title: Collateral projections from vestibular nuclear and inferior olivary neurons to lobules I/II and IX/X of the rat cerebellar vermis: a double retrograde labeling study.
abstract: Axon collateral projections to various lobules of the cerebellar cortex are thought to contribute to the coordination of neuronal activities among different parts of the cerebellum. Even though lobules I/II and IX/X of the cerebellar vermis are located at the opposite poles in the anterior-posterior axis, they have been shown to receive dense vestibular mossy fiber projections. For climbing fibers, there is also a mirror-image-like organisation in their axonal collaterals between the anterior and posterior cerebellar cortex. However, the detailed organisation of mossy and climbing fiber collateral afferents to lobules I/II and IX/X is still unclear. Here, we carried out a double-labeling study with two retrograde tracers (FluoroGold and MicroRuby) in lobules I/II and IX/X. We examined labeled cells in the vestibular nuclei and inferior olive. We found a low percentage of double-labeled neurons in the vestibular nuclei (2.1 ± 0.9% of tracer-labeled neurons in this brain region), and a higher percentage of double-labeled neurons in the inferior olive (6.5 ± 1.9%), especially in its four small nuclei (18.5 ± 8.0%; including the β nucleus, dorsal cap of Kooy, ventrolateral outgrowth, and dorsomedial cell column), which are relevant for vestibular function. These results provide strong anatomical evidence for coordinated information processing in lobules I/II and IX/X for vestibular control.
authors: Department of Life Science, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617, Taiwan.
authors: Ray X
authors: RX
authors: Lee
authors: Jian-Jia
authors: JJ
authors: Huang
authors: Chiming
authors: C
authors: Huang
authors: Meng-Li
authors: ML
authors: Tsai
authors: Chen-Tung
authors: CT
authors: Yen
mesh_terms: D000818:Animals; D065814:Cerebellar Vermis / Q000033:anatomy & histology*; D005260:Female; D009434:Neural Pathways / Q000033:anatomy & histology; D056347:Neuroanatomical Tract-Tracing Techniques; D009474:Neurons / Q000166:cytology*; D009847:Olivary Nucleus / Q000033:anatomy & histology*; D010784:Photomicrography; D020318:Rats, Long-Evans; D014726:Vestibular Nuclei / Q000033:anatomy & histology*
keywords: cerebellar cortex; climbing fiber; mossy fiber; spinocerebellum; vestibulocerebellum