title: Activity-dependent gating of calcium spikes by A-type K+ channels controls climbing fiber signaling in Purkinje cell dendrites.
abstract: In cerebellar Purkinje cell dendrites, heterosynaptic calcium signaling induced by the proximal climbing fiber (CF) input controls plasticity at distal parallel fiber (PF) synapses. The substrate and regulation of this long-range dendritic calcium signaling are poorly understood. Using high-speed calcium imaging, we examine the role of active dendritic conductances. Under basal conditions, CF stimulation evokes T-type calcium signaling displaying sharp proximodistal decrement. Combined mGluR1 receptor activation and depolarization, two activity-dependent signals, unlock P/Q calcium spikes initiation and propagation, mediating efficient CF signaling at distal sites. These spikes are initiated in proximal smooth dendrites, independently from somatic sodium action potentials, and evoke high-frequency bursts of all-or-none fast-rising calcium transients in PF spines. Gradual calcium spike burst unlocking arises from increasing inactivation of mGluR1-modulated low-threshold A-type potassium channels located in distal dendrites. Evidence for graded activity-dependent CF calcium signaling at PF synapses refines current views on cerebellar supervised learning rules.
authors.affiliation: Inhibitory Transmission Team, IBENS, CNRS UMR UMR8197, INSERM U1024, Ecole Normale Supérieure, 75005 Paris, France.
authors.forename: Yo
authors.initials: Y
authors.lastname: Otsu
authors.affiliation: Inhibitory Transmission Team, IBENS, CNRS UMR UMR8197, INSERM U1024, Ecole Normale Supérieure, 75005 Paris, France.
authors.forename: Païkan
authors.initials: P
authors.lastname: Marcaggi
authors.affiliation: Cerebellum Group, IBENS, CNRS UMR UMR8197, INSERM U1024, Ecole Normale Supérieure, 75005 Paris, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Feltz
authors.affiliation: Institut des Neurosciences Cellulaires et Intégratives, CNRS UPR 3212, 67000-Strasbourg, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Isope
authors.affiliation: Laboratory of Cellular Neurophysiology, Institute of Experimental Medicine of the Hungarian Academy of Sciences, 1083 Budapest, Hungary.
authors.forename: Mihaly
authors.initials: M
authors.lastname: Kollo
authors.affiliation: Laboratory of Cellular Neurophysiology, Institute of Experimental Medicine of the Hungarian Academy of Sciences, 1083 Budapest, Hungary.
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Nusser
authors.affiliation: Imaging Facility, IBENS, CNRS UMR 8197, INSERM U1024, Ecole Normale Supérieure, 75005 Paris, France.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Mathieu
authors.affiliation: Department of Neurophysiology, Graduate School of Medicine, University of Tokyo, Tokyo 113-0033, Japan.
authors.forename: Masanobu
authors.initials: M
authors.lastname: Kano
authors.affiliation: Center for Transdisciplinary Research, Niigata University, Niigata 950-2181, Japan.
authors.forename: Mika
authors.initials: M
authors.lastname: Tsujita
authors.affiliation: Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Sakimura
authors.affiliation: Inhibitory Transmission Team, IBENS, CNRS UMR UMR8197, INSERM U1024, Ecole Normale Supérieure, 75005 Paris, France. Electronic address: dieudon@biologie.ens.fr.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Dieudonné
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D020013:Calcium Signaling / Q000502:physiology*; D003712:Dendrites / Q000502:physiology* / Q000648:ultrastructure; D015640:Ion Channel Gating / Q000502:physiology; D051605:Kv Channel-Interacting Proteins / Q000502:physiology*; D051379:Mice; D009924:Organ Culture Techniques; D011689:Purkinje Cells / Q000502:physiology* / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D051605:Kv Channel-Interacting Proteins