Properties of the Spontaneous Fluctuations in Cortical Oxygen Pressure

Manil, Jacqueline; Bourgain, R.H.; Waeyenberge, Michiel Van; Colin, Fabienne; Blockeel, E.; Mey, B. De; Coremans, J. M. C. C.; Paternoster, R.

doi:10.1007/978-1-4684-1188-1_17

Cited by 24 publications

(12 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The resulting spectrum had a dominant peak at about 5 cpm and gradually falling power at higher frequencies. While this is the only demonstration of this in the retina, we and others have observed similar fluctuations at similar frequencies in the brain of anesthetized animals (Hudetz et al, 1998; Manil et al, 1984; Padnick et al, 1999) and awake rabbits (Linsenmeier et al, 2016a). Generally these fluctuations are believed to reflect ongoing local fluctuations of vascular resistance, termed vasomotion (Aalkjaer et al, 2011), but there is no direct proof of this in the retina.…”

Section: Fundamentals Of O2 Supply To the Retinasupporting

confidence: 79%

Retinal oxygen: from animals to humans

Linsenmeier

Zhang

2017

Progress in Retinal and Eye Research

176

150

View full text Add to dashboard Cite

This article discusses retinal oxygenation and retinal metabolism by focusing on measurements made with two of the principal methods used to study O2 in the retina: measurements of PO2 with oxygen-sensitive microelectrodes in vivo in animals with a retinal circulation similar to that of humans, and oximetry, which can be used non-invasively in both animals and humans to measure O2 concentration in retinal vessels. Microelectrodes uniquely have high spatial resolution, allowing the mapping of PO2 in detail, and when combined with mathematical models of diffusion and consumption, they provide information about retinal metabolism. Mathematical models, grounded in experiments, can also be used to simulate situations that are not amenable to experimental study. New methods of oximetry, particularly photoacoustic ophthalmoscopy and visible light optical coherence tomography, provide depth-resolved methods that can separate signals from blood vessels and surrounding tissues, and can be combined with blood flow measures to determine metabolic rate. We discuss the effects on retinal oxygenation of illumination, hypoxia and hyperoxia, and describe retinal oxygenation in diabetes, retinal detachment, arterial occlusion, and macular degeneration. We explain how the metabolic measurements obtained from microelectrodes and imaging are different, and how they need to be brought together in the future. Finally, we argue for revisiting the clinical use of hyperoxia in ophthalmology, particularly in retinal arterial occlusions and retinal detachment, based on animal research and diffusion theory.

show abstract

Section: Fundamentals Of O2 Supply To the Retinasupporting

confidence: 79%

Retinal oxygen: from animals to humans

Linsenmeier

Zhang

2017

Progress in Retinal and Eye Research

176

150

View full text Add to dashboard Cite

show abstract

“…The faster frequency components in the present work at 22.2 and 44.4 cycles/min are the first and second harmonics of the respiratory frequency, respectively. Manil et al (19) also observed fluctuations with a frequency of 21.6 cycles/min, which is presumed to have been the respiratory frequency.…”

Section: Discussionmentioning

confidence: 97%

Oxygenation of the cat primary visual cortex

Padnick

Linsenmeier

Goldstick

1999

Journal of Applied Physiology

View full text Add to dashboard Cite

Tissue PO2 was measured in the primary visual cortex of anesthetized, artificially ventilated normovolemic cats to examine tissue oxygenation with respect to depth. The method utilized 1) a chamber designed to maintain cerebrospinal fluid pressure and prevent ambient PO2 from influencing the brain, 2) a microelectrode capable of recording electrical activity as well as local PO2, and 3) recordings primarily during electrode withdrawal from the cortex rather than during penetrations. Local peaks in the PO2 profiles were consistent with the presence of numerous vessels. Excluding the superficial 200 microm of the cortex, in which the ambient PO2 may have influenced tissue PO2, there was a slight decrease (4.9 Torr/mm cortex) in PO2 as a function of depth. After all depths and cats were weighted equally, the average PO2 in six cats was 12.8 Torr, with approximately one-half of the values being

show abstract

“…A large vascular contribution to the 1/f-like dynamics in tissue oxygen could potentially explain many disparate observations. It would explain why 1/f-like dynamics are seen in tissue oxygenations throughout the body [1,5,8,9], why we see similar oxygen dynamics across layers and cortical regions ( Figure 2) even though there are large differences in neural activity and vascular density across regions and layers [110][111][112]. Fluctuations in oxygenation generated by the stochastic passage of RBCs are 'noise' and could explain the low correlations and coherences between oxygen and neural activity observed both in our experiments and in BOLD fMRI measures [34,113,115].…”

Section: Discussionmentioning

confidence: 99%

“…Fluctuations in oxygen tension are ubiquitous throughout the body, and are found in muscle tissue and tumors [1], in the retina [2,3], in the carotid artery [4], and in the cortex [5][6][7][8][9][10][11][12]. Despite their ubiquity, relatively little is understood about the origin of these oxygen fluctuations.…”

Section: Introductionmentioning

confidence: 99%

“…Despite their ubiquity, relatively little is understood about the origin of these oxygen fluctuations. While some of these fluctuations are driven by fluctuations in respiration, such as the breathing rate and intensity [4,[13][14][15][16][17][18][19][20], fluctuations in oxygen concentration are present covering a wide range of frequency, not just at the respiration frequency, with most of the power concentrated at lower (< 0.1 Hz) frequencies [1,2,5,[7][8][9]. The power spectrum of oxygen concentrations in many tissues show a "1/f-like" behavior, that is, the power at any given frequency is proportional to 1 # , where the exponent is usually between 1 and 2 [8].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Origins of 1/f-like tissue oxygenation fluctuations in the murine cortex

Zhang

Gheres

Drew

2020

Preprint

View full text Add to dashboard Cite

The concentration of oxygen in the brain spontaneously fluctuates, and the power distribution in these fluctuations has 1/f-like dynamics. Though these oscillations have been interpreted as being driven by neural activity, the origins of these 1/f-like oscillations is not well understood. Here, to gain insight of the origin of the 1/f-like oxygen fluctuations, we investigated the dynamics of tissue oxygenation and neural activity in awake behaving mice. We found that oxygen signal recorded from the cortex of mice had 1/f-like spectra. However, band-limited power in the local field potential, did not show corresponding 1/f-like fluctuations. When local neural activity was suppressed, the 1/f-like fluctuations in oxygen concentration persisted. Two-photon measurements of erythrocyte spacing fluctuations (‘stalls’) and mathematical modelling show that stochastic fluctuations in erythrocyte flow and stalling could underlie 1/f-like dynamics in oxygenation. These results show discrete nature of erythrocytes and their irregular flow, rather than neural activity, could drive 1/f-like fluctuations in tissue oxygenation.

show abstract

Properties of the Spontaneous Fluctuations in Cortical Oxygen Pressure

Cited by 24 publications

References 2 publications

Retinal oxygen: from animals to humans

Retinal oxygen: from animals to humans

Oxygenation of the cat primary visual cortex

Origins of 1/f-like tissue oxygenation fluctuations in the murine cortex

Contact Info

Product

Resources

About