Effects of tooth pulp deafferentation on nociceptive and nonnociceptive neurons of the feline trigeminal subnucleus caudalis (medullary dorsal horn).
Effects of tooth pulp deafferentation on nociceptive and nonnociceptive neurons of the feline trigeminal subnucleus caudalis (medullary dorsal horn).
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DOI：
10.1152/jn.1989.61.6.1197
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发表时间：
1989-06
影响因子：
2.5
通讯作者：
J. Hu;B. Sessle
中科院分区：
文献类型：
--
作者：
J. Hu;B. Sessle
1.在成年猫、猫同侧三叉神经脊束核尾侧亚核尾侧亚核记录的单个神经元上，观察了下颌后牙牙髓去传入的影响。通过对亚核的一系列微电极穿透，电生理学测定了每只麻醉动物神经元的功能特性。2.根据所研究的800多个神经元的皮肤机械感受场特性，可将其细分为低阈值机械感受性(LTM)神经元、宽动态范围(WDR)神经元和伤害性感受特异性(NS)神经元。对对照组(完整的)猫和7-15天的去传入猫进行了盲法设计，以及长期去传入猫的分组，以及由于乳牙剥落而经历“自然”去传入的猫咪之间的神经元特性的比较。3.猫和去髓传入猫亚核的躯体定位组织模式无明显变化，除自发活动神经元的出现率发生变化外，猫与对照猫之间除自发活动神经元的发生率改变外，其他各项指标均无统计学差异。4.去传入猫的某些神经元特性发生了有限但有统计学意义的改变。这些变化在LTM神经元中尤为明显。在大多数长时间去传入的猫的神经元中，自发活动的发生率显着降低。在去传入的7-15天组，更多的LTM神经元有一个机械感受场，涉及V神经的所有三个部分，并且电刺激口内部位激活的LTM神经元的出现率显著增加。机械敏感神经元只对敲击刺激有反应，只在猫的去传入组中发现。5.尾侧的这些变化与以前的报道相反，这些报道称，去传入导致尾侧V脑干神经元明显的超兴奋性，并暗示这种影响与疼痛的发展有关。然而，其中一些变化与我们最近在成年猫V脊束核口侧亚核LTM神经元中报道的脊髓躯体感觉神经元去传入引起的变化和髓去传入引起的变化并不矛盾。
1. Effects of deafferentation of the tooth pulps of the posterior mandibular teeth were studied in single neurons recorded in the ipsilateral subnucleus caudalis of the trigeminal (V) spinal tract nucleus of adult cats and kittens. The functional properties of neurons in each anesthetized animal were determined electro-physiologically in a series of microelectrode penetrations of the subnucleus. 2. The more than 800 neurons investigated could be subdivided on the basis of their cutaneous mechanoreceptive field properties into low-threshold mechanoreceptive (LTM) neurons, wide dynamic range (WDR) neurons, or nociceptive-specific (NS) neurons. Comparisons of neuronal properties were made between control (intact) cats and 7-15 day deafferented cats studied in a blind design, as well as groups of longer term deafferented cats, and kittens undergoing a "natural" deafferentation as a result of exfoliation of primary teeth. 3. There was no apparent change in the somatotopic pattern of organization of the subnucleus in the kittens and pulp-deafferented cats and no statistically significant differences were noted between kittens and control cats in any property except for alterations in the incidence of spontaneously active neurons. 4. Limited but statistically significant alterations were noted in some of the neuronal properties in the deafferented cats. These changes were especially apparent in the LTM neurons. The incidence of spontaneous activity was significantly decreased in the neurons of most long-term deafferented groups of cats. In the 7-15 day deafferented group, significantly more LTM neurons had a mechanoreceptive field involving all three divisions of the V nerve, and there was a significant increase in the incidence of LTM neurons activated by electrical stimulation of intraoral sites. Mechanosensitive neurons responsive only to tap stimuli were found only in the deafferented groups of cats. 5. These alterations in caudalis contrast with previous reports claiming marked hyperexcitability of caudal V brain stem neurons as a consequence of deafferentation and implicating such effects in the development of pain. However, some of the changes are in general not inconsistent with deafferentation-induced changes reported in spinal somatosensory neurons and with the pulp deafferentation-induced changes that we have recently documented in LTM neurons of subnucleus oralis of the V spinal tract nucleus of adult cats.(ABSTRACT TRUNCATED AT 400 WORDS)