Abstract
Fast cyclic voltammetry at carbon fibre microelectrodes was used to measure electrically stimulated dopamine release in the striatum of anaesthetised young, adult, and senescent Wistar rats. By alteration of stimulus parameters and by use of nomifensine, investigation of dopamine release, uptake, and compartmentalisation within the striatum was posible. The rate of dopamine release was highest in adult rats. No difference was observed between young and old animals. The size of the releasable (newly synthetized) dopamine pool was also largest in the adult group, again with no significant difference occurring between young and aged rats. The rate of dopamine uptake was highest in adult rats, although, when expressed as a function of dopamine release, young and aged rats showed proportionally greater uptake. Nomifensine (10 mg/kg i.p.] increased dopamine release by mobilising the inert storage pool to a greater extent in young than in adult rats, whereas the effect of the drug on uptake was similar in all groups. The functional significance and possible explanation of these results are discussed.