AAV2/5-EF1a-DIO-hChR2 (H134R)-eYFP was obtained from the UNC Vector Core (Chapel Hill, NC). The pAAV-hSyn-FLEx-mGFP-2A-Synaptophysin mRuby plasmid was a gift from Liqun Luo and was obtained from Addgene (Addgene plasmid #71760; http://n2t.net/addgene:71760; RRID: Addgene_71760). The pHelper and pAAV-RC plasmids used for AAV preparation were generous gifts of Ralph DiLeone. Envelope-A pseudotyped, G-deleted rabies virus expressing mCherry (RvdG-mCherry) (Osakada et al., 2011 (link)), AAV2/1-CMV-eSyn-DIO-TVA950-eYFP (1.13E+12 GC/ml) and AAV2/1- EF1α -DIO-H2B-tagBFP-Flagx3-T2Am-cB19G (1.01E+11 GC/ml) (Faget et al., 2016 (link)) were from the Salk Institute Gene Transfer Targeting and Therapeutics Core (La Jolla, CA). Sterile bacteriostatic saline, ketamine, xylazine, and meloxicam were from Patterson Veterinary Supply, Inc. (Sterling, MA). The fluorescent RetroBeads were from Lumafluor, Inc. Neurotrace fluorescent Nissl stain was from Thermo-Fisher (Waltham, MA).