title: Persistent increase in dopamine release following activation of metabotropic glutamate receptors in the rat nucleus accumbens.
abstract: Intracerebral microdialysis technique was utilized to study the effect of the metabotropic glutamate receptor agonist, 1-aminocyclopentane-1,3-dicarboxylic acid (ACDP), on extracellular dopamine concentration in the nucleus accumbens of unanesthetized, freely moving rats. Perfusion of 1 mM (1S, 3R)-ACPD, a selective metabotropic glutamate receptor agonist, through the microdialysis probe caused a significant and persistent increase in extracellular dopamine level in the nucleus accumbens, which disappeared 2 h after perfusion of (1S, 3R)-ACPD was discontinued. On the other hand, a temporary increase in dopamine overflow was observed when 1 and 3 mM N-methyl-D-aspartate (NMDA), an ionotropic glutamate receptor agonist, was perfused into the nucleus accumbens. Application of 1 mM (1R, 3S)-ACPD, an inactive isomer, into the nucleus accumbens had no effect on the extracellular dopamine concentration. The metabotropic glutamate receptor antagonist, alpha-methyl-4-carboxyphenylglycine (MCPG) (5 mM) did not affect the basal dopamine level, but it attenuated the (1S, 3R)-ACPD-evoked dopamine overflow in the nucleus accumbens when applied concurrently with 1 mM (1S, 3R)-ACPD. These results suggest that a long-lasting dopamine overflow following activation of metabotropic glutamate receptors contrasts with a transient one in response to NMDA receptor activation in the nucleus accumbens.
authors.affiliation: Department of Pharmacology, Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Ohno
authors.forename: S
authors.initials: S
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D001565:Benzoates / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D003515:Cycloleucine / Q000031:analogs & derivatives / Q000494:pharmacology; D004298:Dopamine / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D008297:Male; D017551:Microdialysis; D016202:N-Methylaspartate / Q000494:pharmacology; D009498:Neurotoxins / Q000494:pharmacology; D009714:Nucleus Accumbens / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018094:Receptors, Metabotropic Glutamate / Q000819:agonists* / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D001565:Benzoates; D018691:Excitatory Amino Acid Antagonists; D009498:Neurotoxins; D018094:Receptors, Metabotropic Glutamate; D003515:Cycloleucine; C036361:1-amino-1,3-dicarboxycyclopentane; C079694:alpha-methyl-4-carboxyphenylglycine; D016202:N-Methylaspartate; D005998:Glycine; D004298:Dopamine