Tritiated norepinephrine: release from brain slices by electrical stimulation.

Slices of rat brain and heart that had concentrated H(3)-norepinephrine were superfused and electrically stimulated. Stimulation induced a marked release of H(3)-norepinephrine with a threshold and a maximum repsonse. Release also occurred with increased concentrations of potassium, presumably due to neuronal depolarization. Inhibition of electrically induced release occurred with low calcium and with chlorpromazine and pentobarbital.