Central terminations of periodontal mechanoreceptive and tooth pulp afferents in the trigeminal principal and oral nuclei of the cat
Central terminations of periodontal mechanoreceptive and tooth pulp afferents in the trigeminal principal and oral nuclei of the cat
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DOI：
10.1016/0006-8993(89)90665-3
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发表时间：
1989-04
期刊：
影响因子：
2.9
通讯作者：
K. Tsuru;K. Otani;K. Kajiyama;S. Suemune;Y. Shigenaga
中科院分区：
文献类型：
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作者：
K. Tsuru;K. Otani;K. Kajiyama;S. Suemune;Y. Shigenaga
采用轴突内记录技术和辣根过氧化物酶（HRP）注射技术测定了低阈值机械感受性牙周传入神经和牙髓传入神经的响应特性及其轴突在主核（Vp）和口核（Vo）的背内侧部（Vo.r）和背内侧部（Vo.dm）的形态特征。恢复3个快速适应（FA）和4个慢适应（SA）牙周传入通道和4个牙髓传入通道的中心末端进行详细分析。染色的三叉感觉束轴突上升和下降（分叉纤维），或下降而不分叉（下降的非分叉纤维）。对于每种类型的传入，分叉纤维与下降的非分叉纤维的比例约为3:1。从上升枝发出的主要侧枝终止于副枝。除少数情况外，从下降分支发出的大多数抵押品终止于Vo。在FA传入神经中，上升分支将所有主支支分支入具有背侧和背侧连续性的Vp，而下降分支将除两条支支外的所有主支分支入具有背侧和背侧不连续性的Vo。从FA传入到Vo的投影。在钮扣数和前、终枝长度方面，Dm均占优势。在SA传入的情况下，来自上行和下行分支的侧枝形成了背向和背向不连续的终端乔木。根据钮扣的密度将SA事件分为两个亚型。一个有优先投射到Vp或Vo，而另一个缺乏选择性投射。TP传入时，上升枝的主侧枝形成部分重叠的终端乔木，而下降枝侧枝形成的终端乔木不重叠。TP传入事件的侧枝频率低于其他类型的传入事件。包括髓质传入神经束密度在内的终端乔木分布范围小于其他类型传入神经束。在以下细分中，变异的平均大小变得更小，Vp, Vo。r和Vo。dm表示SA和TP事件。TP事件的变异量比SA事件小，FA事件的变异量比SA事件大。该研究表明，三叉神经感觉核复合体（TSNC）的细胞结构不同区域之间的功能分离与末端分枝的独特形态有很好的相关性。
Intra-axonal recording and horseradish peroxidase (HRP) injection techniques were employed to define the response properties of low-threshold mechanoreceptive periodontal afferents and of the tooth pulp afferents and the morphological characteristics of their axon arbors in the nucleus principalis (Vp) and rostrodorsomedial (Vo.r) and dorsomedial parts (Vo.dm) of the nucleus oralis (Vo). The central terminals of 3 fast adapting (FA) and 4 slowly adapting (SA) periodontal afferents and 4 tooth pulp (TP) afferents were recovered for detailed analyses. Stained axons in the trigeminal sensory tract ascended and descended (bifurcating fibers), or descended without bifurcation (descending non-bifurcating fibers). The ratio of the bifurcating fibers to the descending non-bifurcating fibers was about three to one for each type of afferents. The main collaterals given off from the ascending branches terminated in the Vp. Most collaterals given off from the descending branches terminated in the Vo with the exception of few instances. In case of the FA afferents, the ascending branches gave off all main collaterals into the Vp with rostrocaudal and dorsoventral continuities in their arbors, whereas the descending branches gave off all main collaterals, except two collaterals, into the Vo with rostrocaudal discontinuities. The projections from the FA afferents to the Vo.dm was predominant in terms of the number of boutons and the length of preterminal and terminal branches. In case of the SA afferents, the collaterals from the ascending and descending branches formed rostrocaudally and dorsoventrally discontinuous terminal arbors. In terms of the density of boutons the SA afferents were divided into two subtypes. One had a preferential projection into the Vp or Vo, whereas others lacked a selective projection. In case of the TP afferents, the main collaterals of the ascending branches formed partially overlapping terminal arbors, but the terminal arbors formed by the collateral of the descending branches did not overlap. The frequency of collaterals of the TP afferents was less than of the other types of afferents. The terminal arbors including the density of boutons of the pulpal afferents were less extensive than those of the other types of afferents. The average size of varicosities became smaller in the following subdivisions, Vp, Vo.r and Vo.dm for SA and TP afferents. The size of varicosities of the TP afferents was smaller and that of the FA afferents was larger than that of the SA afferents. This study demonstrates that a distinctive morphology in the terminal arborizations has a good correlation with a functional segregation among the cytoarchitectonically different zones of the trigeminal sensory nuclear complex (TSNC).