[Selective reduction by serotonin, of neuronal excitation in the locus coeruleus evoked by glutamate].

In the rat, iontophoretically applied serotonin substantially attenuated the excitation of locus coeruleus neurons evoked by iontophoretic glutamate but not that elicited by acetylcholine. These results occurred independently of serotonin's variable effects on spontaneous discharge, and indicate a neuromodulatory role of serotonin in locus coeruleus.