BOLD fMRI and functional ultrasound comparisons in co-registered olfactory bulb sections of the same mice

Using UHF (17.2T) BOLD fMRI on the mouse Olfactory Bulb (OB) we recorded odor activation at high spatio-temporal resolution (0.17x0.17x0.3 mm; TR= 250ms). With 6% 1s odor application we found fast unimodal activations. Increasing odor concentration and duration (35% 5s) we revealed the second vascular component. Adding functional ultrasound (fUS) recordings from the co-registered OB coronal section, we could verify an overall good accordance in the dynamics of BOLD and fUS signals in small ROIs (< 0.5 mm^3), although evident differences were also found in some ROIs. We aim at highlighting the relationship between local vascular activity and BOLD fMRI.