Mediation of ionotropic glutamate receptors in domoic acid-induced striatal dopamine release in rats.
Our objective was to characterize the mechanism of action of intrastriatal infusion of domoic acid on extracellular dopamine levels, using in vivo dialysis in conscious and freely moving rats. The local infusion of domoic acid (500 microM) caused an increase (567.9+/-142.5%, versus basal) in dopamine extracellular levels associated with a decrease in its metabolites: dihydroxyphenylacetate (DOPAC) and homovanillate (HVA) (47.3+/-4.4% and 33.8+/-4.2%, respectively, compared to basal). Infusion of the amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/kainate (AMPA/kainate) receptor antagonist, 6,7-dinitroquinoxaline-2,3-dione (DNQX; 200 microM) reversed the effect of domoic acid infusion on striatal dopamine levels. However, the infusion of the selective non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist, dizocilpine (MK-801; 50 microM), did not change significantly the effect of domoic acid on dopamine extracellular levels. In conclusion, based on results with a microdialysis technique, we suggest that domoic acid may act through AMPA/kainate receptors in striatum.
Department of Functional Biology and Health Sciences, Vigo University, Lagoas-Marcosende, 36200, Vigo, Spain. barias@uvigo.es
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Quintela
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Durán
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Alfonso
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004298:Dopamine / Q000378:metabolism*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D006719:Homovanillic Acid / Q000378:metabolism; D007608:Kainic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D008297:Male; D017551:Microdialysis; D009467:Neuromuscular Depolarizing Agents / Q000494:pharmacology*; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017470:Receptors, Glutamate / Q000187:drug effects / Q000502:physiology*
D018691:Excitatory Amino Acid Antagonists; D009467:Neuromuscular Depolarizing Agents; D011810:Quinoxalines; D017470:Receptors, Glutamate; D015102:3,4-Dihydroxyphenylacetic Acid; C056723:FG 9041; D016291:Dizocilpine Maleate; C012301:domoic acid; D007608:Kainic Acid; D004298:Dopamine; D006719:Homovanillic Acid