International Journal of Molecular Sciences Review GPCR-Based Dopamine Sensors—A Detailed Guide to Inform Sensor Choice for In Vivo Imaging 1,2, 3,4, 4,5, Marie A. Labouesse y, Reto B. Cola y and Tommaso Patriarchi * 1 Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA;
[email protected] 2 Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA 3 Anatomy and Program in Neuroscience, University of Fribourg, 1700 Fribourg, Switzerland;
[email protected] 4 Institute of Pharmacology and Toxicology, University of Zurich, 8057 Zurich, Switzerland 5 Neuroscience Center Zurich, University and ETH Zurich, 8057 Zurich, Switzerland * Correspondence:
[email protected]; Tel.: +41-044-635-59-21 These authors share equal co-first contribution. y Received: 10 September 2020; Accepted: 26 September 2020; Published: 28 October 2020 Abstract: Understanding how dopamine (DA) encodes behavior depends on technologies that can reliably monitor DA release in freely-behaving animals. Recently, red and green genetically encoded sensors for DA (dLight, GRAB-DA) were developed and now provide the ability to track release dynamics at a subsecond resolution, with submicromolar affinity and high molecular specificity. Combined with rapid developments in in vivo imaging, these sensors have the potential to transform the field of DA sensing and DA-based drug discovery. When implementing these tools in the laboratory, it is important to consider there is not a ‘one-size-fits-all’ sensor. Sensor properties, most importantly their affinity and dynamic range, must be carefully chosen to match local DA levels.