Angiotensin II modulation of glutamate excitation of locus coeruleus neurons

The effects of iontophoretically applied angiotensin II (AII) have been tested on intracellularly recorded locus coeruleus neurons in an in vitro brain slice preparation. In most neurons, AII strongly depressed the depolarizing effect of l-glutamate in the absence of other effects on membrane properties. This action was specific, in that AII had no effect on depolarizations caused by current injection or application of acetylcholine, and it was blockable by the AII antagonist saralasin. These results appear to demonstrate a potent and previously unreported neuromodulatory action of AII in the central nervous system.