 Certain neural tracts, the retina, and in both atria and ventricles in the hearts are now being elucidated as sites of PNMT expression.Epinephrine is produced in small groups of neurons in the human brain which express PNMT; these neurons project from a nucleus that is adjacent (ventrolateral) to the area postrema and from a nucleus in the dorsal region of the solitary tract.PNMT's normal function and defects are associated with multiple diseases and disorders.