title: Rho GTPases regulate distinct aspects of dendritic arbor growth in Xenopus central neurons in vivo.
abstract: The development and structural plasticity of dendritic arbors are governed by several factors, including synaptic activity, neurotrophins and other growth-regulating molecules. The signal transduction pathways leading to dendritic structural changes are unknown, but likely include cytoskeleton regulatory components. To test whether GTPases regulate dendritic arbor development, we collected time-lapse images of single optic tectal neurons in albino Xenopus tadpoles expressing dominant negative or constitutively active forms of Rac, Cdc42 or RhoA. Analysis of images collected at two-hour intervals over eight hours indicated that enhanced Rac activity selectively increased branch additions and retractions, as did Cdc42 to a lesser extent. Activation of endogenous RhoA decreased branch extension without affecting branch additions and retractions, whereas dominant-negative RhoA increased branch extension. Finally, we provide data suggesting that RhoA mediates the promotion of normal dendritic arbor development by NMDA receptor activation.
authors.affiliation: Cold Spring Harbor Laboratory, Beckman Bldg., 1 Bungtown Rd., Cold Spring Harbor, New York 11724, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Li
authors.forename: L
authors.initials: L
authors.lastname: Van Aelst
authors.forename: H T
authors.initials: HT
authors.lastname: Cline
mesh_terms: D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000199:Actins / Q000378:metabolism; D000818:Animals; D048429:Cell Size / Q000187:drug effects; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D003712:Dendrites / Q000187:drug effects / Q000201:enzymology* / Q000502:physiology* / Q000648:ultrastructure; D004789:Enzyme Activation / Q000235:genetics; D005799:Genes, Dominant / Q000235:genetics; D006801:Humans; D007814:Larva / Q000166:cytology / Q000187:drug effects; D009154:Mutation / Q000235:genetics; D009473:Neuronal Plasticity / Q000187:drug effects; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013477:Superior Colliculi / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D014616:Vaccinia virus / Q000235:genetics; D014982:Xenopus laevis; D020764:cdc42 GTP-Binding Protein / Q000235:genetics / Q000378:metabolism; D020744:rac GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D020741:rho GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D020742:rhoA GTP-Binding Protein / Q000235:genetics / Q000378:metabolism
chemical_list: D000199:Actins; D016194:Receptors, N-Methyl-D-Aspartate; D011993:Recombinant Fusion Proteins; D015763:2-Amino-5-phosphonovalerate; D020764:cdc42 GTP-Binding Protein; D020744:rac GTP-Binding Proteins; D020741:rho GTP-Binding Proteins; D020742:rhoA GTP-Binding Protein