Caloric restriction enhances evoked DA overflow in striatum and nucleus accumbens of aged Fischer 344 rats

Previous studies have shown deficits in DA neuronal systems in senescence. Other studies indicate that prolonged dietary restriction can attenuate many of the detrimental effects of age. We have shown previously using in vivo electrochemistry that K⁺-evoked striatal DA overflow decreases as a function of age. This was a regional effect that appeared to be due to functional changes in DA neurons, rather than a decrease in the storage and synthesis of DA. In the present studies, we used in vivo electrochemistry to investigate the effects of caloric restriction on age related decreases in K⁺-evoked DA overflow along a dorsal to ventral axis in the striatum of aged female Fischer 344 rats. Aged (26-28-month-old) diet restricted animals (DRF) showed evoked DA overflow that was significantly greater in amplitude and duration compared to aged (26-28-month-old) ad lib fed animals (ALF). These results provide additional evidence that decreased DA neuronal function resulting from age is improved by caloric restriction.