Nonassociative plasticity alters competitive interactions among mixture components in early olfactory processing

Authors

  • Fernando F. Locatelli,

    1. School of Life Sciences, Arizona State University, Tempe, AZ, USA
    Current affiliation:
    1. Laboratorio de Neurobiología de la Memoria, Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IFIByNE (UBA CONICET), Ciudad Universitaria, Buenos Aires, Argentina
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  • Patricia C. Fernandez,

    1. School of Life Sciences, Arizona State University, Tempe, AZ, USA
    Current affiliation:
    1. INTA, EEA Delta del Paraná (UBA CONICET), Rio Paraná de las Palmas y Canal Comas, Campana, Argentina
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  • Francis Villareal,

    1. School of Life Sciences, Arizona State University, Tempe, AZ, USA
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  • Kerem Muezzinoglu,

    1. Biocircuits Institute, University of California, San Diego, La Jolla, CA, USA
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  • Ramon Huerta,

    1. Biocircuits Institute, University of California, San Diego, La Jolla, CA, USA
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  • C. Giovanni Galizia,

    1. Department of Biology, University of Konstanz, Konstanz, Germany
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  • Brian H. Smith

    Corresponding authorCurrent affiliation:
    1. Laboratorio de Neurobiología de la Memoria, Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IFIByNE (UBA CONICET), Ciudad Universitaria, Buenos Aires, Argentina
    • School of Life Sciences, Arizona State University, Tempe, AZ, USA
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Correspondence: Brian H. Smith, as above.

E-mail: brian.h.smith@asu.edu

Abstract

Experience-related plasticity is an essential component of networks involved in early olfactory processing. However, the mechanisms and functions of plasticity in these neural networks are not well understood. We studied nonassociative plasticity by evaluating responses to two pure odors (A and X) and their binary mixture using calcium imaging of odor-elicited activity in output neurons of the honey bee antennal lobe. Unreinforced exposure to A or X produced no change in the neural response elicited by the pure odors. However, exposure to one odor (e.g. A) caused the response to the mixture to become more similar to that of the other component (X). We also show in behavioral analyses that unreinforced exposure to A caused the mixture to become perceptually more similar to X. These results suggest that nonassociative plasticity modifies neural networks in such a way that it affects local competitive interactions among mixture components. We used a computational model to evaluate the most likely targets for modification. Hebbian modification of synapses from inhibitory local interneurons to projection neurons most reliably produced the observed shift in response to the mixture. These results are consistent with a model in which the antennal lobe acts to filter olfactory information according to its relevance for performing a particular task.

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