Histochemical fluorescence of tissue and brain monoamines: results in 18 minutes using the sucrose-phosphate-glyoxylic acid (SPG) method.

A rapid and sensitive modification of the glyoxylic acid method for the histofluorescent visualization of catecholamines and serotonin in mammalian brain, and other tissues, from cryostat sections is described. The procedure uses a phosphate-sucrose buffer solution combined with 1% glyoxylic acid. Tissues are reacted for 3 s at room temperature. Catecholaminergic cell bodies, pre-terminal, and terminal varicosities, well-localized and brightly fluorescent, are seen throughout cortical and subcortical structures. Serotoninergic cells show a weak fluorescence in rat and mouse brain but a strong fluorescence in dog and monkey brain.