Uptake and storage of catecholamines in rabbit brain after chronic reserpine treatment

The brains of rabbits treated chronically with small doses of reserpine have been examined by the histochemical fluorescence method for dopamine, noradrenaline and 5-hydroxytryptamine. Measurements were made 4 and 24 hr after the last reserpine injection both in vivo and in vitro. Evidence has been obtained that the small functionally-important pool of amine can be directly visualized in the fluorescence microscope. It was found to be present intraneuronally, probably localized to amine storage granules. The degree of functional recovery was correlated with the recovery, as shown by the increased fluorescence, of a small intraneuronal pool of amine and with the ability of amine storage granules to take up monoamines.