1
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Chausse B, Malorny N, Lewen A, Poschet G, Berndt N, Kann O. Metabolic flexibility ensures proper neuronal network function in moderate neuroinflammation. Sci Rep 2024; 14:14405. [PMID: 38909138 PMCID: PMC11193723 DOI: 10.1038/s41598-024-64872-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 06/13/2024] [Indexed: 06/24/2024] Open
Abstract
Microglia, brain-resident macrophages, can acquire distinct functional phenotypes, which are supported by differential reprogramming of cell metabolism. These adaptations include remodeling in glycolytic and mitochondrial metabolic fluxes, potentially altering energy substrate availability at the tissue level. This phenomenon may be highly relevant in the brain, where metabolism must be precisely regulated to maintain appropriate neuronal excitability and synaptic transmission. Direct evidence that microglia can impact on neuronal energy metabolism has been widely lacking, however. Combining molecular profiling, electrophysiology, oxygen microsensor recordings and mathematical modeling, we investigated microglia-mediated disturbances in brain energetics during neuroinflammation. Our results suggest that proinflammatory microglia showing enhanced nitric oxide release and decreased CX3CR1 expression transiently increase the tissue lactate/glucose ratio that depends on transcriptional reprogramming in microglia, not in neurons. In this condition, neuronal network activity such as gamma oscillations (30-70 Hz) can be fueled by increased ATP production in mitochondria, which is reflected by elevated oxygen consumption. During dysregulated inflammation, high energy demand and low glucose availability can be boundary conditions for neuronal metabolic fitness as revealed by kinetic modeling of single neuron energetics. Collectively, these findings indicate that metabolic flexibility protects neuronal network function against alterations in local substrate availability during moderate neuroinflammation.
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Affiliation(s)
- Bruno Chausse
- Institute of Physiology and Pathophysiology, Heidelberg University, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany.
- MEDISS Doctoral Program, INF 110, Heidelberg University, 69120, Heidelberg, Germany.
| | - Nikolai Malorny
- Institute of Physiology and Pathophysiology, Heidelberg University, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
| | - Andrea Lewen
- Institute of Physiology and Pathophysiology, Heidelberg University, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
| | - Gernot Poschet
- Metabolomics Core Technology Platform, Centre for Organismal Studies, Heidelberg University, 69120, Heidelberg, Germany
| | - Nikolaus Berndt
- Department of Molecular Toxicology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), 14558, Nuthetal, Germany
- Institute of Computer-Assisted Cardiovascular Medicine, Deutsches Herzzentrum der Charité (DHZC), 13353, Berlin, Germany
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117, Berlin, Germany
| | - Oliver Kann
- Institute of Physiology and Pathophysiology, Heidelberg University, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany.
- Interdisciplinary Center for Neurosciences (IZN), Heidelberg University, 69120, Heidelberg, Germany.
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2
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Schoknecht K, Maechler M, Wallach I, Dreier JP, Liotta A, Berndt N. Isoflurane lowers the cerebral metabolic rate of oxygen and prevents hypoxia during cortical spreading depolarization in vitro: An integrative experimental and modeling study. J Cereb Blood Flow Metab 2024; 44:1000-1012. [PMID: 38140913 PMCID: PMC11318408 DOI: 10.1177/0271678x231222306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 10/23/2023] [Accepted: 11/29/2023] [Indexed: 12/24/2023]
Abstract
Cortical spreading depolarization (SD) imposes a massive increase in energy demand and therefore evolves as a target for treatment following acute brain injuries. Anesthetics are empirically used to reduce energy metabolism in critical brain conditions, yet their effect on metabolism during SD remains largely unknown. We investigated oxidative metabolism during SD in brain slices from Wistar rats. Extracellular potassium ([K+]o), local field potential and partial tissue oxygen pressure (ptiO2) were measured simultaneously. The cerebral metabolic rate of oxygen (CMRO2) was calculated using a reaction-diffusion model. By that, we tested the effect of clinically relevant concentrations of isoflurane on CMRO2 during SD and modeled tissue oxygenation for different capillary pO2 values. During SD, CMRO2 increased 2.7-fold, resulting in transient hypoxia in the slice core. Isoflurane decreased CMRO2, reduced peak [K+]o, and prolonged [K+]o clearance, which indicates reduced synaptic transmission and sodium-potassium ATPase inhibition. Modeling tissue oxygenation during SD illustrates the need for increased capillary pO2 levels to prevent hypoxia. In the absence thereof, isoflurane could improve tissue oxygenation by lowering CMRO2. Therefore, isoflurane is a promising candidate for pre-clinical studies on neuronal survival in conditions involving SD.
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Affiliation(s)
- Karl Schoknecht
- Carl-Ludwig-Institute of Physiology, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Mathilde Maechler
- Department of Anesthesiology and Intensive Care, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- Institute of Neurophysiology, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- Institute of Computer-Assisted Cardiovascular Medicine, Deutsches Herzzentrum der Charité (DHZC), Berlin, Germany
| | - Iwona Wallach
- Institute of Computer-Assisted Cardiovascular Medicine, Deutsches Herzzentrum der Charité (DHZC), Berlin, Germany
- Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Jens P Dreier
- Centre for Stroke Research Berlin, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Experimental Neurology, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Neurology, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- Bernstein Centre for Computational Neuroscience Berlin, Berlin, Germany
- Einstein Centre for Neurosciences Berlin, Berlin, Germany
| | - Agustin Liotta
- Department of Anesthesiology and Intensive Care, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- Institute of Neurophysiology, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- Institute of Computer-Assisted Cardiovascular Medicine, Deutsches Herzzentrum der Charité (DHZC), Berlin, Germany
- Department of Experimental Neurology, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- Institute of Health at Charité – Universitätsmedizin Berlin, Berlin
- Neuroscience Research Center, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Nikolaus Berndt
- Institute of Computer-Assisted Cardiovascular Medicine, Deutsches Herzzentrum der Charité (DHZC), Berlin, Germany
- Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), Department of Molecular Toxicology, Nuthetal, Germany
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3
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He Y, He T, Li H, Chen W, Zhong B, Wu Y, Chen R, Hu Y, Ma H, Wu B, Hu W, Han Z. Deciphering mitochondrial dysfunction: Pathophysiological mechanisms in vascular cognitive impairment. Biomed Pharmacother 2024; 174:116428. [PMID: 38599056 DOI: 10.1016/j.biopha.2024.116428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/26/2024] [Accepted: 03/08/2024] [Indexed: 04/12/2024] Open
Abstract
Vascular cognitive impairment (VCI) encompasses a range of cognitive deficits arising from vascular pathology. The pathophysiological mechanisms underlying VCI remain incompletely understood; however, chronic cerebral hypoperfusion (CCH) is widely acknowledged as a principal pathological contributor. Mitochondria, crucial for cellular energy production and intracellular signaling, can lead to numerous neurological impairments when dysfunctional. Recent evidence indicates that mitochondrial dysfunction-marked by oxidative stress, disturbed calcium homeostasis, compromised mitophagy, and anomalies in mitochondrial dynamics-plays a pivotal role in VCI pathogenesis. This review offers a detailed examination of the latest insights into mitochondrial dysfunction within the VCI context, focusing on both the origins and consequences of compromised mitochondrial health. It aims to lay a robust scientific groundwork for guiding the development and refinement of mitochondrial-targeted interventions for VCI.
