title: Differential Dopamine Regulation of Ca(2+) Signaling and Its Timing Dependence in the Nucleus Accumbens.
abstract: Dopamine action in the nucleus accumbens (NAc) is thought to drive appetitive behavior and Pavlovian reward learning. However, it remains controversial how dopamine achieves these behavioral effects by regulating medium spiny projection neurons (MSNs) of the NAc, especially on a behaviorally relevant timescale. Metabotropic glutamate receptor (mGluR)-induced Ca(2+) signaling dependent on the Ca(2+)- releasing messenger inositol 1,4,5-triphosphate (IP3) plays a critical role in controlling neuronal excitability and synaptic plasticity. Here, we show that transient dopamine application facilitates mGluR/IP3-induced Ca(2+) signals within a time window of ∼2-10 s in a subpopulation of MSNs in the NAc core. Dopamine facilitation of IP3-induced Ca(2+) signaling is mediated by D1 dopamine receptors. In dopamine-insensitive MSNs, activation of A2A adenosine receptors causes enhancement of IP3-evoked Ca(2+) signals, which is reversed by D2 dopamine receptor activation. These results show that dopamine differentially regulates Ca(2+) signaling on the order of seconds in two distinct MSN subpopulations.
authors.affiliation: Department of Neuroscience and Waggoner Center for Alcohol and Addiction Research, University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Immani
authors.initials: I
authors.lastname: Swapna
authors.affiliation: Department of Neuroscience and Waggoner Center for Alcohol and Addiction Research, University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Bondy
authors.affiliation: Department of Neuroscience and Waggoner Center for Alcohol and Addiction Research, University of Texas at Austin, Austin, TX 78712, USA. Electronic address: morikawa@utexas.edu.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Morikawa
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects*; D004298:Dopamine / Q000494:pharmacology*; D015544:Inositol 1,4,5-Trisphosphate / Q000494:pharmacology; D008297:Male; D008810:Mice, Inbred C57BL; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism*; D043705:Receptor, Adenosine A2A / Q000378:metabolism; D017447:Receptors, Dopamine D1 / Q000378:metabolism; D017448:Receptors, Dopamine D2 / Q000378:metabolism; D018094:Receptors, Metabotropic Glutamate / Q000378:metabolism; D013997:Time Factors
chemical_list: D043705:Receptor, Adenosine A2A; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D018094:Receptors, Metabotropic Glutamate; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium; D004298:Dopamine