Early divergence of magnocellular and parvocellular functional subsystems in the embryonic primate visual system
AUTOR(ES)
Meissirel, Claire
FONTE
The National Academy of Sciences of the USA
RESUMO
In both human and Old World primates visual information is conveyed by two parallel pathways: the magnocellular (M) and parvocellular (P) streams that project to separate layers of the lateral geniculate nucleus and are involved primarily in motion and color/form discrimination. The present study provides evidence that retinal ganglion cells in the macaque monkey embryo diverge into M and P subtypes soon after their last mitotic division and that optic axons project directly and selectively to either the M or P moieties of the developing lateral geniculate nucleus. Thus, initial M projections from the eyes overlap only in prospective layers 1 and 2, whereas initial P projections overlap within prospective layers 3–6. We suggest that the divergence of the M and P pathways requires developmental mechanisms different from those underlying competition-driven segregation of initially intermixed eye-specific domains in the primate visual system.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=20878Documentos Relacionados
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