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Affiliation(s)
- Yuyao He
- Shenzhen Hospital, Beijing University of Chinese Medicine, Shenzhen, Guangdong, China
| | - Tiantian He
- Sichuan Academy of Chinese Medicine Sciences, China
| | - Hongpei Li
- Shenzhen Hospital, Beijing University of Chinese Medicine, Shenzhen, Guangdong, China
| | - Wei Chen
- Shenzhen Hospital, Beijing University of Chinese Medicine, Shenzhen, Guangdong, China
| | - Biying Zhong
- Shenzhen Hospital, Beijing University of Chinese Medicine, Shenzhen, Guangdong, China
| | - Yue Wu
- Shenzhen Hospital, Beijing University of Chinese Medicine, Shenzhen, Guangdong, China
| | - Runming Chen
- Shenzhen Hospital, Beijing University of Chinese Medicine, Shenzhen, Guangdong, China
| | - Yuli Hu
- Shenzhen Hospital, Beijing University of Chinese Medicine, Shenzhen, Guangdong, China
| | - Huaping Ma
- Shenzhen Hospital, Beijing University of Chinese Medicine, Shenzhen, Guangdong, China
| | - Bin Wu
- Shenzhen Hospital, Beijing University of Chinese Medicine, Shenzhen, Guangdong, China
| | - Wenyue Hu
- Shenzhen Hospital, Beijing University of Chinese Medicine, Shenzhen, Guangdong, China.
| | - Zhenyun Han
- Shenzhen Hospital, Beijing University of Chinese Medicine, Shenzhen, Guangdong, China.
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4
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Kann O. Lactate as a supplemental fuel for synaptic transmission and neuronal network oscillations: Potentials and limitations. J Neurochem 2024; 168:608-631. [PMID: 37309602 DOI: 10.1111/jnc.15867] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 05/15/2023] [Accepted: 05/18/2023] [Indexed: 06/14/2023]
Abstract
Lactate shuttled from the blood circulation, astrocytes, oligodendrocytes or even activated microglia (resident macrophages) to neurons has been hypothesized to represent a major source of pyruvate compared to what is normally produced endogenously by neuronal glucose metabolism. However, the role of lactate oxidation in fueling neuronal signaling associated with complex cortex function, such as perception, motor activity, and memory formation, is widely unclear. This issue has been experimentally addressed using electrophysiology in hippocampal slice preparations (ex vivo) that permit the induction of different neural network activation states by electrical stimulation, optogenetic tools or receptor ligand application. Collectively, these studies suggest that lactate in the absence of glucose (lactate only) impairs gamma (30-70 Hz) and theta-gamma oscillations, which feature high energy demand revealed by the cerebral metabolic rate of oxygen (CMRO2, set to 100%). The impairment comprises oscillation attenuation or moderate neural bursts (excitation-inhibition imbalance). The bursting is suppressed by elevating the glucose fraction in energy substrate supply. By contrast, lactate can retain certain electric stimulus-induced neural population responses and intermittent sharp wave-ripple activity that features lower energy expenditure (CMRO2 of about 65%). Lactate utilization increases the oxygen consumption by about 9% during sharp wave-ripples reflecting enhanced adenosine-5'-triphosphate (ATP) synthesis by oxidative phosphorylation in mitochondria. Moreover, lactate attenuates neurotransmission in glutamatergic pyramidal cells and fast-spiking, γ-aminobutyric acid (GABA)ergic interneurons by reducing neurotransmitter release from presynaptic terminals. By contrast, the generation and propagation of action potentials in the axon is regular. In conclusion, lactate is less effective than glucose and potentially detrimental during neural network rhythms featuring high energetic costs, likely through the lack of some obligatory ATP synthesis by aerobic glycolysis at excitatory and inhibitory synapses. High lactate/glucose ratios might contribute to central fatigue, cognitive impairment, and epileptic seizures partially seen, for instance, during exhaustive physical exercise, hypoglycemia and neuroinflammation.
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Affiliation(s)
- Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
- Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
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5
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Theriault JE, Shaffer C, Dienel GA, Sander CY, Hooker JM, Dickerson BC, Barrett LF, Quigley KS. A functional account of stimulation-based aerobic glycolysis and its role in interpreting BOLD signal intensity increases in neuroimaging experiments. Neurosci Biobehav Rev 2023; 153:105373. [PMID: 37634556 PMCID: PMC10591873 DOI: 10.1016/j.neubiorev.2023.105373] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 07/28/2023] [Accepted: 08/23/2023] [Indexed: 08/29/2023]
Abstract
In aerobic glycolysis, oxygen is abundant, and yet cells metabolize glucose without using it, decreasing their ATP per glucose yield by 15-fold. During task-based stimulation, aerobic glycolysis occurs in localized brain regions, presenting a puzzle: why produce ATP inefficiently when, all else being equal, evolution should favor the efficient use of metabolic resources? The answer is that all else is not equal. We propose that a tradeoff exists between efficient ATP production and the efficiency with which ATP is spent to transmit information. Aerobic glycolysis, despite yielding little ATP per glucose, may support neuronal signaling in thin (< 0.5 µm), information-efficient axons. We call this the efficiency tradeoff hypothesis. This tradeoff has potential implications for interpretations of task-related BOLD "activation" observed in fMRI. We hypothesize that BOLD "activation" may index local increases in aerobic glycolysis, which support signaling in thin axons carrying "bottom-up" information, or "prediction error"-i.e., the BIAPEM (BOLD increases approximate prediction error metabolism) hypothesis. Finally, we explore implications of our hypotheses for human brain evolution, social behavior, and mental disorders.
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Affiliation(s)
- Jordan E Theriault
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA; Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.
| | - Clare Shaffer
- Northeastern University, Department of Psychology, Boston, MA, USA
| | - Gerald A Dienel
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR, USA; Department of Cell Biology and Physiology, University of New Mexico, Albuquerque, NM, USA
| | - Christin Y Sander
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA; Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Jacob M Hooker
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA; Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Bradford C Dickerson
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA; Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA; Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Lisa Feldman Barrett
- Northeastern University, Department of Psychology, Boston, MA, USA; Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA; Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Karen S Quigley
- Northeastern University, Department of Psychology, Boston, MA, USA; VA Bedford Healthcare System, Bedford, MA, USA
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6
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Acute Hypobaric Hypoxia Exposure Causes Neurobehavioral Impairments in Rats: Role of Brain Catecholamines and Tetrahydrobiopterin Alterations. Neurochem Res 2023; 48:471-486. [PMID: 36205808 DOI: 10.1007/s11064-022-03767-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 09/12/2022] [Accepted: 09/22/2022] [Indexed: 02/07/2023]
Abstract
Hypoxia is a state in which the body or a specific part of the body is deprived of adequate oxygen supply at the tissue level. Sojourners involved in different activities at high altitudes (> 2500 m) face hypobaric hypoxia (HH) due to low oxygen in the atmosphere. HH is an example of generalized hypoxia, where the homeostasis of the entire body of an organism is affected and results in neurochemical changes. It is known that lower O2 levels affect catecholamines (CA), severely impairing cognitive and locomotor behavior. However, there is less evidence on the effect of HH-mediated alteration in brain Tetrahydrobiopterin (BH4) levels and its role in neurobehavioral impairments. Hence, this study aimed to shed light on the effect of acute HH on CA and BH4 levels with its neurobehavioral impact on Wistar rat models. After HH exposure, significant alteration of the CA levels in the discrete brain regions, viz., frontal cortex, hippocampus, midbrain, and cerebellum was observed. HH exposure significantly reduced spontaneous motor activity, motor coordination, and spatial memory. The present study suggests that the HH-induced behavioral changes might be related to the alteration of the expression pattern of CA and BH4-related genes and proteins in different rat brain regions. Overall, this study provides novel insights into the role of BH4 and CA in HH-induced neurobehavioral impairments.
