Mihailoff G A, Kosinski R J, Azizi S A, Border B G
Department of Cell Biology, University of Texas Health Science Center, Dallas 75235.
J Comp Neurol. 1989 Apr 22;282(4):617-43. doi: 10.1002/cne.902820411.
The retrograde transport of the conjugate wheat germ agglutinin-horseradish peroxidase (WGA-HRP) was used in the rat to identify the cell bodies of origin for all subcortical projections to the basilar pontine nuclei (BPN). A parapharyngeal surgical approach was used to allow the injection micropipette to enter the BPN from the ventral aspect of the brainstem and thus avoid any potential for false-positive labeling due to transection and injury-filling of axonal systems located dorsal to the basilar pontine gray. A surprisingly large number of BPN afferent cell groups were identified in the present study. Included were labeled somata in the lumbar spinal cord and a large variety of nuclei in the medulla, pons, and midbrain, as well as labeled cells in diencephalic and telencephalic nuclei such as the zona incerta, ventral lateral geniculate, hypothalamus, amygdala, nucleus basalis of Meynert, and the horizontal nucleus of the diagonal band of Broca. Quite a number of cell groups known to project directly to the cerebellum also exhibited labeled somata in the present study. To explore the possibility that such neurons were labeled because their axons were transected and injury-filled as they coursed through the BPN injection site to enter the cerebellum via the brachium pontis, a series of rats received complete, bilateral lesions of the brachium pontis followed 30-60 minutes later with multiple, diffuse injections of WGA-HRP (12-16 placements per animal) throughout the cerebellar cortex. In another series of animals, the massive cerebellar WGA-HRP injections were not preceded by brachium pontis lesions. In the latter cases, each of the cell groups in question that were known to project directly to the cerebellum exhibited labeled somata. However, when the cerebellar HRP injections were preceded by brachium pontis lesions, each of the cell groups in question continued to exhibit labeled somata in numbers comparable to that observed in the nonlesion cases. This implies that such neurons project to the BPN and the cerebellar cortex and that the axons of these particular neurons do not project to the cerebellum via the brachium pontis.
运用结合了小麦胚凝集素 - 辣根过氧化物酶（WGA - HRP）的逆行运输法，在大鼠身上确定了所有向基底桥核（BPN）发出皮质下投射的起源细胞体。采用咽旁手术入路，使注射微吸管从脑干腹侧进入BPN，从而避免因横断和损伤位于基底桥灰质背侧的轴突系统而导致假阳性标记的可能性。在本研究中确定了数量惊人的BPN传入细胞群。其中包括腰脊髓中的标记胞体以及延髓、脑桥和中脑中的多种核团，还有间脑和端脑核团中的标记细胞，如未定带、腹外侧膝状体、下丘脑、杏仁核、迈内特基底核和布罗卡斜角带水平核。在本研究中，相当多已知直接投射到小脑的细胞群也显示出标记胞体。为了探究这些神经元被标记是否是因为它们的轴突在穿过BPN注射部位经脑桥臂进入小脑时被横断并充满损伤物质，一系列大鼠接受了双侧脑桥臂完全损伤，30 - 60分钟后在整个小脑皮质进行多次、弥散性的WGA - HRP注射（每只动物12 - 16个注射点）。在另一组动物中，在大量小脑WGA - HRP注射之前未进行脑桥臂损伤。在后一种情况下，每个已知直接投射到小脑的相关细胞群都显示出标记胞体。然而，当在小脑HRP注射之前进行脑桥臂损伤时，每个相关细胞群仍显示出标记胞体，其数量与未损伤情况下观察到的相当。这意味着这些神经元投射到BPN和小脑皮质，并且这些特定神经元的轴突不通过脑桥臂投射到小脑。
