Abstract

The precise pattern of dopamine fluctuation over time in the presence of a rewarding stimulus may be an important aspect of the addictive liability of the stimulus. Cigarette smoking is one such stimulus but synaptic dopamine in the striatum is elevated for only a short time following cigarette smoking. Because the smoking-induced fluctuations are short-lived (on the order of minutes) they cannot be detected or measured reliably with standard PET kinetic models that presume time-invariant kinetic parameters and steady levels of endogenous neurotransmitters. Our group has been working on models for extracting temporal information about dopamine levels from dynamic PET data. Our model (‘ntPET’) include time-varying components to account for dopamine fluctuations. When applied at the voxel level (‘lpntPET’), the model outputs can be visualized as a ‘dopamine movie’ which envision as a spatio-temporal signature of addiction. This presentation will explore the rationale for, and creation of dopamine movies as a new functional imaging endpoint. Data will be presented from a preliminary study of men and women smoking cigarettes in the PET scanner. We believe our findings may help to shed light on known behavioral differences between men and women smokers.