Effects of Fructose vs Glucose on Regional Cerebral Blood Flow in Brain Regions Involved With Appetite and Reward Pathways

Regional cerebral blood flow (CBF) was measured in isoflurane-anesthetized turtles (Pseudemys scripta) by the hydrogen clearance method. Teflon-coated platinum electrodes (25 microns) were implanted in the olfactory bulbs, midcerebral cortex and cerebellum in eight adult turtles. The electrodes were voltage clamped at +0.30 V relative to a Ag-AgCl electrode implanted in the dorsal neck muscles. Washout kinetics of H2 gas administered via controlled ventilation was used to calculate local blood flow for electrodes exhibiting monoexponential washout kinetics of hydrogen (92 of 104 determinations). Data were obtained in animals with body temperatures of 15, 25, and 35 degrees C under normocapnic conditions during ventilation with 21% O2 and during ventilation with 100% N2. During normoxia, mean blood flows were 1.9 +/- 0.8, 5.0 +/- 1.9, and 6.1 +/- 1.3 (+/- SD) ml.100 g-1.min-1 at 15, 25, and 35 degrees C, respectively. There were no differences between CBF values in the different brain regions. During 1-3 h of anoxia, CBF was 3.0 +/- 2.1, 7.0 +/- 3.7, and 6.6 +/- 2.9 ml.100 g-1.min-1 at 15, 25, and 35 degrees C, respectively (normoxia-anoxia difference not statistically different). Hypercarbia (ventilation with 10-20% CO2 in air or N2), or the transition from anoxia to normoxia, increased CBF up to 80% at each of these temperatures. Maintenance of CBF during anoxia likely contributes to the anoxia tolerance of the turtle brain.

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Effects of tDCS Dose and Electrode Montage on regional cerebral blood flow and motor behavior

10.1101/2021.02.02.429369 ◽

2021 ◽

Author(s):

Anant Shinde ◽

Karl Lerud ◽

Fanny Munsch ◽

David C Alsop ◽

Gottfried Schlaug

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Regional Cerebral Blood Flow ◽

Brain Regions ◽

Regional Cerebral Blood ◽

Left Hand ◽

Motor Region ◽

Left And Right ◽

The Right ◽

Sequence Performance

AbstractWe used three dose levels (Sham, 2mA and 4mA) and two different electrode montages (unihemispheric or bihemispheric) to examine DOSE and MONTAGE effects on regional cerebral blood flow (rCBF) as a surrogate marker of neural activity, and on a finger sequence task, as a surrogate behavioral measure drawing on brain regions targeted by transcranial direct current stimulation (tDCS). We placed the anodal electrode over the right motor region (C4) while the cathodal or return electrode was placed either over a left supraorbital region (unihemispheric montage) or over the left motor region (C3 in the bihemispheric montage). Performance changes in the finger sequence task for both hands (left hand: p = 0.0026, and right hand: p = 0.0002) showed a linear tDCS dose response, but no effect of montage. rCBF in the the right hemispheric perirolandic area increased with dose under the anodal electrode (p = 0.027), while in the perirolandic ROI in the left hemisphere, rCBF showed a trend to increase with dose (p = 0.053), and significant effect of montage (p = 0.00004). The bihemispheric montage showed additional rCBF increases in frontomesial regions in the 4mA condition but not in the 2mA condition. Furthermore, we found correlations between rCBF changes in the right perirolandic region and improvements in the finger sequence task performance (FSP) for left and right hand. Our data support not only a strong direct tDCS dose effect for rCBF and FSP as surrogate measures of targeted brain regions, but also indirect effects on rCBF in functionally connected regions (e.g., frontomesial regions), particularly in the higher dose condition, and on FSP of the ipsilateral hand (to the anodal electrode). At higher dose and irrespective of polarity, a wider network of sensorimotor regions is positively affected by tDCS.Graphical AbstractHighlightstDCS-DOSE had linear effect on finger sequence performance for both handsrCBF changes in both perirolandic ROIs demonstrated tDCS-DOSE effects and left perirolandic ROI demonstrated tDCS-MONTAGE effects.Simulated current intensity in the left and right perirolandic ROI strongly correlated with the contralateral hand’s finger sequence performance.tDCS-Tolerability scores did not correlate with change in rCBF or finger sequence performance of the left hand.

