A SIMPLE COMBINED TECHNIQUE OF HISTOFLUORESCENCE AND PEPTIDE-IMMUNOCYTOCHEMISTRY FOR THE ANALYSIS OF THE COEXISTENCE OF MONOAMINE AND PEPTIDE IN BRAIN-STEM NEURONS

Using a combination of the pretreatments of colchicine and nialamide, a monoamine oxidase inhibitor, we developed a simple technique for examining the coexistence of monoamines and peptides in brain neurons. The fixation used in this study was the modified ''Faglu'' method, with which we detected intense green catecholamine fluorescence and yellow serotonin fluorescence in the same tissue section. Then we applied immunocytochemistry to these sections to show the tyrosine hydroxylase immunoreactivity in catecholamine fluorescent cells, and serotonin immunoreactivity in serotonin fluorescent cells. By applying anti-peptide antisera in the immunocytochemical step, we could detect neurotensin immunoreactivity in catecholamine-fluorescent cell bodies in the raphe dorsalis and substance P-immunoreactivity in serotonin-fluorescent cell bodies in the raphe pallidus. These findings proved the specificity and the usefulness of this method for investigating the coexistence of monoamines and peptides.