Radioenzymatic Micromethods for the Quantitation of Biogenic Amines in Brain

The biogenic amines 5-hydroxytryptamme (5-HT; serotonin), dopamine (DA), noradrenaline (NA), adrenaline (A), and histamine (HA) are present in mammalian brain, in which they play fundamental roles as neurotransmitters. Concentrated in a few brain nuclei and tracts (Dahlstrom and Fuxe, 1964 ; Fuxe, 1965 ), they are involved in the regulation of specific brain functions. Their study requires selective dissection techniques to isolate discrete brain areas and sensitive quantitative microtechniques for the determination of amine levels in submilligram amounts of tissue. This is now possible with the combination of micro-anatomical dissection procedures (the “punch” technique) and the development of radioenzymatic micromethods.