家兔脊髓至桥核及脑桥尾侧被盖腹外侧部的投射

SPINAL PROJECTIONS TO THE PONTINE NUCLEUS AND THE CAUDAL PONTINE VENTROLATERAL TEGMENTUM IN RABBITS

用成年家兔18只,分别在其颈、胸、或腰髓之一侧灰质中注射HRP或WGA-HRP,追踪其在桥核及脑桥尾侧被盖腹外侧区的顺行标记。在桥核中,标记终支见于其尾侧1/3,分布于其旁正中核、脚核之背侧部及背外侧核中。在桥尾侧被盖腹外侧区中见4个小细胞群内有标记终支,暂名之为VLPT_(1~4)细胞群。各核中之标记均为两侧性者,无明显的体部定位关系。我们在Nissl染色片上观察了VLPT_(1~4)细胞群的细胞构筑,讨论了它们与Meessen及Olszewski的“k”、“m”细胞群及桥延体的关系。4细胞群中,VLPT_(2)(相当Meessen及Olszewski“k”细胞群之腹侧部)及VLPT_(3)(相当Meessen及Olszewski“m”细胞群之一部)向吻侧合为一群,并渐融入桥核之背外侧部。这两细胞群可能为桥延体之一部。

The cervical,thoracic,or lumbar spinal gray was injected with HRP or WGAHRP unilaterally in 18 adult rabbits and the anterograde labeling was traced in the pontine nucleus and the caudal pontine ventrolateral tegmentum.In the pontine nucleus labeled terminal arborizations were found in its caudal 1/3,distributing in the paramedian nucleus,the dorsal part of peduncular nucleus and the dorsolateral nucleus.In the ventrolateral tegmentum four small cell groups were found labeled which were temporarily denominated as VLPT_(1~4)groups.In all locations labelings were found bilaterally and no apparent somatotopical localization could be identified.The cytoarchitecture of VLPT_(1~4)was studied on Nissl sections and their relationship with Meessen and Olszewski's(M-O's)"k"and"m"groups and with pontobulbar body was discussed.VLPT_(2)(corresponding to the ventral part of M-O's"k")and VLPT_(3)(corresponding to a part of M-O's"m")join each other to form one group which then merges into the dorsolateral nucleus of the pontine gray.They apparently form a part of the pontobulbar body.