Figure 2.

Reduced hemodynamic responses to forelimb stimulus in chronically stressed animals. A, Experimental settings for in vivo OIS imaging. Light reflected from the exposed S1FL cortex (i.e., the forelimb region of the primary somatosensory cortex) was filtered at the 546 nm wavelength, which is a measure of the Hbt. To assess the NVC relationship during functional hyperemia, LFPs were measured simultaneously with the OIS imaging. B, Representative Hbt-weighted OIS images during forelimb stimulation in control (left) and stressed mice (right). Each image represents the average of 18 trials from a single individual. Scale bars, 1 mm. C, Time course traces of relative changes in the evoked Hbt signal following forelimb stimulation, relative to baseline levels (control, black, n = 10; stressed, red, n = 10). D, Average of the maximum evoked Hbt change. E, Comparison of the area of activated region (spatial extent) for the time point at which the maximum Hbt change was observed. F, Time of onset. G, Time to reach half-maximum of the first peak of the Hbt response. H, Time course traces of heart rate monitored during OIS imaging sessions, including the sensory stimulation period (indicated with the yellow box). I, Average of the heart rate measured throughout the experiments (control, n = 10; stressed, n = 10). J, Blood pressure measured in urethane-anesthetized mice (control, n = 3; stressed, n = 3) using a tail-cuff blood pressure measurement system. Data are mean ± SEM. ^†p < 0.05 (Mann–Whitney U test). *p < 0.05 (independent t test); n.s., not significant.