Stereotaxic injections were performed as previously described 7 (link). Briefly, mice were anesthetized with xylazine (5mg per kg) and ketamine (75mg per kg) diluted in saline and placed into a stereotaxic apparatus (model 963, David Kopf Instruments, Tujunga, CA). For postoperative care, mice were injected intraperitoneally with meloxicam (0.5mg per kg). After exposing the skull via a small incision, a small hole was drilled for injection. A pulled-glass pipette was inserted into the brain and virus was injected by an air pressure system. A micromanipulator (model S48 stimulator, Grass Technologies, Rockland, MA) was used deliver the injection at 5nl per min and the pipette was withdrawn 5 min after injection. For electrophysiology and tracing, AAV1-CBA-Flex-ChR2(H134R)-mCherry (University of Pennsylvania School of Medicine, Philadephia, PA) was injected unilaterally into the arcuate (2–5nL; from Bregma, AP: −1.35mm, DV: −6.00mm, ML: ±0.2mm). For in vivo chemogenetic experiments, AAV8—hSyn-DIO-hM3Dq-mCherry (University of North Carolina Vector Core, Chapel Hill, NC) was bilaterally injected into the arcuate (2–5nL, coordinates as above). For profiling of Arc-ME RIP-Cre neurons, AAV8-EF1a-DIO-eYFP (University of North Carolina Vector Core, Chapel Hill, NC) was injected into arcuate (100nL, coordinates as above).