PIXSIC, a Pixelated β-Sensitive Probe for Radiopharmacological Investigations in Rat Brain: Binding Studies with [F]MPPF.

Purpose: The aim of this work was to demonstrate the pharmacokinetic potential of a wireless pixelated β-sensitive probe (PIXSIC). Procedures: The binding of 2′-methoxyphenyl-( N-2′-pyridinyl)-p-[F]fluoro-benzamidoethylpiperazine ([F]MPPF), a 5-HT serotonin receptor radiopharmaceutical, was measured in anesthetized rats and compared to microPET data. The effects of a 5-HT antagonist injection on in vivo [F]MPPF binding were monitored by PIXSIC. Results: PIXSIC allowed differentiating the radioactive kinetics according to the location of its pixels in the hippocampus, cortex, corpus callosum, and cerebellum. The device accurately detected the changes in [F]MPPF binding, after 5-HT antagonist blockade. The time-activity curves were reproducible and consistent with kinetics obtained simultaneously with a microPET camera. Conclusions: These results demonstrate the ability of the PIXSIC device to record reliably the binding of PET ligands, with a high spatiotemporal resolution in anesthetized rodents. These first in vivo results are a key stage on the path to its implementation in awake freely moving animals. [ABSTRACT FROM AUTHOR]