The study demonstrates the versatility of the AOTF microscope for in vivo physiologic investigation, allowing for the generation of nearly simultaneous SO2 and PO2 maps in the cerebral cortex, and the frequency-domain detection of phosphorescence lifetimes. This class of study opens up exciting new possibilities for investigating the dynamics of hemoglobin and O2 binding during functional activation of neuronal tissues. Schematic representation of the AOTF microscope, showing the major components and light paths for imaging reflected absorbance spectra and phosphorescence lifetimes in the cerebral cortex. Optical elements not present in certain experiments are indicated by dashed lines. The PO2 calculated from the analysis of phosphorescence phase theta using the AOTF microscope is plotted as a function of the measured PO2 from an oxygen electrode using the calibration system described in Materials and Methods.
Error bars indicate standard deviation.
The three rectangles labeled A, V, and T indicate regions from the artery, vein, and tissue, respectively. The reflected intensity in T was used for normalization. The parametric estimates of q and m are shown in the box legends. The artery, containing more oxygen than the vein, is clearly distinguishable by color in both the SO2 and PO2 maps. Error bars indicate standard error of the mean.