The Molecular Imaging Branch (MIB) mainly aims to exploit positron emission tomography (PET) as a radiotracer imaging technique for investigating neuropsychiatric disorders, such as depression, schizophrenia and Alzheimer's disease. Fundamental to the mission of the MIB is the development of novel radiotracers that can be used with PET to deliver new and specific information on molecular entities and processes in the living human or animal brain (e.g. regional neuroreceptor concentrations, neurotransmitter synthesis, enzyme concentrations, regional metabolism, amyloid deposition). PET is uniquely powerful for this purpose provided that it can be coupled to appropriate radioactive probes (PET radiotracers). The chemical development of these probes is the key to exploiting the full potential of PET in neuropsychiatric research, but is also recognized as being highly challenging and demanding. The PET Radiopharmaceutical Sciences Section of the MIB opened in 2002 and is now fulfilling a pressing need for a concerted effort on PET radiotracer discovery (a process that has some parallels with drug discovery). The laboratories are equipped and functioning with modern facilities for medicinal/organic chemistry and automated radiochemistry with positron-emitting carbon-11 (t1/2 = 20 min) and fluorine-18 (t1/2 = 110 min). These short-lived radioisotopes are produced on a daily basis from the adjacent cyclotrons of the NIH Clinical Center in support of this research program. The scientific program focuses on developing novel radiotracers for brain receptors or proteins implicated in neuropsychiatric disorders [e.g. cannabinoid (CB-1), serotonin (5-HT1A), alpha-2, CRF, NET, PBR, glutamate (mGluR5) and beta-amyloid protein deposits]. Initial progress in some of these areas (e.g. NET, 5-HT1A, CB-1, PBR and mGluR5)continues to be encouraging for developing successful radioligands for eventual brain imaging in human subjects in support of clinical research. Thus many candidate radioligands were prepared and then found in PET experiments to give detectable receptor-specific signals in animals in vivo with PET. Methodology underpinning these developments was also advanced in areas such as the development of new radioactive labeling agents, polymer-supported labeling reactions, microwave-enhanced chemistry and radiochemistry and the development of micro-reactors for the miniaturization of radiochemistry. These advances are seen as vital for expanding the scope for generating new radiotracers and for facilitating their applications. New analytical methods, based on for example liquid chromatography coupled to mass spectrometry, have also been developed and exploited to understand the biochemical fate of radiotracers in vivo - information which is need to fully understand the results from PET experiments and to derive meaningful measures, such as brain receptor concentrations. Productive collaborations have been established with external academic chemistry and medicinal chemistry laboratories, nationally and internationally, and also with pharmaceutical companies through a series of CRADAs (Cooperative Research and Development Agreements). Productive collaborations also exist with other centers working with PET and its associated radiochemistry and radiotracer development. This laboratory also produces several radiotracers for regular PET investigations in animals {e.g. [11CCFT (for dopamine transporters) [11C]NNC 112 (for dopamine-type-1 receptor), [18F]SPA-RQ (for NK1-receptor), [18F]Fallypride (for dopamine type-2 receptor imaging), [11C]Rolipram (for PDE4 enzyme)} and some of these have been approved by the FDA and are available for brain imaging in human subjects and clinical research protocols.

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
Intramural Research (Z01)
Project #
1Z01MH002793-04
Application #
7136367
Study Section
(MIB)
Project Start
Project End
Budget Start
Budget End
Support Year
4
Fiscal Year
2005
Total Cost
Indirect Cost
Name
U.S. National Institute of Mental Health
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Kannan, Pavitra; Pike, Victor W; Halldin, Christer et al. (2013) Factors that limit positron emission tomography imaging of p-glycoprotein density at the blood-brain barrier. Mol Pharm 10:2222-9
Skinbjerg, Mette; Liow, Jeih-San; Seneca, Nicholas et al. (2010) D2 dopamine receptor internalization prolongs the decrease of radioligand binding after amphetamine: a PET study in a receptor internalization-deficient mouse model. Neuroimage 50:1402-7
Chun, Joong-Hyun; Lu, Shuiyu; Lee, Yong-Sok et al. (2010) Fast and high-yield microreactor syntheses of ortho-substituted [(18)F]fluoroarenes from reactions of [(18)F]fluoride ion with diaryliodonium salts. J Org Chem 75:3332-8
Lu, Shuiyu; Hong, Jinsoo; Itoh, Tetsuji et al. (2010) [carbonyl-C]Benzyl acetate: automated radiosynthesis via Pd-mediated [C]carbon monoxide chemistry and PET measurement of brain uptake in monkey. J Labelled Comp Radiopharm 53:548-551
Itoh, Tetsuji; Abe, Kohji; Hong, Jinsoo et al. (2010) Effects of cAMP-dependent protein kinase activator and inhibitor on in vivo rolipram binding to phosphodiesterase 4 in conscious rats. Synapse 64:172-6
Ozaki, Harushige; Zoghbi, Sami S; Hong, Jinsoo et al. (2010) In vivo binding of protoporphyrin IX to rat translocator protein imaged with positron emission tomography. Synapse 64:649-53
Seneca, Nicholas; Zoghbi, Sami S; Shetty, H Umesha et al. (2010) Effects of ketoconazole on the biodistribution and metabolism of [11C]loperamide and [11C]N-desmethyl-loperamide in wild-type and P-gp knockout mice. Nucl Med Biol 37:335-45
Lu, Shuiyu; Liow, Jeih-San; Zoghbi, Sami S et al. (2010) Evaluation of [C]S14506 and [F]S14506 in rat and monkey as agonist PET radioligands for brain 5-HT(1A) receptors. Curr Radiopharm 3:9-18
Lu, Shuiyu; Chun, Joong-Hyun; Pike, Victor W (2010) Fluorine-18 chemistry in micro-reactors. J Labelled Comp Radiopharm 53:234-238
Lu, Shuiyu; Pike, Victor W (2010) Synthesis of [F]Xenon Difluoride as a Radiolabeling Reagent from [F]Fluoride Ion in a Micro-reactor and at Production Scale. J Fluor Chem 131:1032-1038

Showing the most recent 10 out of 66 publications