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The inferior olive of a prosimian primate Galago senegalensis . I. conformation and spino‐olivary projections
Author(s) -
Whitworth R. H.,
Haines D. E.
Publication year - 1983
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.902190207
Subject(s) - galago , anatomy , prosimian , biology , zona incerta , fasciculus , spinal cord , inferior olivary nucleus , medulla oblongata , primate , lobe , dorsum , central nervous system , neuroscience , white matter , medicine , magnetic resonance imaging , fractional anisotropy , lemur , radiology
Spino‐olivary projections to inferior olive (10)in a prosimian primate, Galago senegalensis , were studied by using a modification of the Fink and Heimer ('67) technique. Prior to examining the arrangement of spinal axons within 10, its conformation was determined from a series of cresyl violet acetate sections. Galago I0 is composed of typical medial accessory (MAO), dorsal accessory (DAO), and principal (PO) olivary nuclei. The MA0 is divisible into subgroups a, b, c, d, a ventrolateral outgrowth (VLO), and a dorsomedial cell column (DMCC). Cytoarchitectural and experimental data indicate that DAO is subdivided into lateral (DAOI) and medial (DAO,) parts. The PO of Galago consists of dorsal and ventral lamellae connected by a lateral bend. Following hemisections of the spinal cord at cervical, thoracic, and lumbar cord levels, degeneration is present in essentially identical subgroups of Galago 10. The preponderance of degeneration is found throughout the ros‐ trocaudal extent of ipsilateral DAO 1 . Moderate amounts of axonal debris are located in caudal parts of subgroup a of ipsilateral MAO, and only a few degenerated fibers extend into adjacent subgroup b after cervical lesions. A distinct contralateral component is evident only following a C 1 hemisection. The moderate numbers of degenerated axons found in contralateral DAO M arise exclusively from cervical levels C 1 to C 3 . Spinoalivary fibers terminating in MAO appear to ascend in the ventral funiculus while the majority of those to DAO l course through the lateral funiculus.