Receptive field properties of human periodontal afferents responding to loading of premolar and molar teeth
Receptive field properties of human periodontal afferents responding to loading of premolar and molar teeth
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DOI：
10.1152/jn.00537.2002
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发表时间：
2003-03-01
影响因子：
2.5
通讯作者：
Trulsson, M
中科院分区：
文献类型：
--
作者：
Johnsen, SE;Trulsson, M
用经黏膜插入钨微电极记录了45个来自人下肺泡神经的单机械感受传入神经的脉冲。所有传入神经都对一颗或多颗前磨牙或磨牙的机械刺激有反应，并且很可能支配它们的牙周韧带。对于每个传入，在记录侧的下第一前磨牙、第二前磨牙和第一磨牙上施加类似大小（252 +/- 24 mN；平均+/- SD）的孤立的“斜坡-保持”形状的力分布。牙齿在水平方向上分别在舌、面、中、远端和牙齿垂直方向上、下六个方向上施加载荷。分析了静态刺激阶段的传入反应。所有传入信号都缓慢适应，在至少一个刺激方向上响应静态力连续放电。29个传入事件（64%）自发活跃，在没有外部刺激的情况下表现出持续的放电。对单个牙齿的刺激对每个传入神经的刺激最为强烈。最敏感牙（MST）为第一前磨牙（23例）、第二前磨牙（13例）和第一磨牙（9例）。大约一半的传入人群对多装一颗或两颗牙齿也有反应。这些传入神经的反应谱表明，多齿接受野是由于齿间的机械耦合而形成的，而不是单个传入神经分支来支配多个齿。第一磨牙近端和远端负荷的传入反应非常相似。因此，当加载牙齿一侧时，传入响应的密集和定向方面在很大程度上保留了另一侧。加载MST时，传入神经在6个刺激方向中的2 ~ 4个方向上表现出兴奋性反应，即传入神经大致向牙齿加载方向调谐。在水平面上，前磨牙的传入种群没有明确的方向偏好。在磨牙的传入，然而，显示出强烈的方向偏向远舌方向。在垂直平面上，倾向于向下的力，远端沿着牙弓的敏感性逐渐降低。目前的结果表明，人类牙周传入供应前牙和后牙不同的能力信号水平和垂直力分别。
Impulses in 45 single mechanoreceptive afferents were recorded from the human inferior alveolar nerve with permucosally inserted tungsten microelectrodes. All afferents responded to mechanical stimulation of one or more premolar or molar teeth and most likely innervated their periodontal ligaments. For each afferent, isolated "ramp-and-hold" shaped force profiles of similar magnitudes (252 +/- 24 mN; mean +/- SD) were applied to the lower first premolar, the second premolar, and the first molar on the recording side. The tooth loads were applied in six directions: lingual, facial, mesial, and distal in the horizontal plane and up and down in the vertical direction of the tooth. The afferents response during the static phase of the stimulus was analyzed. All afferents were slowly adapting, discharging continuously in response to static forces in at least one stimulation direction. Twenty-nine afferents (64%) were spontaneously active, exhibiting an ongoing discharge in the absence of external stimulation. Stimulation of a single tooth was found to excite each afferent most strongly. The most sensitive tooth (MST) was the first premolar for 23, the second premolar for 13, and the first molar for 9 afferents. About half of the afferent population also responded to loading of one or two more teeth. The response profiles of these afferents indicated that the multiple-teeth receptive fields were due to mechanical coupling between the teeth rather than branching of single afferents to innervate several teeth. The afferent responses to loading the mesial and distal halves of the first molars were very similar. Thus both intensive and directional aspects of the afferent response when loading one side of the tooth was preserved to a great extent when loading the other side. When loading the MST, the afferents typically showed excitatory responses in two to four of the six stimulation directions, i.e., the afferents were broadly tuned to direction of tooth loading. In the horizontal plane, the afferent populations at the premolar teeth expressed no clear directional preferences. The afferents at the molar, however, showed a strong directional bias in the distal-lingual direction. In the vertical plane, there was a preference for downward-directed forces with a gradually decreasing sensitivity distally along the dental arch. The present results demonstrate that human periodontal afferents supplying anterior and posterior teeth differ in their capacity to signal horizontal and vertical forces, respectively.