EFFECTS OF TEMPOROMANDIBULAR-JOINT STIMULATION ON NOCICEPTIVE AND NONNOCICEPTIVE NEURONS OF THE CATS TRIGEMINAL SUBNUCLEUS CAUDALIS (MEDULLARY DORSAL HORN)
EFFECTS OF TEMPOROMANDIBULAR-JOINT STIMULATION ON NOCICEPTIVE AND NONNOCICEPTIVE NEURONS OF THE CATS TRIGEMINAL SUBNUCLEUS CAUDALIS (MEDULLARY DORSAL HORN)
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DOI：
10.1152/jn.1988.59.5.1575
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发表时间：
1988-05-01
影响因子：
2.5
通讯作者：
SESSLE, BJ
中科院分区：
文献类型：
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作者：
BROTON, JG;HU, JW;SESSLE, BJ
1.在氯醛糖麻醉、麻痹的猫上，观察了三叉神经脊束核尾侧亚核（延髓背角）内196个单个神经元的细胞外活动。电，机械，和algesic化学刺激施加到暴露的颞下颌关节（TMJ），以激活TMJ传入。研究了78个神经元，这些神经元对颞下颌关节的电刺激作出反应，平均潜伏期为9.9 ± 1.5。4.8（SD）2.所有的神经元与颞下颌关节输入额外的传入输入，主要是从面部皮肤或口内网站。尾侧神经元根据其皮肤机械感受野特性分类为低阈值机械感受野（LTM）、宽动态范围（WDR）或伤害性特异性（NS）;少数对皮肤刺激无反应的神经元对深层皮下结构的操纵有反应。尾侧肌神经元的样品进行了测试后，神经元的机械感受野特性的电颞下颌关节刺激的反应。在该样本中，24%的LTM神经元、29%的WDR神经元、36%的NS神经元和57%的具有来自深部结构的输入的神经元对TMJ刺激有反应。与颞下颌关节输入的WDR和NS神经元的机械感受野特性和层状位置在尾侧，与先前描述的皮肤伤害性神经元在尾侧;也根据最近的研究，74%的神经元测试显示收敛的牙髓和/或舌下（XII）神经传入输入。3.与LTM神经元相反，WDR和NS神经元对TMJ的强烈机械和痛觉化学刺激以及TMJ传入的电刺激特别敏感。例如，71%的WDR和NS神经元兴奋的电刺激颞下颌关节的传入和测试他们的反应注射到颞下颌关节的痛觉化学品（7%氯化钠，氯化钾，缓激肽，组胺）至少有一个这些化学品。这些反应的时间特性进行了量化。4.对WDR和NS神经元的TMJ传入输入被认为主要具有伤害性特征，因为（1）大多数TMJ诱发反应的长潜伏期和高阈值，这与先前的小直径传入主要供应TMJ的证明一致，（二）TMJ传入神经元对伤害性机械和化学刺激的优先反应性，这些神经元在功能上被鉴定为皮肤神经元。伤害性神经元。5.这项研究是第一次详细的文件和功能分类的神经元在尾侧亚核的反应，电刺激和自然刺激颞下颌关节传入。由于我们的研究结果表明，许多WDR和NS神经元中继伤害性信息不仅从皮肤或口内的网站，但也从颞下颌关节，在深颅面疼痛以及浅表疼痛的作用，这些神经元amny的建议。与我们最近的研究结果一致，肌肉和牙髓传入神经元的会聚，这些观察进一步表明，这些会聚的输入模式，以WDR和NS神经元也可能是重要的元素，潜在的传播和转诊的疼痛，这是常见的临床症状表现颞下颌关节疼痛。
1. The extracellular activity of 196 single neurons in subnucleus caudalis (medullary dorsal horn) of the trigeminal (V) spinal tract nucleus was examined in chloralose-anesthetized, paralyzed cats. Electrical, mechanical, and algesic chemical stimuli were applied to the exposed temporomandibular joint (TMJ) in order to activate TMJ afferents. Seventy-eight neurons were studied that responded to electrical stimulation of the TMJ at a mean latency of 9.9 .+-. 4.8 (SD) ms. 2. All neurons with TMJ input received additional afferent input, predominantly from facial skin or intraoral sites. Caudalis neurons were classified on the basis of their cutaneous mechanoreceptive field properties as low-threshold mechanoreceptive (LTM), wide dynamic range (WDR), or nociceptive specific (NS); a few neurons unresponsive to cutaneous stimuli were responsive to manipulation of deep subcutaneous structures. A sample of caudalis neurons was tested for responsiveness to electrical TMJ stimulation after the mechanoreceptive field properties of the neurons were determined. In this sample, 24% of the LTM neurons, 29% of the WDR neurons, 36% of the NS neurons, and 57% of the neurons with input from deep structures were responsive to TMJ stimulation. The WDR and NS neurons with TMJ inputs had mechanoreceptive field properties and laminar locations in caudalis that were comparable to those previously described for cutaneous nociceptive neurons in caudalis; also in accordance with recent studies, 74% of the neurons tested showed convergence of tooth pulp and/or hypoglossal (XII) nerve afferent inputs. 3. In contrast to the LTM neurons, the WDR and NS neurons were especially responsive to intense mechanical and algesic chemical stimulation of the TMJ as well as to electrical stimulation of TMJ afferents. For example, 71% of the WDR and NS neurons excited by electrical stimulation of the TMJ afferents and tested for their responsiveness to injections of algesic chemicals (7% NaCl, KCl, bradykinin, histamine) into the TMJ responded to at least one of these chemicals. The temporal characteristics of these responses were quantified. 4. The TMJ afferent inputs to the WDR and NS neurons were considered to be predominantly of a nociceptive character because of (1) the long latency and high threshold of most TMJ-evoked responses, which are consistent with previous demonstrations that small-diameter afferents predominantly supply the TMJ and, (2) the preferential responsiveness To noxious mechanical and chemical stimulation of TMJ afferents of neurons which were functionally identified as cutaneous nociceptive neurons. 5. This study represents the first detailed documentation and functional classification of the responses of neurons in subnucleus caudalis to electrical and natural stimulation of TMJ afferents. Since our findings indicate that many WDR and NS neurons relay nociceptive information not only from cutaneous or intraoral sites but also from the TMJ, a role for amny of these neurons in deep craniofacial pain as well as in superficial pain is suggested. In accordance with our recent findings of convergence of muscle and tooth pulp afferents to comparable neurons in caudalis, these observations further suggest that these convergent input patterns to WDR and NS neurons may also be important elements underlying the spread and referral of pain that is commonly seen in clinical conditions manifesting TMJ pain.