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Measurement of Local Partial Pressure of Oxygen in the Brain Tissue under Normoxia and Epilepsy with Phosphorescence Lifetime Microscopy.

Zhang C, Bélanger S, Pouliot P, Lesage F - PLoS ONE (2015)

Bottom Line: In this work a method for measuring brain oxygen partial pressure with confocal phosphorescence lifetime microscopy system is reported.When used in conjunction with a dendritic phosphorescent probe, Oxyphor G4, this system enabled minimally invasive measurements of oxygen partial pressure (pO2) in cerebral tissue with high spatial and temporal resolution during 4-AP induced epileptic seizures.Our results reveal a correlation between the percent change in the pO2 signal during the "initial dip" and the duration of seizure-like activity, which can help localize the epileptic focus and predict the length of seizure.

View Article: PubMed Central - PubMed

Affiliation: École Polytechnique de Montréal, Department of Electrical Engineering, C.P. 6079 succ.Centre-ville, Montreal, Quebec, Canada, H3C 3A7.

ABSTRACT
In this work a method for measuring brain oxygen partial pressure with confocal phosphorescence lifetime microscopy system is reported. When used in conjunction with a dendritic phosphorescent probe, Oxyphor G4, this system enabled minimally invasive measurements of oxygen partial pressure (pO2) in cerebral tissue with high spatial and temporal resolution during 4-AP induced epileptic seizures. Investigating epileptic events, we characterized the spatio-temporal distribution of the "initial dip" in pO2 near the probe injection site and along nearby arterioles. Our results reveal a correlation between the percent change in the pO2 signal during the "initial dip" and the duration of seizure-like activity, which can help localize the epileptic focus and predict the length of seizure.

No MeSH data available.


Related in: MedlinePlus

Measured pO2 values during normoxia (color dots), overlaid with a grayscale angiogram of cortical pial tissue from an exposed window(with an artery shown by the red arrows).The size of scale bar is 0.2mm.
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pone.0135536.g003: Measured pO2 values during normoxia (color dots), overlaid with a grayscale angiogram of cortical pial tissue from an exposed window(with an artery shown by the red arrows).The size of scale bar is 0.2mm.

Mentions: The spatial pO2 profiles of tissue near an artery at 38 locations were measured in the somatosensory cortex of an anesthetized mouse during normoxia (Fig 3). Obtained pO2 values were within the range of 6-25mmHg, in concordance with previously established cortical pO2 levels by two-photon phosphorescence quenching technique [27]. Relatively high pO2 values were measured close to a large artery, with a rapid pO2 decrease at locations slightly further away from it reflecting values from the capillary bed. These results were in concordance with the fact that tissue pO2 gradients exist at the cortical surface near arteries [32].


Measurement of Local Partial Pressure of Oxygen in the Brain Tissue under Normoxia and Epilepsy with Phosphorescence Lifetime Microscopy.

Zhang C, Bélanger S, Pouliot P, Lesage F - PLoS ONE (2015)

Measured pO2 values during normoxia (color dots), overlaid with a grayscale angiogram of cortical pial tissue from an exposed window(with an artery shown by the red arrows).The size of scale bar is 0.2mm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4549327&req=5

pone.0135536.g003: Measured pO2 values during normoxia (color dots), overlaid with a grayscale angiogram of cortical pial tissue from an exposed window(with an artery shown by the red arrows).The size of scale bar is 0.2mm.
Mentions: The spatial pO2 profiles of tissue near an artery at 38 locations were measured in the somatosensory cortex of an anesthetized mouse during normoxia (Fig 3). Obtained pO2 values were within the range of 6-25mmHg, in concordance with previously established cortical pO2 levels by two-photon phosphorescence quenching technique [27]. Relatively high pO2 values were measured close to a large artery, with a rapid pO2 decrease at locations slightly further away from it reflecting values from the capillary bed. These results were in concordance with the fact that tissue pO2 gradients exist at the cortical surface near arteries [32].

Bottom Line: In this work a method for measuring brain oxygen partial pressure with confocal phosphorescence lifetime microscopy system is reported.When used in conjunction with a dendritic phosphorescent probe, Oxyphor G4, this system enabled minimally invasive measurements of oxygen partial pressure (pO2) in cerebral tissue with high spatial and temporal resolution during 4-AP induced epileptic seizures.Our results reveal a correlation between the percent change in the pO2 signal during the "initial dip" and the duration of seizure-like activity, which can help localize the epileptic focus and predict the length of seizure.

View Article: PubMed Central - PubMed

Affiliation: École Polytechnique de Montréal, Department of Electrical Engineering, C.P. 6079 succ.Centre-ville, Montreal, Quebec, Canada, H3C 3A7.

ABSTRACT
In this work a method for measuring brain oxygen partial pressure with confocal phosphorescence lifetime microscopy system is reported. When used in conjunction with a dendritic phosphorescent probe, Oxyphor G4, this system enabled minimally invasive measurements of oxygen partial pressure (pO2) in cerebral tissue with high spatial and temporal resolution during 4-AP induced epileptic seizures. Investigating epileptic events, we characterized the spatio-temporal distribution of the "initial dip" in pO2 near the probe injection site and along nearby arterioles. Our results reveal a correlation between the percent change in the pO2 signal during the "initial dip" and the duration of seizure-like activity, which can help localize the epileptic focus and predict the length of seizure.

No MeSH data available.


Related in: MedlinePlus