Saralasin increases activity of hippocampal neurons inhibited by angiotensin II

Angiotensin II (AII) has previously been shown to specifically excite neurons in several areas of the rat brain including the hippocampus. Using a brain slice preparation for extra- and intracellular recording, we have found a small proportion of hippocampal neurons which were inhibited by AII. By applying saralasin to those pyramidal cells which are inhibited by AII, we have tested for excitatory effects of saralasin. The results showed that saralasin antagonizes AII whether its effects are inhibitory or excitatory. Saralasin alone generally decreases spontaneous activity and the results indicate that this effect may be due to an inhibition of endogenous brain angiotensin II.