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Presynaptic group I and II metabotropic glutamate receptors oppositely modulate striatal acetylcholine release
Author(s) -
Marti M.,
Paganini F.,
Stocchi S.,
Bianchi C.,
Beani L.,
Morari M.
Publication year - 2001
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1046/j.0953-816x.2001.01750.x
Subject(s) - metabotropic glutamate receptor , metabotropic receptor , chemistry , agonist , acetylcholine , metabotropic glutamate receptor 5 , glutamate receptor , metabotropic glutamate receptor 1 , metabotropic glutamate receptor 2 , muscarinic acetylcholine receptor , pharmacology , antagonist , muscarinic acetylcholine receptor m3 , receptor , biochemistry , biology
The effect of metabotropic glutamate receptor agonists and antagonists on KCl (20 m m )‐induced endogenous acetylcholine release from rat striatal synaptosomes was investigated. The group I agonist (S)‐3,5‐dihydroxyphenylglycine (DHPG), 1–1000 n m , potentiated in a concentration‐dependent way the KCl‐induced acetylcholine release, reaching maximal efficacy at 100 n m (+93 ± 14%). The effect of DHPG (10 n m ) was counteracted by coapplication of (7‐hydroximino)cyclopropan‐b‐chromen‐1a‐carboxylate (CPCCOEt), 10 µ m , a metabotropic glutamate receptor type one selective antagonist, and 2‐methyl‐6‐(phenylethynyl)pyridine (MPEP), 10 µ m , a metabotropic glutamate receptor type five selective antagonist, but not by application of either antagonist alone. The group II agonist (2S, 1′R, 2′R, 3′R)‐2‐(2,3‐dicarboxycyclopropyl)glycine (DCG‐IV), 1–1000 n m , inhibited in a concentration‐dependent way the KCl‐induced acetylcholine release displaying maximal efficacy at 300 n m (−32 ± 2%). The effect of DCG‐IV 300 n m was counteracted by the group II selective antagonist (2S)‐α‐ethylglutamic acid (EGLU), 300 µ m . The group III agonist l ‐amino‐4‐phosphonobutyric acid (L‐AP4) failed to alter the KCl‐induced acetycholine release up to 300 µ m . We conclude that metabotropic glutamate receptors belonging to group I and II are located on the axon terminals of striatal cholinergic interneurons, their activation resulting in facilitation and inhibition, respectively, of acetylcholine release.