Abstract #1596

Spatiotemporal Investigation of the FMRI Response to Brief Somatosensory Stimulation in Awake Marmosets

Yoshiyuki Hirano¹, Junjie V. Liu¹, Bojana Stefanovic², Afonso C. Silva¹

¹Cerebral Microcirculation Unit, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA; ²Sunnybrook Health Sciences Centre, Toronto, ON, Canada

The unceasing perfection of MRI hardware has led to continued improvement of the spatial and temporal resolution of fMRI. Here, the spatiotemporal features of the BOLD hemodynamic response (HDR) to brief somatosensory stimulation were measured in awake marmosets. The HDR to a single 333 s electrical pulse could be robustly detected in S1 and S2, but not in caudate. Longer stimulus durations increased both the amplitude and spatial coverage of the HDR. The onset time of the BOLD HDR was shorter in S1 than either S2, suggesting the HDR starts in S1 before progressing to higher-order brain regions.