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

Introduction: Understanding the spatiotemporal features of the hemodynamic response (HDR) to functional brain stimulation is essential to the proper application of fMRI to study brain function. Previously, we showed that the BOLD-, CBF-, and CBV-HDR to a single electrical pulse can be robustly detected in α-chloralose anesthetized rats [1], and that both spatial and temporal characteristics of such responses are fine enough to resolve the heterogeneity of fMRI amplitudes, onset times, and time-to-peak across the cortical layers. Here, we extend that work to investigate the spatial and temporal evolution of the BOLD-HDR in awake nonhuman primates.