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7
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Joshi SN, Joshi AN, Joshi ND. Interplay between biochemical processes and network properties generates neuronal up and down states at the tripartite synapse. Phys Rev E 2023; 107:024415. [PMID: 36932559 DOI: 10.1103/physreve.107.024415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 01/03/2023] [Indexed: 06/18/2023]
Abstract
Neuronal up and down states have long been known to exist both in vitro and in vivo. A variety of functions and mechanisms have been proposed for their generation, but there has not been a clear connection between the functions and mechanisms. We explore the potential contribution of cellular-level biochemistry to the network-level mechanisms thought to underlie the generation of up and down states. We develop a neurochemical model of a single tripartite synapse, assumed to be within a network of similar tripartite synapses, to investigate possible function-mechanism links for the appearance of up and down states. We characterize the behavior of our model in different regions of parameter space and show that resource limitation at the tripartite synapse affects its ability to faithfully transmit input signals, leading to extinction-down states. Recovery of resources allows for "reignition" into up states. The tripartite synapse exhibits distinctive "regimes" of operation depending on whether ATP, neurotransmitter (glutamate), both, or neither, is limiting. Our model qualitatively matches the behavior of six disparate experimental systems, including both in vitro and in vivo models, without changing any model parameters except those related to the experimental conditions. We also explore the effects of varying different critical parameters within the model. Here we show that availability of energy, represented by ATP, and glutamate for neurotransmission at the cellular level are intimately related, and are capable of promoting state transitions at the network level as ignition and extinction phenomena. Our model is complementary to existing models of neuronal up and down states in that it focuses on cellular-level dynamics while still retaining essential network-level processes. Our model predicts the existence of a "final common pathway" of behavior at the tripartite synapse arising from scarcity of resources and may explain use dependence in the phenomenon of "local sleep." Ultimately, sleeplike behavior may be a fundamental property of networks of tripartite synapses.
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Affiliation(s)
- Shubhada N Joshi
- National Center for Adaptive Neurotechnologies (NCAN), David Axelrod Institute, Wadsworth Center, New York State Department of Health, 120 New Scotland Ave., Albany, New York 12208, USA
| | - Aditya N Joshi
- Stanford University School of Medicine, 300 Pasteur Dr., Stanford, California 94305, USA
| | - Narendra D Joshi
- General Electric Global Research, 1 Research Circle, Niskayuna, New York 12309, USA
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8
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Hammer M, Jung F, Brankačk J, Yanovsky Y, Tort ABL, Draguhn A. Respiration and rapid eye movement (
REM)
sleep substructure: short versus long episodes. J Sleep Res 2022; 32:e13777. [PMID: 36398708 DOI: 10.1111/jsr.13777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 09/11/2022] [Accepted: 10/18/2022] [Indexed: 11/19/2022]
Abstract
Rapid eye movement (REM) sleep in rodents is defined by the presence of theta rhythm in the absence of movement. The amplitude and frequency of theta oscillations have been used to distinguish between tonic and phasic REM sleep. However, tonic REM sleep has not been further subdivided, although characteristics of network oscillations such as cross-frequency coupling between theta and gamma vary within this sub-state. Recently, it has been shown that theta-gamma coupling depends on an optimal breathing rate of ~5 Hz. The frequency of breathing varies strongly throughout REM sleep, and the duration of single REM sleep episodes ranges from several seconds to minutes, whereby short episodes predominate. Here we studied the relation between breathing frequency, accelerometer activity, and the length of REM sleep periods. We found that small movements detected with three-dimensional accelerometry positively correlate with breathing rate. Interestingly, breathing is slow in short REM sleep episodes, while faster respiration regimes exclusively occur after a certain delay in longer REM sleep episodes. Thus, merging REM sleep episodes of different lengths will result in a predominance of slow respiration due to the higher occurrence of short REM sleep periods. Moreover, our results reveal that not only do phasic REM sleep epochs predominantly occur during long REM sleep episodes, but that the long episodes also have faster theta and higher gamma activity. These observations suggest that REM sleep can be further divided from a physiological point of view depending on its duration. Higher levels of arousal during REM sleep, indicated by higher breathing rates, can only be captured in long REM sleep episodes.
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Affiliation(s)
- Maximilian Hammer
- Department of Physiology and Pathophysiology University of Heidelberg Heidelberg Germany
| | - Felix Jung
- Department of Physiology and Pathophysiology University of Heidelberg Heidelberg Germany
- Department of Neuroscience Karolinska Institute Stockholm Sweden
| | - Jurij Brankačk
- Department of Physiology and Pathophysiology University of Heidelberg Heidelberg Germany
| | - Yevgenij Yanovsky
- Department of Physiology and Pathophysiology University of Heidelberg Heidelberg Germany
| | - Adriano B. L. Tort
- Brain Institute Federal University of Rio Grande do Norte Natal Rio Grande do Norte Brazil
| | - Andreas Draguhn
- Department of Physiology and Pathophysiology University of Heidelberg Heidelberg Germany
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Zalachoras I, Ramos-Fernández E, Hollis F, Trovo L, Rodrigues J, Strasser A, Zanoletti O, Steiner P, Preitner N, Xin L, Astori S, Sandi C. Glutathione in the nucleus accumbens regulates motivation to exert reward-incentivized effort. eLife 2022; 11:77791. [DOI: 10.7554/elife.77791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 10/17/2022] [Indexed: 11/09/2022] Open
Abstract
Emerging evidence is implicating mitochondrial function and metabolism in the nucleus accumbens in motivated performance. However, the brain is vulnerable to excessive oxidative insults resulting from neurometabolic processes, and whether antioxidant levels in the nucleus accumbens contribute to motivated performance is not known. Here, we identify a critical role for glutathione (GSH), the most important endogenous antioxidant in the brain, in motivation. Using proton magnetic resonance spectroscopy at ultra-high field in both male humans and rodent populations, we establish that higher accumbal GSH levels are highly predictive of better, and particularly, steady performance over time in effort-related tasks. Causality was established in in vivo experiments in rats that, first, showed that downregulating GSH levels through micro-injections of the GSH synthesis inhibitor buthionine sulfoximine in the nucleus accumbens impaired effort-based reward-incentivized performance. In addition, systemic treatment with the GSH precursor N-acetyl-cysteine increased accumbal GSH levels in rats and led to improved performance, potentially mediated by a cell-type-specific shift in glutamatergic inputs to accumbal medium spiny neurons. Our data indicate a close association between accumbal GSH levels and an individual’s capacity to exert reward-incentivized effort over time. They also suggest that improvement of accumbal antioxidant function may be a feasible approach to boost motivation.
