title: Differential Dendritic Integration of Synaptic Potentials and Calcium in Cerebellar Interneurons.
abstract: Dendritic voltage integration determines the transformation of synaptic inputs into output firing, while synaptic calcium integration drives plasticity mechanisms thought to underlie memory storage. Dendritic calcium integration has been shown to follow the same synaptic input-output relationship as dendritic voltage, but whether similar operations apply to neurons exhibiting sublinear voltage integration is unknown. We examined the properties and cellular mechanisms of these dendritic operations in cerebellar molecular layer interneurons using dendritic voltage and calcium imaging, in combination with synaptic stimulation or glutamate uncaging. We show that, while synaptic potentials summate sublinearly, concomitant dendritic calcium signals summate either linearly or supralinearly depending on the number of synapses activated. The supralinear dendritic calcium triggers a branch-specific, short-term suppression of neurotransmitter release that alters the pattern of synaptic activation. Thus, differential voltage and calcium integration permits dynamic regulation of neuronal input-output transformations without altering intrinsic nonlinear integration mechanisms.
authors.affiliation: Unit of Dynamic Neuronal Imaging, Institut Pasteur, 25 Rue du Dr Roux, 75724 Paris Cedex 15, France; Centre National de la Recherche Scientifique (CNRS), UMR 3571, Genes, Synapses and Cognition, Institut Pasteur, 25 Rue du Dr Roux, 75724 Paris Cedex 15, France.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Tran-Van-Minh
authors.affiliation: Unit of Dynamic Neuronal Imaging, Institut Pasteur, 25 Rue du Dr Roux, 75724 Paris Cedex 15, France; Centre National de la Recherche Scientifique (CNRS), UMR 3571, Genes, Synapses and Cognition, Institut Pasteur, 25 Rue du Dr Roux, 75724 Paris Cedex 15, France.
authors.forename: Therése
authors.initials: T
authors.lastname: Abrahamsson
authors.affiliation: Sorbonne Universités, UPMC Univ. Paris 06, CNRS UMR 8256, B2A, F-75005 Paris, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Cathala
authors.affiliation: Unit of Dynamic Neuronal Imaging, Institut Pasteur, 25 Rue du Dr Roux, 75724 Paris Cedex 15, France; Centre National de la Recherche Scientifique (CNRS), UMR 3571, Genes, Synapses and Cognition, Institut Pasteur, 25 Rue du Dr Roux, 75724 Paris Cedex 15, France. Electronic address: david.digregorio@pasteur.fr.
authors.forename: David A
authors.initials: DA
authors.lastname: DiGregorio
mesh_terms: D000818:Animals; D002118:Calcium / Q000502:physiology*; D002531:Cerebellum / Q000166:cytology*; D003712:Dendrites / Q000502:physiology*; D007395:Interneurons / Q000502:physiology*; D051379:Mice; D055366:Synaptic Potentials / Q000502:physiology*; D009435:Synaptic Transmission
chemical_list: D002118:Calcium
keywords: calcium imaging; cerebellum; dendritic integration; interneuron; neuronal computation; synaptic plasticity; synaptic transmission; voltage imaging