AKT1 and diabetes mellitus: We have shown previously that amphetamine (AMPH)-evoked striatal DA release measured by high-speed chronoamperometry (HSCA) is a reporter of striatal DAT activity in vivo, and that, consonant with decreased DAT surface expression and activity, the functional magnetic resonance imaging (fMRI) response to AMPH is blunted with insulin depletion and subsequent reduction of downstream Akt (protein kinase B) signaling in a rat model of Type 1 diabetes mellitus [5].