Impaired dopamine release and uptake in R6/1 Huntington's disease model mice.

Huntington's disease (HD) is a progressive, neurodegenerative movement disorder. Here, we used fast-scan cyclic voltammetry to measure dopamine release and uptake in striatal brain slices from R6/1 HD model mice. Peak dopamine release ([DA](max)) was significantly diminished in R6/1 mice (52% of wild-type at 24 weeks of age). Similarly, dopamine released per locally applied electrical stimulus pulse ([DA](p)), which is [DA](max) corrected for uptake and electrode performance, was also diminished in R6/1 mice (43% of wild-type by 24 weeks of age). Moreover, V(max), the maximum rate of dopamine uptake, obtained by modeling the stimulated release plots, was decreased at 16 and 24 weeks of age in R6/1 mice (51 and 48% of wild-type, respectively). Thus, impairments in both dopamine release and uptake appear to progress in an age-dependent manner in R6/1 mice.