NMR spectroscopy and imaging of the neonatal brain

2000 ◽  
Vol 28 (2) ◽  
pp. 121-126 ◽  
Author(s):  
C. E. Cooper ◽  
J. S. Wyatt
Keyword(s):  
Blood Flow ◽  
Brain Function ◽  
Blood Oxygenation ◽  
Cell Swelling ◽  
Resonance Spectroscopy ◽  
Neonatal Brain ◽  
Cellular Processes ◽  
Nmr Techniques ◽  
The Brain ◽  
Ischaemic Insult

Magnetic resonance spectroscopy and imaging provide unique information about the brain to the biochemist and the clinician. In particular, the ability to image metabolites other than water and to get detailed information about dynamic cellular processes (such as blood flow, blood oxygenation and cell swelling) is leading to many new insights into brain function and dysfunction. This review describes the use of old and new NMR techniques which demonstrate that mitochondrial dysfunction plays an important role in the cell death that occurs following an hypoxic-ischaemic insult to the neonatal brain.

scholarly journals Use of 19F NMR Spectroscopy for Measurement of Cerebral Blood Flow: A Comparative Study Using Microspheres

1989 ◽  
Vol 9 (6) ◽  
pp. 886-891 ◽  
Author(s):  
David Barranco ◽  
Leslie N. Sutton ◽  
Sandra Florin ◽  
Joel Greenberg ◽  
Teresa Sinnwell ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Arterial Blood ◽  
Radioactive Microsphere ◽  
Low Concentrations ◽  
Cat Brain ◽  
Nmr Techniques ◽  
High Concentrations ◽  
Washout Curves ◽  
The Brain

19F NMR was used to determine washout curves of an inert, diffusible gas (CHF3) from the cat brain. The cerebral blood flow was estimated from a bi- or tri-phasic fit to the deconvoluted wash-out curve, using the Kety-Schmidt approach. Cerebral blood flow values determined by 19F NMR show the expected responsiveness to alterations in Paco2, but are approximately 28% lower than cerebral blood flow values determined simultaneously by radioactive microsphere techniques. High concentrations of CHF3 have little effect on intracranial pressure, mean arterial blood pressure or Paco2, but cause small changes in the blood flow to certain regions of the brain. We conclude that 19F NMR techniques utilizing low concentrations of CHF3 have potential for the noninvasive measurement of cerebral blood flow.

scholarly journals Arterial Spin Labeling (ASL) fMRI: Advantages, Theoretical Constrains and Experimental Challenges in Neurosciences

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Ajna Borogovac ◽  
Iris Asllani
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Brain Function ◽  
Arterial Spin Labeling ◽  
Spin Labeling ◽  
Absolute Quantification ◽  
Full Potential ◽  
Neuroscience Research ◽  
Essential Parameter ◽  
The Brain

Cerebral blood flow (CBF) is a well-established correlate of brain function and therefore an essential parameter for studying the brain at both normal and diseased states. Arterial spin labeling (ASL) is a noninvasive fMRI technique that uses arterial water as an endogenous tracer to measure CBF. ASL provides reliable absolute quantification of CBF with higher spatial and temporal resolution than other techniques. And yet, the routine application of ASL has been somewhat limited. In this review, we start by highlighting theoretical complexities and technical challenges of ASL fMRI for basic and clinical research. While underscoring the main advantages of ASL versus other techniques such as BOLD, we also expound on inherent challenges and confounds in ASL perfusion imaging. In closing, we expound on several exciting developments in the field that we believe will make ASL reach its full potential in neuroscience research.

scholarly journals Relationship of the BOLD Signal with VEP for Ultrashort Duration Visual Stimuli (0.1 to 5 ms) in Humans

2009 ◽  
Vol 30 (2) ◽  
pp. 449-458 ◽  
Author(s):  
Barış Yeşilyurt ◽  
Kevin Whittingstall ◽  
Kâmil Uğurbil ◽  
Nikos K Logothetis ◽  
Kâmil Uludağ
Keyword(s):  
Brain Function ◽  
Temporal Dynamics ◽  
Visual Stimulation ◽  
Impulse Response Function ◽  
Blood Oxygenation ◽  
Context Dependency ◽  
Oxygenation Level ◽  
Relationship Of ◽  
The Relationship ◽  
The Brain

There is currently a great interest to combine electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) to study brain function. Earlier studies have shown different EEG components to correlate well with the fMRI signal arguing for a complex relationship between both measurements. In this study, using separate EEG and fMRI measurements, we show that (1) 0.1 ms visual stimulation evokes detectable hemodynamic and visual-evoked potential (VEP) responses, (2) the negative VEP deflection at ∼80 ms (N2) co-varies with stimulus duration/intensity such as with blood oxygenation level-dependent (BOLD) response; the positive deflection at ∼120 ms (P2) does not, and (3) although the N2 VEP–BOLD relationship is approximately linear, deviation is evident at the limit of zero N2 VEP. The latter finding argues that, although EEG and fMRI measurements can co-vary, they reflect partially independent processes in the brain tissue. Finally, it is shown that the stimulus-induced impulse response function (IRF) at 0.1 ms and the intrinsic IRF during rest have different temporal dynamics, possibly due to predominance of neuromodulation during rest as compared with neurotransmission during stimulation. These results extend earlier findings regarding VEP–BOLD coupling and highlight the component- and context-dependency of the relationship between evoked potentials and hemodynamic responses.

