Neurovascular Uncoupling under Mild Hypoxic Hypoxia: An EEG–fMRI Study in Rats

  title={Neurovascular Uncoupling under Mild Hypoxic Hypoxia: An EEG–fMRI Study in Rats},
  author={Akira Sumiyoshi and Hideaki Suzuki and Hiroaki Shimokawa and Ryuta Kawashima},
  journal={Journal of Cerebral Blood Flow \& Metabolism},
  pages={1853 - 1858}
The effects of oxygen availability on neurovascular coupling were investigated using simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI), in addition to the monitoring of physiological parameters, in 16 α-chloralose-anesthetized rats. Mild hypoxic hypoxia (oxygen saturation=83.6±12.1%) induced significant reductions in fMRI responses (P<0.05) to electrical stimulation in the forepaw, but EEG responses remained unchanged. In addition, the changes in oxygen… 

Indication of dynamic neurovascular coupling from inconsistency between EEG and fMRI indices across sleep–wake states

The cross-modality inconsistencies across sleep–wake states provided preliminary evidence that the neurovascular relationship may not change in a linear consistency during NREM sleep, and caution shall be exercised when applying the NVC presumption to investigating sleep/wake transitions, even among healthy young adults.

Effects of mild hypoxia on oxygen extraction fraction responses to brain stimulation

Investigation of the motor-evoked OEF response in both normoxia and hypoxia showed that OEF activation decreased in the brain areas involved in motor task execution, suggesting a different relationship between oxygen delivery and consumption during Hypoxia compared to normxia.

Reversal of neurovascular coupling in the default mode network: Evidence from hypoxia

Hypoxia reversed both positive and negative task-evoked BOLD responses in theDMN, suggesting hypoxia reverses neurovascular coupling in the DMN of healthy adults and may enhance understanding of regional specificity in neurodegenerative disease pathology.

The power of using functional fMRI on small rodents to study brain pharmacology and disease

Several BOLD fMRI techniques are introduced, including resting state (rsf MRI), stimulus-evoked (st-fMRI), and pharmacological MRI (phMRI), to highlight the advantages of functional MRI in exploring the acute and long-term effects of pharmacological substances and/or pathology on brain functioning along with several methodological considerations.

Association between tissue hypoxia, perfusion restrictions, and microvascular architecture alterations with lesion-induced impairment of neurovascular coupling

  • A. StadlbauerT. Kinfe S. Brandner
  • Biology, Medicine
    Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism
  • 2020
It is demonstrated that perilesional hypoxia with reduced vascular perfusion and architecture is associated with lesion-induced impairment of NVC, and the physiologic MRI approach is a clinically applicable method for preoperative risk assessment for the presence of false-negative fMRI results and may prevent severe postoperative functional deficits.

Neural basis for reduced executive performance with hypoxic exercise

Effects of acute mild hypoxia on cerebral blood flow in pilots

Hypoxia decreased CBF in various brain regions, including the right temporal and bilateral occipital lobes, the anterior and posterior lobes of the Cerebellum, the culmen and declive, and the inferior semilunar lobule of the cerebellum.

Noninvasive High-Speed Photoacoustic Tomography of Cerebral Hemodynamics in Awake-Moving Rats

  • Jianbo TangLei Xi Hua-bei Jiang
  • Medicine
    Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism
  • 2015
By providing a light-weight, high-resolution technology for in vivo monitoring of cerebral hemodynamics in awake-behaving animals, it will be possible to develop a comprehensive understanding on how activity alters hemodynamic status in normal and diseased states.

Alteration of spontaneous brain activity in COPD patients

Altered spontaneous brain activity of patients with COPD is demonstrated, which may have a pathophysiologic meaning and show positive correlations with visual reproduction.



Heterogeneous Oxygen Extraction in the Visual Cortex during Activation in Mild Hypoxic Hypoxia Revealed by Quantitative Functional Magnetic Resonance Imaging

These spatially localised regions of tissue oxygen extraction and metabolism argue for dissociation between CBF and BOLD fMRI signals in mild hypoxia, and point to heterogeneity with regard to oxygen requirement and its coupling to the haemodynamic response in the brain.

Oxygen modulation of neurovascular coupling in the retina

It is shown that although O2 can modulate neurovascular coupling when raised sufficiently high, the hyperoxia-induced rise in retinal pO2 in vivo is not sufficient to produce a modulatory effect.

Contribution of nitric oxide to cerebral blood flow regulation under hypoxia in rats

It is suggested that NO plays a major role in the regulation of baseline and evoked CBF during hypoxia, whereas the heart rate decreased and the mean blood pressure increased during Hypoxia in comparison with these during normoxia.

Neurovascular Coupling in Rat Brain Operates Independent of Hemoglobin Deoxygenation

  • U. LindauerC. Leithner U. Dirnagl
  • Biology, Medicine
    Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism
  • 2010
Results show that activation-induced CBF regulation in the brain does not operate through the release of vasoactive mediators on hemoglobin deoxygenation or through a tissue-based oxygen-sensing mechanism, and experimental evidence challenging this view is presented.

Cerebral blood flow and BOLD fMRI responses to hypoxia in awake and anesthetized rats

MRI measurement of the temporal evolution of relative CMRO2 during rat forepaw stimulation

This study reports the first measurement of the relative cerebral metabolic rate of oxygen utilization (rCMRO2) during functional brain activation with sufficient temporal resolution to address the

Brain metabolism dictates the polarity of astrocyte control over arterioles

The ability of astrocytes to induce vasodilations over vasoconstrictions relies on the metabolic state of the rat brain tissue and is revealed, which reveals the role of metabolic substrates in regulating brain blood flow and provides a mechanism for differentialAstrocyte control over cerebrovascular diameter during different states of brain activation.

Longitudinal MRI studies in the isoflurane‐anesthetized rat: long‐term effects of a short hypoxic episode on regulation of cerebral blood flow as assessed by pulsed arterial spin labelling

The findings indicate that, in isoflurane‐anesthetized rats, even a short hypoxic episode can have long‐lasting effects on cerebrovascular regulation.