PHARMACOLOGICAL PROPERTIES OF THE NMDA RECEPTOR INVOLVED IN SOMATOSTATIN RELEASE FROM CORTICAL-NEURONS

Glutamate increases somatostatin release from cultured cerebral cortical neurons, presumably through a N-methyl-D-aspartate (NMDA) receptor type. We report here that the NMDA response was potentiated by D-serine (10 μM) and that this potentiation was blocked by kynurenic acid (4-hydroxyquinoline-2-carboxylic acid; KYN). A higher concentration of D-serine (100 μM) reduced the antagonistic effect of KYN. Furthermore, the NMDA response exhibited another characteristic property of the NMDA receptor: it was decreased by low concentration of Zn2+ (50 μM). In contrast, Zn2+ slightly but significantly potentiated the quisqualate (QA)- and kainate (KA)-induced responses. © 1990.