Correlation among [18F]FDOPA-PET, biochemical measurements, and behavioral index. (a) The striatal levels of DA and its metabolites (% of the contralateral side value) vs. the Ki (% of the contralateral side value) in the PET study. 6-OHDA: 0 μg, n = 3; 7, 14, 28 μg, n = 5. (b) Ki (% of the contralateral side value) vs. the logarithm of the number of methamphetamine-induced rotations. 6-OHDA: 0 μg, n = 3; 7, 14, 28 μg, n = 5. (c) The striatal levels of DA and its metabolites (% of the contralateral side value) vs. the logarithm of the number of methamphetamine-induced rotations. 6-OHDA: 0 μg, n = 3; 7, 14, 28 μg, n = 5. Symbols show the values of 0 μg (open circle), 7 μg (closed circle), 14 μg (closed square), and 28 μg (closed triangle) for each individual.