Selective uptake of exogenous catecholamines into nerve fibers in crustaceans. A fluorescense histochemical investigation

1. The depletion and uptake of exogenous catecholamines into the central nervous system of crustaceans were investigated by the Falck & Hillarp histochemical fluorescence method. 2. Depletion experiments with reserpine showed an almost complete disappearance of the fluorescence in the optic ganglia and the brain. 3. Some monoaminergic fibres in the photocerebrum and medulla terminals appeared to be reserpine-resistant. 4. Dopamine and α-methylnoradrenaline were actively taken up in vitro by monoaminergic structures after pretreatment with reserpine. 5. Benztropine and ouabain failed to inhibit this uptake. 6. 6-Hydroxydopamine had no effect on the fluorescence of the catecholaminergic neurones.