Group II, but not group I, metabotropic glutamate receptors in the rat nucleus accumbens contribute to amphetamine-induced locomotion.
Recently, it was reported that blocking metabotropic glutamate receptors (mGluRs) in the rat nucleus accumbens (NAcc) prevents the generation of locomotion by amphetamine (AMPH) in this site. In these studies, the non-selective group I/group II mGluR antagonist (R,S)-alpha-methyl-4-carboxyphenylglycine [(R,S)-MCPG] was used. The present study used more selective receptor antagonists to examine the specific contribution of group I and group II mGluRs to this effect. When co-injected bilaterally with AMPH into the NAcc, the group II selective mGluR antagonist (2S)-alpha-ethylglutamic acid [EGLU; 0.5-5.0 nmole/side] dose-dependently blocked the locomotion and rearing produced by AMPH. Equimolar concentrations of the group I selective antagonist (R,S)-1-aminoindan-1,5-dicarboxylic acid [AIDA; 0.5-5.0 nmole/side] were without effect. As previously reported for (R,S)-MCPG, neither of these receptor antagonists produced locomotor effects when injected alone in these concentrations into the NAcc. These results suggest that group II, but not group I, mGluRs in the rat NAcc contribute importantly to the ability of AMPH to produce locomotor activation.
Kim
J H
JH
Department of Psychiatry, The University of Chicago, 5841 South Maryland Avenue, MC 3077, Chicago, IL 60637, USA.
Beeler
J A
JA
Vezina
P
P
D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001565:Benzoates / Q000494:pharmacology; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005971:Glutamates / Q000494:pharmacology; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D007189:Indans / Q000494:pharmacology; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D009714:Nucleus Accumbens / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018094:Receptors, Metabotropic Glutamate / Q000037:antagonists & inhibitors / Q000502:physiology*
C095756:1-aminoindan-1,5-dicarboxylic acid; D001565:Benzoates; D000697:Central Nervous System Stimulants; D018691:Excitatory Amino Acid Antagonists; D005971:Glutamates; D007189:Indans; D018094:Receptors, Metabotropic Glutamate; C108822:metabotropic glutamate receptor 2; C104077:metabotropic glutamate receptor type 1; C017302:alpha-ethylglutamic acid; C079694:alpha-methyl-4-carboxyphenylglycine; D000661:Amphetamine; D005998:Glycine