Figure 2.
Alternation of dopamine turnover in CamDAT mice. A, A schematic illustration of genetically engineered synapse in the striatum. Most dopamine released by presynaptic dopamine terminal is taken up by postsynaptic neurons expressing ectopic DAT. There is no VMAT2 expression in postsynaptic neurons. Uptaken dopamine is degraded in cytoplasm and produces quinine, H2O2, and other reactive species in postsynaptic neurons. B, After 3 weeks of DOX withdrawal, striatum and cortex dopamine content decreased and its metabolites, DOPAC and HVA, increased. In cerebellum, dopamine level was unchanged, whereas HVA and DOPAC levels increased. Note the differences in y-axis scales (n = 8 per group, unpaired t test, p < 0.001 for dopamine in striatum, p < 0.001 for DOPAC in striatum, p = 0.01 for HVA in striatum, p < 0.001 for dopamine in cortex, p = 0.018 for DOPAC in cortex, p < 0.001 for HVA in cortex, p = 0.015 for DOPAC in cerebellum, p = 0.013 for HVA in cerebellum).