Stimulation of noradrenaline release in the cerebral cortex via presynaptic N-methyl-D-aspartate (NMDA) receptors and their pharmacological characterization.

In rat brain cortex synaptosomes superfused with Mg(2+)-free solution containing glycine, [3H]noradrenaline (3H-NA) release evoked by NMDA was abolished by omission of glycine or Ca2+ and inhibited by Mg2+, the competitive and noncompetitive NMDA receptor antagonists CGP 37849 and dizocilpine (MK-801), respectively, as well as by ethanol, but was not affected by tetrodotoxin. The 3H-NA release evoked by L-glutamate was also competitively inhibited by CGP 37849. In conclusion, presynaptic NMDA receptors mediate stimulation of NA release. Ethanol probably acts at this receptor system.