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Effects of route of administration on oxytocin-induced changes in regional cerebral blood flow in humans

10.1101/563056 ◽

2019 ◽

Cited By ~ 3

Author(s):

D. A. Martins ◽

N. Mazibuko ◽

F. Zelaya ◽

S. Vasilakopoulou ◽

J. Loveridge ◽

...

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Regional Cerebral Blood Flow ◽

Systemic Circulation ◽

Brain Regions ◽

Regional Cerebral Blood ◽

Intranasal Route ◽

Brain Physiology ◽

Induced Changes ◽

Robust Evidence

ABSTRACTCould nose-to-brain pathways mediate the effects of peptides such as oxytocin (OT) on brain physiology when delivered intranasally? We address this question by contrasting two methods of intranasal administration (a standard nasal spray, and a nebulizer expected to improve OT deposition in nasal areas putatively involved in direct nose-to-brain transport) to intravenous administration in terms of effects on regional cerebral blood flow during two hours post-dosing. We demonstrate that OT-induced decreases in amygdala perfusion, a key hub of the OT central circuitry, are explained entirely by OT increases in systemic circulation following both intranasal and intravenous OT administration. Yet we also provide robust evidence confirming the validity of the intranasal route to target specific brain regions. Our work has important translational implications and demonstrates the need to carefully consider the method of administration in our efforts to engage specific central oxytocinergic targets for the treatment of neuropsychiatric disorders.

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Effect of hypoxia and hypercapnia on neurohypophyseal blood flow

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1986.250.1.h7 ◽

1986 ◽

Vol 250 (1) ◽

pp. H7-H15

Author(s):

D. F. Hanley ◽

D. A. Wilson ◽

R. J. Traystman

Keyword(s):

Blood Pressure ◽

Carbon Monoxide ◽

Blood Flow ◽

Cerebral Blood Flow ◽

Regional Cerebral Blood Flow ◽

Brain Regions ◽

Regulatory Mechanisms ◽

Similar Increase ◽

Regional Cerebral Blood ◽

Pressure Controlled

Neurohypophyseal blood flow responses to hypoxia and hypercapnia were studied in pentobarbital anesthetized, paralyzed dogs. Arterial O2 content was lowered from control (18 +/- 2 vol%) to 8 +/- 1 vol% by either decreasing O2 tension (hypoxic hypoxia, HH) or by increasing carboxyhemoglobin saturation (carbon monoxide hypoxia, COH) at normal O2 tension. In all animals HH and COH resulted in similar increases in total cerebral blood flow (239 and 300%, respectively). Regional cerebral blood flow showed a similar increase for all brain regions except the neurohypophysis (NH). The NH increased its blood flow with HH (approximately 320% of control) but was unchanged with COH (117% of control). The responsiveness of NH blood vessels was tested under conditions of hypercapnia (10% CO2) and HH with blood pressure controlled by concurrent hemorrhage. The response of NH vessels to altered arterial O2 tension occurs independently of blood pressure. Systemic [H+] or CO2 tension produce only small changes in NH blood flow. These data suggest that hypoxic and hypercapnic regulatory mechanisms for the NH are different from those of other brain regions. The precise mechanism by which the NH hypoxic response occurs remains unclear, but our data suggest an important role for systemic arterial O2 tension and chemoreceptors.

