Acetylcholine α7 nicotinic and dopamine D2 receptors are targeted to many of the same postsynaptic dendrites and astrocytes in the rodent prefrontal cortex

Authors

  • Aine M. Duffy,

    1. Department of Neurology and Neuroscience, Division of Neurobiology, Weill Cornell Medical College, New York, New York 10065
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  • Megan L. Fitzgerald,

    1. Department of Neurology and Neuroscience, Division of Neurobiology, Weill Cornell Medical College, New York, New York 10065
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  • June Chan,

    1. Department of Neurology and Neuroscience, Division of Neurobiology, Weill Cornell Medical College, New York, New York 10065
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  • Danielle C. Robinson,

    1. Department of Neurology and Neuroscience, Division of Neurobiology, Weill Cornell Medical College, New York, New York 10065
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  • Teresa A. Milner,

    1. Department of Neurology and Neuroscience, Division of Neurobiology, Weill Cornell Medical College, New York, New York 10065
    2. Laboratory of Neuroendocrinology, The Rockefeller University, New York, New York 10065
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  • Kenneth Mackie,

    1. Department of Psychological and Brain Sciences and the Gill Center, Indiana University, Bloomington, Indiana 47405
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  • Virginia M. Pickel

    Corresponding author
    1. Department of Neurology and Neuroscience, Division of Neurobiology, Weill Cornell Medical College, New York, New York 10065
    • Division of Neurobiology, Weill Cornell Medical College, 407 East 61st Street, New York, NY 10065
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Abstract

The alpha-7 nicotinic acetylcholine receptor (α7nAChR) and the dopamine D2 receptor (D2R) are both implicated in attentional processes and cognition, mediated in part through the prefrontal cortex (PFC). We examined the dual electron microscopic immunolabeling of α7nAChR and either D2R or the vesicular acetylcholine transporter (VAChT) in rodent PFC to assess convergent functional activation sites. Immunoreactivity (ir) for α7nAChR and/or D2R was seen in the same as well as separate neuronal and glial profiles. At least half of the dually labeled profiles were somata and dendrites, while most labeled axon terminals expressed only D2R-ir. The D2R-labeled terminals were without synaptic specializations or formed inhibitory or excitatory-type synapses with somatodendritic profiles, some of which expressed the α7nAChR and/or D2R. Astrocytic glial processes comprised the majority of nonsomatodendritic α7nAChR or α7nAChR and D2R-labeled profiles. Glial processes containing α7nAChR-ir were frequently located near VAChT-labeled terminals and also showed perisynaptic and perivascular associations. We conclude that in rodent PFC α7nACh and D2R activation can dually modulate (1) postsynaptic dendritic responses within the same or separate but synaptically linked neurons in which the D2R has the predominately presynaptic distribution, and (2) astrocytic signaling that may be crucial for synaptic transmission and functional hyperemia. Synapse, 2011. © 2011 Wiley-Liss, Inc.

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