猫红核向三叉神经脊束核尾侧亚核的投射——HRP法研究

THE PROJECTION OF THE RED NUCLEUS TO THE SUBNUCLEUS CAUDALIS OF THE SPINAL TRIGEMINAL NUCLEUS IN THE CAT

向猫三叉神经脊束核尾侧亚核注入30%HRP溶液,在对侧红核吻侧2/3段的背外侧角部出现集中的标记细胞群。此部主要由多种形态的中、小型神经元组成,由红核中段开始出现,向吻侧逐渐向背外方突出。通过与向延髓下部网状结构和脊髓C_(2~3)节注入HRP的对照例以及关于红核—脊髓投射的文献对比,证明了此部是红核向对侧尾侧亚核发送纤维的特定区域。经过全面分析还发现,红核向下位结构的投射显示着吻侧2/3段向脊髓颈上段以上结构、尾侧2/3段向颈下段(颈膨)以下结构投射的体部定位关系。

1.The subnucleus caudalis of the spinal trigeminal nucleus of cat was injected with 30%HRP(Sigma,typeⅥ).Well localized groups of labeled neurons were observed in the dorsolateral horn of the contralateral red nucleus.This dorsolateral horn,being present in the rostral and middle thirds of the nucleus,consisted mainly of middle-sized and small neurons.2.Injections were also made into the second and third segments of the cervical spinal cord and the caudal part of the bulbar reticular formation.The labeled neurons appearing in these experiments were diffusely distributed in the red nucleus,yet limited in the rostral third of it.3.Summarizing our findings and the data from the literature,we got the impression that the rostral two thirds of the red nucleus gave projections to the central structures rostral to the upper cervical spinal cord,and the caudal two thirds of it to those caudal to the lower cervical cord,which indicating a somatotopic organization of the red nucleus neurons giving descending projection fibers.