Barmack N H, Baughman R W, Errico P, Shojaku H
Department of Ophthalmology, R.S. Dow Neurological Sciences Institute, Good Samaritan Hospital & Medical Center, Portland, Oregon 97209.
J Comp Neurol. 1993 Jan 22;327(4):521-34. doi: 10.1002/cne.903270405.
The vestibular primary afferent projection to the cerebellum of the rabbit was studied with retrograde and orthograde tracers. We injected individual lobules of the cerebellum with horseradish peroxidase (HRP) or wheat germ agglutinin-HRP (WGA-HRP). Following these injections the numbers of labeled and unlabeled cells in Scarpa's ganglion were counted. Approximately 64-89% of the cells in Scarpa's ganglion were labeled retrogradely following uvula-nodular injections. About 2% of the cells in the ipsilateral Scarpa's ganglion were labeled after injections of the flocculus. Virtually no cells were labeled following injections of the ventral paraflocculus. The vestibular primary afferent projection to the uvula-nodulus is so extensive that it must be part of a collateral system that also innervates the vestibular nuclei. This collateral projection pattern was confirmed by using fluorescent tracers injected into the uvula-nodulus and vestibular complex. Fluorogold was injected into the uvula-nodulus and peroxidase-rhodamine isothiocyanate was injected into the vestibular complex. More than 50% of the neurons in Scarpa's ganglion were double labeled by these subtotal injections. The dense vestibular primary afferent projection to the uvula-nodulus was confirmed by using the C fragment of tetanus toxin (TTC) injected into the labyrinth as an orthograde tracer. With the TTC technique, the vestibular primary afferent projection to the uvula-nodulus terminated exclusively in the ipsilateral granule cell layer of lobules 9d and 10. Much sparser vestibular primary afferent projections were found in the banks of major cerebellar sulci. A barely detectable projection was found to the flocculus and ventral paraflocculus.
采用逆行和顺行示踪剂研究了家兔前庭初级传入纤维向小脑的投射。我们将辣根过氧化物酶（HRP）或小麦胚凝集素-HRP（WGA-HRP）注入小脑的各个小叶。注射后，对斯卡帕神经节中标记和未标记的细胞进行计数。在蚓垂-小结注射后，斯卡帕神经节中约64-89%的细胞被逆行标记。在注射绒球后，同侧斯卡帕神经节中约2%的细胞被标记。在注射腹侧旁绒球后，几乎没有细胞被标记。前庭初级传入纤维向蚓垂-小结的投射非常广泛，以至于它必定是一个也支配前庭核的侧支系统的一部分。通过将荧光示踪剂注入蚓垂-小结和前庭复合体，证实了这种侧支投射模式。将荧光金注入蚓垂-小结，将异硫氰酸罗丹明过氧化物酶注入前庭复合体。这些不完全注射使斯卡帕神经节中超过50%的神经元被双重标记。通过将破伤风毒素C片段（TTC）注入迷路作为顺行示踪剂，证实了前庭初级传入纤维向蚓垂-小结的密集投射。采用TTC技术，前庭初级传入纤维向蚓垂-小结的投射仅终止于第9d和第10小叶的同侧颗粒细胞层。在小脑主要沟的边缘发现前庭初级传入纤维投射要稀疏得多。在绒球和腹侧旁绒球发现了几乎检测不到的投射。
