title: GABA regulates dendritic growth by stabilizing lamellipodia in newly generated interneurons of the olfactory bulb.
abstract: The initial formation and growth of dendrites is a critical step leading to the integration of newly generated neurons into postnatal functional networks. However, the cellular mechanisms and extracellular signals regulating this process remain mostly unknown. By directly observing newborn neurons derived from the subventricular zone in culture as well as in olfactory bulb slices, we show that ambient GABA acting through GABA(A) receptors is essential for the temporal stability of lamellipodial protrusions in dendritic growth cones but did not interfere with filopodia dynamics. Furthermore, we provide direct evidence that ambient GABA is required for the proper initiation and elongation of dendrites by promoting the rapid stabilization of new dendritic segments after their extension. The effects of GABA on the initial formation of dendrites depend on depolarization and Ca2+ influx and are associated with a higher stability of microtubules. Together, our results indicate that ambient GABA is a key regulator of dendritic initiation in postnatally generated olfactory interneurons and offer a mechanism by which this neurotransmitter drives early dendritic growth.
authors.affiliation: Department of Neuroscience, University of Geneva Medical School, CH-1211 Geneva, Switzerland.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Gascon
authors.forename: Alexandre G
authors.initials: AG
authors.lastname: Dayer
authors.forename: Marc-Olivier
authors.initials: MO
authors.lastname: Sauvain
authors.forename: Gael
authors.initials: G
authors.lastname: Potter
authors.forename: Benoit
authors.initials: B
authors.lastname: Jenny
authors.forename: Mathias
authors.initials: M
authors.lastname: De Roo
authors.forename: Eloisa
authors.initials: E
authors.lastname: Zgraggen
authors.forename: Nicolas
authors.initials: N
authors.lastname: Demaurex
authors.forename: Dominique
authors.initials: D
authors.lastname: Muller
authors.forename: Jozsef Z
authors.initials: JZ
authors.lastname: Kiss
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D003712:Dendrites / Q000502:physiology*; D058785:GABA-A Receptor Agonists; D020439:Growth Cones / Q000502:physiology*; D007395:Interneurons / Q000502:physiology*; D009830:Olfactory Bulb / Q000254:growth & development*; D011554:Pseudopodia / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011963:Receptors, GABA-A / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
chemical_list: D058785:GABA-A Receptor Agonists; D011963:Receptors, GABA-A; D005680:gamma-Aminobutyric Acid