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Responses to Cortical Spreading Depression under Oxygen Deficiency.

Sonn J, Mayevsky A - Open Neurol J (2012)

Bottom Line: CSD under the 3 pathological conditions caused an initial increase in NADH and a further decrease in CBF during the first phase of CSD, indicating an imbalance between oxygen supply and demand as a result of the increase in oxygen requirements.The special design of the MPA enabled identifying differences in the simultaneous responses of the measured parameters, which may indicate changes in the interrelation between oxygen demand, oxygen supply and oxygen balance during CSD propagation, under the conditions tested. 6.In conclusion, brain oxygenation was found to be a critical factor in the responses of the brain to CSD.

View Article: PubMed Central - PubMed

Affiliation: The Mina & Everard Goodman, Faculty of Life Sciences and Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University RAMAT-GAN 52900, Israel.

ABSTRACT

Objectives: The effect of cortical spreading depression (CSD) on extracellular K(+) concentrations ([K(+)](e)), cerebral blood flow (CBF), mitochondrial NADH redox state and direct current (DC) potential was studied during normoxia and three pathological conditions: hypoxia, after NOS inhibition by L-NAME and partial ischemia.

Methods: A SPECIAL DEVICE (MPA) WAS USED FOR MONITORING CSD WAVE PROPAGATION, CONTAINING: mitochondrial NADH redox state and reflected light, by a fluorometry technique; DC potential by Ag/AgCl electrodes; CBF by laser Doppler flowmetry; and [K(+)](e) by a mini-electrode.

Results and discussion: CSD under the 3 pathological conditions caused an initial increase in NADH and a further decrease in CBF during the first phase of CSD, indicating an imbalance between oxygen supply and demand as a result of the increase in oxygen requirements. The hyperperfusion phase in CBF was significantly reduced during hypoxia and ischemia showing a further decline in oxygen supply during CSD. CSD wave duration increased during the pathological conditions, showing a disturbance in energy production.Extracellular K(+) levels during CSD, increased to identical levels during normoxia and during the three pathological groups, indicating correspondingly increase in oxygen demand. 5. The special design of the MPA enabled identifying differences in the simultaneous responses of the measured parameters, which may indicate changes in the interrelation between oxygen demand, oxygen supply and oxygen balance during CSD propagation, under the conditions tested. 6. In conclusion, brain oxygenation was found to be a critical factor in the responses of the brain to CSD.

No MeSH data available.


Related in: MedlinePlus

Schematic illustrations of the multiprobe assembly (MPA) system. Left side: The localization of the various sensors on the cortex.Right side: Location of the MPA on the rat cranium. LDF - light guide connected to the laser Doppler flowmeter; NADH - light guideconnected to the fluorometer/reflectometer for NADH fluorescence and 366 nm reflectance; EK - selective K+ electrode; DC - direct currentelectrode; KCl - push-pull cannula for CSD initiation; ECoG - bipolar ECoG electrodes. R - radii of the circumference of the embeddedprobes.
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Figure 1: Schematic illustrations of the multiprobe assembly (MPA) system. Left side: The localization of the various sensors on the cortex.Right side: Location of the MPA on the rat cranium. LDF - light guide connected to the laser Doppler flowmeter; NADH - light guideconnected to the fluorometer/reflectometer for NADH fluorescence and 366 nm reflectance; EK - selective K+ electrode; DC - direct currentelectrode; KCl - push-pull cannula for CSD initiation; ECoG - bipolar ECoG electrodes. R - radii of the circumference of the embeddedprobes.

Mentions: The MPA system is schematically illustrated in Fig. (1). It contains: 1) An optical fiber to monitor mitochondrial NADH redox state (surface fluorometry) and tissue absorption properties (reflected light); 2) Surface mini-electrodes for measuring extracellular K+ concentration ([K+]e) and DC steady potential; 3) A laser Doppler flowmeter to evaluate relative CBF; 4) Two platinum electrodes to detect spontaneous bipolar ECoG. The MPA measured the changes in the various detected parameters from the front line until the complete recovery period of CSD wave, continuously and simultaneously. The probes were embedded in a rectangular cannula and were arranged along a circumference of a circle. The KCl cannula (for CSD initiation) was implanted in the center of this circle, as illustrated in Fig. (1). All details regarding the MPA construction and calibration of the various probes were previously published [7, 8, 30]. In addition, the probes were arranged in the cannula according to the shape of the pre-determined CSD wave, allowing the CSD wave to be monitored from its front line until complete recovery, by all of the detected parameters. This enabled to evaluate and compare the order (in time) of amplitude changes (maximum, minimum) in the measured parameters according to the beginning of the CSD wave propagation. Thus, we were able to evaluate the interrelation between the measured parameters during the CSD wave propagation.


