Regulation of dendritic length and branching by semaphorin 3A.
The molecular mechanisms that control dendritic development are still unclear. Semaphorin 3A, a class III semaphorin, has been shown to regulate the radial orientation of pyramidal neurons in the developing neocortex. Here, we investigate the effects of Sema3A on the development of dendritic topology. Neocortical slices from Sema3A null mutant mice were cultured and neurons were transfected with GFP, reconstructed, and compared with neurons from wild-type and heterozygote littermates. We also added exogenous Sema3A to cultured wild-type neocortical slices to further test its effects on dendritic development. We document reductions in dendritic length and branching in Sema3A null mice and increases in dendritic length and branching after the addition of exogenous Sema3A to wild-type neurons. We conclude that Sema3A is necessary for the elaboration of second and third order dendritic branches in pyramidal neurons.
Fenstermaker
Vivian
V
Department of Biological Sciences, Columbia University, New York, New York 10027, USA. vlf7@columbia.edu
Chen
Yachi
Y
Ghosh
Anirvan
A
Yuste
Rafael
R
D000818:Animals; D000831:Animals, Newborn; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D048429:Cell Size / Q000235:genetics; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*; D003712:Dendrites / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D040121:Semaphorin-3A / Q000172:deficiency / Q000235:genetics* / Q000494:pharmacology; D014162:Transfection
D040121:Semaphorin-3A