Diverse receptive fields in the lateral geniculate nucleus during thalamocortical development.
Most models of thalamocortical development in the visual system assume a homogeneous population of thalamic inputs to the cortex, each with concentric on- or off-center receptive fields. To test this, we made high-resolution spatial maps of receptive fields in the developing ferret lateral geniculate nucleus (LGN). Developing receptive fields (RFs), had a variety of shapes: some concentric, others elongated (like adult cortical receptive fields) and some with 'hot spots' of sensitivity. These receptive fields seemed to arise from convergence of multiple retinal afferents onto LGN neurons. We present a Hebbian model whereby imprecise retinogeniculate connections help refine geniculocortical connections, sharpening both thalamocortical topography and perhaps orientation selectivity.
Tavazoie
S F
SF
Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, Massachusetts 02115, USA.
Reid
R C
RC
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001931:Brain Mapping; D005260:Female; D005289:Ferrets; D005829:Geniculate Bodies / Q000254:growth & development / Q000502:physiology; D008959:Models, Neurological; D016011:Normal Distribution; D011930:Reaction Time / Q000502:physiology; D015203:Reproducibility of Results; D012160:Retina / Q000502:physiology; D012165:Retinal Ganglion Cells / Q000502:physiology; D013788:Thalamus / Q000254:growth & development* / Q000502:physiology; D014793:Visual Cortex / Q000254:growth & development* / Q000502:physiology; D014795:Visual Pathways / Q000502:physiology*