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Neuropsychological dysfunction in depression: the relationship to regional cerebral blood flow

Psychological Medicine ◽

10.1017/s0033291700028944 ◽

1994 ◽

Vol 24 (4) ◽

pp. 849-857 ◽

Cited By ~ 96

Author(s):

R. J. Dolan ◽

C. J. Bench ◽

R. G. Brown ◽

L. C. Scott ◽

R. S. J. Frackowiak

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Prefrontal Cortex ◽

Medial Prefrontal Cortex ◽

Test Performance ◽

Regional Cerebral Blood Flow ◽

Brain Regions ◽

Regional Cerebral Blood ◽

Neuropsychological Dysfunction ◽

The Relationship

SynopsisThe relationship between neuropsychological test performance and regional cerebral blood flow (rCBF) was examined in 29 patients meeting Research Diagnostic Criteria (RDC) for major depression. Following a comprehensive neuropsychological assessment two subsets of tests, comprising tests that discriminated between patients and controls or between patients with varying degrees of global cognitive impairment, were selected. These subtests were entered into a principal components analysis (PCA) which generated a two-factor solution, accounting for 50% of the overall variance in test scores. Individual patient loadings on each of these factors were subsequently correlated with regional cerebral blood flow (rCBF), as measured by positron emission tomography (PET). Both factors demonstrated significant correlations with rCBF in the medial prefrontal cortex and frontal polar cortex while for each factor there were also unique patterns of correlations with posterior brain regions. The findings provide additional evidence that neuropsychological deficits in depression are associated with abnormalities in regional brain function and in particular with the function of the medial prefrontal cortex.

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Effects of Immobilization Stress on Regional Cerebral Blood Flow in the Conscious Rat

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.1981.19 ◽

1981 ◽

Vol 1 (2) ◽

pp. 187-194 ◽

Cited By ~ 46

Author(s):

M. Ohata ◽

W. R. Fredericks ◽

U. Sundaram ◽

S. I. Rapoport

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Frontal Lobe ◽

Regional Cerebral Blood Flow ◽

Immobilization Stress ◽

Brain Regions ◽

Regional Cerebral Blood ◽

Conscious Rat ◽

Average Slope ◽

Wistar Kyoto

Immobilization stress of conscious, normotensive, freely breathing 10-month-old Wistar-Kyoto rats produced an overall decline in regional cerebral blood flow (rCBF), as measured with [14C]iodoantipyrine, except at the frontal lobe. In 14 brain regions, rCBF fell by an average of 14.3% after 5 min of immobilization and by 11.9% after 15 min. Immobilization stress also stimulated hyperventilation and thereby reduced Paco2. The slope relating rCBF to Paco2 averaged 1.5 ml 100 g−1 min−1 mm Hg−1 in 9 significantly affected regions. The findings suggest that rCBF declines during immobilization stress because of cerebrovascular constriction caused by a reduction in Paco2. Comparison of the average slope with published values indicates furthermore that were Paco2 to remain unchanged during immobilization, rCBF would increase by at most 20%.

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Alterations in Regional Cerebral Blood Flow following Brain Injury in the Rat

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.1991.117 ◽

1991 ◽

Vol 11 (4) ◽

pp. 655-660 ◽

Cited By ~ 133

Author(s):

Iwao Yamakami ◽

Tracy K. McIntosh

Keyword(s):

