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Thin dendrites of cerebellar interneurons confer sublinear synaptic integration and a gradient of short-term plasticity.

Abstract

Interneurons are critical for neuronal circuit function, but how their dendritic morphologies and membrane properties influence information flow within neuronal circuits is largely unknown. We studied the spatiotemporal profile of synaptic integration and short-term plasticity in dendrites of mature cerebellar stellate cells by combining two-photon guided electrical stimulation, glutamate uncaging, electron microscopy, and modeling. Synaptic activation within thin (0.4 μm) dendrites produced somatic responses that became smaller and slower with increasing distance from the soma, sublinear subthreshold input-output relationships, and a somatodendritic gradient of short-term plasticity. Unlike most studies showing that neurons employ active dendritic mechanisms, we found that passive cable properties of thin dendrites determine the sublinear integration and plasticity gradient, which both result from large dendritic depolarizations that reduce synaptic driving force. These integrative properties allow stellate cells to act as spatiotemporal filters of synaptic input patterns, thereby biasing their output in favor of sparse presynaptic activity.

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  • Publisher Full Text

    • Authors

    Abrahamsson T, Cathala L, Matsui K, Shigemoto R, Digregorio DA

    Institution

    Institut Pasteur, Unit of Dynamic Neuronal Imaging, 25 Rue du Dr Roux, 75724 Paris Cedex 15, France.

    Source

    Neuron 73:6 2012 Mar 22 pg 1159-72

    MeSH

    Age Factors
    Animals
    Animals, Newborn
    Benzodiazepines
    Biophysics
    Cadmium Chloride
    Cerebellum
    Cesium
    Chlorides
    Dendrites
    Electric Stimulation
    Excitatory Amino Acid Antagonists
    Excitatory Postsynaptic Potentials
    Glutamates
    Imaging, Three-Dimensional
    Indoles
    Interneurons
    Lasers
    Mice
    Microscopy, Confocal
    Microscopy, Electron, Transmission
    Models, Neurological
    Neuronal Plasticity
    Patch-Clamp Techniques
    Potassium Channel Blockers
    Receptors, AMPA
    Sodium Channel Blockers
    Statistics, Nonparametric
    Synapses
    Tetraethylammonium
    Tetrodotoxin
    Time Factors

    Pub Type(s)

    In Vitro
    Journal Article
    Research Support, Non-U.S. Gov't

    Language

    eng

    PubMed ID

    22445343