A new developmental neural model is proposed to
describe how the cortical subplate learns a map of
orientation preference and ocular dominance tuning,
and teaches this map to the other cortical layers via
known anatomical connections from the subplate to the
cortical layers. The model accounts for the
coordination of orientation and ocular dominance maps
across layers, the coordination of ON and OFF
subregions of simple cell receptive fields, the crude
clustering of horizontal connections in layer 2/3,
and the development of precise columns of coordinated
receptive field properties across the multiple
cortical layers. Modeling simulations emulate the
order of biological development. Inputs from the LGN
to the cortical subplate induce a map, which is
taught to the other cortical layers. Interlaminar
connections next develop, and the model is shown to
be stable after subplate atrophy. Finally, patterned
vision segregates ON and OFF receptive fields.
Simulations also clarify how manipulating the level
of neurotrophic factor BDNF, which has been shown to
disrupt map formation in vivo, can influence map
development by disrupting the balance of excitation
and inhibition.
describe how the cortical subplate learns a map of
orientation preference and ocular dominance tuning,
and teaches this map to the other cortical layers via
known anatomical connections from the subplate to the
cortical layers. The model accounts for the
coordination of orientation and ocular dominance maps
across layers, the coordination of ON and OFF
subregions of simple cell receptive fields, the crude
clustering of horizontal connections in layer 2/3,
and the development of precise columns of coordinated
receptive field properties across the multiple
cortical layers. Modeling simulations emulate the
order of biological development. Inputs from the LGN
to the cortical subplate induce a map, which is
taught to the other cortical layers. Interlaminar
connections next develop, and the model is shown to
be stable after subplate atrophy. Finally, patterned
vision segregates ON and OFF receptive fields.
Simulations also clarify how manipulating the level
of neurotrophic factor BDNF, which has been shown to
disrupt map formation in vivo, can influence map
development by disrupting the balance of excitation
and inhibition.