Understanding Dopamine Mechanisms in Cocaine Addiction Using AMPT and Methylphenidate With [11C]RAC/[11C]PHNO PET

Summary

Studies using positron emission tomography (PET) have been used with great success in demonstrating specific abnormalities in several facets of dopaminergic system function in human populations (Narendran and Martinez 2009). Among the first, most consistent, and broadly replicated of such findings in drug- (including cocaine) dependent individuals has been the reduction in subcortical (striatal) D2/3 receptors as imaged, most commonly, by the reversible, non-selective, D2/3 receptor antagonist radiotracer, \[11C\]raclopride. Certain dissociations on D2/3 availability by radioligand (\[11C\]raclopride vs. \[11C\]PHNO) and by brain region (striatum vs. SN; terminal vs. somatodendritic, respectively) are poorly understood in relationship to prior antagonist tracer results. In the current study the investigators will use pharmacological interventions (AMPT and methylphenidate) with both antagonist and agonist radiotracers to experimentally reconcile these discordant findings and clarify potential mechanistic inter-relationships.

Timeline

Start

2014-05

Primary completion

2014-06-09

Completion

2014-06-09

Drugs

Indications