Mobius-Strip-Like Columnar Functional Connections are Revealed in Somato-Sensory Receptive Field Centroids

James Wright1,2 Paul Bourke3 Oleg Favorov4

Frontiers in Neuroanatomy. Front. Neuroanat. doi: 10.3389/fnana.2014.00119

1Department of Psychological Medicine, Faculty of Medicine, University of Auckland, Auckland, New Zealand.
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 Mobius-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.

Keywords

cortical column, cortical development, synaptic organization, cortical response properties, neuromicrocircuitry, S1 segregates

Pre-Press manuscript (pdf)