Figure 7: Transgenic ChR2(H134R)-bladder subjected to continuous and pulsed optical stimulation protocols for 60 s ex vivo.

(a) Representative traces of bladder pressure evoked by repeated light illuminations of 60 s-ON with 840 s-OFF. Blue bar indicates the stimulation with blue laser (473 nm). (b) An isolated bladder contraction over the illumination period of 60 s (red box in (a)) was compared among three different optical protocols using blue laser with 63 mW power: a continuous illumination for 60 s (energy emission = 3.78 J, black), an intermittent illumination with ON for 1 s and OFF for 1 s (energy emission = 1.89 J, red), and an intermittent, pulsed illumination with 100 Hz for 1 s and OFF for 1 s (energy emission = 0.19 J, blue). All three protocols produce a relaxation of the peak pressure over the illumination period of 60 s. (c) The average pressure changes over the 60 s illumination period between three illumination protocols. Pressure changes to the 100 Hz protocol are slightly lower than those to the continuous one (p < 0.001, repeated measures ANOVA (n = 5)). All error bars indicate SE.