Intrastriatal AP5 differentially affects behaviors induced by local infusions of D1 vs. D2 dopamine agonists.
Using bilateral infusions into the rat striatum, the effects of the competitive NMDA receptor antagonist 2-amino-5-phosphopentanoic acid (AP5) on behaviors induced by the dopamine (DA) D1 receptor agonist SKF 82526 (fenoldopam) or the D2 receptor agonist quinpirole were determined. These effects were tested in DA-replete (intact) rats and in rats that were receiving injections of the monoamine-depleting drug reserpine. In both intact and reserpinized rats, fenoldopam induced significant sniffing. This effect was attenuated by simultaneous co-infusion of AP5 in the reserpinized rats. Quinpirole induced locomotion, sniffing, and oral behaviors, all of which were attenuated by AP5 co-infusion in the intact rats. In contrast, AP5 enhanced the quinpirole-induced sniffing of reserpinized rats. These findings suggest that distinct D1/glutamate and D2/glutamate relationships exist in the striatum, and that the nature of the latter is influenced by DA tone.
McPherson
R J
RJ
Psychobiology Department, University of California, Irvine 92717-4550, USA.
Marshall
J F
JF
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D003342:Corpus Striatum / Q000187:drug effects*; D018491:Dopamine Agonists / Q000494:pharmacology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D018818:Fenoldopam / Q000494:pharmacology; D007263:Infusions, Parenteral; D008297:Male; D019257:Quinpirole / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017447:Receptors, Dopamine D1 / Q000819:agonists*; D017448:Receptors, Dopamine D2 / Q000819:agonists*; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors; D012110:Reserpine / Q000494:pharmacology
D018491:Dopamine Agonists; D018691:Excitatory Amino Acid Antagonists; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D016194:Receptors, N-Methyl-D-Aspartate; D019257:Quinpirole; D015763:2-Amino-5-phosphonovalerate; D012110:Reserpine; D018818:Fenoldopam