近代神经解剖学将脑干中缝的核团命名为中缝核或缝际核(Nuclei raphe)。Tabet等又把猫中缝核分为8个核团。DahIstrom等用荧光组织化学的方法

进一步研究了大白鼠脑干5-羟色胺神经元胞体的分布

并将其分为9群。而且证明中缝核团A totai of 35 cats were used in this investigation. Following sterectaxic injections

3

H-Leucine or electrolytic lesions in the nucleus raphe magnus

efferent fibers were observed to emerge from the nucleus raphe magnus. The terminations were examined microscopically under brightfield and dark-field illumination. The terminal fields were distributed as follows Ascending fibers of nucleus raphe magnus were found in the nucleus parafascicularis and nucleus centralis of the thalamus

posterior area of the hypothalamus

central gray matter and reticular formation of midbrain. A few fibers were terminated in the nucleus raphe pontis

nucleus reticularis pontis

nucleus posterior commissure

superior colliculus

nucleus interpeduncularis and the pretetal area. Descending fibers of the nucleus raphe magnus terminated in the nucleus reticularis gigantocellularis

nucleus reticularis paramedianus

nucleus olivaris inferior

nucleus tractus solitarii

nucleus motorius dorsalis ncrvi vagi and the marginal

gelatinous and magnocellular layer of the. spinal trigeminal nucleus caudalis. The projection to the spinal cord is bilateral

via the dorsolateral funiculus. Terminal fields are found in the lamina Ⅰ Ⅱ and Lamina Ⅴ-Ⅶ of the dorsal horn and intermediate zone. In summary

the efferents of nucleus raphe magnus not only directly connect with the structure of the pain control but also with many of the other nuclei. It suggests that the nucleu raphe magnus is an important relay station for pain control.