Journal of Computer Assisted Tomography · 2002 · 40 citations · 38 references
Life SciencesNeurobiologyNeuroscienceDevelopmental NeurobiologyDevelopmental NeuroscienceNeurophysiologyCerebral Cortex PhysiologyCerebral PhysiologyDevelopmental NeurophysiologyFunctional NeuroimagingVisual Cortex DevelopmentVisual SystemAge-dependent ProcessesBlood Oxygenation Level-dependent ContrastBlood Oxygenation Level-dependent ImagingCerebral Blood Flow AlterationsCerebral Metabolic RateMetabolic Rate RegulationPrimary Visual Cortex FunctionSynaptic Density
The blood oxygen level-dependent (BOLD) response to photic stimulation in the primary visual cortex (V1) reverses from positive to negative around 8 weeks of age. This phenomenon may be caused by increased oxygen consumption during stimulation as the result of a rapid increase of synaptic density at this age. To test this hypothesis, we applied existing mathematic models of BOLD signals to the experimental data from infants. When the stimulus-related increments of cerebral blood flow and cerebral blood volume were fixed at 60% and 20%, respectively, the mean estimated increment of the cerebral metabolic rate of oxygen of the V1 in the elder infant group (57.1% +/- 8.8%) was twice as large as that in the younger infant group (32.2% +/- 4.7%), which corresponds to the reported difference in synaptic density. The present data confirmed that a change in oxygen consumption could explain a transition from a positive to a negative BOLD response.
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Brain magnetic resonance imaging with contrast dependent on blood oxygenation.
Satoshi Ogawa, T M Lee, A R Kay et al. · Proceedings of the National Academy of Sciences · 1990 · 6.5K citations · Full text
Medicine, Neuroscience, Radiology +17
Analysis of fMRI Time-Series Revisited
Karl Friston, Andrew P. Holmes, J.-B. Poline et al. · NeuroImage · 1995 · 2.5K citations