Next Article in Journal
Capturing the Alternative Cleavage and Polyadenylation Sites of 14 NAC Genes in Populus Using a Combination of 3′-RACE and High-Throughput Sequencing
Next Article in Special Issue
Recent Advances in Zirconium-89 Chelator Development
Previous Article in Journal
The Detailed Bactericidal Process of Ferric Oxide Nanoparticles on E. coli
Previous Article in Special Issue
[18F]fallypride-PET/CT Analysis of the Dopamine D2/D3 Receptor in the Hemiparkinsonian Rat Brain Following Intrastriatal Botulinum Neurotoxin A Injection
Article Menu
Issue 3 (March) cover image

Export Article

Open AccessReview
Molecules 2018, 23(3), 607;

PET Imaging of Microglial Activation—Beyond Targeting TSPO

Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
Department of Radiology & Nuclear Medicine, VU University Medical Center, 1081 HV Amsterdam, The Netherlands
Author to whom correspondence should be addressed.
Received: 14 February 2018 / Revised: 5 March 2018 / Accepted: 6 March 2018 / Published: 8 March 2018
(This article belongs to the Special Issue Current Aspects of Radiopharmaceutical Chemistry)
Full-Text   |   PDF [2825 KB, uploaded 8 March 2018]   |  


Neuroinflammation, which involves microglial activation, is thought to play a key role in the development and progression of neurodegenerative diseases and other brain pathologies. Positron emission tomography is an ideal imaging technique for studying biochemical processes in vivo, and particularly for studying the living brain. Neuroinflammation has been traditionally studied using radiotracers targeting the translocator protein 18 kDa, but this comes with certain limitations. The current review describes alternative biological targets that have gained interest for the imaging of microglial activation over recent years, such as the cannabinoid receptor type 2, cyclooxygenase-2, the P2X7 receptor and reactive oxygen species, and some promising radiotracers for these targets. Although many advances have been made in the field of neuroinflammation imaging, current radiotracers all target the pro-inflammatory (M1) phenotype of activated microglia, since the number of known biological targets specific for the anti-inflammatory (M2) phenotype that are also suited as a target for radiotracer development is still limited. Next to proceeding the currently available tracers for M1 microglia into the clinic, the development of a suitable radiotracer for M2 microglia would mean a great advance in the field, as this would allow for imaging of the dynamics of microglial activation in different diseases. View Full-Text
Keywords: positron emission tomography; microglia; neuroinflammation positron emission tomography; microglia; neuroinflammation

Graphical abstract

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
Printed Edition Available!
A printed edition of this Special Issue is available here.

Share & Cite This Article

MDPI and ACS Style

Janssen, B.; Vugts, D.J.; Windhorst, A.D.; Mach, R.H. PET Imaging of Microglial Activation—Beyond Targeting TSPO. Molecules 2018, 23, 607.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Molecules EISSN 1420-3049 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top