1
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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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2
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Maex R. Energy optimisation predicts the capacity of ion buffering in the brain. BIOLOGICAL CYBERNETICS 2023; 117:467-484. [PMID: 38103053 DOI: 10.1007/s00422-023-00980-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 11/23/2023] [Indexed: 12/17/2023]
Abstract
Neurons store energy in the ionic concentration gradients they build across their cell membrane. The amount of energy stored, and hence the work the ions can do by mixing, can be enhanced by the presence of ion buffers in extra- and intracellular space. Buffers act as sources and sinks of ions, however, and unless the buffering capacities for different ion species obey certain relationships, a complete mixing of the ions may be impeded by the physical conditions of charge neutrality and isotonicity. From these conditions, buffering capacities were calculated that enabled each ion species to mix completely. In all valid buffer distributions, the [Formula: see text] ions were buffered most, with a capacity exceeding that of [Formula: see text] and [Formula: see text] buffering by at least an order of magnitude. The similar magnitude of the (oppositely directed) [Formula: see text] and [Formula: see text] gradients made extracellular space behave as a [Formula: see text]-[Formula: see text] exchanger. Anions such as [Formula: see text] were buffered least. The great capacity of the extra- and intracellular [Formula: see text] buffers caused a large influx of [Formula: see text] ions as is typically observed during energy deprivation. These results explain many characteristics of the physiological buffer distributions but raise the question how the brain controls the capacity of its ion buffers. It is suggested that neurons and glial cells, by their great sensitivity to gradients of charge and osmolarity, respectively, sense deviations from electro-neutral and isotonic mixing, and use these signals to tune the chemical composition, and buffering capacity, of the extra- and intracellular matrices.
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Affiliation(s)
- Reinoud Maex
- School of Physics, Engineering and Computer Science, University of Hertfordshire, College Lane, Hatfield, AL10 9AB, UK.
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3
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Trieu C, Rajagopalan S, Kofke WA, Cruz Navarro J. Overview of Hypothermia, Its Role in Neuroprotection, and the Application of Prophylactic Hypothermia in Traumatic Brain Injury. Anesth Analg 2023; 137:953-962. [PMID: 37115720 DOI: 10.1213/ane.0000000000006503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
The current standard of practice is to maintain normothermia in traumatic brain injury (TBI) patients despite the theoretical benefits of hypothermia and numerous animal studies with promising results. While targeted temperature management or induced hypothermia to support neurological function is recommended for a select patient population postcardiac arrest, similar guidelines have not been instituted for TBI. In this review, we will examine the pathophysiology of TBI and discuss the benefits and risks of induced hypothermia in this patient population. In addition, we provide an overview of the largest randomized controlled trials testing-induced hypothermia. Our literature review on hypothermia returned a myriad of studies and trials, many of which have inconclusive results. The aim of this review was to recognize the effects of hypothermia, summarize the latest trials, address the inconsistencies, and discuss future directions for the study of hypothermia in TBI.
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Affiliation(s)
- Christine Trieu
- From the Department of Anesthesiology, Baylor College of Medicine, Houston, Texas; Departments of
| | - Suman Rajagopalan
- From the Department of Anesthesiology, Baylor College of Medicine, Houston, Texas; Departments of
| | - W Andrew Kofke
- Anesthesiology and Critical Care
- Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania; and Departments of
| | - Jovany Cruz Navarro
- Anesthesiology and Critical Care
- Neurosurgery, Baylor College of Medicine, Houston, Texas
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4
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Yang S, Park JH, Lu HC. Axonal energy metabolism, and the effects in aging and neurodegenerative diseases. Mol Neurodegener 2023; 18:49. [PMID: 37475056 PMCID: PMC10357692 DOI: 10.1186/s13024-023-00634-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 06/08/2023] [Indexed: 07/22/2023] Open
Abstract
Human studies consistently identify bioenergetic maladaptations in brains upon aging and neurodegenerative disorders of aging (NDAs), such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and Amyotrophic lateral sclerosis. Glucose is the major brain fuel and glucose hypometabolism has been observed in brain regions vulnerable to aging and NDAs. Many neurodegenerative susceptible regions are in the topological central hub of the brain connectome, linked by densely interconnected long-range axons. Axons, key components of the connectome, have high metabolic needs to support neurotransmission and other essential activities. Long-range axons are particularly vulnerable to injury, neurotoxin exposure, protein stress, lysosomal dysfunction, etc. Axonopathy is often an early sign of neurodegeneration. Recent studies ascribe axonal maintenance failures to local bioenergetic dysregulation. With this review, we aim to stimulate research in exploring metabolically oriented neuroprotection strategies to enhance or normalize bioenergetics in NDA models. Here we start by summarizing evidence from human patients and animal models to reveal the correlation between glucose hypometabolism and connectomic disintegration upon aging/NDAs. To encourage mechanistic investigations on how axonal bioenergetic dysregulation occurs during aging/NDAs, we first review the current literature on axonal bioenergetics in distinct axonal subdomains: axon initial segments, myelinated axonal segments, and axonal arbors harboring pre-synaptic boutons. In each subdomain, we focus on the organization, activity-dependent regulation of the bioenergetic system, and external glial support. Second, we review the mechanisms regulating axonal nicotinamide adenine dinucleotide (NAD+) homeostasis, an essential molecule for energy metabolism processes, including NAD+ biosynthetic, recycling, and consuming pathways. Third, we highlight the innate metabolic vulnerability of the brain connectome and discuss its perturbation during aging and NDAs. As axonal bioenergetic deficits are developing into NDAs, especially in asymptomatic phase, they are likely exaggerated further by impaired NAD+ homeostasis, the high energetic cost of neural network hyperactivity, and glial pathology. Future research in interrogating the causal relationship between metabolic vulnerability, axonopathy, amyloid/tau pathology, and cognitive decline will provide fundamental knowledge for developing therapeutic interventions.