Monitoring of Blood Flow by Drug Stimulation on Mouse Brain Using Non-Invasive Photoacoustic Imaging Technology

2007 ◽  
Vol 364-366 ◽  
pp. 1123-1127
Author(s):  
Shi Hua Yang ◽  
Ye Qi Lao
Keyword(s):  
Blood Flow ◽  
Mouse Brain ◽  
Light Absorption ◽  
Brain Function ◽  
Photoacoustic Imaging ◽  
Non Invasive ◽  
Mouse Cerebral Cortex ◽  
Flow Changes ◽  
The Brain

The highlight of photoacosutic imaging (PAI) is a method that combines ultrasonic resolution with high contrast due to light absorption. Photoacoustic signals carry the information of the light absorption distribution of biological tissue, which is often related to its character of structure, physiological and pathological changes because of different physiology conditions in response to different light absorption coefficients. A non-invasive PAI system was developed and successfully acquired in vivo images of mouse brain. Based on the intrinsic PA signals from the brain, the vascular network and the detailed structures of the mouse cerebral cortex were clearly visualized. The ability of PAI monitoring of cerebral hemodynamics was also demonstrated by mapping of the mouse superficial cortex with and without drug stimulation. The extracted PA signals intensity profiles obviously testified that the cerebral blood flow (CBF) in the mouse brain was changed under the stimulation of acetazolamide (ACZ). The experimental results suggest that PAI can provide non-invasive images of blood flow changes, and has the potential for brain function detection.

scholarly journals A studyforrest extension, MEG recordings while watching the audio-visual movie "Forrest Gump"

2021 ◽  
Author(s):  
Xingyu Liu ◽  
Yuxuan Dai ◽  
Hailun Xie ◽  
Zonglei Zhen
Keyword(s):  
Neuronal Activity ◽  
Brain Function ◽  
Ecological Validity ◽  
Blood Oxygenation ◽  
Free Access ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Oxygenation Level ◽  
The Brain ◽  
The Magnetic Field

Naturalistic stimuli, such as movies, are being increasingly used to map brain function because of their high ecological validity. The pioneering studyforrest and other naturalistic neuroimaging projects have provided free access to multiple movie-watching functional magnetic resonance imaging (fMRI) datasets to prompt the community for naturalistic experimental paradigms. However, sluggish blood-oxygenation-level-dependent fMRI signals are incapable of resolving neuronal activity with the temporal resolution at which it unfolds. Instead, magnetoencephalography (MEG) measures changes in the magnetic field produced by neuronal activity and is able to capture rich dynamics of the brain at the millisecond level while watching naturalistic movies. Herein, we present the first public prolonged MEG dataset collected from 11 participants while watching the 2 h long audio-visual movie "Forrest Gump". Minimally preprocessed data was also provided to facilitate the use. As a studyforrest extension, we envision that this dataset, together with fMRI data from the studyforrest project, will serve as a foundation for exploring the neural dynamics of various cognitive functions in real-world contexts.

Personality and Regional Cerebral Blood Flow

1984 ◽  
Vol 144 (5) ◽  
pp. 529-532 ◽  
Author(s):  
Roy J. Mathew ◽  
Maxine L. Weinman ◽  
Deborah L. Barr
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Brain Function ◽  
Regional Cerebral Blood Flow ◽  
Cortical Arousal ◽  
Regional Cerebral Blood ◽  
Capillary Perfusion ◽  
Brain Capillary ◽  
Eysenck Personality Inventory ◽  
The Brain

SummaryThe extraversion–introversion dimension of personality is believed to have an inverse relationship with cortical arousal. Brain capillary perfusion is a well established index of brain function and arousal. Regional cerebral blood flow was measured in 51 right-handed females whose personality structure was examined with the Eysenck Personality Inventory (EPI). Significant inverse correlations were found between the brain blood flow and the extraversion–introversion score of EPI.

scholarly journals AKT isoforms have distinct hippocampal expression and roles in synaptic plasticity

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Josien Levenga ◽  
Helen Wong ◽  
Ryan A Milstead ◽  
Bailey N Keller ◽  
Lauren E LaPlante ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Synaptic Plasticity ◽  
Brain Function ◽  
Expression Patterns ◽  
Direct Role ◽  
Cellular Processes ◽  
Akt Isoforms ◽  
Hippocampal Synaptic Plasticity ◽  
The Brain ◽  
Unique Expression Pattern

