scholarly journals Circadian and Homeostatic Modulation of Functional Connectivity and Regional Cerebral Blood Flow in Humans under Normal Entrained Conditions

2014 ◽  
Vol 34 (9) ◽  
pp. 1493-1499 ◽  
Author(s):  
Duncan J Hodkinson ◽  
Owen O'Daly ◽  
Patricia A Zunszain ◽  
Carmine M Pariante ◽  
Vitaly Lazurenko ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Functional Connectivity ◽  
Hpa Axis ◽  
Resting State ◽  
Regional Cerebral Blood Flow ◽  
Time Of Day ◽  
Anterior Cingulate ◽  
Diurnal Rhythms ◽  
Regional Cerebral Blood

Diurnal rhythms have been observed in human behaviors as diverse as sleep, olfaction, and learning. Despite its potential impact, time of day is rarely considered when brain responses are studied by neuroimaging techniques. To address this issue, we explicitly examined the effects of circadian and homeostatic regulation on functional connectivity (FC) and regional cerebral blood flow (rCBF) in healthy human volunteers, using whole-brain resting-state functional magnetic resonance imaging (rs-fMRI) and arterial spin labeling (ASL). In common with many circadian studies, we collected salivary cortisol to represent the normal circadian activity and functioning of the hypothalamic–pituitary–adrenal (HPA) axis. Intriguingly, the changes in FC and rCBF we observed indicated fundamental decreases in the functional integration of the default mode network (DMN) moving from morning to afternoon. Within the anterior cingulate cortex (ACC), our results indicate that morning cortisol levels are negatively correlated with rCBF. We hypothesize that the homeostatic mechanisms of the HPA axis has a role in modulating the functional integrity of the DMN (specifically, the ACC), and for the purposes of using fMRI as a tool to measure changes in disease processes or in response to treatment, we demonstrate that time of the day is important when interpreting resting-state data.

Chronic whiplash symptoms are related to altered regional cerebral blood flow in the resting state

2009 ◽  
Vol 13 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Clas Linnman ◽  
Lieuwe Appel ◽  
Anne Söderlund ◽  
Örjan Frans ◽  
Henry Engler ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Resting State ◽  
Regional Cerebral Blood Flow ◽  
Regional Cerebral Blood ◽  
Chronic Whiplash

Altered regional cerebral blood flow and hypothalamic connectivity immediately prior to a migraine headache

Cephalalgia ◽  
2020 ◽  
Vol 40 (5) ◽  
pp. 448-460 ◽  
Author(s):  
Noemi Meylakh ◽  
Kasia K Marciszewski ◽  
Flavia Di Pietro ◽  
Vaughan G Macefield ◽  
Paul M Macey ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Functional Connectivity ◽  
Lateral Hypothalamus ◽  
Regional Cerebral Blood Flow ◽  
Migraine Headache ◽  
Pain Processing ◽  
Activity Levels ◽  
Regional Cerebral Blood ◽  
Hypothalamic Function

Background There is evidence of altered resting hypothalamic activity patterns and connectivity prior to a migraine, however it remains unknown if these changes are driven by changes in overall hypothalamic activity levels. If they are, it would corroborate the idea that changes in hypothalamic function result in alteration in brainstem pain processing sensitivity, which either triggers a migraine headache itself or allows an external trigger to initiate a migraine headache. We hypothesise that hypothalamic activity increases immediately prior to a migraine headache and this is accompanied by altered functional connectivity to pain processing sites in the brainstem. Methods In 34 migraineurs and 26 healthy controls, we collected a series comprising 108 pseudo-continuous arterial spin labelling images and 180 gradient-echo echo planar resting-state functional magnetic resonance volumes to measure resting regional cerebral blood flow and functional connectivity respectively. Images were pre-processed and analysed using custom SPM12 and Matlab software. Results Our results reflect that immediately prior to a migraine headache, resting regional cerebral blood flow decreases in the lateral hypothalamus. In addition, resting functional connectivity strength decreased between the lateral hypothalamus and important regions of the pain processing pathway, such as the midbrain periaqueductal gray, dorsal pons, rostral ventromedial medulla and cingulate cortex, only during this critical period before a migraine headache. Conclusion These data suggest altered hypothalamic function and connectivity in the period immediately prior to a migraine headache and supports the hypothesis that the hypothalamus is involved in migraine initiation.

