鸡脊髓上行投射在脑干的分布

THE DISTRIBUTION OF ASCENDING SPINAL PROJECTIONS IN THE CHICKEN

本文用Nauta法追踪鸡在颈髓半横切后脊髓上行的溃变纤维,观察的结果可知,鸟类动物脊髓有上行纤维直接向丘脑投射,主要终止于丘脑的背外侧核(DL)及背内侧核(DM)的腹侧份。根据比较解剖学的结果认为该区域相当于哺乳类动物的板内核群,是旧脊丘系的一部分,可能与动物的原始感觉有关。脊髓还发出纤维向下丘脑的内细胞层(SI)和外细胞层(SE)投射,该联系可能与动物痛的情绪反应有关。此外,在中脑的顶盖、中央灰质及网状结构中也有溃变标记。在延、桥脑的下橄榄(IO)、迷走背核(NX)、孤束核(S)、外侧网状核(RL)、小细胞网状核(Rpc)及巨细胞网状核(Rgc)等都有溃变标记,通过对这些通路及终末前溃变分布的研究,进一步探讨了哺乳类动物中枢神经系统中在种族发育上部分属于比较古老的结构。

The distribution of ascending spinal projection in the chicken was studied with theNauta method.Hemisections of the spinal cord were made at C_(12).Degenerating ascending fibers were found to project to the thalamus and terminate in the ventral portion of dorsolateral nucleus and dorsomedial nucleus.From the veiw point of comparative neuroanatomy this area of the thalamus has been tentatively identified as homologous to the intralaminar nuclear group of mammals and the demonstrated connection between the spinal cord and this thalamic area may he one part of the paleospinothalamie system concerned with the protopathic sensation.Degenerating fibers were also traced to the stratum cellulare internum and stratum cellulare externum in the hypothalamus.At the mesencephalon level,preterminal degeneration was seen in the optic tectum,central grey substance and the reticular formation.In the medulla and pons,profuse preterminal and pericellular terminal degenerations were observed in the inferior olivary nucleus,dorsal vagus nucleus,solitary nucleus,nucleus reticularis gigantocellularis and nucleus reticularis parvocellularis.