Abstract
The effect of aging on the levels of dopamine (DA) in striatum and noradrenaline (NA) in cerebral cortex, cerebellum, hypothalamus, midbrain and pons-medulla from young adult and five groups of aging rats was evaluated. Determinations of the levels of these amines were conducted. Age-related changes which commenced at 12 months were observed in specific brain regions. The endogenous content of NA decreased significantly in hypothalamus, midbrain, and pons-medulla when compared with the same regions from young adult animals. These results show that central noradrenergic system is markedly vulnerable to the aging process in rats.