大鼠脊髓中间带内单胺能和某些肽能传入纤维的分布特征

DISTRIBUTION OF MONOAMINERGIC AND SOME PEPTIDERGIC AFFERENT FIBERS IN THE INTERMEDIATE ZONE OF THE RAT SPINAL CORD

以免疫细胞化学 ABC 方法,所显示的大鼠脊髓胸部和上腰部中间带内的 TH、5-HT、L-ENK、SP 和 OXY 免疫反应纤维,有着相似的分布形式。这些纤维和末梢见于外侧索、侧角、中间灰质和中央管周围,共同连成一条横带。TH、5-HT、SP 和 L-ENK 纤维和末梢在侧角内都聚成纤维簇,也有纤维形成纵束,穿行在纤维簇之中。中央管周围的纤维和末梢多数分布在其背方。TH 和5-HT 纤维在中央管背方中线处多,并有纵束形成,向两侧则是分散的纤维束和末梢。SP 和 L-ENK 纤维在中线处相对较少,中线两侧者多,纵行纤维束分成两条,并有纤维和末梢延续到后角基部内缘处。各类纤维均见有紧贴室管膜者。此外,5-HT 纤维在中央管两旁聚成两条纵行小束,而 SP 纤维在中央管腹侧正中线处形成一条纵束。中间灰质内的各种免疫反应纤维以一定间隔出现,组成横束,连接于侧角纤维簇与中央管背方的纤维之间。外侧索内各种纤维以邻接侧角处为多。OXY 纤维较其它4种纤维少得多,纤维簇、纵束和横束并不显著。TH、5-HT、SP和 L-ENK 纤维在中央管背侧的纵束和侧角内的纵束及纤维簇分居灰质的内、外两侧,中间灰质的纤维横架在两者之间,共同构成梯子形结构。由上述纤维构成的这个梯子形结构与交感节前神经元及其树突的分布形式相互吻合。

This study demonstrated with the immunocytochemical ABC method that the distribution pattern of TH,5-TH,SP,L-ENK and OXY immunoreactive fibers were alike in the intermediate zone of the thoracic and upper lumbar spinal cord. These fibers located in the lateral funiculus,lateral horn,intermediate gray and the area surrounding the central canal,forming a transversal fiber band with most of the fibers in the lateral horn.In the lateral horn,TH,5-HT,SP and L-ENK immunoreactive fibers and terminals aggregated in fiber clusters and numerous fib- ers made up a longitudinal bundle running through the fiber clusters.These immuno- reative fibers and terminals surrounding the central canal and distributed mainly dorsal to it.TH and 5-HT fibers accumulated in midplane where some fibers ran in a longitudinal fiber bundle and bilateral fibers and terminals distributed sparsely. SP and L-ENK fibers and terminals were relatively less in the midplane while dense laterally.All kinds of the immunoreactive fibers were found close to the ependyma.Two small 5-HT fiber bundles ran parallel and lateral to the central canal and a small SP fiber bundle ventral to it.Moderate immunoreactive fibers were found periodically in the intermediate gray and formed distinct bands to link fiber clusters in the lateral horn and fibers dorsal to the central canal.The imm- unoreactive fibers in lateral funiculus accumulated near the lateral horn and most densely in upper thoracic cord.OXY-containing fibers were much less than the others,thus obvious fiber clusters,longitudinal bundle or transversal bands had not been found.In general,the distribution pattern of some monoaminergic and pepti- dergic fibers in the intermediate zone was provided with a laddershaped configura- tion.The two longitudinal immunoreactive fiber bundles——dorsal to the central canal and within the lateral horn,located medial and lateral in the spinal gray respectively,and the transversal bands appeared periodically in the intermediate gray bridging between the two longitudinal bundles.This configuration of immunorea- ctive fibers coincided with nuclear regions which contained preganglionic sympathetic neurons as well as their dendrites.