TY - JOUR
T1 - Activation of quisqualate metabotropic receptors reduces glutamate and GABA-mediated synaptic potentials in the rat striatum
AU - Calabresi, Paolo
AU - Mercuri, Nicola B.
AU - Bernardi, Giorgio
PY - 1992/5/11
Y1 - 1992/5/11
N2 - The role of quisqualate (QUIS) metabotropic receptors in the synaptic transmission in the striatum was investigated using the cortico-striatal slice preparation. Low concentrations (1-30 μM) of trans-1-amino-cyclopentyl-1,3-dicarboxylic acid (t-ACPD), a selective agonist of QUIS metabotropic receptors, decreased glutamate-mediated synaptic potentials (EPSPs) evoked in the striatum by the stimulation of cortico-striatal fibers. This agonist decreased also GABA-mediated depolarizing synaptic potentials evoked by intrastriatal stimulation in the presence of 6-cyano-7-nitro-quinoxaline-2,3-dione (CNQX); this effect was less potent than the action of t-ACPD on glutamate-mediated potentials. Low concentrations of t-ACPD did not affect the intrinsic membrane properties of striatal neurons and their postsynaptic responses to exogenous glutamate and GABA. Higher concentrations (50-100 μM) to t-ACPD caused membrane depolarizations and inward currents in several neurons. Our data suggest that low concentrations of t-ACPD selectively reduce synaptic transmission while higher concentrations of this agonist may cause a direct excitatory action on striatal neurons.
AB - The role of quisqualate (QUIS) metabotropic receptors in the synaptic transmission in the striatum was investigated using the cortico-striatal slice preparation. Low concentrations (1-30 μM) of trans-1-amino-cyclopentyl-1,3-dicarboxylic acid (t-ACPD), a selective agonist of QUIS metabotropic receptors, decreased glutamate-mediated synaptic potentials (EPSPs) evoked in the striatum by the stimulation of cortico-striatal fibers. This agonist decreased also GABA-mediated depolarizing synaptic potentials evoked by intrastriatal stimulation in the presence of 6-cyano-7-nitro-quinoxaline-2,3-dione (CNQX); this effect was less potent than the action of t-ACPD on glutamate-mediated potentials. Low concentrations of t-ACPD did not affect the intrinsic membrane properties of striatal neurons and their postsynaptic responses to exogenous glutamate and GABA. Higher concentrations (50-100 μM) to t-ACPD caused membrane depolarizations and inward currents in several neurons. Our data suggest that low concentrations of t-ACPD selectively reduce synaptic transmission while higher concentrations of this agonist may cause a direct excitatory action on striatal neurons.
KW - Glutamate metabotropic receptor
KW - Presynaptic receptor
KW - Striatum
KW - Synaptic potential
KW - t-ACPD
UR - http://www.scopus.com/inward/record.url?scp=0026513646&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0026513646&partnerID=8YFLogxK
U2 - 10.1016/0304-3940(92)90852-X
DO - 10.1016/0304-3940(92)90852-X
M3 - Article
C2 - 1357603
AN - SCOPUS:0026513646
VL - 139
SP - 41
EP - 44
JO - Neuroscience Letters
JF - Neuroscience Letters
SN - 0304-3940
IS - 1
ER -