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Affiliation(s)
- Ioannis Zalachoras
- Laboratory of Behavioral Genetics (LGC), Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL)
| | - Eva Ramos-Fernández
- Laboratory of Behavioral Genetics (LGC), Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL)
| | - Fiona Hollis
- Laboratory of Behavioral Genetics (LGC), Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL)
- Department of Pharmacology, Physiology, and Neuroscience, University of South Carolina School of Medicine
| | - Laura Trovo
- Nestlé Institute of Health Sciences, Nestlé Research, Société des Produits Nestlé SA, Vers-chez-les-Blanc
| | - João Rodrigues
- Laboratory of Behavioral Genetics (LGC), Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL)
| | - Alina Strasser
- Laboratory of Behavioral Genetics (LGC), Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL)
| | - Olivia Zanoletti
- Laboratory of Behavioral Genetics (LGC), Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL)
| | - Pascal Steiner
- Nestlé Institute of Health Sciences, Nestlé Research, Société des Produits Nestlé SA, Vers-chez-les-Blanc
| | - Nicolas Preitner
- Nestlé Institute of Health Sciences, Nestlé Research, Société des Produits Nestlé SA, Vers-chez-les-Blanc
| | - Lijing Xin
- Animal Imaging and Technology Core (AIT), Center for Biomedical Imaging (CIBM), EPFL
| | - Simone Astori
- Laboratory of Behavioral Genetics (LGC), Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL)
| | - Carmen Sandi
- Laboratory of Behavioral Genetics (LGC), Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL)
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10
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Aksenov DP, Doubovikov ED, Serdyukova NA, Gascoigne DA, Linsenmeier RA, Drobyshevsky A. Brain tissue oxygen dynamics while mimicking the functional deficiency of interneurons. Front Cell Neurosci 2022; 16:983298. [PMID: 36339824 PMCID: PMC9630360 DOI: 10.3389/fncel.2022.983298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 10/06/2022] [Indexed: 11/13/2022] Open
Abstract
The dynamic interaction between excitatory and inhibitory activity in the brain is known as excitatory-inhibitory balance (EIB). A significant shift in EIB toward excitation has been observed in numerous pathological states and diseases, such as autism or epilepsy, where interneurons may be dysfunctional. The consequences of this on neurovascular interactions remains to be elucidated. Specifically, it is not known if there is an elevated metabolic consumption of oxygen due to increased excitatory activity. To investigate this, we administered microinjections of picrotoxin, a gamma aminobutyric acid (GABA) antagonist, to the rabbit cortex in the awake state to mimic the functional deficiency of GABAergic interneurons. This caused an observable shift in EIB toward excitation without the induction of seizures. We used chronically implanted electrodes to measure both neuronal activity and brain tissue oxygen concentrations (PO2) simultaneously and in the same location. Using a high-frequency recording rate for PO2, we were able to detect two important phenomena, (1) the shift in EIB led to a change in the power spectra of PO2 fluctuations, such that higher frequencies (8-15 cycles per minute) were suppressed and (2) there were brief periods (dips with a duration of less than 100 ms associated with neuronal bursts) when PO2 dropped below 10 mmHg, which we defined as the threshold for hypoxia. The dips were followed by an overshoot, which indicates either a rapid vascular response or decrease in oxygen consumption. Our results point to the essential role of interneurons in brain tissue oxygen regulation in the resting state.
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Affiliation(s)
- Daniil P. Aksenov
- Department of Radiology, NorthShore University HealthSystem, Evanston, IL, United States,Department of Anesthesiology, NorthShore University HealthSystem, Evanston, IL, United States,Pritzker School of Medicine, University of Chicago, Chicago, IL, United States,*Correspondence: Daniil P. Aksenov,
| | - Evan D. Doubovikov
- Department of Radiology, NorthShore University HealthSystem, Evanston, IL, United States
| | - Natalya A. Serdyukova
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, United States,Department of Pediatrics, NorthShore University HealthSystem, Evanston, IL, United States
| | - David A. Gascoigne
- Department of Radiology, NorthShore University HealthSystem, Evanston, IL, United States
| | - Robert A. Linsenmeier
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, United States
| | - Alexander Drobyshevsky
- Pritzker School of Medicine, University of Chicago, Chicago, IL, United States,Department of Pediatrics, NorthShore University HealthSystem, Evanston, IL, United States
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11
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Taylor E, Hill RP, Létourneau D. Modeling the impact of spatial oxygen heterogeneity on radiolytic oxygen depletion during FLASH radiotherapy. Phys Med Biol 2022; 67. [PMID: 35576920 DOI: 10.1088/1361-6560/ac702c] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 05/16/2022] [Indexed: 12/12/2022]
Abstract
Purpose.It has been postulated that the delivery of radiotherapy at ultra-high dose rates ('FLASH') reduces normal tissue toxicities by depleting them of oxygen. The fraction of normal tissue and cancer cells surviving radiotherapy depends on dose and oxygen levels in an exponential manner and even a very small fraction of tissue at low oxygen levels can determine radiotherapy response. To quantify the differential impact of FLASH radiotherapy on normal and tumour tissues, the spatial heterogeneity of oxygenation in tissue should thus be accounted for.Methods.The effect of FLASH on radiation-induced normal and tumour tissue cell killing was studied by simulating oxygen diffusion, metabolism, and radiolytic oxygen depletion (ROD) over domains with simulated capillary architectures. To study the impact of heterogeneity, two architectural models were used: (1) randomly distributed capillaries and (2) capillaries forming a regular square lattice array. The resulting oxygen partial pressure distribution histograms were used to simulate normal and tumour tissue cell survival using the linear quadratic model of cell survival, modified to incorporate oxygen-enhancement ratio effects. The ratio ('dose modifying factors') of conventional low-dose-rate dose and FLASH dose at iso-cell survival was computed and compared with empirical iso-toxicity dose ratios.Results.Tumour cell survival was found to be increased by FLASH as compared to conventional radiotherapy, with a 0-1 order of magnitude increase for expected levels of tumour hypoxia, depending on the relative magnitudes of ROD and tissue oxygen metabolism. Interestingly, for the random capillary model, the impact of FLASH on well-oxygenated (normal) tissues was found to be much greater, with an estimated increase in cell survival by up to 10 orders of magnitude, even though reductions in mean tissue partial pressure were modest, less than ∼7 mmHg for the parameter values studied. The dose modifying factor for normal tissues was found to lie in the range 1.2-1.7 for a representative value of normal tissue oxygen metabolic rate, consistent with preclinical iso-toxicity results.Conclusions.The presence of very small nearly hypoxic regions in otherwise well-perfused normal tissues with high mean oxygen levels resulted in a greater proportional sparing of normal tissue than tumour cells during FLASH irradiation, possibly explaining empirical normal tissue sparing and iso-tumour control results.
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Affiliation(s)
- Edward Taylor
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Richard P Hill
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Daniel Létourneau
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
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12
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Abstract
Mitochondria play a central role in the pathophysiological processes of acute ischemic stroke. Disruption of the cerebral blood flow during acute ischemic stroke interrupts oxygen and glucose delivery, leading to the dysfunction of mitochondrial oxidative phosphorylation and cellular bioenergetic stress. Cells can respond to such stress by activating mitochondrial quality control mechanisms, including the mitochondrial unfolded protein response, mitochondrial fission and fusion, mitophagy, mitochondrial biogenesis, and intercellular mitochondrial transfer. Collectively, these adaptive response strategies contribute to retaining the integrity and function of the mitochondrial network, thereby helping to recover the homeostasis of the neurovascular unit. In this review, we focus on mitochondrial quality control mechanisms occurring in acute ischemic stroke. A better understanding of how these regulatory pathways work in maintaining mitochondrial homeostasis will provide a rationale for developing innovative neuroprotectants when these mechanisms fail in acute ischemic stroke.
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Affiliation(s)
- Hong An
- Department of Neurology and China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Bing Zhou
- Department of Neurology and China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China.,Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Beihang University, Beijing, China.,Interdisciplinary Innovation Institute of Medicine and Engineering Interdisciplinary, Beihang University, Beijing, China
| | - Xunming Ji
- Department of Neurology and China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China.,Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Beihang University, Beijing, China.,Interdisciplinary Innovation Institute of Medicine and Engineering Interdisciplinary, Beihang University, Beijing, China.,Department of Neurosurgery, 71044Xuanwu Hospital, Xuanwu Hospital, Capital Medical University, Beijing, China
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13
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Özugur S, Chávez MN, Sanchez-Gonzalez R, Kunz L, Nickelsen J, Straka H. Green oxygen power plants in the brain rescue neuronal activity. iScience 2021; 24:103158. [PMID: 34755084 PMCID: PMC8560625 DOI: 10.1016/j.isci.2021.103158] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 09/03/2021] [Accepted: 09/17/2021] [Indexed: 10/30/2022] Open
Abstract
Neuronal activity in the brain depends on mostly aerobic generation of energy equivalents and thus on a constant O2 supply. Oxygenation of the vertebrate brain has been optimized during evolution by species-specific uptake and transport of O2 that originally derives from the phototrophic activity of prokaryotic and eukaryotic organisms in the environment. Here, we employed a concept that exploits transcardial injection and vascular distribution of unicellular green algae or cyanobacteria in the brain of Xenopus laevis tadpoles. Using oxygen measurements in the brain ventricle, we found that these microorganisms robustly produce sizable amounts of O2 upon illumination. In a severe hypoxic environment, when neuronal activity has completely ceased, the photosynthetic O2 reliably provoked a restart and rescue of neuronal activity. In the future, phototrophic microorganisms might provide a novel means to directly increase oxygen levels in the brain in a controlled manner under particular eco-physiological conditions or following pathological impairments.
