Imaging dopamine transmission in the frontal cortex: a simultaneous microdialysis and [(11)C]FLB 457 PET study Narendran R, Jedema HP, Lopresti BJ, Mason NS, Gurnsey K, Ruszkiewicz J, Chen CM, Deuitch L, Frankle WG, Bradberry CW. Abnormal dopamine levels in the brain?s prefrontal cortex have a negative effect on neurocognitive functions, such as memory, attention and problem-solving. Altered levels of the...