Alterations of 3,4-dihydroxyphenylethylamine and its metabolite 3,4-dihydroxyphenylacetic produced in rat brain tissues after systemic administration of saxitoxin

► Systemic STX administration in rat brain regions produces DA acute alterations. ► STX exert different effects on DA levels as a function of the dose. ► DOPAC increases may produced by activation of intraneuronal metabolism of DA to DOPAC. ► STX lethality is involved in both systems: central and peripheral cardio-respiratory.