Circulatory basis of fMRI signals: relationship between changes in the hemodynamic parameters and BOLD signal intensity

Seiyama, Akitoshi; Seki, Junji; Tanabe, Hiroki C.; Sase, Ichiro; Takatsuki, Akira; Miyauchi, Satoru; Eda, Hideo; Hayashi, Shigeru; Imaruoka, Toshihide; Iwakura, Takeo; Yanagida, Toshio

doi:10.1016/j.neuroimage.2003.12.002

Cited by 78 publications

(60 citation statements)

References 31 publications

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“…During stimulation, the BOLD signal, oxy-, total Hb, and CytOx increased, whereas deoxy-Hb decreased in accordance with recent studies (Buxton et al, 1998;Heekeren et al, 1999;Obrig et al, 2000b;Schroeter et al, 2004a;Seiyama et al, 2004;Wobst et al, 2001), indicating an increase in regional cerebral blood flow (rCBF) and rCBV due to neurovascular coupling (Villringer and Dirnagl, 1995). The post-stimulus undershoot of the BOLD signal was accompanied by a decrease of oxy-Hb and an increase of deoxy-Hb.…”

Section: Discussionsupporting

confidence: 89%

“…Several recent studies compared the hemodynamic response to brain activation as measured by functional near-infrared spectroscopy (fNIRS) with another imaging method, such as functional magnetic resonance imaging (fMRI) (Hoge et al, 2005;Kennan et al, 2002;Kleinschmidt et al, 1996;Mehagnoul-Schipper et al, 2002;Obrig et al, 2000b;Seiyama et al, 2004;Siegel et al, 2003;Strangman et al, 2002;Toronov et al, 2001aToronov et al, ,b, 2003Wenzel et al, 2000) or positron emission tomography (PET) . While optical measurements are poorer in spatial resolution and depth penetration than fMRI, they are biochemical specific and, consequently, provide information about changes in oxy-, deoxy-, and total hemoglobin (Hb) with a high temporal resolution (Hoshi, 2003;Villringer and Chance, 1997).…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2006

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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. D

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Section: Discussionsupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

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

et al. 2006

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“…However, the origin of change in [HHb] concentration remains unclear. [HHb], in fact, varies in a complex way with changes in both venous oxygenation (i.e., oxygen consumption) and blood volume (i.e., oxygen supply) (Hoshi et al, 2001;Seiyama et al, 2004). Thus, if [HHb] variations reflect the change in oxygen consumption, it will be considered as a measure of metabolic deactivation.…”

Section: Discussionmentioning

confidence: 99%

Acute Mobile Phones Exposure Affects Frontal Cortex Hemodynamics as Evidenced by Functional Near-Infrared Spectroscopy

Curcio

Ferrara

Limongi

et al. 2009

J Cereb Blood Flow Metab

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This study aimed to evaluate by functional near-infrared spectroscopy (fNIRS), the effects induced by an acute exposure (40 mins) to a GSM (Global System for Mobile Communications) signal emitted by a mobile phone (MP) on the oxygenation of the frontal cortex. Eleven healthy volunteers underwent two sessions (Real and Sham exposure) after a crossover, randomized, double-blind paradigm. The whole procedure lasted 60 mins: 10-mins baseline (Bsl), 40-mins (Exposure), and 10-mins recovery (Post-Exp). Together with frontal hemodynamics, heart rate, objective and subjective vigilance, and self-evaluation of subjective symptoms were also assessed. The fNIRS results showed a slight influence of the GSM signal on frontal cortex, with a linear increase in [HHb] as a function of time in the Real exposure condition (F 4,40 = 2.67; P = 0.04). No other measure showed any GSM exposure-dependent changes. These results suggest that fNIRS is a convenient tool for safely and noninvasively investigating the cortical activation in MP exposure experimental settings. Given the short-term effects observed in this study, the results should be confirmed on a larger sample size and using a multichannel instrument that allows the investigation of a wider portion of the frontal cortex.

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“…The total-Hb signal is generally considered to reflect rCBV changes (Ferrari et al, 1992;Seiyama et al, 2004). Malonek et al (1997) reported that the rCBV at activation onset was a fast observable vascular signal, preceding by more than 1 sec the increase in regional cerebral blood flow (rCBF), possibly reflecting a blood volume increase at the capillary level.…”

Section: Nirsmentioning

confidence: 99%

Water-Diffusion Slowdown in the Human Visual Cortex on Visual Stimulation Precedes Vascular Responses

Kohno

Sawamoto

Urayama

et al. 2009

J Cereb Blood Flow Metab

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We used magnetic resonance imaging (MRI) to investigate the temporal dynamics of changes in water diffusion and blood oxygenation level-dependent (BOLD) responses in the brain cortex of eight subjects undergoing visual stimulation, and compared them with changes of the vascular hemoglobin content (oxygenated, deoxygenated, and total hemoglobin) acquired simultaneously from intrinsic optical recordings (near infrared spectroscopy). The group average rise time for the diffusion MRI signal was statistically significantly shorter than those of the BOLD signal and total hemoglobin content optical signal, which is assumed to be the fastest observable vascular signal. In addition, the group average decay time for the diffusion MRI also was shortest. The overall time courses of the BOLD and optical signals were strongly correlated, but the covariance was weaker with the diffusion MRI response. These results suggest that the observed decrease in water diffusion reflects early events that precede the vascular responses, which could originate from changes in the extravascular tissue.

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Circulatory basis of fMRI signals: relationship between changes in the hemodynamic parameters and BOLD signal intensity

Cited by 78 publications

References 31 publications

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

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

Acute Mobile Phones Exposure Affects Frontal Cortex Hemodynamics as Evidenced by Functional Near-Infrared Spectroscopy

Water-Diffusion Slowdown in the Human Visual Cortex on Visual Stimulation Precedes Vascular Responses

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