三叉神经脊束核及其纤维联系在针剌镇痛中的作用

哺乳类动物的三叉神经脊束核有相似的形态结构。其尾侧与颈段脊髓后角尖端灰质相连续。根据细胞构筑的特点,该核可分为尾侧脊束核、极间脊束核和咀侧脊束核。家兔的三叉神经脊束核只包括咀侧与尾侧两部分。三叉神经尾侧脊束核又分为带状亚核、胶状质亚核和巨细胞亚核,它们分别与脊髓后角灰质的RexedⅠ、Ⅱ和ⅢⅣ层相当。三叉神经尾侧脊束核主要与头面部的痛、温觉有关,并参与了头面部的针刺镇痛过程。三叉神经尾侧脊束核接受三叉神经、面神经、舌咽神经、迷走神经、脑干网状结构、中缝大核、兰斑、大脑皮质和脊髓的传入纤维。该核的传出纤维投射至丘脑的腹后内侧核及板内核、内侧膝状体、脑干网状结构、某些脑神经核(孤束核、三叉神经感觉主核、前庭核、舌下神经核、迷走神经背核、疑核、三叉神经运动核、面神经核和动眼神经核)、非脑神经核(中缝大核、中脑顶盖与中央灰质、楔核、楔外核和内侧橄榄副核等)和上颈段脊髓。三叉神经传入纤维及其尾侧脊束核与中枢内的许多核团发生联系,并在那里与来源于不同部位的躯体或内脏的传入纤维发生会聚,这种直接的会聚可能为颜面部针刺冲动与来自躯体或内脏的痛冲动在同一部位相互作用提供了解剖学基础。三叉神经尾侧脊束核与脊髓、巨细胞网状核、中缝大核和丘脑板内核的纤维联系可能为颜面部针刺镇痛以及颜面部针刺麻醉能进行身体其他部位手术提供了神经学基础。三叉神经尾侧脊束核与巨细胞网状核、孤束核和延髓背外侧网状结构的纤维联系可能为颜面部针刺抑制内脏痛和内脏牵拉反应提供了解剖学基础,这对支持体表内脏相关学说也是很重要的。

THE PRINCIPLE OF THE ACTION OF THE SPINAL TRIGBMINAL NUCLEUS AND ITS FIBER CONNECTION IN ACUPUNCTURE ANALGESIA

The spinal trigeminal nucleus of mammals has similar morphological characteristics. Its caudal partis continuous with the tip of the posterior horn of the cervical spinal cord. On the basis of the cytoar-chitecture, the spinal trigeminal nucleus may be divided into three parts: the spinal caudal, the spinalinterpolar and the spinal oral nuclei. The spinal trigeminal nucleus of the rabbit consists of the caudaland the oral parts only. The spinal caudal trigeminal nucleus is subdivided into three parts, namely,the subnucleus zonalis, the subnucleus gelatinosus and the subnucleus magnocellularis, corresponding re-spectively to the Rexed Ⅰ, Ⅱ and Ⅲ, Ⅱ layers of the posterior horn. The spinal trigeminal nucleusassociates mainly with pain and the temperature sensation of the cephalo-facial origin, and lakes part inthe processing of facial acupuncture analgesia. The spinal caudal trigeminal nucleus receives afferent fibers from the trigeminal nerve, the facialnerve, the glossopharyngeal nerve, the vague nerve, the reticular formation of the brain stem, the raphemagnus nucleus, the locus coeruleus, the cerebral cortex and the spinal cord: the efferent fibers fromthis nucleus project into the ventroposterior medial nucleus and the intralaminar nucleus of the thalmus,the medial geniculate body, the reticular formation of the brain stem, and some cranial nerve nuclei(the solitary tract nucleus, the principal sensory nucleus of the trigeminal nerve, the vestibular nucleus,the hypoglossal nucleus, the dorsal vagal nucleus, the ambiguous nucleus, the motor trigeminal nucleus,the facial nucleus and the oculomotor nucleus), and also project into non-cranial nerve nuclei (theraphe magnus nucleus, the tectum of the midbrain, periaqueductal gray matter, the cuneatus nucleus,the cuneatus lateral and the medial accessary olivary nuclei, etc) and the upper cervical spinal cord. The primary afferent fibers and the spinal caudal nucleus of the trigeminal nerve are associated with many nuclei in the central nervous system, to which the somatic or visceral afferent fibers from differentportions converge. This direct convergence may be considered as the anatomical basis for the facialacupuncture impulses acting on the somatic or the visceral pain impulses in the same portion. The fiberconnections of the spinal caudal trigeminal nucleus with the spinal cord, the gigantocellular reticularnucleus, the raphe magnus nucleus and the intralaminar nucleus of thalamus probably provide the neuralbasis for facial acupuncture analgesia and for the operations on other parts of body performed under thefacial acupuncture analgesia. The fiber connections of this nucleus with the gigantocellular nucleus, thesolitary tract nucleus and the dorso-lateral reticular formation of the medulla oblongata perhaps providethe anatomical explanation for the facial acupuncture inhibiting the visceral pain and the visceral trac-tive response, which may be very important in supporting Integument-Visera correlation theory.