Imaging Striatal Dopamine Release Using a Non-Genetically Encoded Near-Infrared Fluorescent Catecholamine Nanosensor

Abraham G. Beyene; Kristen Delevich; Jackson Travis Del Bonis-O’Donnell; David J. Piekarski; Wan Chen Lin; A. Wren Thomas; Sarah J. Yang; Polina Kosillo; Darwin Yang; Linda Wilbrecht; Markita P. Landry

In ex vivo brain slices (dorsal striatum), application of quinpirole (1 µM) abolished nIRCat fluorescent transients in response to single electrical pulse stimulation which was rescued following 15-minute drug wash-out (Figure 4b, 4c) . Conversely, application of sulpiride (1 µM) significantly increased nIRCat ∆F/F (Figure 4d, 4e) . The effects of quinpirole and sulpiride were reproducible in n=3 biological replicates (Figure 4f) . Importantly, the effects of D2 receptor pharmacology on nIRCat fluorescence modulation by dopamine were absent in vitro and only present in brain tissue. In brain tissue, presynaptic dopamine receptors play a critical role in regulating dopamine release, and our results are consistent with powerful inhibition of dopamine efflux by the DRD2 agonist quinpirole and facilitation of dopamine efflux by the DRD2 antagonist sulpiride.