Imaging Endogenous Neurotransmitters In Vivo with Positron Emission Tomography Displacement Studies

Positron Emission Tomography (PET) can be used to assess changes of endogenous neurotransmitters induced by pharmacological or physiological challenges and has been successfully applied to the study of the dopaminergic system, and, to a lower extent, to the serotonergic, opioid and cholinergic systems. This review first introduces the principles underlying the assessment of fluctuations of endogenous neurotransmitters with PET and then summarizes the main results obtained for dopamine, with emphasis on clinical studies. The studies of serotonin, opioid peptides, acetylcholine and the few studies dealing with other neurotransmitters (GABA, glutamate) are subsequently reviewed. In conclusion the chances of successfully imaging endogenous neurotransmitters with PET as well as possible trends for the future are discussed.