Traumatic Brain Injury ◽

Blood Flow ◽

Cerebral Blood Flow ◽

Brain Injury ◽

Regional Cerebral Blood Flow ◽

Brain Regions ◽

Regional Cerebral Blood ◽

Microsphere Method ◽

Left Parietal Cortex ◽

Experimental Traumatic Brain Injury

To elucidate the temporal changes in regional cerebral blood flow (rCBF) after experimental traumatic brain injury, serial rCBF measurements were made during a 24-h period following fluid-percussion (F-P) traumatic brain injury in the rat. Brain injury of 2.2 atm was induced over the left parietal cortex and serial measurements of rCBF were performed using the radiolabeled microsphere method. rCBF values were obtained prior to injury and at 15 and 30 min and 1, 2, 4, and 24 h postinjury. At 15 min postinjury, there was a profound, widespread reduction in rCBF in all brain regions studied (p < 0.05). At 30 min and 1 h postinjury, all brain regions except pons-medulla and cerebellum showed significantly reduced rCBF compared to the preinjury values (p < 0.05). By 2 h postinjury, however, a significant focal reduction of rCBF was observed only in the cerebral tissue surrounding the trauma site (p < 0.05); rCBF in the remaining brain regions had recovered to the preinjury levels. By 4 h postinjury, rCBF had returned to normal in all brain regions studied. This recovery of rCBF was still evident at 24 h postinjury. The present study demonstrates that, following the experimental traumatic brain injury in the rat, (a) an initial global suppression of rCBF occurs up to 1 h postinjury; (b) at the trauma site, a more persistent focal reduction of rCBF occurs; and (c) these alterations in rCBF after trauma dissolve by 4 h postinjury. The result was discussed in the context of the neurological, electroencephalographic, magnetic resonance spectroscopic, and pathological findings observed in our lateral F-P brain injury rat model.

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Effects of Xenon and Krypton on Regional Cerebral Blood Flow in the Rat

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.1985.16 ◽

1985 ◽

Vol 5 (1) ◽

pp. 126-132 ◽

Cited By ~ 24

Author(s):

L. Junck ◽

V. Dhawan ◽

H. T. Thaler ◽

D. A. Rottenberg

Keyword(s):

Computed Tomography ◽

Blood Flow ◽

Cerebral Blood Flow ◽

Regional Cerebral Blood Flow ◽

Brain Regions ◽

Quantitative Autoradiography ◽

Regional Cerebral Blood ◽

Xenon Computed Tomography ◽

Source Of Error

The effects of high inspired concentrations of xenon and krypton on regional CBF (rCBF) were assessed in the rat using [14C]iodoantipyrine and quantitative autoradiography. Inhalation of 80% xenon for 1 or 2 min and inhalation of 40% xenon for 2 min were found to have significant effects on rCBF, including average increases of 75–96% in cerebral neocortical regions. Inhalation of 40% xenon for 1 min and of 80% krypton for 2 min had no significant effect on rCBF in most brain regions studied. If xenon inhalation produces effects on rCBF in humans similar to those observed in the rat, such effects could be an important source of error in xenon computed tomography rCBF studies.

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Distribution of regional cerebral blood flow in voluntarily diving rats.

Journal of Experimental Biology ◽

10.1242/jeb.201.4.549 ◽

1998 ◽

Vol 201 (4) ◽

pp. 549-558

Author(s):

G P Ollenberger ◽

N H West

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Regional Cerebral Blood Flow ◽

Regional Distribution ◽

Detailed Examination ◽

Brain Regions ◽

Regional Cerebral Blood ◽

Output Only ◽

Almost All ◽

The Brain

The distribution of regional cerebral blood flow (rCBF) was examined in conscious, voluntarily diving rats using the brain blood flow tracer N-[14C]isopropyl-p-iodoamphetamine and quantitative autoradiography. A detailed examination of the regional distribution of cerebral blood flow revealed that almost all brain regions were hyperperfused during diving. During diving, rCBF increased by an average of 1.7-fold in 29 of the 33 brain regions examined, despite a 69.2 % decrease in cardiac output. Only some regions of the basal ganglia (caudate-putamen and globus pallidus) and limbic areas (hippocampus and amygdala) did not increase rCBF significantly during diving. We determined that the increase in rCBF during diving is primarily due to a corresponding 20.9 % decrease in cerebrovascular resistance. A significant increase in perfusion pressure during diving also potentially contributed to the increase in rCBF. Because some brain regions did not increase flow significantly during diving, these results suggest that not all brain regions participate equally in the global cerebrovascular response to diving. This study provides evidence to support the view that the brain is preferentially perfused during conscious voluntary diving in the rat. The mechanism(s) that probably produce the cerebrovascular changes during diving are discussed.

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