fig3

Figure 3. PPF behaviors of (A₁) the pristine devices, and those after the treatment of H₂S, and (A₂) the pristine devices, and those after the treatment of H₂O₂; The inset shows the PPF indices for different pulse intervals (1 s, 15.17 mW·cm^-2 light pulses). SIDP emulation of the device after the treatment of (B₁) H₂S and (B₂) H₂O₂ with light intensities ranging from 2.013 mW·cm^-2 to 82.38 mW·cm^-2 (1 s light pulses); SDDP emulation of the device after treatment of (C₁) H₂S and (C₂) H₂O₂ with pulse durations ranging from 0.5 s to 8 s (15.17 mW·cm^-2 light pulses); SNDP emulation of the device after treatment of (D₁) H₂S and (D₂) H₂O₂ with 2 to 10 pulses (15.17 mW·cm^-2 light pulses); SRDP emulation of the device after treatment of (E₁) H₂S and (E₂) H₂O₂ with light pulse intervals ranging from 10 s to 2 s (1 s, 15.17 mW·cm^-2 light pulses); (F₁) H₂S-mediated synaptic plasticity; (F₂) H₂O₂-mediated synaptic plasticity (1 s, 15.17 mW·cm^-2 light pulses). ΔPSC: Postsynaptic current response; PPF: paired-pulse facilitation; H₂S: hydrogen sulfide; H₂O₂: hydrogen peroxide; SIDP: spike-intensity-dependent plasticity; SDDP: spike-duration-dependent plasticity; SNDP: spike-number-dependent plasticity; SRDP: spike-rate-dependent plasticity.