Ephrin-As mediate targeting of eye-specific projections to the lateral geniculate nucleus.
Axon guidance cues contributing to the development of eye-specific visual projections to the lateral geniculate nucleus (LGN) have not previously been identified. Here we show that gradients of ephrin-As and their receptors (EphAs) direct retinal ganglion cell (RGC) axons from the two eyes into their stereotyped pattern of layers in the LGN. Overexpression of EphAs in ferret RGCs using in vivo electroporation induced axons from both eyes to misproject within the LGN. The effects of EphA overexpression were competition-dependent and restricted to the early postnatal period. These findings represent the first demonstration of eye-specific pathfinding mediated by axon guidance cues and, taken with other reports, indicate that ephrin-As can mediate several mapping functions within individual target structures.
Huberman
Andrew D
AD
Center for Neuroscience, 1544 Newton Ct., University of California, Davis, California 95616, USA.
Murray
Karl D
KD
Warland
David K
DK
Feldheim
David A
DA
Chapman
Barbara
B
D000375:Aging / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D001369:Axons / Q000502:physiology; D018274:Electroporation; D036384:Ephrin-A3 / Q000378:metabolism / Q000502:physiology*; D036386:Ephrin-A5 / Q000378:metabolism / Q000502:physiology*; D005260:Female; D005289:Ferrets; D005829:Geniculate Bodies / Q000502:physiology*; D049452:Green Fluorescent Proteins; D049408:Luminescent Agents; D008297:Male; D036121:Receptor, EphA3 / Q000502:physiology; D036123:Receptor, EphA5 / Q000502:physiology; D036081:Receptors, Eph Family / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000502:physiology*; D009435:Synaptic Transmission; D014795:Visual Pathways / Q000378:metabolism
D036384:Ephrin-A3; D036386:Ephrin-A5; D049408:Luminescent Agents; D049452:Green Fluorescent Proteins; D036121:Receptor, EphA3; D036123:Receptor, EphA5; D036081:Receptors, Eph Family