FACILITATION OF RESPONSES TO AMPA BUT NOT KAINATE BY CYCLOTHIAZIDE INPRIMATE SOMATOSENSORY THALAMUS

This study examines the possibility of multiple ionotropic non-N-methy l-D-aspartate (NMDA) receptors in the chief sensory nuclei of the prim ate thalamus. Cyclothiazide, an antagonist of rapid desensitization of non-NMDA receptors, is shown to produce a facilitation of responses t o the synthetic agonist lpha-amino-3-hydroxy-5-methylisoxazole-4-propi onic acid (AMPA) but not kainate or NMDA in cells of the ventral poste rior lateral and medial thalamic nuclei in the anesthetized monkey. Th ese differential effects suggest the presence of multiple ionotropic n on-NMDA excitatory amino acid receptors in the primate ventral posteri or (VP) thalamus. Cyclothiazide-sensitive excitatory amino acid recept ors have important roles in mechanisms of plasticity and excitotoxicit y in other neural systems and so may mediate similar mechanisms in the somatosensory thalamus. (C) 1998 Published by Elsevier Science Irelan d Ltd.