Fig. 4. IR light transiently alters membrane capacitance from Shapiro et al²².

(a) As the energy of a 1 ms IR pulse is increased, higher capacitive currents are measured in response to the light in a voltage-clamped artificial bilayer. (b) As the energy of a 10ms IR pulse is increased, higher capacitive currents are measured in response to the light in an artificial bilayer. With each size pulse the current closely follows the timing of the IR pulse. Red bars and grey shading indicate the timing of laser stimulation. In both (a) and (b) the characteristic transient of a voltage-gated channel is not seen. (c) Q–V curves acquired in artificial bilayers with increasing IR stimulation in H₂O (red) and D₂O (blue). The different absorption of D₂O results in a significantly decreased the IR-induced transient, further validating that H₂O plays a significant role.