title: Dopamine enhances glutamate-induced excitation of rat striatal neurons by cooperative activation of D1 and D2 class receptors.
abstract: Although dopamine (DA) usually inhibits firing of rat striatal neurons in vivo, iontophoresis of DA with low ejection currents can also potentiate glutamate-evoked activity. We used extracellular single cell recording to examine the DA receptor subtypes involved in such potentiation. At low iontophoretic currents (1-8 nA), both the DA D1 class receptor agonist SKF 38393 and the DA D2 class receptor agonist quinpirole mimicked the ability of DA to facilitate glutamate-induced activity. Acute depletion of DA abolished the excitatory modulation produced by either D1 or D2 agonists but not by DA. Co-administration of SKF 38393 and quinpirole restored the facilitation of glutamate effects in DA-depleted rats. Stimulation of both D1 and D2 class receptors appears to be required for DA to enhance glutamate-induced firing of striatal neurons.
authors.affiliation: Department of Neuroscience Finch University of Health Sciences/Chicago Medical School, IL 60064-3095, USA.
authors.forename: X T
authors.initials: XT
authors.lastname: Hu
authors.forename: F J
authors.initials: FJ
authors.lastname: White
mesh_terms: D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000494:pharmacology; D000818:Animals; D003342:Corpus Striatum / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D004298:Dopamine / Q000494:pharmacology*; D018491:Dopamine Agonists / Q000494:pharmacology; D004338:Drug Combinations; D004594:Electrophysiology; D018698:Glutamic Acid / Q000494:pharmacology*; D008297:Male; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D019257:Quinpirole / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017447:Receptors, Dopamine D1 / Q000187:drug effects / Q000502:physiology*; D017448:Receptors, Dopamine D2 / Q000187:drug effects / Q000502:physiology*
chemical_list: D018491:Dopamine Agonists; D004338:Drug Combinations; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D019257:Quinpirole; D018698:Glutamic Acid; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D004298:Dopamine