martesae

• Mächler, Philipp; Fomin-Thunemann, Natalie; Thunemann, Martin; Sætra, Marte Julie; Desjardins, Michèle & Kılıç, Kıvılcım [Show all 21 contributors for this article] (2022). Baseline oxygen consumption decreases with cortical depth. PLoS Biology. ISSN 1544-9173. 20(10). doi: 10.1371/journal.pbio.3001440. Full text in Research Archive Show summary

  The cerebral cortex is organized in cortical layers that differ in their cellular density, composition, and wiring. Cortical laminar architecture is also readily revealed by staining for cytochrome oxidase—the last enzyme in the respiratory electron transport chain located in the inner mitochondrial membrane. It has been hypothesized that a high-density band of cytochrome oxidase in cortical layer IV reflects higher oxygen consumption under baseline (unstimulated) conditions. Here, we tested the above hypothesis using direct measurements of the partial pressure of O2 (pO2) in cortical tissue by means of 2-photon phosphorescence lifetime microscopy (2PLM). We revisited our previously developed method for extraction of the cerebral metabolic rate of O2 (CMRO2) based on 2-photon pO2 measurements around diving arterioles and applied this method to estimate baseline CMRO2 in awake mice across cortical layers. To our surprise, our results revealed a decrease in baseline CMRO2 from layer I to layer IV. This decrease of CMRO2 with cortical depth was paralleled by an increase in tissue oxygenation. Higher baseline oxygenation and cytochrome density in layer IV may serve as an O2 reserve during surges of neuronal activity or certain metabolically active brain states rather than reflecting baseline energy needs. Our study provides to our knowledge the first quantification of microscopically resolved CMRO2 across cortical layers as a step towards better understanding of brain energy metabolism.

• Sætra, Marte Julie; Einevoll, Gaute & Halnes, Geir (2021). An electrodiffusive neuron-extracellular-glia model for exploring the genesis of slow potentials in the brain. PLoS Computational Biology. ISSN 1553-734X. 17(7). doi: 10.1371/journal.pcbi.1008143. Full text in Research Archive Show summary

  Within the computational neuroscience community, there has been a focus on simulating the electrical activity of neurons, while other components of brain tissue, such as glia cells and the extracellular space, are often neglected. Standard models of extracellular potentials are based on a combination of multicompartmental models describing neural electrodynamics and volume conductor theory. Such models cannot be used to simulate the slow components of extracellular potentials, which depend on ion concentration dynamics, and the effect that this has on extracellular diffusion potentials and glial buffering currents. We here present the electrodiffusive neuron-extracellular-glia (edNEG) model, which we believe is the first model to combine compartmental neuron modeling with an electrodiffusive framework for intra- and extracellular ion concentration dynamics in a local piece of neuro-glial brain tissue. The edNEG model (i) keeps track of all intraneuronal, intraglial, and extracellular ion concentrations and electrical potentials, (ii) accounts for action potentials and dendritic calcium spikes in neurons, (iii) contains a neuronal and glial homeostatic machinery that gives physiologically realistic ion concentration dynamics, (iv) accounts for electrodiffusive transmembrane, intracellular, and extracellular ionic movements, and (v) accounts for glial and neuronal swelling caused by osmotic transmembrane pressure gradients. The edNEG model accounts for the concentration-dependent effects on ECS potentials that the standard models neglect. Using the edNEG model, we analyze these effects by splitting the extracellular potential into three components: one due to neural sink/source configurations, one due to glial sink/source configurations, and one due to extracellular diffusive currents. Through a series of simulations, we analyze the roles played by the various components and how they interact in generating the total slow potential. We conclude that the three components are of comparable magnitude and that the stimulus conditions determine which of the components that dominate.

• Fomin-Thunemann, Natalie; Mächler, Philipp; Sætra, Marte Julie; Thunemann, Martin; Desjardins, Michèle & Saisan, Payam [Show all 13 contributors for this article] (2020). Estimation of cortical oxygen metabolism in awake mice using two-photon imaging of oxyphor 2p. Biomedical Optics 2020. doi: 10.1364/BRAIN.2020.BTu4C.5.
• Sætra, Marte Julie; Solbrå, Andreas Våvang; Devor, Anna; Sakadžić, Sava; Dale, Anders M. & Einevoll, Gaute (2020). Spatially Resolved Estimation of Metabolic Oxygen Consumption From Optical Measurements in Cortex. Neurophotonics. ISSN 2329-423X. 7(3). doi: 10.1117/1.NPh.7.3.035005. Full text in Research Archive
• Sætra, Marte Julie; Einevoll, Gaute & Halnes, Geir (2020). An electrodiffusive, ion conserving Pinsky-Rinzel model with homeostatic mechanisms. PLoS Computational Biology. ISSN 1553-734X. 16(4), p. 1–36. doi: 10.1371/journal.pcbi.1007661. Full text in Research Archive

