The negative BOLD signal unmasked.
Many fMRI experiments show regions of cortex that seem to respond in antiphase with the primary stimulus. In this issue of Neuron, Shmuel et al. show that this "negative BOLD response" is spatially and temporally linked to reductions in blood flow. By combining BOLD and blood flow data to model the energy consumption in cortex, they conclude that the NBR is primarily due to active neuronal inhibition.
Wade
Alex R
AR
Smith-Kettlewell Eye Research Institute, 2318 Fillmore Street, San Francisco, CA 94115, USA.
D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D005071:Evoked Potentials / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008959:Models, Neurological; D009433:Neural Inhibition / Q000502:physiology*; D009474:Neurons / Q000502:physiology