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Lateral cerebellum: functional localization within crus I and correspondence to cortical zones
Author(s) -
Edge Antonia L.,
MarpleHorvat Dilwyn E.,
Apps Richard
Publication year - 2003
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1046/j.1460-9568.2003.02873.x
Subject(s) - anatomy , neuroscience , cerebellum , optic chiasm , climbing fiber , lobe , nucleus , biology , cerebellar cortex , optic nerve
The present study investigates the functional connections of different parts of the medial‐most folium of crus I in the cat cerebellar hemisphere. Three areas were identified physiologically by recording on the cerebellar surface climbing fibre (CF) field potentials evoked by electrical stimulation of different body sites. From medial to lateral in relation to the long axis of the folium, area 1 receives convergent input from all body sites tested (optic chiasm, ipsilateral periorbital region, ipsilateral and contralateral forelimbs), area 2 receives input mainly from the ipsilateral periorbital region, while area 3 receives input mainly from the optic chiasm. These physiological differences were used to guide injections of bi‐directional tracer material into individual cortical areas. The inferior olive and cerebellar nuclei were then mapped, revealing a precise topography within the olivo‐cerebellar and cortico‐nuclear projections for each area. On the basis of their anatomical and physiological characteristics areas 1, 2 and 3 correspond to zones C 2 , C 3 and D 1 , respectively. CF inputs arise from the rostral medial accessory olive (C 2 ), the interface between the rostral dorsal accessory olive and ventral lamella of the principal olive (vlPO, C 3 ), and from vlPO (D 1 ). The corresponding cortico‐nuclear projections are nucleus interpositus posterior (C 2 ), the transitional region between the dentate nucleus and nucleus interpositus anterior (C 3 ), and the dentate nucleus (D 1 ). Overall, the results provide a comprehensive description of the functional localization of different zones within crus I (folium 1), and suggest that a potent source of CF input to the C 2 and D 1 zones within this region of cortex arises from visual pathways.