Microdetermination of norepinephrine, 3,4-dihydroxyphenylethylamine, and 5-hydroxyyptamine from single extracts of specific rat brain areas

The conditions reported by Toru and Aprison (4) for extracting ACh in specific brain areas were tested to determine whether 5-HT, NE, and dopamine were also extracted quantitatively. It was found that the extraction solution used in brain ACh determinations, 15% 1N formic acid plus 85% acetone ($\text{v}\text{v}$), was also excellent for extraction of NE, 5-HT, and dopamine from different brain areas. Experimental conditions are given for the microdetermination of all three biogenic amines in such a single extract of a specific rat brain area. The methods are based on previously published fluorometric methods; these have been scaled down or modified slightly to permit analyses of small aliquots. The concentration of 5-HT, NE, and dopamine in the telencephalon, diencephalon plus mesencephalon, pons plus medulla oblongata, and cerebellum of the rat are also reported using the described micromethods after extraction with 15% 1 N formic acid plus 85% acetone ($\text{v}\text{v}$).