Kinetics of the evoked dopamine release and subsequent uptake in the parts of the rat striatum has not been studied sufficiently.
The aim of this study is to fill this gap and to investigate kinetics of dopamine release and uptake in vivo so that comparison can be made between the dorsal and the parts of the ventral striatum and with taking into account the overlapping electrochemical factors during the subsequent analysis of voltammetry recordings.
Materials and methods. The evoked wave of dopamine release and uptake in the dorsal striatum, core, and shell of the nucleus accumbens in the different groups of rats was recorded by the fast-scan cyclic voltammetry. Voltammetry recordings were subjected to principal component analysis and only the components associated with dopamine were taken for further analysis. The values of the parameters of the curves of dopamine release and uptake were defined. Then factor and variance analyses of the parameters were carried out.
Results. Factor analysis showed that the set of parameters of the dopamine wave can be reduced to the 4 factors that are comparable with the variables of the known from the literature mathematical model that describes the dopamine wave based on the MichaelisMenten equation. Two of the factors and the corresponding parameters of the dopamine curve differ within the dorsal and ventral striatum. Factor 1 is associated with the parameters HL, T80_20, T20_0, slope_T20T0, which are significantly larger in the core of the nucleus accumbens. Factor 3 is associated with the parameters T50_2, AUC, FWHH, T100_80 which are significantly less in the dorsal striatum.
Conclusions. The parameters of the curve of dopamine release and uptake are determined by 4 factors. Among the dopamine curve parameters, the best measures of the factors are T50_1, DAC, T100_80 и T20_0. The kinetics of stimulated dopamine release and uptake varies within the dorsal and ventral striatum. The final phase of dopamine uptake is slowed in the core of the nucleus accumbens in comparison to the shell, and the dorsal striatum. The slope of initial phase of dopamine uptake in the dorsal striatum is steeper.
Amphetamine augments vesicular dopamine release in the dorsal and ventral striatum through different mechanisms