Distribution of adrenaline-synthesizing enzyme activity in the human brain.

A study of the distribution of phenylethanolamine-N-methyl-transferase (PNMT) activity in normal human brain is presented. After a preliminary dissection to separate brain tissue for formalin fixation and tissue designed for biochemical studies, the hemi-brain stem is cut in slices by hand and a cerebral hemisphere is cut on a cyromicrotome. "Punches" are made with an operating microscope. The dissection method was used to study the distribution of PNMT activity in 117 "punches" made on 21 slices obtained from 5 normal human brains. The caudo-rostral distribution of PNMT activity in C1 and C2 groups was found to be identical in each brain. The distribution of PNMT activity was found to be similar to that in the rat, but, in addition, important activity was found in the substantia nigra, internal pallidium and nucleus accumbens.