Nathalie Just1,2, Stephane Germain1,2, Martin Lauritzen3,4, Rolf Gruetter1,2
1LIFMET, CIBM, EPFL, Lausanne, Switzerland; 2Department of Radiology, UNIL and HUG, Lausanne and Geneva, Switzerland; 3Department of Clinical Neurophysiology, Glostrup Hospital, Glostrup, Denmark; 4Department of Medical Physiology, Panum Institute and University of Copenhafen, Copenhagen, Denmark
The present study examined the BOLD fMRI response of the rat barrel cortex upon trigeminal nerve stimulation. BOLD changes as a function of current intensity and stimulus frequency were measured under α -chloralose anesthesia. The BOLD responses showed non-linear behavior as a function of current intensity and stimulus frequency that can be compared to the non-linear patterns found for cerebral blood flow and local field potentials measured in the barrel cortex as a function of the same stimulus parameters and stimulation model. Linear coupling between the neuronal and BOLD responses cannot be generalized for every condition or brain region.