REAGENT or RESOURCE	SOURCE	IDENTIFIER
Antibodies
anti-GFP rabbit polyclonal Alexa Fluor™-488 conjugate	Invitrogen	Cat#A-21311
Anti-Tryptophan Hydroxylase/Tyrosine Hydroxylase/Phenylalanine Hydroxylase Antibody, clone PH8	Millipore Sigma	Cat#MAB5278
Cy5 AffiniPure Goat Anti-Rabbit IgG (H+L) (min X Hu, Ms, Rat Sr Prot)	Jackson ImmunoResearch Laboratories	Cat#111-175-144
goat anti-rabbit IgG (H+L) Cross-Adsorbed Secondary Antibody AlexaFluor 555	Invitrogen	Cat#A-21428
anti-serotonin (5-HT) transporter (602-622) rabbit polyclonal antibody	Millipore Sigma	Cat#PC177L-100UL
Bacterial and Virus Strains
AAVDJ-DIO-EF1a-GCaMP6m	Stanford	Cat#GVVC-AAV-092
AAV9-CAG-flex-GCaMP6m-WPRE-S	U Penn Vector Core	Cat#AV-9-PV2817
AAV2-retro-DIO-EF1a-GCaMP6m	Stanford	N/A, custom preparation
AAV5-flex-GFP	UNC Gene Therapies	Cat#AV4531
AAV9-CAG-flex-tdTomato-WPRE	U Penn Vector Core	Cat#AV-9-ALL864
AAVDJ-hSyn-GCaMP6m	Stanford	Cat#GVCC-AAV-095
Chemicals, Peptides, and Recombinant Proteins
Sucrose	Sigma-Aldrich	Cat#S7903-5KG
Quinine hydrochloride dihydrate	Sigma-Aldrich	Cat#Q1125-10G
Vectashield Antifade Mounting Medium	Vector Laboratories	Cat#H-1000
Experimental Models: Organisms/Strains
C57BL/6J mice	Jackson Laboratory	Cat#000664; RRID:SCR_004633; https://www.jax.org/index.html
B6.129(Cg)-Slc6a4tm1(cre)Xz/J (SERT-Cre) mice	Jackson Laboratory	Cat#014554; https://www.jax.org/index.html
Software and Algorithms
Ethovision XT11	Noldus	http://www.noldus.com; RRID:SCR_000441
Inscopix Data Processing Software	Inscopix	https://www.inscopix.com
Observer XT	Noldus	http://www.noldus.com/human-behavior-research/products/the-observer-xt
MATLAB	Mathworks	https://www.mathworks.com/products/matlab/; RRID:SCR_001622
CNMF-E	GitHub	https://github.com/zhoupc/CNMFE
Image J	Fiji	https://imagej.nih.gov/ij/
CalTracer 3 (beta)	Yuste Lab	http://www.columbia.edu/cu/biology/faculty/yuste/methods