scholarly journals Changes in regional cerebral blood flow due to cognitive activation among patients with schizophrenia

2000 ◽  
Vol 177 (3) ◽  
pp. 222-228 ◽  
Author(s):  
B. K. Toone ◽  
C. I. Okocha ◽  
K. Sivakumar ◽  
G. M. Syed
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Single Photon ◽  
Photon Emission ◽  
Anterior Cingulate ◽  
Control Group ◽  
Wisconsin Card Sort Test ◽  
Card Sorting ◽  
Regional Cerebral Blood

BackgroundThe regional cerebral blood flow (rCBF) response to the Wisconsin Card Sort Test (WCST) has been used to assess the functional integrity of the prefrontal cortex in patients with schizophrenia.AimsIn this study, patients were divided into two groups according to whether they had made few or many perseverative errors on a modified version of the WCST. A control group consisted of normal volunteers. The groups were then compared with respect to rCBF response to WCST activation.MethodrCBF was measured during administration of a modified version of the WCST and during a card sorting control task, using single photon emission computerised tomography (SPECT).ResultsPerformance of the modified WCST was associated with a widespread and substantial increase in rCBF, particularly in the frontal region. The poorly performing group of patients with schizophrenia showed only a modest increase in rCBF in the left anterior cingulate region.ConclusionSubjects with schizophrenia are able to respond to specific neuropsychological challenge with activation of the frontal regions.

scholarly journals Estimating regional cerebral blood flow using resting-state functional MRI via machine learning

2020 ◽  
Vol 331 ◽  
pp. 108528
Author(s):  
Ganesh B Chand ◽  
Mohamad Habes ◽  
Sudipto Dolui ◽  
John A Detre ◽  
David A Wolk ◽  
...  
Keyword(s):  
Machine Learning ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Functional Mri ◽  
Resting State ◽  
Regional Cerebral Blood Flow ◽  
Regional Cerebral Blood

Brain activation by central command during actual and imagined handgrip under hypnosis

2002 ◽  
Vol 92 (3) ◽  
pp. 1317-1324 ◽  
Author(s):  
J. W. Williamson ◽  
R. McColl ◽  
D. Mathews ◽  
J. H. Mitchell ◽  
P. B. Raven ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Perceived Exertion ◽  
Brain Activation ◽  
Cardiovascular Responses ◽  
Rating Of Perceived Exertion ◽  
Anterior Cingulate ◽  
Handgrip Exercise ◽  
Regional Cerebral Blood

The purpose was to compare patterns of brain activation during imagined handgrip exercise and identify cerebral cortical structures participating in “central” cardiovascular regulation. Subjects screened for hypnotizability, five with higher (HH) and four with lower hypnotizability (LH) scores, were tested under two conditions involving 3 min of 1) static handgrip exercise (HG) at 30% of maximal voluntary contraction (MVC) and 2) imagined HG (I-HG) at 30% MVC. Force (kg), forearm integrated electromyography, rating of perceived exertion, heart rate (HR), mean blood pressure (MBP), and differences in regional cerebral blood flow distributions were compared using an ANOVA. During HG, both groups showed similar increases in HR (+13 ± 5 beats/min) and MBP (+17 ± 3 mmHg) after 3 min. However, during I-HG, only the HH group showed increases in HR (+10 ± 2 beats/min; P < 0.05) and MBP (+12 ± 2 mmHg; P < 0.05). There were no significant increases or differences in force or integrated electromyographic activity between groups during I-HG. The rating of perceived exertion was significantly increased for the HH group during I-HG, but not for the LH group. In comparison of regional cerebral blood flow, the LH showed significantly lower activity in the anterior cingulate (−6 ± 2%) and insular cortexes (−9 ± 4%) during I-HG. These findings suggest that cardiovascular responses elicited during imagined exercise involve central activation of insular and anterior cingulate cortexes, independent of muscle afferent feedback; these structures appear to have key roles in the central modulation of cardiovascular responses.

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