title: Zonal organization of the mouse flocculus: physiology, input, and output.
abstract: The zones of the flocculus have been mapped in many species with a noticeable exception, the mouse. Here, the functional map of the mouse was constructed via extracellular recordings followed by tracer injections of biotinylated-dextran-amine and immunohistochemistry for heat-shock protein-25. Zones were identified based on the Purkinje cell complex spike modulation occurring in response to optokinetic stimulation. In zones 1 and 3 Purkinje cells responded best to rotation about a horizontal axis oriented at 135 degrees ipsilateral azimuth, whereas in zones 2 and 4 they responded best to rotation about the vertical axis. The tracing experiments showed that Purkinje cells of zone 1 projected to the parvicellular part of lateral cerebellar nucleus and superior vestibular nucleus, while Purkinje cells of zone 3 projected to group Y and the superior vestibular nucleus. Purkinje cells of zones 2 and 4 projected to the magnocellular and parvicellular parts of the medial vestibular nucleus, while some also innervated the lateral vestibular nucleus or nucleus prepositus hypoglossi. The climbing fiber inputs to Purkinje cells in zones 1 and 3 were derived from neurons in the ventrolateral outgrowth of the contralateral inferior olive, whereas those in zones 2 and 4 were derived from the contralateral caudal dorsal cap. Purkinje cells in zones 1 and 2, but not in zones 3 and 4, were positively labeled for heat-shock protein-25. The present study illustrates that Purkinje cells in the murine flocculus are organized in discrete zones with specific functions, specific input - output relations, and a specific histochemical signature.
authors.affiliation: Department of Neuroscience, Erasmus MC, 3000 DR Rotterdam, The Netherlands. m.schonewille@erasmusmc.nl
authors.forename: Martijn
authors.initials: M
authors.lastname: Schonewille
authors.forename: Chongde
authors.initials: C
authors.lastname: Luo
authors.forename: Tom J H
authors.initials: TJ
authors.lastname: Ruigrok
authors.forename: Jan
authors.initials: J
authors.lastname: Voogd
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Schmolesky
authors.forename: Mandy
authors.initials: M
authors.lastname: Rutteman
authors.forename: Freek E
authors.initials: FE
authors.lastname: Hoebeek
authors.forename: Marcel T G
authors.initials: MT
authors.lastname: De Jeu
authors.forename: Chris I
authors.initials: CI
authors.lastname: De Zeeuw
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000344:Afferent Pathways / Q000033:anatomy & histology* / Q000502:physiology; D000818:Animals; D001369:Axons / Q000502:physiology / Q000648:ultrastructure*; D001710:Biotin / Q000031:analogs & derivatives; D002525:Cerebellar Cortex / Q000033:anatomy & histology* / Q000502:physiology; D003911:Dextrans; D004525:Efferent Pathways / Q000033:anatomy & histology* / Q000502:physiology; D005133:Eye Movements / Q000502:physiology; D006360:Heat-Shock Proteins / Q000378:metabolism; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D018832:Molecular Chaperones; D009363:Neoplasm Proteins / Q000378:metabolism; D017120:Nystagmus, Optokinetic / Q000502:physiology; D009847:Olivary Nucleus / Q000033:anatomy & histology / Q000502:physiology; D009949:Orientation / Q000502:physiology; D004856:Postural Balance / Q000502:physiology; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*; D014726:Vestibular Nuclei / Q000033:anatomy & histology* / Q000502:physiology
chemical_list: D003911:Dextrans; D006360:Heat-Shock Proteins; C486113:Hsbp1 protein, mouse; D018832:Molecular Chaperones; D009363:Neoplasm Proteins; C076397:biotinylated dextran amine; D001710:Biotin