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dc.contributor.authorIbbotson, M
dc.contributor.authorJung, YJ
dc.date.accessioned2020-11-27T00:11:28Z
dc.date.available2020-11-27T00:11:28Z
dc.date.issued2020
dc.identifier.citationIbbotson, M. & Jung, Y. J. (2020). Origins of Functional Organization in the Visual Cortex.. Front Syst Neurosci, 14, pp.10-. https://doi.org/10.3389/fnsys.2020.00010.
dc.identifier.issn1662-5137
dc.identifier.urihttp://hdl.handle.net/11343/252375
dc.description.abstractHow are the complex maps for orientation selectivity (OS) created in the primary visual cortex (V1)? Rodents and rabbits have a random distribution of OS preferences across V1 while in cats, ferrets, and all primates cells with similar OS preferences cluster together into relatively wide cortical columns. Given other clear similarities in the organization of the visual pathways, why is it that maps coding OS preferences are so radically different? Prominent models have been created of cortical OS mapping that incorporate Hebbian plasticity, intracortical interactions, and the properties of growing axons. However, these models suggest that the maps arise primarily through intracortical interactions. Here we focus on several other features of the visual system and brain that may influence V1 structure. These are: eye divergence, the total number of cells in V1, the thalamocortical networks, the topography of the retina and phylogeny. We outline the evidence for and against these factors contributing to map formation. One promising theory is that the central-to-peripheral ratio (CP ratio) of retinal cell density can be used to predict whether or not a species has pinwheel maps. Animals with high CP ratios (>7) have orientation columns while those with low CP ratios (<4) have random OS maps. The CP ratio is related to the total number of cells in cortex, which also appears to be a reasonable contributing factor. However, while these factors correlate with map structure to some extent, there is a gray area where certain species do not fit elegantly into the theory. A problem with the existing literature is that OS maps have been investigated in only a small number of mammals, from a small fraction of the mammalian phylogenetic tree. We suggest four species (agouti, fruit bat, sheep, and wallaby) that have a range of interesting characteristics, which sit at intermediate locations between primates and rodents, that make them good targets for filling in the missing gaps in the literature. We make predictions about the map structures of these species based on the organization of their brains and visual systems and, in doing so, set possible paths for future research.
dc.languageeng
dc.publisherFrontiers Media SA
dc.rights.urihttps://creativecommons.org/licenses/by/4.0
dc.titleOrigins of Functional Organization in the Visual Cortex.
dc.typeJournal Article
dc.identifier.doi10.3389/fnsys.2020.00010
melbourne.affiliation.departmentOptometry and Vision Sciences
melbourne.affiliation.department
melbourne.source.titleFrontiers in Systems Neuroscience
melbourne.source.volume14
melbourne.source.pages10-
dc.rights.licenseCC BY
melbourne.elementsid1444432
melbourne.openaccess.pmchttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC7063058
melbourne.contributor.authorIbbotson, Michael
melbourne.contributor.authorJung, Young Jun
dc.identifier.eissn1662-5137
melbourne.accessrightsOpen Access


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