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• Sætra, Marte Julie (2019). Abels tårn. [Radio]. P2.
• Sætra, Marte Julie (2019). Abels tårn . [TV]. NRK2.
• Sætra, Marte Julie; Einevoll, Gaute & Halnes, Geir (2019). A two-compartment neuron model with ion conservation and ion pumps.
• Sætra, Marte Julie; Einevoll, Gaute T. & Halnes, Geir (2019). A two-compartment neuron model with ion conservation and ion pumps.
• Sætra, Marte Julie (2018). Intervju i Nitimen om matematikk og kjærlighet. [Radio]. NRK P1.
• Sætra, Marte Julie & Heiberg, Hallvard (2018). Kommunikasjon mellom hjerneceller.
• Sætra, Marte Julie & Heiberg, Hallvard (2018). Kommunikasjon mellom hjerneceller.
• Sætra, Marte Julie (2018). Foredrag om hjernefysikk.
• Sætra, Marte Julie (2018). Foredrag om hjernefysikk.
• Sætra, Marte Julie (2018). Foredrag om hjernefysikk.
• Sætra, Marte Julie (2018). En enkel matematisk formel for å finne kjærligheten. argument. ISSN 1504-6087.
• Sætra, Marte Julie (2018). Fysikeren som ble hjerneforsker.
• Sætra, Marte Julie (2018). Foredrag om hjernefysikk.
• Sætra, Marte Julie (2018). Abels Tårn. [TV]. NRK.
• Sætra, Marte Julie (2017). Intervju om blåtimen. [Radio]. Ekko - NRK.
• Sætra, Marte Julie (2017). Foredrag om hjernefysikk.
• Sætra, Marte Julie (2017). Foredrag om hjernefysikk.
• Sætra, Marte Julie (2017). Foredrag om hjernefysikk.
• Sætra, Marte Julie (2017). Foredrag om hjernefysikk.
• Sætra, Marte Julie (2017). Foredrag om hjernefysikk.
• Sætra, Marte Julie (2017). Foredrag om hjernefysikk.
• Sætra, Marte Julie (2017). Foredrag om hjernefysikk.
• Sætra, Marte Julie (2017). Foredrag om hjernefysikk.
• Sætra, Marte Julie; Dale, Anders M.; Devor, Anna & Einevoll, Gaute T. (2017). Estimation of Oxygen Consumption From Optical Measurements in Cortex.
• Sætra, Marte Julie; Dale, Anders M.; Devor, Anna & Einevoll, Gaute T. (2017). Estimation of Oxygen Consumption From Optical Measurements in Cortex.
• Sætra, Marte Julie; Dale, Anders M.; Devor, Anna & Einevoll, Gaute T. (2017). Estimation of Oxygen Consumption From Optical Measurements in Cortex.
• Sætra, Marte Julie (2017). Can Computer Simulations Substitute Animal Research? digitallifenorway.org.
• Sætra, Marte Julie (2017). Kan databeregninger erstatte dyreforsøk? Aftenposten (morgenutg. : trykt utg.). ISSN 0804-3116.
• Sætra, Marte Julie (2017). Hva har krefter med hjernen vår å gjøre? Titan.uio.no.
• Sætra, Marte Julie; Raklev, Are; Hrubos-Strøm, Harald & Jemterud, Torkild (2017). Abels Tårn. [Radio]. Ekko - NRK.
• Sætra, Marte Julie (2016). Foredrag om hjernefysikk.
• Sætra, Marte Julie (2016). Intervju om fysikk og hjerneforskning. [Newspaper]. Enebakk Avis.
• Sætra, Marte Julie (2016). Foredrag om hjernefysikk.
• Sætra, Marte Julie (2016). Foredrag om hjernefysikk.
• Sætra, Marte Julie; Dale, Anders M.; Devor, Anna & Einevoll, Gaute T. (2016). Estimation of Oxygen Consumption From Optical Measurements in Cortex.
• Sætra, Marte Julie (2015). Ja takk, mer enn hjerne. argument. ISSN 1504-6087. p. 40–41.

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