Trans-1-aminocyclopentane-1,3-dicarboxylic acid (t-ACPD) decreases synaptic excitation in rat striatal slices through a presynaptic action.
Excitatory synaptic transmission was decreased in the presence of trans-1-aminocyclopentane-1,3-dicarboxylic acid (t-ACPD) during whole-cell recordings from striatal slices. This effect of t-ACPD increased in a concentration-dependent manner at drug concentrations from 5-100 microM. Decreased transmission appeared to result from a presynaptic effect as indicated by the observations that: (1) t-ACPD decreased the amplitude of excitatory postsynaptic potentials (EPSPs) mediated by either quisqualate alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionate (AMPA) or N-methyl-D-aspartate (NMDA) receptors, but did not block responses to agonist application; indicating that t-ACPD is not a glutamate receptor antagonist; (2) t-ACPD decreased transmission in the absence of changes in postsynaptic cell properties. The t-ACPD-activated receptor appears to differ from previously identified presynaptic receptors. These findings indicate that t-ACPD activates a presynaptic receptor; most likely a glutamate receptor.
Lovinger
D M
DM
Section of Electrophysiology, National Institute on Alcohol Abuse and Alcoholism, Rockville, MD 20852.
D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects* / Q000502:physiology; D003515:Cycloleucine / Q000031:analogs & derivatives* / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D009498:Neurotoxins / Q000494:pharmacology*; D051381:Rats; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects; D017981:Receptors, Neurotransmitter / Q000187:drug effects; D013569:Synapses / Q000187:drug effects* / Q000502:physiology
D009498:Neurotoxins; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter; D003515:Cycloleucine; C036361:1-amino-1,3-dicarboxycyclopentane