Adenosine A2A receptors inhibit the N-methyl-D-aspartate component of excitatory synaptic currents in rat striatal neurons.
The effects of the adenosine A(2A) receptor agonist 2-p-(2-carboxyethyl)phenethyl-amino-5'-N-ethylcarboxamidoadenosine (CGS 21680) on currents mediated by excitatory amino acid receptors were examined in rat striatal brain slices. In a Mg(2+)-free superfusion medium, CGS 21680 decreased the amplitude of excitatory postsynaptic currents (EPSCs) in about 70% of striatal neurons. The inhibitory effect of CGS 21680 disappeared both in the presence of the adenosine A(2A) receptor antagonist 8-(3-chlorostyryl) caffeine and the NMDA receptor antagonist 2-amino-5-phosphonopentanoic acid (AP-5). NMDA-induced currents were also depressed by CGS 21680 in a subset of striatal cells, whereas alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA)-induced currents were not affected. The results suggest that adenosine A(2A) receptor agonists inhibit the NMDA component of the EPSC.
Gerevich
Zoltan
Z
Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, Härtelstrasse 16-18, D-04107 Leipzig, Germany. gerz@medizin.uni-leipzig.de
Wirkner
Kerstin
K
Illes
Peter
P
D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects / Q000502:physiology*; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology*; D016202:N-Methylaspartate / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D058906:Purinergic P1 Receptor Agonists; D058915:Purinergic P1 Receptor Antagonists; D051381:Rats; D017208:Rats, Wistar; D043705:Receptor, Adenosine A2A; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000502:physiology*; D018047:Receptors, Purinergic P1 / Q000502:physiology*
D058906:Purinergic P1 Receptor Agonists; D058915:Purinergic P1 Receptor Antagonists; D043705:Receptor, Adenosine A2A; D016194:Receptors, N-Methyl-D-Aspartate; D018047:Receptors, Purinergic P1; D016202:N-Methylaspartate