subnucleus caudalis (SpVc), one of the important relay nuclei for processing the nociceptive information from the oro-facial regions, following induction of experimental tooth movement in rat upper molars. Furthermore, the effect of morphine and naloxone on the levels of Fos-IR neurons in the SpVc was examined. The experimental tooth movement was induced by insertion of an elastic rubber between the first and second upper molars. In normal animals, Fos-IR neurons were rarely observed in the SpVc. Immediately after insertion of the elastic band, the distribution of Fos-IR neurons was comparable to that observed in normal animals. The number of Fos-IR neurons increased significantly from 1 to 4 h following the induction of experimental tooth movement, reaching a maximum at 2 h, and then decreasing gradually. Most of the neurons were localized in the dorsomedial portion of the superficial layers of the ipsilateral SpVc near the obex, but a few were observed at the ventral portion of the SpVc. The neurons at the superficial layers and ventral portion of the contralateral SpVc also showed Fos-like immunoreactivity, but their numbers were significantly smaller than those on the ipsilateral side. Pretreatment with morphine (3 and 10 mg/kg, i.p.) significantly reduced the induction of Fos-IR neurons at the superficial layers of the ipsilateral SpVc in a dose-dependent manner, and its effect was antagonized by the subsequent treatment of naloxone (2 mg/kg, i.p.). Naloxone pretreatment enhanced the expression of Fos-IR neurons on the ipsilateral SpVc. The present results of a reduction of Fos-IR neurons by morphine pretreatment suggest that the induction of Fos-IR neurons may be due to the noxious stimulation caused by induction of experimental tooth movement.