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Glutamatergic antagonists attenuate ability of dopamine uptake blockers to increase extracellular levels of dopamine: Implications for tonic influence of glutamate on dopamine release
Author(s) -
Moghaddam Bita,
Bolinao Maria L.
Publication year - 1994
Publication title -
synapse
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.809
H-Index - 106
eISSN - 1098-2396
pISSN - 0887-4476
DOI - 10.1002/syn.890180409
Subject(s) - microdialysis , nomifensine , kainate receptor , dopamine , excitatory postsynaptic potential , chemistry , tonic (physiology) , glutamate receptor , glutamatergic , ampa receptor , pharmacology , extracellular , excitatory amino acid antagonists , nmda receptor , dopamine uptake inhibitors , striatum , 2 amino 5 phosphonovalerate , neuroscience , receptor , biology , biochemistry , nucleus accumbens , dopaminergic
Previous in vivo studies reporting a dose‐dependent increase in extracellular dopamine (DA) levels by excitatory amino acid (EAA) antagonists have been interpreted to indicate a lack of tonic excitatory effect exerted by these amino acids on striatal DA release. Alternatively, a tonic excitatory influence on DA release may affect a small fraction of DA terminals, so that blockade of this effect does not make a great enough contribution to the extracellular fluid to be detected by microdialysis. To examine this possibility, the effect of EAA antagonists was assessed by microdialysis in the presence of DA uptake blockers. It was found that in the presence of nomifensine or cocaine, antagonists of either NMDA or AMPA/kainate receptors decreased extracellular DA levels in the striatum. These data suggest that EAAs may exert a tonic facilitatory influence on striatal DA release and/or that endogenous EAAs may potentiate the action of DA uptake blockers through mechanisms that are mediated by EAA receptors. © 1994 Wiley‐Liss, Inc.