Name
Abstract | ||
|---|---|---|
Prior measures of the blood oxygenation level-dependent (BOLD) and cerebral blood flow (CBF) responses to a memory-encoding task within the medial temporal lobe have suggested that the coupling between functional changes in CBF and changes in the cerebral metabolic rate of oxygen (CMRO2) may be tighter in the medial temporal lobe as compared to the primary sensory areas. In this study, we used a calibrated functional magnetic resonance imaging (fMRI) approach to directly estimate memory-encoding-related changes in CMRO2 and to assess the coupling between CBF and CMRO2 in the medial temporal lobe. The CBF–CMRO2 coupling ratio was estimated using a linear fit to the flow and metabolism changes observed across subjects. In addition, we examined the effect of region-of-interest (ROI) selection on the estimates. In response to the memory-encoding task, CMRO2 increased by 23.1±8.8% to 25.3±5.7% (depending upon ROI), with an estimated CBF–CMRO2 coupling ratio of 1.66±0.07 to 1.75±0.16. There was not a significant effect of ROI selection on either the CMRO2 or coupling ratio estimates. The observed coupling ratios were significantly lower than the values (2 to 4.5) that have been reported in previous calibrated fMRI studies of the visual and motor cortices. In addition, the estimated coupling ratio was found to be less sensitive to the calibration procedure for functional responses in the medial temporal lobe as compared to the primary sensory areas. |
Year | DOI | Venue |
|---|---|---|
2008 | 10.1016/j.neuroimage.2008.01.038 | NeuroImage |
Keywords | Field | DocType |
Medial temporal lobe,Calibrated BOLD,Functional MRI,Arterial spin labeling,Neurovascular coupling | Neuroscience,Primary sensory areas,Functional magnetic resonance imaging,Cognitive psychology,Psychology,Oxygenation,Cerebral blood flow,Nuclear magnetic resonance,Coupling ratio,Magnetic resonance imaging,Encoding (memory),Temporal lobe | Journal |
Volume | Issue | ISSN |
40 | 4 | 1053-8119 |
Citations | PageRank | References |
7 | 0.54 | 10 |
Authors | ||
3 | ||
Name | Order | Citations | PageRank |
|---|---|---|---|
| Khaled Restom | 1 | 438 | 24.27 |
| Joanna E Perthen | 2 | 139 | 8.49 |
| Thomas T Liu | 3 | 1022 | 76.03 |