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

To confirm that dopamine neurons were transfected with ChR2 in animals used for optogenetic dopamine stimulation experiments, we perfused DAT-Cre mice that had been injected into the SNc with Cre-dependent ChR2-EYFP virus with 4% paraformaldehyde in PBS and post-fixed brains overnight. Coronal sections that included the injection site (SNc) and imaging site (dorsal striatum) were cut at 50 µM and immunolabeled using antibody against tyrosine hydroxylase (TH) (rabbit anti-TH 1:1000, Millipore), the rate-limiting enzyme for catecholamine synthesis. Goat anti-rabbit Dylight 594 secondary antibody (1:1000, Invitrogen) was used to visualize TH. Image acquisition was performed on a Zeiss Axio ScanZ.1 using a 5x objective.