アイテム詳細

要旨

BOLD fMRI is currently the mainstay of neuroimaging in cognitive neuroscience. Advances in scanner technology, image acquisition protocols, experimental design, and analysis methods promise to push forward fMRI from mere cartography to the true study of brain organization. However, fundamental questions concerning the interpretation of fMRI data abound, as the conclusions drawn often ignore the actual limitations of the methodology.
In my talk I shall describe our current understanding of the neurophysiological and hemodynamic signals, and of the structural and functional neurovascular coupling in the anesthetized and alert behaving monkey. Over the last ten years we have been studying the neurovascular coupling by means of simultaneous physiological and fMRI experiments, neuropharmacology, with micro-sampling and mass spectrometry, as well as with combined electrical microstimulation and fMRI (esfMRI). Our findings together with those from other laboratories suggest that the limitations of fMRI are mainly due to the circuitry and functional organization of the brain, as well as to inappropriate experimental protocols that ignore this organization. Our current knowledge of cortical microcircuits, inhibition, neuromodulation, and glia cell activity suggests that fMRI can be used as an excellent tool for formulating intelligent, data-based hypotheses, but only in certain special cases can it be useful for unambiguously selecting one of them, or for explaining the detailed neural mechanisms underlying the studied cognitive capacities. In the vast majority of cases, it is the combination of fMRI with other techniques and the parallel use of animal models that will be the most effective strategy for understanding brain function.