The Role of the Sublate in the Development of VisualCortex

A new developmental neural model is proposed todescribe how the cortical subplate learns a map oforientation preference and ocular dominance tuning,and teaches this map to the other cortical layers viaknown anatomical connections from the subplate to thecortical layers. The model accounts for thecoordination of orientation and ocular dominance mapsacross layers, the coordination of ON and OFFsubregions of simple cell receptive fields, the crudeclustering of horizontal connections in layer 2/3,and the development of precise columns of coordinatedreceptive field properties across the multiplecortical layers. Modeling simulations emulate theorder of biological development. Inputs from the LGNto the cortical subplate induce a map, which istaught to the other cortical layers. Interlaminarconnections next develop, and the model is shown tobe stable after subplate atrophy. Finally, patternedvision segregates ON and OFF receptive fields.Simulations also clarify how manipulating the levelof neurotrophic factor BDNF, which has been shown todisrupt map formation in vivo, can influence mapdevelopment by disrupting the balance of excitationand inhibition.