1：Experimental Design and Method Selection:

The study used in vitro and in vivo experiments to characterize photoelectric stimulation. In vitro tests involved an agar brain phantom to measure electrochemical properties and temperature changes, while in vivo tests used transgenic mice to validate neural activation. Methods included chronoamperometry, chronopotentiometry, and fluorescence imaging with a 2-photon microscope.

2：Sample Selection and Data Sources:

In vitro samples consisted of a saline-based agar gel phantom with Rhodamine-B dye. In vivo samples were Thy1-GCaMP3 transgenic mice (N=5) with implanted carbon fiber electrodes in the visual or somatosensory cortex.

3：List of Experimental Equipment and Materials:

Equipment included a 2-photon microscope (Bruker), ultra-fast laser (Insight DS+; Spectra-Physics), photomultiplier tubes (Hamamatsu), objective lens (Nikon), hot plate (PC-410; Corning), temperature probe (50304; Stoelting), Autolab unit with ECD module (PGSTAT128N; Metrohm Autolab), carbon fiber electrodes (CarboStar-1; Kation Scientific), tungsten probe (Microprobes), carbon-fiber bundle counter (Cytec Thornel T650), Ag|AgCl reference electrode, and MATLAB for data analysis. Materials included agar gel, Rhodamine-B dye, saline, PBS, and GCaMP transgenic mice.

4：Experimental Procedures and Operational Workflow:

In vitro: The phantom was prepared, electrodes were inserted, and laser stimulation was applied with varying powers. Electrochemical measurements and temperature imaging were conducted. In vivo: Mice were anesthetized, craniotomy performed, electrodes implanted, and laser stimulation applied while imaging GCaMP fluorescence. Electrical stimulation controls were also performed.

5：Data Analysis Methods:

Data were analyzed in MATLAB. Temperature calibration used linear regression of Rhodamine-B fluorescence. Charge injection was calculated by numerical integration of current. Statistical significance was determined using Welch's T-test.