All animal studies were approved by the Washington University School of Medicine Animal Studies Committee (protocol #20160217) under guidelines and regulations consistent with the guide for the Care and Use of Laboratory Animals, Public Health Service Policy on Humane Care and Use of Laboratory Animals, the Animal Welfare Act and Animal Welfare Regulations, and ARRIVE guidelines. Male C57/BL6 mice (, 5 to 7 weeks, 26 to 32 g, Jackson Laboratories, Bar Harbor, Maine) were used for imaging. At least 1 day before imaging, mice were anesthetized with 2% isoflurane for hair removal using Veet. For imaging, mice were anesthetized with a ketamine–xylazine mixture ( ketamine, xylazine) at with body temperature maintained at 37°C using an electric heating pad (mTCII, Cell Microcontrols, Norfolk, Virginia). Mice were secured using a Dazai imaging sled (Dazai Research Instruments, Toronto, Canada), with Velcro straps behind the ears and over the nose to prevent motion artifacts due to breathing. Each mouse was imaged for 35 min. Forepaw electrical stimulation was performed using A-M Systems Model 2100 Isolated Pulse Stimulator (A-M Systems, Sequim, Washington), with trigger sequences syncing stimulation, camera frames, and DMD patterns created in MATLAB (Mathworks, Natick, Massachusetts) and generated using a National Instruments Analog Output DAQ (National Instruments, Austin, Texas).