title: Regulation of radial glial motility by visual experience.
abstract: Radial glia in the developing optic tectum express the key guidance molecules responsible for topographic targeting of retinal axons. However, the extent to which the radial glia are themselves influenced by retinal inputs and visual experience remains unknown. Using multiphoton live imaging of radial glia in the optic tectum of intact Xenopus laevis tadpoles in conjunction with manipulations of neural activity and sensory stimuli, radial glia were observed to exhibit spontaneous calcium transients that were modulated by visual stimulation. Structurally, radial glia extended and retracted many filopodial processes within the tectal neuropil over minutes. These processes interacted with retinotectal synapses and their motility was modulated by nitric oxide (NO) signaling downstream of neuronal NMDA receptor (NMDAR) activation and visual stimulation. These findings provide the first in vivo demonstration that radial glia actively respond both structurally and functionally to neural activity, via NMDAR-dependent NO release during the period of retinal axon ingrowth.
authors.affiliation: McGill Graduate Program in Neuroscience, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada.
authors.forename: Marc
authors.initials: M
authors.lastname: Tremblay
authors.forename: Vincent
authors.initials: V
authors.lastname: Fugère
authors.forename: Jennifer
authors.initials: J
authors.lastname: Tsui
authors.forename: Anne
authors.initials: A
authors.lastname: Schohl
authors.forename: Aydin
authors.initials: A
authors.lastname: Tavakoli
authors.forename: Bruno A N
authors.initials: BA
authors.lastname: Travençolo
authors.forename: Luciano da F
authors.initials: Lda F
authors.lastname: Costa
authors.forename: Edward S
authors.initials: ES
authors.lastname: Ruthazer
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002465:Cell Movement / Q000502:physiology*; D066298:In Vitro Techniques; D009457:Neuroglia / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D019581:Neuropil / Q000502:physiology; D009569:Nitric Oxide / Q000378:metabolism; D010775:Photic Stimulation; D011554:Pseudopodia / Q000502:physiology; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D012165:Retinal Ganglion Cells / Q000502:physiology; D015398:Signal Transduction; D013477:Superior Colliculi / Q000254:growth & development / Q000502:physiology*; D013569:Synapses / Q000502:physiology; D014795:Visual Pathways / Q000254:growth & development / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*; D014982:Xenopus laevis
chemical_list: D016194:Receptors, N-Methyl-D-Aspartate; D009569:Nitric Oxide; D002118:Calcium