Figure 1.
DWLSCI and DOMAG system setup.
(a) Synchronized dual wavelength laser speckle contrast imaging system setup. C = camera, DBS = dichroic beam splitter, EL = expanding lens, LD = laser diodes, M = mirror, N2 = nitrogen, O2 = oxygen, ZL = zoom lens. (b) Doppler optical microangiography system setup. CL = collimator, OC = optical coupler, OL = objective lens, PC = polarization controller, SLD = superluminescent diode. (c) Ventral view image of the cochlea after opening the bulla. The regions of the apical (A) and basal (B) turns, the stapedial artery (S) and the round window (RW) can be observed. (d) Mean and standard deviation of the systemic oxygen saturation of the five mice, indicating the hypoxia between minutes 3 and 7.
Figure 2.
Localization of cochlear regions.
(a) Maximum projection view of the scalas inside the cochlea in the z-direction (en-face). The red-dotted line is the cross-section visualized by the DOMAG systems during the hypoxic challenge. The blue line highlights the location of the lower apical turn. (b) Maximum projection view of the scalas inside the cochlea in the y-direction. The apical (A) and basal (B) turn regions have been indicated. (c) Laser speckle contrast image of the cochlea, highlighting the stapedial artery (S). Scale bar = 500 µm. Three regions of interest are shown. A.U. = arbitrary unit.
Figure 3.
Image of changes in the ischemic parameters.
Spatial map indicating the changes in the concentration of (a) deoxyhemoglobin, (b) oxyhemoglobin and (c) total hemoglobin at the last minute of the hypoxia. (d) Spatial map indicating the relative change in blood flow in normalized percent. Three regions of interest are shown. M = molar.
Figure 4.
Changes in the concentration of Hb, HbO and HbT.
(a) Change in the concentration of Hb, HbO and HbT through time. The purple curves are the fits of Eqn. 7 and 8 to the change in the concentration of Hb. The shaded area indicates the time points for the hypoxic stimulus. (b) Mean and standard deviation of the change in the concentrations of Hb, HbO and HbT at the last time point of the hypoxia phase. (c) Mean and standard deviation of the rate b1 and b2 from the change in concentration of Hb. M = molar.
Figure 5.
Changes in cochlear blood flow.
(a) Structural image of the cross-section of the cochlea. The scalas of the lower apical (A) and basal (B) turns are indicated. The velocity obtained by the Doppler signal from the cochlea vessels is shown, and the colormap indicates the total velocity. Scale bar = 250 µm. (b) Relative change in cochlear blood flow measured by DWLSCI in ROI 2, and DOMAG indicated by the red oval in (a) and also highlighted by the blue line in Figure 2(a). The shaded area indicates the time points for the hypoxic stimulus.