Analysis of laminar organization of spinal trigeminal nucleus based on physiological, morphological and immunohistochemical properties of neurons.

三叉神经脊束核根据细胞构筑结构分为3个亚核。尾侧亚核（Vc）具有形态学层状结构，而头外侧亚核则不具有。然而，最近对向更高水平投射的神经元和初级传入纤维的终止的研究表明，吻侧亚核也有功能层压（Hayashi，'80，' 81，'84）。本研究通过对三叉神经脊束核的体视结构和三叉神经能免疫反应纤维的分布进行分析，结果表明：（1）在三叉神经脊束核的背内侧部至腹外侧部，有明显的由下颌神经、上颌神经或眶下神经支配的感受野的LTM神经元排列;面吻尾侧感受野在吻侧亚核腹内侧至束侧方向 ...更多信息 而在Vc中，核的排列方向相反，但这种排列并不明显。此外，在极间亚核（Vi）中，接受口区传入的神经元位于面吻侧感受野神经元的外侧。（2）从第一个锋电位潜伏期短和对外周高频刺激的反应来看，推测二级神经元分布在Vi核的背外侧半核，而整个核则分布在奥贝斯附近。Vc尾部分布于Ⅲ/Ⅳ层。（3）Vc组5-羟色胺能纤维在I、II层密集分布，在V层粗大分布，而Vi组5-羟色胺能纤维消失。这些结果表明，Vi中存在功能性层状结构，但与Vc中不同，且III/IV层与脊髓后角的III、IV层不同，三叉旁核是Vc I层的延续。少

The spinal trigeminal nucleus consists of 3 subnuclei based on cytoarchitectonic structures. The subnucleus caudalis (Vc) shows morphological laminar organization, on the other hand, the subnuclei rostral to the obex does not. However, recent studies on the projection neurons to higher levels and the terminations of primary afferent fibers suggest that the rostral subnuclei also have functional lamination (Hayashi,'80,'81,'84). This study has been aimed to analyze the functional laminar organization based on analysis of somatotopic organization of the nucleus and distribution of serotonergic immunoreactive fibers.The results were (1)LTM-neurons having receptive fields innervated by mandibular, maxilla or infraorbital nerve clearly arranged in the dorsomedial to ventrolateral part of the nucleus throughout the spinal trigeminal nucleus. Receptive fields on the rostral to caudal part of the face represented in the direction of ventromedial to the tract side of nucleus in the rostral subn … More uclei, on the other hand, in the reverse direction in Vc, Although this arrangement was not so clear. In addition, neurons receiving input from oral area located lateral to the neurons having receptive fields on the rostral part of the face in the subnucleus interpolarlis(Vi). (2)Presumed second order neurons judging from the short first spike latency and the response to high frequency stimulation to the peripheral distributed in the dorsolateral half of the nucleus in Vi, while whole part of the nucleus near the obex. But, in the caudal part of Vc they scattered in the layer III/IV. (3)Serotonergic fiber distributed densely in layers I and II, and coarsely in layer V in Vc, but disappeared in Vi. Instead, they exist in the paratrigeminal nucleus near the obex.These results suggest that in Vi functional laminar organization exists, but it is different from that in Vc, and layer III/IV is not identical to the layers III and IV of the spinal dorsal horn, and the paratrigeminal nucleus is the continuation of layer I of Vc. Less