scholarly journals Effects of aging on cerebral blood flow, oxygen metabolism, and blood oxygenation level dependent responses to visual stimulation

2009 ◽  
Vol 30 (4) ◽  
pp. 1120-1132 ◽  
Author(s):  
Beau M. Ances ◽  
Christine L. Liang ◽  
Oleg Leontiev ◽  
Joanna E. Perthen ◽  
Adam S. Fleisher ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Visual Stimulation ◽  
Oxygen Metabolism ◽  
Blood Oxygenation Level Dependent ◽  
Blood Oxygenation ◽  
Blood Oxygenation Level ◽  
Oxygenation Level ◽  
Effects Of Aging

The Effect of Esmolol on Cerebral Blood Flow, Cerebral Vasoreactivity, and Cognitive Performance: A Functional Magnetic Resonance Imaging Study

2005 ◽  
Vol 102 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Wolfgang Heinke ◽  
Stefan Zysset ◽  
Margret Hund-Georgiadis ◽  
Derk Olthoff ◽  
D Yves von Cramon
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Functional Magnetic Resonance Imaging ◽  
Blood Oxygenation Level Dependent ◽  
Blood Oxygenation ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Blood Oxygenation Level ◽  
Oxygenation Level

Background Esmolol is often applied perioperatively to maintain stable hemodynamic conditions in neurosurgical patients. Little is known, however, about its effects on cerebral circulation. The authors employed functional magnetic resonance imaging based on blood oxygenation level-dependent contrast to explore the effect of esmolol on the human brain. The purpose of the study was to investigate the effect of esmolol on cerebral blood flow, cerebral vasoreactivity, and cognitive performance. Methods Ten healthy volunteers were investigated in two separate experimental sessions using functional magnetic resonance imaging. During the first experimental session, a hyperventilation task and a cognitive task, subjects had to perform both tasks twice, once after administration of an esmolol bolus of 1 mg/kg followed by a continuous infusion of 150 microg.kg.min and once without beta-blockade, in a random order. During the second experimental session subjects were scanned at resting state after administration of esmolol. Furthermore, the effect of the esmolol dose on hemodynamic changes caused by beta-adrenergic stimulation with orciprenaline was investigated. Results Esmolol decreased heart rate and blood pressure during the various experimental conditions and blunted the increase in heart rate and blood pressure caused by orciprenaline. Infusion of esmolol affects neither the blood oxygenation level-dependent contrast during the functional challenges nor the reaction times during the cognitive task. However, the esmolol bolus caused a brief blood oxygenation level-dependent contrast increase. Conclusion The results indicate that effective beta-blockade with esmolol does not affect cerebral blood flow, cerebrovascular reactivity, or cognitive performance.

Sex Differences in Blood-Oxygenation-Level-Dependent Functional MRI With Primary Visual Stimulation

1998 ◽  
Vol 155 (3) ◽  
pp. 434-436 ◽  
Author(s):  
Jonathan M. Levin ◽  
Marjorie H. Ross ◽  
Jack H. Mendelson ◽  
Nancy K. Mello ◽  
Bruce M. Cohen ◽  
...  
Keyword(s):  
Sex Differences ◽  
Functional Mri ◽  
Visual Stimulation ◽  
Blood Oxygenation Level Dependent ◽  
Blood Oxygenation ◽  
Blood Oxygenation Level ◽  
Oxygenation Level

scholarly journals Anatomical, blood oxygenation level-dependent, and blood flow MRI of nonhuman primate (baboon) retina

2011 ◽  
Vol 66 (2) ◽  
pp. 546-554 ◽  
Author(s):  
Yi Zhang ◽  
Hsiao-Ying Wey ◽  
Oscar San Emeterio Nateras ◽  
Qi Peng ◽  
Bryan H. De La Garza ◽  
...  
Keyword(s):  
Blood Flow ◽  
Nonhuman Primate ◽  
Blood Oxygenation Level Dependent ◽  
Blood Oxygenation ◽  
Blood Oxygenation Level ◽  
Oxygenation Level ◽  
Flow Mri

Blood Oxygenation Level Dependent Signal Time Courses During Prolonged Visual Stimulation

