Retinal fibers alter tectal positional markers during the expansion of the half retinal projection in goldfish

Show simple item record Schmidt, John T. en_US 2007-04-06T18:17:07Z 2007-04-06T18:17:07Z 1978-01-15 en_US
dc.identifier.citation Schmidt, John T. (1978)."Retinal fibers alter tectal positional markers during the expansion of the half retinal projection in goldfish." The Journal of Comparative Neurology 177(2): 279-299. <> en_US
dc.identifier.issn 0021-9967 en_US
dc.identifier.issn 1096-9861 en_US
dc.identifier.uri en_US
dc.description.abstract Although widely accepted, the theory, that neurones carry immutable cytochemical markers which specify their synaptic connections, is not consistent with plastic reorganizations. Half retinal fish were therefore tested for changed markers following expansion. Optic nerve crush at the time of the half retinal ablation resulted in regeneration of a normal, restricted projection; but nerve crush following expansion (many months later) resulted in reestablishment of the expanded projection, assessed both by electrophysiological mapping and by radioautography. Since this implied changed markers, the half retina and tectum were tested independently using the ipsilateral tectum and eye as controls. In normal fish, removal of one tectum and deflection of the corresponding optic tract toward the remaining tectum resulted in regeneration of a positionally normal but ipsilateral map. In experimental fish, after the half retina had expanded its projection to the contralateral tectum, its optic tract was deflected to the control tectum. After 40 days it had regenerated a normal, restricted map indicating that the retinal markers had not changed. Such restricted projections did not expand in the presence of the normal projection even after a year or more. Similarly, the optic tract from the normal eye was deflected to cause innervation of the tectum containing the expanded half retinal projection. After 40 days, the projection regenerated from the normal eye was similar to the expanded half retinal projection. Areas of the normal retina corresponding to the missing areas of the half retina were not represented. Tectal markers had been altered by the half retinal fibers. In a final group, tecta were denervated and tested at various intervals by innervation from ipsilateral half retinal eyes. After five months of denervation, the regenerating fibers were no longer restricted to the rostral tectum but formed an expanded projection initially. Apparently tectal markers are induced by the retinal fibers, changed during expansion, and disappear during long-term denervation. en_US
dc.format.extent 1366250 bytes
dc.format.extent 3118 bytes
dc.format.mimetype application/pdf
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dc.publisher The Wistar Institute of Anatomy and Biology en_US
dc.publisher Wiley Periodiocals, Inc. en_US
dc.subject.other Life and Medical Sciences en_US
dc.subject.other Neuroscience, Neurology and Psychiatry en_US
dc.title Retinal fibers alter tectal positional markers during the expansion of the half retinal projection in goldfish en_US
dc.type Article en_US
dc.rights.robots IndexNoFollow en_US
dc.subject.hlbsecondlevel Neurosciences en_US
dc.subject.hlbtoplevel Health Sciences en_US
dc.description.peerreviewed Peer Reviewed en_US
dc.contributor.affiliationum Biophysics Research Division and Division of Biological Sciences, University of Michigan, Ann Arbor, Michigan 48109, U.S.A. en_US
dc.identifier.pmid 621292 en_US
dc.description.bitstreamurl en_US
dc.identifier.doi en_US
dc.identifier.source The Journal of Comparative Neurology en_US
dc.owningcollname Interdisciplinary and Peer-Reviewed
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