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

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

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 Multi-Regional Investigation of the Relationship between Functional MRI Blood Oxygenation Level Dependent (BOLD) Activation and GABA Concentration

PLoS ONE ◽  
2015 ◽  
Vol 10 (2) ◽  
pp. e0117531 ◽  
Author(s):  
Ashley D. Harris ◽  
Nicolaas A. J. Puts ◽  
Brian A. Anderson ◽  
Steven Yantis ◽  
James J. Pekar ◽  
...  
Keyword(s):  
Functional Mri ◽  
Blood Oxygenation Level Dependent ◽  
Blood Oxygenation ◽  
Gaba Concentration ◽  
Blood Oxygenation Level ◽  
Oxygenation Level ◽  
The Relationship

scholarly journals The Stability of the Blood Oxygenation Level-Dependent Functional MRI Response to Motor Tasks Is Altered in Patients With Chronic Ischemic Stroke

Stroke ◽  
2010 ◽  
Vol 41 (9) ◽  
pp. 1921-1926 ◽  
Author(s):  
Kelley C. Mazzetto-Betti ◽  
Renata F. Leoni ◽  
Octavio M. Pontes-Neto ◽  
Antonio C. Santos ◽  
Joao P. Leite ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Functional Mri ◽  
Blood Oxygenation Level Dependent ◽  
Blood Oxygenation ◽  
Motor Tasks ◽  
Blood Oxygenation Level ◽  
Oxygenation Level ◽  
The Stability
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