1998 ◽  
Vol 16 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Alistair M. Howseman ◽  
David A. Porter ◽  
Chloe Hutton ◽  
Oliver Josephs ◽  
Robert Turner
Keyword(s):  
Visual Stimulation ◽  
Blood Oxygenation Level Dependent ◽  
Blood Oxygenation ◽  
Blood Oxygenation Level ◽  
Oxygenation Level ◽  
Dependent Signal ◽  
Time Courses ◽  
Signal Time

scholarly journals Origin of Negative Blood Oxygenation Level—Dependent fMRI Signals

2002 ◽  
Vol 22 (8) ◽  
pp. 908-917 ◽  
Author(s):  
Noam Harel ◽  
Sang-Pil Lee ◽  
Tsukasa Nagaoka ◽  
Dae-Shik Kim ◽  
Seong-Gi Kim
Keyword(s):  
Neural Activity ◽  
Spike Activity ◽  
Visual Stimulation ◽  
Blood Oxygenation Level Dependent ◽  
Blood Oxygenation ◽  
Bold Signal ◽  
Area 18 ◽  
Blood Oxygenation Level ◽  
Oxygenation Level ◽  
Negative Bold

Functional magnetic resonance imaging (fMRI) techniques are based on the assumption that changes in spike activity are accompanied by modulation in the blood oxygenation level—dependent (BOLD) signal. In addition to conventional increases in BOLD signals, sustained negative BOLD signal changes are occasionally observed and are thought to reflect a decrease in neural activity. In this study, the source of the negative BOLD signal was investigated using T2*-weighted BOLD and cerebral blood volume (CBV) techniques in isoflurane-anesthetized cats. A positive BOLD signal change was observed in the primary visual cortex (area 18) during visual stimulation, while a prolonged negative BOLD change was detected in the adjacent suprasylvian gyrus containing higher-order visual areas. However, in both regions neurons are known to increase spike activity during visual stimulation. The positive and negative BOLD amplitudes obtained at six spatial-frequency stimuli were highly correlated, and negative BOLD percent changes were approximately one third of the postitive changes. Area 18 with positive BOLD signals experienced an increase in CBV, while regions exhibiting the prolonged negative BOLD signal underwent a decrease in CBV. The CBV changes in area 18 were faster than the BOLD signals from the same corresponding region and the CBV changes in the suprasylvian gyrus. The results support the notion that reallocation of cortical blood resources could overcome a local demand for increased cerebral blood flow induced by increased neural activity. The findings of this study imply that caution should be taken when interpreting the negative BOLD signals as a decrease in neuronal activity.

scholarly journals Blood oxygenation level-dependent (BOLD) functional MRI of visual stimulation in the rat retina at 11.7 T

2010 ◽  
Vol 24 (2) ◽  
pp. 188-193 ◽  
Author(s):  
Bryan H. De La Garza ◽  
Eric R. Muir ◽  
Guang Li ◽  
Yen-Yu I. Shih ◽  
Timothy Q. Duong
Keyword(s):  
Functional Mri ◽  
Visual Stimulation ◽  
Blood Oxygenation Level Dependent ◽  
Blood Oxygenation ◽  
Rat Retina ◽  
Blood Oxygenation Level ◽  
Oxygenation Level

scholarly journals Quantitative aspects of brain perfusion dynamic induced by BOLD fMRI

2006 ◽  
Vol 64 (4) ◽  
pp. 895-898 ◽  
Author(s):  
Katia C. Andrade ◽  
Octavio M. Pontes-Neto ◽  
Joao P. Leite ◽  
Antonio Carlos Santos ◽  
Oswaldo Baffa ◽  
...  
Keyword(s):  
Blood Flow ◽  
Grey Matter ◽  
Brain Perfusion ◽  
Blood Oxygenation Level Dependent ◽  
Blood Oxygenation ◽  
Breath Holding ◽  
Bold Signal ◽  
Blood Oxygenation Level ◽  
Oxygenation Level ◽  
Dependent Signal

The increase of relative cerebral blood flow (rCBF) may contribute for a change in blood oxygenation level dependent signal (BOLD). The main purpose of this study is to investigate some aspects of perfusional alterations in the human brain in response to a uniform stimulation: hypercapnia induced by breath holding. It was observed that the BOLD signal increased globally during hypercapnia and that it is correlated with the time of breath holding. This signal increase shows a clear distinction between gray and white matter, being greater in the grey matter.

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