Alteration of medullary dorsal horn neuronal activity following inferior alveolar nerve transection in rats
Alteration of medullary dorsal horn neuronal activity following inferior alveolar nerve transection in rats
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DOI：
10.1152/jn.2001.86.6.2868
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发表时间：
2001-12-01
影响因子：
2.5
通讯作者：
Hu, J
中科院分区：
文献类型：
--
作者：
Iwata, K;Imai, T;Hu, J
精确分析了下牙槽神经 (IAN) 横断对逃避行为和 MDH 神经元活动对面部伤害性和非伤害性刺激的影响。直到横断后 28 天，施加于横断同侧胡须垫区域的逃避机械刺激的相对阈值显着低于对侧和假手术胡须垫的相对阈值，然后在横断后 40 天恢复到术前水平。未处理的幼鼠的髓质背角 (MDH) 总共记录了 540 个神经元 [低阈值机械感受 (LTM)，27；宽动态范围 (WDR)，31；伤害感受特异性（NS），11]和假手术大鼠，具有皮肤切口（LTM，34；WDR，30；NS，23）以及相对于 IAN 横切的同侧（LTM，82；WDR，82；NS，31）和对侧 MDH（LTM，77；WDR，82；NS，33）。精确分析了这些神经元的电生理特性。与初始大鼠相比，术后2-14天，相对于横断面的同侧WDR神经元的背景活性显着增加。 IAN 横断后 2-14 天，LTM 和 WDR 神经元的无害和有害机械诱发反应显着增强。横断后2-7天，同侧MDH上WDR神经元感受野的平均面积明显大于初始大鼠。我们无法观察到 IAN 横断后 WDR 和 NS 神经元热响应的任何调节。此外，假手术大鼠的 MDH 神经元没有受到显着影响。目前的研究结果表明，IAN 横断后 MDH 中 WDR 神经元的神经元活动增加可能在与受伤神经支配的区域相邻的区域诱发的机械性异常性疼痛的发展中发挥重要作用。
The effects of inferior alveolar nerve (IAN) transection on escape behavior and MDH neuronal activity to noxious and nonnoxious stimulation of the face were precisely analyzed. Relative thresholds for escape from mechanical stimulation applied to the whisker pad area ipsilateral to the transection were significantly lower than that for the contralateral and sham-operated whisker pad until 28 days after the transection, then returned to the preoperative level at 40 days after transection. A total of 540 neurons were recorded from the medullary dorsal horn (MDH) of the nontreated naive rats [low-threshold mechanoreceptive (LTM), 27; wide dynamic range (WDR), 31; nociceptive specific (NS), 11] and sham-operated rats with skin incision (LTM, 34; WDR, 30; NS, 23) and from the ipsilateral (LTM, 82; WDR, 82; NS, 31) and contralateral MDH relative to the IAN transection (LTM, 77; WDR, 82; NS, 33). The electrophysiological properties of these neurons were precisely analyzed. Background activity of WDR neurons on the ipsilateral side relative to the transection was significantly increased at 2-14 days after the operation as compared with that of naive rats. Innocuous and noxious mechanical-evoked responses of LTM and WDR neurons were significantly enhanced at 2-14 days after IAN transection. The mean area of the receptive fields of WDR neurons was significantly larger on the ipsilateral MDH at 2-7 days after transection than that of naive rats. We could not observe any modulation of thermal responses of WDR and NS neurons following IAN transection. Also, no MDH neurons were significantly affected in the rats with sham operations. The present findings suggest that the increment of neuronal activity of WDR neurons in the MDH following IAN transection may play an important role in the development of the mechano-allodynia induced in the area adjacent to the area innervated by the injured nerve.