title: Local postsynaptic voltage-gated sodium channel activation in dendritic spines of olfactory bulb granule cells.
abstract: Neuronal dendritic spines have been speculated to function as independent computational units, yet evidence for active electrical computation in spines is scarce. Here we show that strictly local voltage-gated sodium channel (Nav) activation can occur during excitatory postsynaptic potentials in the spines of olfactory bulb granule cells, which we mimic and detect via combined two-photon uncaging of glutamate and calcium imaging in conjunction with whole-cell recordings. We find that local Nav activation boosts calcium entry into spines through high-voltage-activated calcium channels and accelerates postsynaptic somatic depolarization, without affecting NMDA receptor-mediated signaling. Hence, Nav-mediated boosting promotes rapid output from the reciprocal granule cell spine onto the lateral mitral cell dendrite and thus can speed up recurrent inhibition. This striking example of electrical compartmentalization both adds to the understanding of olfactory network processing and broadens the general view of spine function.
authors.affiliation: Systems Neurobiology, Department II of Biology, Ludwig-Maximilians-Universität München, 82152 Martinsried, Germany; Neurophysiology, Institute of Zoology, Universität Regensburg, 93040 Regensburg, Germany.
authors.forename: Wolfgang G
authors.initials: WG
authors.lastname: Bywalez
authors.affiliation: Computational Neuroscience, Department II of Biology, Ludwig-Maximilians-Universität München, 82152 Martinsried, Germany.
authors.forename: Dinu
authors.initials: D
authors.lastname: Patirniche
authors.affiliation: Neurophysiology, Institute of Zoology, Universität Regensburg, 93040 Regensburg, Germany.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Rupprecht
authors.affiliation: Computational Neuroscience, Department II of Biology, Ludwig-Maximilians-Universität München, 82152 Martinsried, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Stemmler
authors.affiliation: Computational Neuroscience, Department II of Biology, Ludwig-Maximilians-Universität München, 82152 Martinsried, Germany.
authors.forename: Andreas V M
authors.initials: AV
authors.lastname: Herz
authors.affiliation: Two-Photon Imaging Center, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1039 Budapest, Hungary; Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, 1083 Budapest, Hungary.
authors.forename: Dénes
authors.initials: D
authors.lastname: Pálfi
authors.affiliation: Two-Photon Imaging Center, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1039 Budapest, Hungary; Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, 1083 Budapest, Hungary.
authors.forename: Balázs
authors.initials: B
authors.lastname: Rózsa
authors.affiliation: Neurophysiology, Institute of Zoology, Universität Regensburg, 93040 Regensburg, Germany. Electronic address: veronica.egger@ur.de.
authors.forename: Veronica
authors.initials: V
authors.lastname: Egger
mesh_terms: D000818:Animals; D049229:Dendritic Spines / Q000187:drug effects / Q000502:physiology*; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology*; D005260:Female; D008297:Male; D009830:Olfactory Bulb / Q000187:drug effects / Q000502:physiology*; D009924:Organ Culture Techniques; D051381:Rats; D017208:Rats, Wistar; D061585:Voltage-Gated Sodium Channel Agonists / Q000494:pharmacology*; D061566:Voltage-Gated Sodium Channels / Q000502:physiology*
chemical_list: D061585:Voltage-Gated Sodium Channel Agonists; D061566:Voltage-Gated Sodium Channels