Visual thalamocortical projections in the flying fox: Parallel pathways to striate and extrastriate areas

Manger, P. R. and Rosa, M. G. P. (2005) Visual thalamocortical projections in the flying fox: Parallel pathways to striate and extrastriate areas. Neuroscience, 130 2: 497-511. doi:10.1016/j.neuroscience.2004.09.047

Author Manger, P. R.
Rosa, M. G. P.
Title Visual thalamocortical projections in the flying fox: Parallel pathways to striate and extrastriate areas
Journal name Neuroscience   Check publisher's open access policy
ISSN 0306-4522
Publication date 2005
Sub-type Article (original research)
DOI 10.1016/j.neuroscience.2004.09.047
Volume 130
Issue 2
Start page 497
End page 511
Total pages 15
Place of publication Oxford UK
Publisher Elsevier
Collection year 2005
Language eng
Subject C1
270502 Neurobiology
730104 Nervous system and disorders
1103 Clinical Sciences
1109 Neurosciences
Abstract We studied thalamic projections to the visual cortex in flying foxes, animals that share neural features believed to resemble those present in the brains of early primates. Neurones labeled by injections of fluorescent tracers in striate and extrastriate cortices were charted relative to the architectural boundaries of thalamic nuclei. Three main findings are reported: First, there are parallel lateral geniculate nucleus (LGN) projections to striate and extrastriate cortices. Second, the pulvinar complex is expansive, and contains multiple subdivisions. Third, across the visual thalamus, the location of cells labeled after visual cortex injections changes systematically, with caudal visual areas receiving their strongest projections from the most lateral thalamic nuclei, and rostral areas receiving strong projections from medial nuclei. We identified three architectural layers in the LGN, and three subdivisions of the pulvinar complex. The outer LGN layer contained the largest cells, and had strong projections to the areas V1, V2 and V3. Neurones in the intermediate LGN layer were intermediate in size, and projected to V1 and, less densely, to V2. The layer nearest to the origin of the optic radiation contained the smallest cells, and projected not only to V1, V2 and V3, but also, weakly, to the occipitotemporal area (OT, which is similar to primate middle temporal area) and the occipitoparietal area (OP, a third tier area located near the dorsal midline). V1, V2 and V3 received strong projections from the lateral and intermediate subdivisions of the pulvinar complex, while OP and OT received their main thalamic input from the intermediate and medial subdivisions of the pulvinar complex. These results suggest parallels with the carnivore visual system, and indicate that the restriction of the projections of the large- and intermediatesized LGN layers to V1, observed in present-day primates, evolved from a more generalized mammalian condition. (C) 2004 IBRO. Published by Elsevier Ltd. All rights reserved.
Keyword Neurosciences
Lateral Geniculate Nucleus
Lateral Posterior Nucleus
Lateral Geniculate-nucleus
Old-world Monkeys
Retinotopic Organization
Cortical Projections
Superior Colliculus
Inferior Pulvinar
Tree Shrews
Architectonic Subdivisions
Visuotopic Organization
Q-Index Code C1

Document type: Journal Article
Sub-type: Article (original research)
Collections: UQ Centre for Clinical Research Publications
2006 Higher Education Research Data Collection
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Citation counts: TR Web of Science Citation Count  Cited 4 times in Thomson Reuters Web of Science Article | Citations
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Created: Wed, 15 Aug 2007, 04:14:32 EST