[Capillary fluorescence in brain smears]

A histochemical technique for the detection of catecholamines accumulated by endothelial cells of the capillaries of rat brain after L-DOPA treatment is reported. The main point is to obtain smaers from the cut surface of the brain without damage to the capillaries. Catecholamine raction in the latter, then should be examined by the Fakk's technique. The method described is very quick and gives an exact localization of catecholamines accumulated in the wall of the cerebral cpaillaries. It is a useful tool for the investigation of the monoaminoerg brain-blood barriere.