AKT is a kinase regulating numerous cellular processes in the brain, and mutations in AKT are known to affect brain function. AKT is indirectly implicated in synaptic plasticity, but its direct role has not been studied. Moreover, three highly related AKT isoforms are expressed in the brain, but their individual roles are poorly understood. We find in Mus musculus, each AKT isoform has a unique expression pattern in the hippocampus, with AKT1 and AKT3 primarily in neurons but displaying local differences, while AKT2 is in astrocytes. We also find isoform-specific roles for AKT in multiple paradigms of hippocampal synaptic plasticity in area CA1. AKT1, but not AKT2 or AKT3, is required for L-LTP through regulating activity-induced protein synthesis. Interestingly, AKT activity inhibits mGluR-LTD, with overlapping functions for AKT1 and AKT3. In summary, our studies identify distinct expression patterns and roles in synaptic plasticity for AKT isoforms in the hippocampus.

scholarly journals Magnetic resonance spectroscopy of the brain: a review of physical principles and technical methods

2015 ◽  
Vol 26 (6) ◽  
pp. 609-632 ◽  
Author(s):  
Michael H. Buonocore ◽  
Richard J. Maddock
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Brain Function ◽  
Pulse Sequences ◽  
Resonance Spectroscopy ◽  
Resonance Imaging ◽  
Neurobiological Substrates ◽  
Health And Disease ◽  
The Brain ◽  
Physical Principles

AbstractMagnetic resonance spectroscopy (MRS) provides unique information about the neurobiological substrates of brain function in health and disease. However, many of the physical principles underlying MRS are distinct from those underlying magnetic resonance imaging, and they may not be widely understood by neuroscientists new to this methodology. This review describes these physical principles and many of the technical methods in current use for MRS experiments. A better understanding these principles and methods may help investigators select pulse sequences and quantification methods best suited to the aims of their research program and avoid pitfalls that can hamper new investigators in this field.

scholarly journals AKT isoforms have distinct hippocampal expression and roles in synaptic plasticity

2017 ◽  
Author(s):  
Josien Levenga ◽  
Helen Wong ◽  
Ryan A. Milstead ◽  
Bailey N. Keller ◽  
Lauren E. Laplante ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Synaptic Plasticity ◽  
Brain Function ◽  
Expression Patterns ◽  
Direct Role ◽  
Cellular Processes ◽  
Akt Isoforms ◽  
Hippocampal Synaptic Plasticity ◽  
The Brain ◽  
Unique Expression Pattern

ABSTRACTAKT is a kinase that regulates numerous cellular processes in the brain and mutations in AKT are known to affect brain function. AKT is indirectly implicated in synaptic plasticity, but its direct role has not been studied. Moreover, three highly related AKT isoforms are expressed in the brain, but their individual roles are poorly understood. We find that each AKT isoform has a unique expression pattern in the hippocampus, with AKT1 and AKT3 primarily in neurons but displaying local differences, while AKT2 is in astrocytes. We also find isoform-specific roles for AKT in multiple paradigms of hippocampal synaptic plasticity. AKT1, but not AKT2 or AKT3, is required for L-LTP through regulating activity-induced protein synthesis. Interestingly, AKT activity inhibits mGluR-LTD, with overlapping functions for AKT1 and AKT3. In summary, our studies identify distinct expression patterns and roles in synaptic plasticity for AKT isoforms in the hippocampus.

scholarly journals Time delay processing of hypercapnic fMRI allows quantitative parameterization of cerebrovascular reactivity and blood flow delays

2016 ◽  
Vol 36 (10) ◽  
pp. 1767-1779 ◽  
Author(s):  
Manus J Donahue ◽  
Megan K Strother ◽  
Kimberly P Lindsey ◽  
Lia M Hocke ◽  
Yunjie Tong ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cross Correlation ◽  
Blood Oxygenation Level Dependent ◽  
Blood Oxygenation ◽  
Intracranial Stenosis ◽  
Peak Time ◽  
Surgical Revascularization ◽  
Blood Oxygenation Level ◽  
Oxygenation Level ◽  
The Brain

Blood oxygenation level-dependent fMRI contrast depends on the volume and oxygenation of blood flowing through the circulatory system. The effects on image intensity depend temporally on the arrival of blood within a voxel, and signal can be monitored during the time course of such blood flow. It has been previously shown that the passage of global endogenous variations in blood volume and oxygenation can be tracked as blood passes through the brain by determining the strength and peak time lag of their cross-correlation with blood oxygenation level-dependent data. By manipulating blood composition using transient hypercarbia and hyperoxia, we can induce much larger oxygenation and volume changes in the blood oxygenation level-dependent signal than result from natural endogenous fluctuations. This technique was used to examine cerebrovascular parameters in healthy subjects (n = 8) and subjects with intracranial stenosis (n = 22), with a subgroup of intracranial stenosis subjects scanned before and after surgical revascularization (n = 6). The halfwidth of cross-correlation lag times in the brain was larger in IC stenosis subjects (21.21 ± 14.22 s) than in healthy control subjects (8.03 ± 3.67), p < 0.001, and was subsequently reduced in regions that co-localized with surgical revascularization. These data show that blood circulatory timing can be measured robustly and longitudinally throughout the brain using simple respiratory challenges.

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