Figure 6.

(A) Schematic of experimental setup with neurons cultured on a microelectrode array (MEA), collagen foam loaded with PDA NP placed on the culture and stimulated with NIR laser. (B) SEM image (inset: higher magnification SEM) and (C) Absorption spectra of collagen foam loaded with PDA NP. (D) Temperature changes of collagen foam + PDA NP in wet state at different laser power densities. (E) Spike rates of neurons with collagen foam loaded with PDA NP and NIR irradiation at different power densities. (F) A single trace of spike recording for different NIR irradiation periods (10 s, 20 s and 30 s laser irradiation at power density of 6 mW mm⁻²). (G) Quantification of spike rate changes in panel E (effect of laser power density on spike rate change and inhibition of neuron activity).