Dg822

The LIFUS system consists of (1) two function generators (DG4162 and DG822, RIGOL, Beijing, China), (2) a custom-designed radio frequency amplifier (SWA400A, North Star, Shijia zhuang, China), (3) a 0.5MHz single element immersion transducer (V318, Olympus, Tokyo, Japan), and (4) a custom-designed acoustic collimator (Zhang et al., 2019 (link)). The schematic diagram of LIFUS system is shown in Figure 1A. The LIFUS parameters used in this study were as follows (shown in Figure 1B): center frequency = 0.5 MHz; pulse repetition frequency (PRF) = 2.0 kHz; the number of cycles = 150 (0.3 ms tone burst duration, TBD); the sonication duration (SD) = 0.5 s; the interstimulus interval (ISI) = 2 s, and the spatial peak temporal average intensity (I_spta) = 500 mW/cm². The targets of LIFUS are the bilateral mPFC. In addition, the LIFUS treatment was performed daily for 10 min on each side. During the LIFUS, all rats were mounted on the stereotaxic apparatus (RWD, Shenzhen, China) and anesthetized with 1% isoflurane (RWD, Shenzhen, China). Before applying the LIFUS, the hair on the bilateral mPFC was shaved. The other rats in either CON or VD groups underwent the same procedures including anesthesia but without LIFUS.

The electrical measurements were performed under ambient conditions at room temperature. All static behaviors of the photodetector were characterized by a semiconductor parameter analyzer (Keithley 4200) on a probe station (EVERBEING, C-4) in the dark and under illumination by different lasers: IR (2200, 1550, 1310, 1064, 980 and 808 nm), red (635 nm), green (532 nm). The device has been measured multiple times to ensure the consistency of the dark current, and the spot area of incident light was confirmed based on an optical microscope^{64 (link)}. The temporal responses of the device were recorded by a current meter after the light illumination switching on-off. The device 3 dB bandwidth is measured by modulating the laser switching frequency through a signal generator (RIGOL, DG822), and the modulated optical signal was focused on the photodetector through an optical microscope.