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Affiliation(s)
- Suzan Özugur
- Department Biology II, Ludwig-Maximilians-University Munich, Großhaderner Str. 2, 82152 Planegg, Germany.,Graduate School of Systemic Neurosciences, Ludwig-Maximilians-University Munich, Großhaderner Str. 2, 82152 Planegg, Germany
| | - Myra N Chávez
- Department Biology I, Ludwig-Maximilians-University Munich, Großhaderner Str. 4, 82152 Planegg, Germany
| | - Rosario Sanchez-Gonzalez
- Department Biology II, Ludwig-Maximilians-University Munich, Großhaderner Str. 2, 82152 Planegg, Germany
| | - Lars Kunz
- Department Biology II, Ludwig-Maximilians-University Munich, Großhaderner Str. 2, 82152 Planegg, Germany
| | - Jörg Nickelsen
- Department Biology I, Ludwig-Maximilians-University Munich, Großhaderner Str. 4, 82152 Planegg, Germany
| | - Hans Straka
- Department Biology II, Ludwig-Maximilians-University Munich, Großhaderner Str. 2, 82152 Planegg, Germany
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14
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Intermittent Hypoxia and Effects on Early Learning/Memory: Exploring the Hippocampal Cellular Effects of Pediatric Obstructive Sleep Apnea. Anesth Analg 2021; 133:93-103. [PMID: 33234943 DOI: 10.1213/ane.0000000000005273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
This review provides an update on the neurocognitive phenotype of pediatric obstructive sleep apnea (OSA). Pediatric OSA is associated with neurocognitive deficits involving memory, learning, and executive functioning. Adenotonsillectomy (AT) is presently accepted as the first-line surgical treatment for pediatric OSA, but the executive function deficits do not resolve postsurgery, and the timeline for recovery remains unknown. This finding suggests that pediatric OSA potentially causes irreversible damage to multiple areas of the brain. The focus of this review is the hippocampus, 1 of the 2 major sites of postnatal neurogenesis, where new neurons are formed and integrated into existing circuitry and the mammalian center of learning/memory functions. Here, we review the clinical phenotype of pediatric OSA, and then discuss existing studies of OSA on different cell types in the hippocampus during critical periods of development. This will set the stage for future study using preclinical models to understand the pathogenesis of persistent neurocognitive dysfunction in pediatric OSA.
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15
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Grieb B, Uppala S, Sapir G, Shaul D, Gomori JM, Katz-Brull R. Curbing action potential generation or ATP-synthase leads to a decrease in in-cell pyruvate dehydrogenase activity in rat cerebrum slices. Sci Rep 2021; 11:10211. [PMID: 33986346 PMCID: PMC8119472 DOI: 10.1038/s41598-021-89534-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Accepted: 04/19/2021] [Indexed: 11/24/2022] Open
Abstract
Direct and real-time monitoring of cerebral metabolism exploiting the drastic increase in sensitivity of hyperpolarized 13C-labeled metabolites holds the potential to report on neural activity via in-cell metabolic indicators. Here, we followed the metabolic consequences of curbing action potential generation and ATP-synthase in rat cerebrum slices, induced by tetrodotoxin and oligomycin, respectively. The results suggest that pyruvate dehydrogenase (PDH) activity in the cerebrum is 4.4-fold higher when neuronal firing is unperturbed. The PDH activity was 7.4-fold reduced in the presence of oligomycin, and served as a pharmacological control for testing the ability to determine changes to PDH activity in viable cerebrum slices. These findings may open a path towards utilization of PDH activity, observed by magnetic resonance of hyperpolarized 13C-labeled pyruvate, as a reporter of neural activity.
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Affiliation(s)
- Benjamin Grieb
- Department of Radiology, Hadassah Medical Center, The Faculty of Medicine, Hebrew University of Jerusalem, 9112001, Jerusalem, Israel. .,Department of Psychiatry and Psychotherapie I (Weissenau), Ulm University, ZfP Suedwuerttemberg, Ravensburg, Germany.
| | - Sivaranjan Uppala
- Department of Radiology, Hadassah Medical Center, The Faculty of Medicine, Hebrew University of Jerusalem, 9112001, Jerusalem, Israel
| | - Gal Sapir
- Department of Radiology, Hadassah Medical Center, The Faculty of Medicine, Hebrew University of Jerusalem, 9112001, Jerusalem, Israel
| | - David Shaul
- Department of Radiology, Hadassah Medical Center, The Faculty of Medicine, Hebrew University of Jerusalem, 9112001, Jerusalem, Israel
| | - J Moshe Gomori
- Department of Radiology, Hadassah Medical Center, The Faculty of Medicine, Hebrew University of Jerusalem, 9112001, Jerusalem, Israel
| | - Rachel Katz-Brull
- Department of Radiology, Hadassah Medical Center, The Faculty of Medicine, Hebrew University of Jerusalem, 9112001, Jerusalem, Israel. .,The Wohl Institute for Translational Medicine, Jerusalem, Israel.
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16
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Brain Energy Deficit as a Source of Oxidative Stress in Migraine: A Molecular Basis for Migraine Susceptibility. Neurochem Res 2021; 46:1913-1932. [PMID: 33939061 DOI: 10.1007/s11064-021-03335-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 04/06/2021] [Accepted: 04/22/2021] [Indexed: 02/06/2023]
Abstract
People with migraine are prone to a brain energy deficit between attacks, through increased energy demand (hyperexcitable brain) or decreased supply (mitochondrial impairment). However, it is uncertain how this precipitates an acute attack. Here, the central role of oxidative stress is adduced. Specifically, neurons' antioxidant defenses rest ultimately on internally generated NADPH (reduced nicotinamide adenine dinucleotide phosphate), whose levels are tightly coupled to energy production. Mitochondrial NADPH is produced primarily by enzymes involved in energy generation, including isocitrate dehydrogenase of the Krebs (tricarboxylic acid) cycle; and an enzyme, nicotinamide nucleotide transhydrogenase (NNT), that depends on the Krebs cycle and oxidative phosphorylation to function, and that works in reverse, consuming antioxidants, when energy generation fails. In migraine aura, cortical spreading depression (CSD) causes an initial severe drop in level of NADH (reduced nicotinamide adenine dinucleotide), causing NNT to impair antioxidant defense. This is followed by functional hypoxia and a rebound in NADH, in which the electron transport chain overproduces oxidants. In migraine without aura, a similar biphasic fluctuation in NADH very likely generates oxidants in cortical regions farthest from capillaries and penetrating arterioles. Thus, the perturbations in brain energy demand and/or production seen in migraine are likely sufficient to cause oxidative stress, triggering an attack through oxidant-sensing nociceptive ion channels. Implications are discussed for the development of new classes of migraine preventives, for the current use of C57BL/6J mice (which lack NNT) in preclinical studies of migraine, for how a microembolism initiates CSD, and for how CSD can trigger a migraine.