Responses to Cortical Spreading Depression under Oxygen Deficiency.

Sonn J, Mayevsky A - Open Neurol J (2012)

Schematic illustrations of the multiprobe assembly (MPA) system. Left side: The localization of the various sensors on the cortex.Right side: Location of the MPA on the rat cranium. LDF - light guide connected to the laser Doppler flowmeter; NADH - light guideconnected to the fluorometer/reflectometer for NADH fluorescence and 366 nm reflectance; EK - selective K+ electrode; DC - direct currentelectrode; KCl - push-pull cannula for CSD initiation; ECoG - bipolar ECoG electrodes. R - radii of the circumference of the embeddedprobes.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3367297&req=5

Figure 1: Schematic illustrations of the multiprobe assembly (MPA) system. Left side: The localization of the various sensors on the cortex.Right side: Location of the MPA on the rat cranium. LDF - light guide connected to the laser Doppler flowmeter; NADH - light guideconnected to the fluorometer/reflectometer for NADH fluorescence and 366 nm reflectance; EK - selective K+ electrode; DC - direct currentelectrode; KCl - push-pull cannula for CSD initiation; ECoG - bipolar ECoG electrodes. R - radii of the circumference of the embeddedprobes.
Mentions: The MPA system is schematically illustrated in Fig. (1). It contains: 1) An optical fiber to monitor mitochondrial NADH redox state (surface fluorometry) and tissue absorption properties (reflected light); 2) Surface mini-electrodes for measuring extracellular K+ concentration ([K+]e) and DC steady potential; 3) A laser Doppler flowmeter to evaluate relative CBF; 4) Two platinum electrodes to detect spontaneous bipolar ECoG. The MPA measured the changes in the various detected parameters from the front line until the complete recovery period of CSD wave, continuously and simultaneously. The probes were embedded in a rectangular cannula and were arranged along a circumference of a circle. The KCl cannula (for CSD initiation) was implanted in the center of this circle, as illustrated in Fig. (1). All details regarding the MPA construction and calibration of the various probes were previously published [7, 8, 30]. In addition, the probes were arranged in the cannula according to the shape of the pre-determined CSD wave, allowing the CSD wave to be monitored from its front line until complete recovery, by all of the detected parameters. This enabled to evaluate and compare the order (in time) of amplitude changes (maximum, minimum) in the measured parameters according to the beginning of the CSD wave propagation. Thus, we were able to evaluate the interrelation between the measured parameters during the CSD wave propagation.

Bottom Line: CSD under the 3 pathological conditions caused an initial increase in NADH and a further decrease in CBF during the first phase of CSD, indicating an imbalance between oxygen supply and demand as a result of the increase in oxygen requirements.The special design of the MPA enabled identifying differences in the simultaneous responses of the measured parameters, which may indicate changes in the interrelation between oxygen demand, oxygen supply and oxygen balance during CSD propagation, under the conditions tested. 6.In conclusion, brain oxygenation was found to be a critical factor in the responses of the brain to CSD.

View Article: PubMed Central - PubMed

Affiliation: The Mina & Everard Goodman, Faculty of Life Sciences and Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University RAMAT-GAN 52900, Israel.

ABSTRACT

Objectives: The effect of cortical spreading depression (CSD) on extracellular K(+) concentrations ([K(+)](e)), cerebral blood flow (CBF), mitochondrial NADH redox state and direct current (DC) potential was studied during normoxia and three pathological conditions: hypoxia, after NOS inhibition by L-NAME and partial ischemia.

Methods: A SPECIAL DEVICE (MPA) WAS USED FOR MONITORING CSD WAVE PROPAGATION, CONTAINING: mitochondrial NADH redox state and reflected light, by a fluorometry technique; DC potential by Ag/AgCl electrodes; CBF by laser Doppler flowmetry; and [K(+)](e) by a mini-electrode.

Results and discussion: CSD under the 3 pathological conditions caused an initial increase in NADH and a further decrease in CBF during the first phase of CSD, indicating an imbalance between oxygen supply and demand as a result of the increase in oxygen requirements. The hyperperfusion phase in CBF was significantly reduced during hypoxia and ischemia showing a further decline in oxygen supply during CSD. CSD wave duration increased during the pathological conditions, showing a disturbance in energy production.Extracellular K(+) levels during CSD, increased to identical levels during normoxia and during the three pathological groups, indicating correspondingly increase in oxygen demand. 5. The special design of the MPA enabled identifying differences in the simultaneous responses of the measured parameters, which may indicate changes in the interrelation between oxygen demand, oxygen supply and oxygen balance during CSD propagation, under the conditions tested. 6. In conclusion, brain oxygenation was found to be a critical factor in the responses of the brain to CSD.

No MeSH data available.


Related in: MedlinePlus