Retinal input instructs alignment of visual topographic maps.
Sensory information is represented in the brain in the form of topographic maps, in which neighboring neurons respond to adjacent external stimuli. In the visual system, the superior colliculus receives topographic projections from the retina and primary visual cortex (V1) that are aligned. Alignment may be achieved through the use of a gradient of shared axon guidance molecules, or through a retinal-matching mechanism in which axons that monitor identical regions of visual space align. To distinguish between these possibilities, we take advantage of genetically engineered mice that we show have a duplicated functional retinocollicular map but only a single map in V1. Anatomical tracing revealed that the corticocollicular projection bifurcates to align with the duplicated retinocollicular map in a manner dependent on the normal pattern of spontaneous activity during development. These data suggest a general model in which convergent maps use coincident activity patterns to achieve alignment.
Triplett
Jason W
JW
Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA.
Owens
Melinda T
MT
Yamada
Jena
J
Lemke
Greg
G
Cang
Jianhua
J
Stryker
Michael P
MP
Feldheim
David A
DA
D000818:Animals; D001931:Brain Mapping; D055879:Gene Knock-In Techniques; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology; D060850:LIM-Homeodomain Proteins; D051379:Mice; D055495:Neurogenesis; D009799:Ocular Physiological Phenomena; D036121:Receptor, EphA3 / Q000235:genetics / Q000502:physiology; D012160:Retina / Q000502:physiology*; D013477:Superior Colliculi / Q000502:physiology*; D014157:Transcription Factors; D014793:Visual Cortex / Q000502:physiology*; D014795:Visual Pathways
D018398:Homeodomain Proteins; D060850:LIM-Homeodomain Proteins; D014157:Transcription Factors; C063843:insulin gene enhancer binding protein Isl-1; C491717:Epha3 protein, mouse; D036121:Receptor, EphA3