Möbius-Strip-Like Columnar Functional Connections are Revealed in Somato-Sensory Receptive Field CentroidsJames Wright1,2 Paul Bourke3 Oleg Favorov4Frontiers in Neuroanatomy. Front. Neuroanat. doi: 10.3389/fnana.2014.00119
2Liggins Institute, University of Auckland, Auckland, New Zealand. 3iVEC@UWA, University of Western Australia, Perth, Australia. 4Department of Biomedical Engineering, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7575, USA Abstract
Receptive fields of neurons in the forelimb region of areas 3b and 1 of primary somatosensory cortex, in cats and monkeys, were mapped using extracellular recordings obtained sequentially from nearly radial penetrations. Locations of the field centroids indicated the presence of a functional system, in which cortical homotypic representations of the limb surfaces are entwined in three-dimensional Möbius-strip-like patterns of synaptic connections. Boundaries of somatosensory receptive field in nested groups irregularly overlie the centroid order, and are interpreted as arising from the superposition of learned connections upon the embryonic order. Since the theory of embryonic synaptic self-organisation used to model these results was devised and earlier used to explain findings in primary visual cortex, the present findings suggest the theory may be of general application throughout cortex, and may reveal a modular functional synaptic system, which, only in some parts of the cortex, and in some species, is manifest as anatomical ordering into columns. Keywordscortical column, cortical development, synaptic organization, cortical response properties, neuromicrocircuitry, S1 segregates
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