EFFECTS OF A NITRIC-OXIDE SYNTHASE INHIBITOR ON NMDA RECEPTOR FUNCTION IN ORGANOTYPIC HIPPOCAMPAL CULTURES

Nitric oxide (NO) has been proposed to trigger long-term potentiation (LTP) at CA3 to CA1 synapses. We previously reported that NO synthesis inhibitors and blockers reduce an electrophysiological index of NMDA receptor activation in acute hippocampal slices. We now show that the NOS inhibitor, N-G-methyl-L-arginine (MLA), also reversibly prevents L TP induction in organotypic hippocampal slices and significantly reduc es a biochemical index of NMDA receptor function. These results furthe r indicate that MLA inhibits LTP induction by interfering with NMDA re ceptor functions. (C) 1997 Elsevier Science B.V.