摘要
用猫8只,在脊髓之颈髓或腰髓注射HRP后,追踪后索核中顺行标记的后索非初级纤维终枝的分布,以及标记终枝与逆行标记的后索核-脊髓投射细胞的关系。后索核内非初级传入纤维的投射范围广泛。无论是颈髓或腰髓,一个节段注射HRP后均在后索核之全长内见到标记终枝。颈6或颈7注射后,在内侧楔束核内有大量标记,主要分布于“细胞团”以外地区,即核之上部及核之中下部的腹侧。此外,在核中段发现在其背外侧部有一小细胞区,向上渐与外侧楔束核相接,也是标记终枝密集的部位。薄束核中也有标记终枝但少得多。腰5或腰6注射后标记终枝的量较颈髓注射例少,主要分布于薄束核内。在核之下部占其背、内、腹侧区,在核之上部较弥散。内侧楔束核的腹内侧部也有少量标记。标记终枝的分布区与标记细胞的分布区有重叠,但两者的中心区并不相合,有的标记细胞周围无、或仅有少量标记终枝。有的标记细胞却正位于密集标记终枝区域,胞体周围有大量终末,证明后索之非初级传入纤维可能和后索核一脊髓神经元形成直接联系,构成单突触反馈。
HRP was injected into the cervical or lumbar spinal cord in 8 adult cats.The anterogradely labeled terminal arborization and its relation with the retrogradely labeled cells in the DCN were studied.The non-primary afferent fibers were distributed diffusely in the DCN.Injection of HRP in one spinal segment,either cervical or lumbar,resulted in labeling of terminal branches throughout the rostrocaudal extent of the DCN.In C6 or C7 injection cases large amount of labeled terminal branches were found in the medial cuneate nucleus,chiefly in its extraclusteral regions,viz.in the rostral part and in the ventral area of the caudal two thirds of the nucleus.A small celled area at the dorsolateral brim of the middle part of the medial cuneate nucleus was found to approach and to be contiguous with the external cuneate nucleus at higher level.This area was likewise densely labeled.Labeled terminal branches were also found in the gracile nucleus in lesser amount.After L5 or L6 injections the labeled terminals were much less in amount than in cervical injection cases.They were distributed mainly in the gracile nucleus.In the lower part of the nucleus the labeled terminals were found in its dorsal,medial,and ventrar areas.In the upper part of the nucleus they projected diffusely.A slight degree of labeling was also found in the ventromedial angle of the medial cuneate nucleus.The areas of distribution of the labeled terminals and labeled cells overlapped but did not coincide with eachother.No or merely a few labeled terminals were found around some of the labeled cells,while other cells were located right in the center of heaviest terminal labeling with abundant terminal branches surrounding their somata and dendrites.This proved that the non-primary afferent fibers of the DCN might form monosynaptic feed-back loop with the DGN-spinal cells.
作者
鞠躬
Ju Gong(The Fourth Army Medical College of the People's Liberation Army)
出处
《解剖学报》
CAS
1981年第2期134-143,226,共11页
Acta Anatomica Sinica
