Investigating the post-stimulus undershoot of the BOLD signal--a simultaneous fMRI and fNIRS study. Export

@article{citeulike:645271, abstract = {Measuring the hemodynamic response with functional magnetic resonance imaging (fMRI) together with functional near-infrared spectroscopy (fNIRS) may overcome limitations of single-method approaches. Accordingly, we measured the event-related hemodynamic response with both imaging methods simultaneously in young subjects during visual stimulation. An intertrial interval of 60 s was chosen to include the prolonged post-stimulus undershoot of the blood oxygenation level dependent (BOLD) signal. During visual stimulation, the BOLD signal, oxy-, and total hemoglobin (Hb) increased, whereas deoxy-Hb decreased. The post-stimulus period was characterized by an undershoot of the BOLD signal, oxy-Hb, and an overshoot of deoxy-Hb. Total Hb as measured by fNIRS returned to baseline immediately after the end of stimulation. Results suggest that the post-stimulus events as measured by fNIRS are dominated by a prolonged high-level oxygen consumption in the microvasculature. The contribution of a delayed return of blood volume to the BOLD post-stimulus undershoot in post-capillary veins as suggested by the Balloon and Windkessel models remains ambiguous. Temporal changes in the BOLD signal were highly correlated with deoxy-Hb, with lower correlation values for oxy- and total Hb. Furthermore, data show that fNIRS covers the outer 1 cm of the brain cortex. These results were confirmed by simultaneous fMRI/fNIRS measurements during rest. In conclusion, multimodal imaging approaches may contribute to the understanding of neurovascular coupling.}, address = {Max-Planck-Institute for Human Cognitive and Brain Sciences, Stephanstr. 1A, Germany. schroet@cbs.mpg.de}, author = {Schroeter, M. L. and Kupka, T. and Mildner, T. and Uluda\u{g}, K. and von Cramon, D. Y.}, citeulike-article-id = {645271}, citeulike-linkout-0 = {http://dx.doi.org/10.1016/j.neuroimage.2005.09.048}, citeulike-linkout-1 = {http://linkinghub.elsevier.com/retrieve/pii/S1053811905007251}, citeulike-linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/16257236}, citeulike-linkout-3 = {http://www.hubmed.org/display.cgi?uids=16257236}, citeulike-linkout-4 = {http://www.sciencedirect.com/science/article/B6WNP-4HDX6TS-4/2/5ec02caa141e441f51a7ec3d5881628f}, day = {1}, doi = {10.1016/j.neuroimage.2005.09.048}, issn = {1053-8119}, journal = {Neuroimage}, keywords = {bold, event-related, fmri, nirs, undershoot}, month = {April}, number = {2}, pages = {349--358}, posted-at = {2007-02-06 23:50:37}, priority = {2}, title = {Investigating the post-stimulus undershoot of the BOLD signal--a simultaneous fMRI and fNIRS study.}, url = {http://dx.doi.org/10.1016/j.neuroimage.2005.09.048}, volume = {30}, year = {2006} }

TY - JOUR ID - citeulike:645271 L3 - citeulike-article-id:645271 N2 - Measuring the hemodynamic response with functional magnetic resonance imaging (fMRI) together with functional near-infrared spectroscopy (fNIRS) may overcome limitations of single-method approaches. Accordingly, we measured the event-related hemodynamic response with both imaging methods simultaneously in young subjects during visual stimulation. An intertrial interval of 60 s was chosen to include the prolonged post-stimulus undershoot of the blood oxygenation level dependent (BOLD) signal. During visual stimulation, the BOLD signal, oxy-, and total hemoglobin (Hb) increased, whereas deoxy-Hb decreased. The post-stimulus period was characterized by an undershoot of the BOLD signal, oxy-Hb, and an overshoot of deoxy-Hb. Total Hb as measured by fNIRS returned to baseline immediately after the end of stimulation. Results suggest that the post-stimulus events as measured by fNIRS are dominated by a prolonged high-level oxygen consumption in the microvasculature. The contribution of a delayed return of blood volume to the BOLD post-stimulus undershoot in post-capillary veins as suggested by the Balloon and Windkessel models remains ambiguous. Temporal changes in the BOLD signal were highly correlated with deoxy-Hb, with lower correlation values for oxy- and total Hb. Furthermore, data show that fNIRS covers the outer 1 cm of the brain cortex. These results were confirmed by simultaneous fMRI/fNIRS measurements during rest. In conclusion, multimodal imaging approaches may contribute to the understanding of neurovascular coupling. IS - 2 JF - Neuroimage SN - 1053-8119 AD - Max-Planck-Institute for Human Cognitive and Brain Sciences, Stephanstr. 1A, Germany. schroet@cbs.mpg.de EP - 358 TI - Investigating the post-stimulus undershoot of the BOLD signal--a simultaneous fMRI and fNIRS study. VL - 30 SP - 349 KW - bold KW - event-related KW - fmri KW - nirs KW - undershoot AU - Schroeter, ML AU - Kupka, T AU - Mildner, T AU - Uludağ, K AU - von Cramon, DY PY - 2006/04/01/ UR - http://dx.doi.org/10.1016/j.neuroimage.2005.09.048 ER -