EFFECT OF GLUTAMATE-RECEPTOR ANTAGONISTS ON EXCITATORY POSTSYNAPTIC POTENTIALS IN STRIATUM

Glutamate, as the main transmitter of corticostriatal pathway, has a c rucial role in the regulation of the activity of striatal cells as wel l as in pathogenesis of some diseases characterized by striatal malfun ction caused by overexcitation of neurons. In the present study, the r ole of ionotropic excitatory amino acid receptors was investigated in the striatal synaptic transmission. Using conventional intracellular e lectrophysiological methods in brain slices, we have investigated the effects of the N-methyl-D-aspartate (NMDA) antagonist (+/-) 2-amino-5- phosphono-valerate (APV) and the alpha-amino-3-hydroxy-5-methyl-isoxaz ole-4- propionate (AMPA) antagonist (+/-) carbamoyl-7,8-methylenedioxy -5H-2,3-benzodiazepine (GYKI 53655) on the excitatory postsynaptic pot entials (EPSPs) evoked by electrical stimulation of corpus callosum. T he AMPA antagonist significantly decreased electrically evoked respons es and a weak inhibition was also observed after APV application. The results were compared to similar data obtained in a cortical slice stu dy. (C) 1998 Elsevier Science Inc.