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17
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Elzoheiry S, Lewen A, Schneider J, Both M, Hefter D, Boffi JC, Hollnagel JO, Kann O. Mild metabolic stress is sufficient to disturb the formation of pyramidal cell ensembles during gamma oscillations. J Cereb Blood Flow Metab 2020; 40:2401-2415. [PMID: 31842665 PMCID: PMC7820691 DOI: 10.1177/0271678x19892657] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Disturbances of cognitive functions occur rapidly during acute metabolic stress. However, the underlying mechanisms are not fully understood. Cortical gamma oscillations (30-100 Hz) emerging from precise synaptic transmission between excitatory principal neurons and inhibitory interneurons, such as fast-spiking GABAergic basket cells, are associated with higher brain functions, like sensory perception, selective attention and memory formation. We investigated the alterations of cholinergic gamma oscillations at the level of neuronal ensembles in the CA3 region of rat hippocampal slice cultures. We combined electrophysiology, calcium imaging (CamKII.GCaMP6f) and mild metabolic stress that was induced by rotenone, a lipophilic and highly selective inhibitor of complex I in the respiratory chain of mitochondria. The detected pyramidal cell ensembles showing repetitive patterns of activity were highly sensitive to mild metabolic stress. Whereas such synchronised multicellular activity diminished, the overall activity of individual pyramidal cells was unaffected. Additionally, mild metabolic stress had no effect on the rate of action potential generation in fast-spiking neural units. However, the partial disinhibition of slow-spiking neural units suggests that disturbances of ensemble formation likely result from alterations in synaptic inhibition. Our study bridges disturbances on the (multi-)cellular and network level to putative cognitive impairment on the system level.
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Affiliation(s)
- Shehabeldin Elzoheiry
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Andrea Lewen
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Justus Schneider
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Martin Both
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Dimitri Hefter
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany.,RG Animal Models in Psychiatry, Clinic of Psychiatry and Psychotherapy, Central Institute of Mental Health, Mannheim, Germany
| | - Juan Carlos Boffi
- Institute for Anatomy and Cell Biology, University of Heidelberg, Heidelberg, Germany
| | - Jan-Oliver Hollnagel
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany.,Interdisciplinary Centre for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
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18
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Bas-Orth C, Schneider J, Lewen A, McQueen J, Hasenpusch-Theil K, Theil T, Hardingham GE, Bading H, Kann O. The mitochondrial calcium uniporter is crucial for the generation of fast cortical network rhythms. J Cereb Blood Flow Metab 2020; 40:2225-2239. [PMID: 31722597 PMCID: PMC7585921 DOI: 10.1177/0271678x19887777] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The role of the mitochondrial calcium uniporter (MCU) gene (Mcu) in cellular energy homeostasis and generation of electrical brain rhythms is widely unknown. We investigated this issue in mice and rats using Mcu-knockout and -knockdown strategies in vivo and in situ and determined the effects of these genetic manipulations on hippocampal gamma oscillations (30-70 Hz) and sharp wave-ripples. These physiological network states require precise neurotransmission between pyramidal cells and inhibitory interneurons, support spike-timing and synaptic plasticity and are associated with perception, attention and memory. Absence of the MCU resulted in (i) gamma oscillations with decreased power (by >40%) and lower synchrony, including less precise neural action potential generation ('spiking'), (ii) sharp waves with decreased incidence (by about 22%) and decreased fast ripple frequency (by about 3%) and (iii) lack of activity-dependent pyruvate dehydrogenase dephosphorylation. However, compensatory adaptation in gene expression related to mitochondrial function and glucose metabolism was not detected. These data suggest that the neuronal MCU is crucial for the generation of network rhythms, most likely by influences on oxidative phosphorylation and perhaps by controlling cytoplasmic Ca2+ homeostasis. This work contributes to an increased understanding of mitochondrial Ca2+ uptake in cortical information processing underlying cognition and behaviour.
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Affiliation(s)
- Carlos Bas-Orth
- Department of Neurobiology, University of Heidelberg, Heidelberg, Germany.,Institute of Anatomy and Cell Biology, University of Heidelberg, Heidelberg, Germany.,Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
| | - Justus Schneider
- Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany.,Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Andrea Lewen
- Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany.,Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Jamie McQueen
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK.,Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | | | - Thomas Theil
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Giles E Hardingham
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK.,Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Hilmar Bading
- Department of Neurobiology, University of Heidelberg, Heidelberg, Germany.,Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
| | - Oliver Kann
- Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany.,Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
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19
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Chausse B, Kakimoto PA, Kann O. Microglia and lipids: how metabolism controls brain innate immunity. Semin Cell Dev Biol 2020; 112:137-144. [PMID: 32807643 DOI: 10.1016/j.semcdb.2020.08.001] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/31/2020] [Accepted: 08/01/2020] [Indexed: 12/26/2022]
Abstract
Microglia are universal sensors of alterations in CNS physiology. These cells integrate complex molecular signals and undergo comprehensive phenotypical remodeling to adapt inflammatory responses. In the last years, single-cell analyses have revealed that microglia exhibit diverse phenotypes during development, growth and disease. Emerging evidence suggests that such phenotype transitions are mediated by reprogramming of cell metabolism. Indeed, metabolic pathways are distinctively altered in activated microglia and are central nodes controlling microglial responses. Microglial lipid metabolism has been specifically involved in the control of microglial activation and effector functions, such as migration, phagocytosis and inflammatory signaling, and minor disturbances in microglial lipid handling associates with altered brain function in disorders featuring neuroinflammation. In this review, we explore new and relevant aspects of microglial metabolism in health and disease. We give special focus on how different branches of lipid metabolism, such as lipid sensing, synthesis and oxidation, integrate and control essential aspects of microglial biology, and how disturbances in these processes associate with aging and the pathogenesis of, for instance, multiple sclerosis and Alzheimer's disease. Finally, challenges and advances in microglial lipid research are discussed.
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Affiliation(s)
- Bruno Chausse
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany.
| | - Pamela A Kakimoto
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, 05508-000, São Paulo, Brazil
| | - Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany; Interdisciplinary Center for Neurosciences, University of Heidelberg, D-69120 Heidelberg, Germany
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20
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Lewen A, Ta TT, Cesetti T, Hollnagel JO, Papageorgiou IE, Chausse B, Kann O. Neuronal gamma oscillations and activity-dependent potassium transients remain regular after depletion of microglia in postnatal cortex tissue. J Neurosci Res 2020; 98:1953-1967. [PMID: 32638411 DOI: 10.1002/jnr.24689] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 06/09/2020] [Accepted: 06/12/2020] [Indexed: 12/28/2022]
Abstract
Microglial cells (resident macrophages) feature rapid activation in CNS disease and can acquire multiple phenotypes exerting neuroprotection or neurotoxicity. The functional impact of surveying ("resting") microglia on neural excitability and neurotransmission in physiology is widely unknown, however. We addressed this issue in male rat hippocampal slice cultures (in situ) by pharmacological microglial ablation within days and by characterizing neuronal gamma-band oscillations (30-70 Hz) that are highly sensitive to neuromodulators and disturbances in ion and energy regulation. Gamma oscillations support action potential timing and synaptic plasticity, associate with higher brain functions like perception and memory, and require precise communication between excitatory pyramidal cells and inhibitory (GABAergic) interneurons. The slice cultures featured well-preserved hippocampal cytoarchitecture and parvalbumin-positive interneuron networks, microglia with ramified morphology, and low basal levels of IL-6, TNF-α, and nitric oxide (NO). Stimulation of slice cultures with the pro-inflammatory cytokine IFN-γ or bacterial LPS serving as positive controls for microglial reactivity induced MHC-II expression and increased cytokine and NO release. Chronic exposure of slice cultures to liposome-encapsulated clodronate reduced the microglial cell population by about 96%, whereas neuronal structures, astrocyte GFAP expression, and basal levels of cytokines and NO were unchanged. Notably, the properties of gamma oscillations reflecting frequency, number and synchronization of synapse activity were regular after microglial depletion. Also, electrical stimulus-induced transients of the extracellular potassium concentration ([K+ ]o ) reflecting cellular K+ efflux, clearance and buffering were unchanged. This suggests that nonreactive microglia are dispensable for neuronal homeostasis and neuromodulation underlying network signaling and rhythm generation in cortical tissue.
