TY - JOUR T1 - The Potential of a Radiosensitive Intracerebral Probe to Monitor <sup>18</sup>F-MPPF Binding in Mouse Hippocampus In Vivo JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1155 LP - 1161 DO - 10.2967/jnumed.107.050047 VL - 49 IS - 7 AU - Aurélie Desbrée AU - Mathieu Verdurand AU - Jeremy Godart AU - Albertine Dubois AU - Roland Mastrippolito AU - Frédéric Pain AU - Laurent Pinot AU - Thierry Delzescaux AU - Hirac Gurden AU - Luc Zimmer AU - Philippe Lanièce Y1 - 2008/07/01 UR - http://jnm.snmjournals.org/content/49/7/1155.abstract N2 - As mouse imaging has become more challenging in preclinical research, efforts have been made to develop dedicated PET systems. Although these systems are currently used for the study of physiopathologic murine models, they present some drawbacks for brain studies, including a low temporal resolution that limits the pharmacokinetic study of radiotracers. The aim of this study was to demonstrate the ability of a radiosensitive intracerebral probe to measure the binding of a radiotracer in the mouse brain in vivo. Methods: The potential of a probe 0.25 mm in diameter for pharmacokinetic studies was assessed. First, Monte Carlo simulations followed by experimental studies were used to evaluate the detection volume and sensitivity of the probe and its adequacy for the size of loci in the mouse brain. Second, ex vivo autoradiography of 5-hydroxytryptamine receptor 1A (5-HT1A) receptors in the mouse brain was performed with the PET radiotracer 2′-methoxyphenyl-(N-2′-pyridinyl)-p-18F-fluorobenzamidoethylpiperazine (18F-MPPF). Finally, the binding kinetics of 18F-MPPF were measured in vivo in both the hippocampus and the cerebellum of mice. Results: Both the simulations and the experimental studies demonstrated the feasibility of using small probes to measure radioactive concentrations in specific regions of the mouse brain. Ex vivo autoradiography showed a heterogeneous distribution of 18F-MPPF consistent with the known distribution of 5-HT1A in the mouse brain. Finally, the time–activity curves obtained in vivo were reproducible and validated the capacity of the new probe to accurately measure 18F-MPPF kinetics in the mouse hippocampus. Conclusion: Our results demonstrate the ability of the tested radiosensitive intracerebral probe to monitor binding of PET radiotracers in anesthetized mice in vivo, with high temporal resolution suited for compartmental modeling. ER -