Figure 3: Blue light can mediate contraction of urinary bladder smooth muscles from transgenic ChR2-mice.
From: Optogenetic Modulation of Urinary Bladder Contraction for Lower Urinary Tract Dysfunction
(a) Schematics of experimental setup for optical stimulation and pressure recordings of a whole urinary bladder sample ex vivo: After animal was sacrificed, the bladder was isolated, instrumented with a polyethylene catheter along with a spherical light diffuser, and submerged in a organ bath of carbonated physiological saline. (b) Representative traces of pressure changes of whole bladder in response to 1 s of various light power stimuli (0.063, 0.63, 6.3, 63 and 189 mW). The red line is the control response of bladder from wild type mice (C57BL/6) to the maximum blue light (189 mW). (c) Representative traces of pressure changes of bladder in response to 63 mW light power with various illumination periods (1, 10, 100, 1000 and 10000 ms). (d) Relationship between the peak pressure changes of bladders and varying light parameters, the illumination period and the light power (n = 5). (e) ChR2-mediated bladder contractions (6.3 mW) were comparable to those induced by carbachol (3 μM) and EFS (50 V, 0.1 ms pulse duration and 20 Hz). All error bars indicate SE.
