Effect of amphetamine on extrastriatal D2 dopamine receptor binding in the primate brain: A PET study

✍ Scribed by Yuan-Hwa Chou; Christer Halldin; Lars Farde

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 237 KB
• Volume: 38
• Category: Article
• ISSN: 0887-4476
• DOI: 10.1002/1098-2396(200011)38:2<138::aid-syn4>3.0.co;2-7

✦ Synopsis

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C]raclopride binding to D2 dopamine receptors in the striatum is sensitive to drug-induced changes of endogenous dopamine concentration. We recently developed the new radioligand [ 11 C]FLB 457, which is suitable for positron emission tomography (PET) studies of extrastriatal D2 dopamine receptors. The purpose of this PET study was to examine the effect of amphetamine on [ 11 C]FLB 457 binding in extrastriatal regions. Each of three cynomolgus monkeys was examined at baseline conditions, 15 min and 3 h after I.V. injection of amphetamine (2 mg/kg). The effect of amphetamine was calculated from the ratio of specific [ 11 C]FLB 457 binding to the binding in the cerebellum, a region which was used as reference for free and nonspecific binding in the brain. The changes of the ratio in the striatum, the thalamus, and the neocortex were between Ϫ1.2% and Ϫ15.5% at 15 min and Ϫ2.1% and Ϫ16.3% at 3 h, respectively, after amphetamine administration. The reductions of the binding ratios in the extrastriatal regions are similar to those reported for [ 11 C]raclopride binding in the striatum. These data in a limited series of monkeys suggest that [ 11 C]FLB 457 binding to D2 dopamine receptors in extrastriatal regions is sensitive to changes in the concentration of endogenous dopamine. Synapse 38:138 -143, 2000.