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Affiliation(s)
- Andrea Lewen
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Thuy-Truc Ta
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Tiziana Cesetti
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Jan-Oliver Hollnagel
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Ismini E Papageorgiou
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Bruno Chausse
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany.,Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
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21
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Özugur S, Kunz L, Straka H. Relationship between oxygen consumption and neuronal activity in a defined neural circuit. BMC Biol 2020; 18:76. [PMID: 32615976 PMCID: PMC7333326 DOI: 10.1186/s12915-020-00811-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 06/16/2020] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Neuronal computations related to sensory and motor activity along with the maintenance of spike discharge, synaptic transmission, and associated housekeeping are energetically demanding. The most efficient metabolic process to provide large amounts of energy equivalents is oxidative phosphorylation and thus dependent on O2 consumption. Therefore, O2 levels in the brain are a critical parameter that influences neuronal function. Measurements of O2 consumption have been used to estimate the cost of neuronal activity; however, exploring these metabolic relationships in vivo and under defined experimental conditions has been limited by technical challenges. RESULTS We used isolated preparations of Xenopus laevis tadpoles to perform a quantitative analysis of O2 levels in the brain under in vivo-like conditions. We measured O2 concentrations in the hindbrain in relation to the spike discharge of the superior oblique eye muscle-innervating trochlear nerve as proxy for central nervous activity. In air-saturated bath Ringer solution, O2 levels in the fourth ventricle and adjacent, functionally intact hindbrain were close to zero. Inhibition of mitochondrial activity with potassium cyanide or fixation of the tissue with ethanol raised the ventricular O2 concentration to bath levels, indicating that the brain tissue consumed the available O2. Gradually increasing oxygenation of the Ringer solution caused a concurrent increase of ventricular O2 concentrations. Blocking spike discharge with the local anesthetics tricaine methanesulfonate diminished the O2 consumption by ~ 50%, illustrating the substantial O2 amount related to neuronal activity. In contrast, episodes of spontaneous trochlear nerve spike bursts were accompanied by transient increases of the O2 consumption with parameters that correlated with burst magnitude and duration. CONCLUSIONS Controlled experimental manipulations of both the O2 level as well as the neuronal activity under in vivo-like conditions allowed to quantitatively relate spike discharge magnitudes in a particular neuronal circuitry with the O2 consumption in this area. Moreover, the possibility to distinctly manipulate various functional parameters will yield more insight in the coupling between metabolic and neuronal activity. Thus, apart from providing quantitative empiric evidence for the link between physiologically relevant spontaneous spike discharge in the brain and O2-dependent metabolism, isolated amphibian preparations are promising model systems to further dissociate the O2 dynamics in relation to neuronal computations.
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Affiliation(s)
- Suzan Özugur
- Department Biology II, Ludwig-Maximilians-University Munich, Großhaderner Str. 2, 82152, Planegg, Germany
- Graduate School of Systemic Neurosciences, Ludwig-Maximilians-University Munich, Großhaderner Str. 2, 82152, Planegg, Germany
| | - Lars Kunz
- Department Biology II, Ludwig-Maximilians-University Munich, Großhaderner Str. 2, 82152, Planegg, Germany
| | - Hans Straka
- Department Biology II, Ludwig-Maximilians-University Munich, Großhaderner Str. 2, 82152, Planegg, Germany.
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22
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Hollnagel JO, Cesetti T, Schneider J, Vazetdinova A, Valiullina-Rakhmatullina F, Lewen A, Rozov A, Kann O. Lactate Attenuates Synaptic Transmission and Affects Brain Rhythms Featuring High Energy Expenditure. iScience 2020; 23:101316. [PMID: 32653807 PMCID: PMC7350153 DOI: 10.1016/j.isci.2020.101316] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 06/09/2020] [Accepted: 06/23/2020] [Indexed: 01/29/2023] Open
Abstract
Lactate shuttled from blood, astrocytes, and/or oligodendrocytes may serve as the major glucose alternative in brain energy metabolism. However, its effectiveness in fueling neuronal information processing underlying complex cortex functions like perception and memory is unclear. We show that sole lactate disturbs electrical gamma and theta-gamma oscillations in hippocampal networks by either attenuation or neural bursts. Bursting is suppressed by elevating the glucose fraction in substrate supply. By contrast, lactate does not affect electrical sharp wave-ripple activity featuring lower energy use. Lactate increases the oxygen consumption during the network states, reflecting enhanced oxidative ATP synthesis in mitochondria. Finally, lactate attenuates synaptic transmission in excitatory pyramidal cells and fast-spiking, inhibitory interneurons by reduced neurotransmitter release from presynaptic terminals, whereas action potential generation in the axon is regular. In conclusion, sole lactate is less effective and potentially harmful during gamma-band rhythms by omitting obligatory ATP delivery through fast glycolysis at the synapse. Lactate fuels network oscillations featuring low energy expenditure Lactate can disturb the neuronal excitation-inhibition balance Lactate attenuates neurotransmission at glutamatergic and GABAergic synapses Lactate increases oxygen consumption, whereas neural activity can even decrease
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Affiliation(s)
- Jan-Oliver Hollnagel
- Institute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120 Heidelberg, Germany
| | - Tiziana Cesetti
- Institute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120 Heidelberg, Germany
| | - Justus Schneider
- Institute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120 Heidelberg, Germany
| | - Alina Vazetdinova
- OpenLab of Neurobiology, Kazan Federal University, 420008 Kazan, Russia
| | | | - Andrea Lewen
- Institute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120 Heidelberg, Germany
| | - Andrei Rozov
- Institute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120 Heidelberg, Germany; OpenLab of Neurobiology, Kazan Federal University, 420008 Kazan, Russia
| | - Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120 Heidelberg, Germany; Interdisciplinary Center for Neurosciences, University of Heidelberg, 69120 Heidelberg, Germany.
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Flavin Adenine Dinucleotide Fluorescence as an Early Marker of Mitochondrial Impairment During Brain Hypoxia. Int J Mol Sci 2020; 21:ijms21113977. [PMID: 32492921 PMCID: PMC7312830 DOI: 10.3390/ijms21113977] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 05/28/2020] [Accepted: 05/30/2020] [Indexed: 12/31/2022] Open
Abstract
Multimodal continuous bedside monitoring is increasingly recognized as a promising option for early treatment stratification in patients at risk for ischemia during neurocritical care. Modalities used at present are, for example, oxygen availability and subdural electrocorticography. The assessment of mitochondrial function could be an interesting complement to these modalities. For instance, flavin adenine dinucleotide (FAD) fluorescence permits direct insight into the mitochondrial redox state. Therefore, we explored the possibility of using FAD fluorometry to monitor consequences of hypoxia in brain tissue in vitro and in vivo. By combining experimental results with computational modeling, we identified the potential source responsible for the fluorescence signal and gained insight into the hypoxia-associated metabolic changes in neuronal energy metabolism. In vitro, hypoxia was characterized by a reductive shift of FAD, impairment of synaptic transmission and increasing interstitial potassium [K+]o. Computer simulations predicted FAD changes to originate from the citric acid cycle enzyme α-ketoglutarate dehydrogenase and pyruvate dehydrogenase. In vivo, the FAD signal during early hypoxia displayed a reductive shift followed by a short oxidation associated with terminal spreading depolarization. In silico, initial tissue hypoxia followed by a transient re-oxygenation phase due to glucose depletion might explain FAD dynamics in vivo. Our work suggests that FAD fluorescence could be readily used to monitor mitochondrial function during hypoxia and represents a potential diagnostic tool to differentiate underlying metabolic processes for complementation of multimodal brain monitoring.
