Fig. 3

Effects of frequency modulation. (A) Typical optical responses to bipolar (top line) and monopolar (bottom line) stimulations with different frequencies. Vessel maps obtained with green light were shown on the far left. Significant changing areas were labeled with red lines. A: anterior; L: lateral. (B) Maximum reflectance changes to frequency changes among all rats imaged. The cortical responses showed peaking changes at 100 Hz. The black line with gray shadows indicates the calculated changing ratios of monopolar to bipolar stimulations. (C) Calculated changing area ratios of momopolar to bipolar stimulations. The pixels of the areas having more than 3‰, 5‰, 7‰ reflectance changes were calculated respectively