Chiaia N L, Rhoades R W, Bennett-Clarke C A, Fish S E, Killackey H P
Department of Anatomy, Medical College of Ohio, Toledo 43699.
J Comp Neurol. 1991 Dec 8;314(2):201-16. doi: 10.1002/cne.903140202.
Retrograde tracing with true blue (TB) and diamidino yellow (DY) and anterograde tracing with either wheatgerm agglutinin-conjugated horseradish peroxidase (WGA-HRP) or Phaseolus vulgaris leucoagglutinin (PHA-L) were employed to investigate the projections from trigeminal nucleus principalis (PrV) and trigeminal subnucleus interpolaris (SpI) to their targets in the medial ventral posterior (VPM) and posterior (POm) nuclei of the thalamus. Many more cells in both PrV and SpI were labeled by tracer injections into VPM than into POm. Only a very small number of double-labeled neurons were observed in either PrV or SpI. However, a significantly higher percentage of SpI cells projected to POm or to both POm and VPM than was the case for PrV. Anterograde tracing with WGA-HRP showed that the projections from both PrV and SpI to VPM were much denser than those from the same nuclei to POm. Small injections of PHA-L into either PrV or SpI produced a focus of fairly dense labeling in VPM and much more diffuse terminal labeling in POm. These anatomical data provide evidence for two separate trigeminothalamic pathways, one originating from PrV and the second originating from SpI. Both of these pathways converge and diverge at the thalamic level. That is, information from the PrV pathway and from the SpI pathway are both provided to VPM in a morphologically restricted fashion and to POm in a morphologically widespread fashion.
采用真蓝（TB）和双脒基黄（DY）逆行追踪法，以及小麦胚芽凝集素结合辣根过氧化物酶（WGA-HRP）或菜豆白细胞凝集素（PHA-L）顺行追踪法，研究三叉神经脑桥核（PrV）和三叉神经脑桥中间亚核（SpI）向丘脑腹后内侧核（VPM）和丘脑后核（POm）的投射。与注射到POm相比，向VPM注射示踪剂后，PrV和SpI中标记的细胞更多。在PrV或SpI中仅观察到极少数双标记神经元。然而，与PrV相比，投射到POm或同时投射到POm和VPM的SpI细胞百分比显著更高。用WGA-HRP顺行追踪显示，PrV和SpI向VPM的投射比相同核团向POm的投射密集得多。向PrV或SpI小剂量注射PHA-L，在VPM中产生相当密集的标记焦点，在POm中产生更弥散的终末标记。这些解剖学数据为两条独立的三叉丘脑通路提供了证据，一条起源于PrV，另一条起源于SpI。这两条通路在丘脑水平上既有汇聚又有发散。也就是说，来自PrV通路和SpI通路的信息都以形态学上受限的方式提供给VPM，并以形态学上广泛的方式提供给POm。