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Abstract
Glucose is the long-established, obligatory fuel for brain that fulfills many critical functions, including ATP production, oxidative stress management, and synthesis of neurotransmitters, neuromodulators, and structural components. Neuronal glucose oxidation exceeds that in astrocytes, but both rates increase in direct proportion to excitatory neurotransmission; signaling and metabolism are closely coupled at the local level. Exact details of neuron-astrocyte glutamate-glutamine cycling remain to be established, and the specific roles of glucose and lactate in the cellular energetics of these processes are debated. Glycolysis is preferentially upregulated during brain activation even though oxygen availability is sufficient (aerobic glycolysis). Three major pathways, glycolysis, pentose phosphate shunt, and glycogen turnover, contribute to utilization of glucose in excess of oxygen, and adrenergic regulation of aerobic glycolysis draws attention to astrocytic metabolism, particularly glycogen turnover, which has a high impact on the oxygen-carbohydrate mismatch. Aerobic glycolysis is proposed to be predominant in young children and specific brain regions, but re-evaluation of data is necessary. Shuttling of glucose- and glycogen-derived lactate from astrocytes to neurons during activation, neurotransmission, and memory consolidation are controversial topics for which alternative mechanisms are proposed. Nutritional therapy and vagus nerve stimulation are translational bridges from metabolism to clinical treatment of diverse brain disorders.
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Affiliation(s)
- Gerald A Dienel
- Department of Neurology, University of Arkansas for Medical Sciences , Little Rock, Arkansas ; and Department of Cell Biology and Physiology, University of New Mexico , Albuquerque, New Mexico
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Kovács R, Gerevich Z, Friedman A, Otáhal J, Prager O, Gabriel S, Berndt N. Bioenergetic Mechanisms of Seizure Control. Front Cell Neurosci 2018; 12:335. [PMID: 30349461 PMCID: PMC6187982 DOI: 10.3389/fncel.2018.00335] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 09/12/2018] [Indexed: 12/14/2022] Open
Abstract
Epilepsy is characterized by the regular occurrence of seizures, which follow a stereotypical sequence of alterations in the electroencephalogram. Seizures are typically a self limiting phenomenon, concluding finally in the cessation of hypersynchronous activity and followed by a state of decreased neuronal excitability which might underlie the cognitive and psychological symptoms the patients experience in the wake of seizures. Many efforts have been devoted to understand how seizures spontaneously stop in hope to exploit this knowledge in anticonvulsant or neuroprotective therapies. Besides the alterations in ion-channels, transmitters and neuromodulators, the successive build up of disturbances in energy metabolism have been suggested as a mechanism for seizure termination. Energy metabolism and substrate supply of the brain are tightly regulated by different mechanisms called neurometabolic and neurovascular coupling. Here we summarize the current knowledge whether these mechanisms are sufficient to cover the energy demand of hypersynchronous activity and whether a mismatch between energy need and supply could contribute to seizure control.
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Affiliation(s)
- Richard Kovács
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institut für Neurophysiologie, Berlin, Germany
| | - Zoltan Gerevich
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institut für Neurophysiologie, Berlin, Germany
| | - Alon Friedman
- Departments of Physiology and Cell Biology, Cognitive and Brain Sciences, The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beersheba, Israel.,Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Jakub Otáhal
- Institute of Physiology, Czech Academy of Sciences, Prague, Czechia
| | - Ofer Prager
- Departments of Physiology and Cell Biology, Cognitive and Brain Sciences, The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beersheba, Israel
| | - Siegrun Gabriel
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institut für Neurophysiologie, Berlin, Germany
| | - Nikolaus Berndt
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institut für Biochemie, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute for Computational and Imaging Science in Cardiovascular Medicine, Berlin, Germany
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Berndt N, Rösner J, Haq RU, Kann O, Kovács R, Holzhütter HG, Spies C, Liotta A. Possible neurotoxicity of the anesthetic propofol: evidence for the inhibition of complex II of the respiratory chain in area CA3 of rat hippocampal slices. Arch Toxicol 2018; 92:3191-3205. [PMID: 30143847 PMCID: PMC6132669 DOI: 10.1007/s00204-018-2295-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 08/20/2018] [Indexed: 12/14/2022]
Abstract
Propofol is the most frequently used intravenous anesthetic for induction and maintenance of anesthesia. Propofol acts first and formost as a GABAA-agonist, but effects on other neuronal receptors and voltage-gated ion channels have been described. Besides its direct effect on neurotransmission, propofol-dependent impairment of mitochondrial function in neurons has been suggested to be responsible for neurotoxicity and postoperative brain dysfunction. To clarify the potential neurotoxic effect in more detail, we investigated the effects of propofol on neuronal energy metabolism of hippocampal slices of the stratum pyramidale of area CA3 at different activity states. We combined oxygen-measurements, electrophysiology and flavin adenine dinucleotide (FAD)-imaging with computational modeling to uncover molecular targets in mitochondrial energy metabolism that are directly inhibited by propofol. We found that high concentrations of propofol (100 µM) significantly decrease population spikes, paired pulse ratio, the cerebral metabolic rate of oxygen consumption (CMRO2), frequency and power of gamma oscillations and increase FAD-oxidation. Model-based simulation of mitochondrial FAD redox state at inhibition of different respiratory chain (RC) complexes and the pyruvate-dehydrogenase show that the alterations in FAD-autofluorescence during propofol administration can be explained with a strong direct inhibition of the complex II (cxII) of the RC. While this inhibition may not affect ATP availability under normal conditions, it may have an impact at high energy demand. Our data support the notion that propofol may lead to neurotoxicity and neuronal dysfunction by directly affecting the energy metabolism in neurons.
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Affiliation(s)
- Nikolaus Berndt
- Institute of Biochemistry, Charité-Universitätsmedizin Berlin, 10117, Berlin, Germany.,Institute for Computational and Imaging Science in Cardiovascular Medicine Charité, Universitätsmedizin Berlin, 13353, Berlin, Germany
| | - Jörg Rösner
- Neuroscience Research Center, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charité-Universitätsmedizin Berlin, 10117, Berlin, Germany
| | - Rizwan Ul Haq
- Neuroscience Research Center, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charité-Universitätsmedizin Berlin, 10117, Berlin, Germany
| | - Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, 69120, Heidelberg, Germany
| | - Richard Kovács
- Institute for Neurophysiology, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charité-Universitätsmedizin Berlin, 10117, Berlin, Germany
| | | | - Claudia Spies
- Department of Anesthesiology and Intensive Care, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Charité-Universitätsmedizin Berlin, 10117, Berlin, Germany.,Berlin Institute of Health, Charité-Universitätsmedizin Berlin, 10117, Berlin, Germany
| | - Agustin Liotta
- Neuroscience Research Center, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charité-Universitätsmedizin Berlin, 10117, Berlin, Germany. .,Department of Anesthesiology and Intensive Care, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Charité-Universitätsmedizin Berlin, 10117, Berlin, Germany. .,Berlin Institute of Health, Charité-Universitätsmedizin Berlin, 10117, Berlin, Germany.
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Vodovozov W, Schneider J, Elzoheiry S, Hollnagel JO, Lewen A, Kann O. Metabolic modulation of neuronal gamma-band oscillations. Pflugers Arch 2018; 470:1377-1389. [DOI: 10.1007/s00424-018-2156-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 04/06/2018] [Accepted: 05/17/2018] [Indexed: 01/08/2023]
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