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Affiliation(s)
- Sen Yang
- The Linda and Jack Gill Center for Biomolecular Sciences, Indiana University, Bloomington, IN, 47405, USA
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA
- Program in Neuroscience, Indiana University, Bloomington, IN, 47405, USA
| | - Jung Hyun Park
- The Linda and Jack Gill Center for Biomolecular Sciences, Indiana University, Bloomington, IN, 47405, USA
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA
- Program in Neuroscience, Indiana University, Bloomington, IN, 47405, USA
| | - Hui-Chen Lu
- The Linda and Jack Gill Center for Biomolecular Sciences, Indiana University, Bloomington, IN, 47405, USA.
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA.
- Program in Neuroscience, Indiana University, Bloomington, IN, 47405, USA.
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5
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Thapaliya P, Pape N, Rose CR, Ullah G. Modeling the heterogeneity of sodium and calcium homeostasis between cortical and hippocampal astrocytes and its impact on bioenergetics. Front Cell Neurosci 2023; 17:1035553. [PMID: 36794264 PMCID: PMC9922870 DOI: 10.3389/fncel.2023.1035553] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 01/13/2023] [Indexed: 01/31/2023] Open
Abstract
Emerging evidence indicates that neuronal activity-evoked changes in sodium concentration in astrocytes Na a represent a special form of excitability, which is tightly linked to all other major ions in the astrocyte and extracellular space, as well as to bioenergetics, neurotransmitter uptake, and neurovascular coupling. Recently, one of us reported that Na a transients in the neocortex have a significantly higher amplitude than those in the hippocampus. Based on the extensive data from that study, here we develop a detailed biophysical model to further understand the origin of this heterogeneity and how it affects bioenergetics in the astrocytes. In addition to closely fitting the observed experimental Na a changes under different conditions, our model shows that the heterogeneity in Na a signaling leads to substantial differences in the dynamics of astrocytic Ca2+ signals in the two brain regions, and leaves cortical astrocytes more susceptible to Na+ and Ca2+ overload under metabolic stress. The model also predicts that activity-evoked Na a transients result in significantly larger ATP consumption in cortical astrocytes than in the hippocampus. The difference in ATP consumption is mainly due to the different expression levels of NMDA receptors in the two regions. We confirm predictions from our model experimentally by fluorescence-based measurement of glutamate-induced changes in ATP levels in neocortical and hippocampal astrocytes in the absence and presence of the NMDA receptor's antagonist (2R)-amino-5-phosphonovaleric acid.
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Affiliation(s)
- Pawan Thapaliya
- Department of Physics, University of South Florida, Tampa, FL, United States
| | - Nils Pape
- Faculty of Mathematics and Natural Sciences, Institute of Neurobiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Christine R. Rose
- Faculty of Mathematics and Natural Sciences, Institute of Neurobiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Ghanim Ullah
- Department of Physics, University of South Florida, Tampa, FL, United States,*Correspondence: Ghanim Ullah ✉
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6
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Energy-efficient network activity from disparate circuit parameters. Proc Natl Acad Sci U S A 2022; 119:e2207632119. [PMID: 36279461 PMCID: PMC9636970 DOI: 10.1073/pnas.2207632119] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Neural circuits can produce similar activity patterns from vastly different combinations of channel and synaptic conductances. These conductances are tuned for specific activity patterns but might also reflect additional constraints, such as metabolic cost or robustness to perturbations. How do such constraints influence the range of permissible conductances? Here we investigate how metabolic cost affects the parameters of neural circuits with similar activity in a model of the pyloric network of the crab
Cancer borealis
. We present a machine learning method that can identify a range of network models that generate activity patterns matching experimental data and find that neural circuits can consume largely different amounts of energy despite similar circuit activity. Furthermore, a reduced but still significant range of circuit parameters gives rise to energy-efficient circuits. We then examine the space of parameters of energy-efficient circuits and identify potential tuning strategies for low metabolic cost. Finally, we investigate the interaction between metabolic cost and temperature robustness. We show that metabolic cost can vary across temperatures but that robustness to temperature changes does not necessarily incur an increased metabolic cost. Our analyses show that despite metabolic efficiency and temperature robustness constraining circuit parameters, neural systems can generate functional, efficient, and robust network activity with widely disparate sets of conductances.
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7
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Meyer DJ, Díaz-García CM, Nathwani N, Rahman M, Yellen G. The Na +/K + pump dominates control of glycolysis in hippocampal dentate granule cells. eLife 2022; 11:e81645. [PMID: 36222651 PMCID: PMC9592084 DOI: 10.7554/elife.81645] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 10/11/2022] [Indexed: 11/13/2022] Open
Abstract
Cellular ATP that is consumed to perform energetically expensive tasks must be replenished by new ATP through the activation of metabolism. Neuronal stimulation, an energetically demanding process, transiently activates aerobic glycolysis, but the precise mechanism underlying this glycolysis activation has not been determined. We previously showed that neuronal glycolysis is correlated with Ca2+ influx, but is not activated by feedforward Ca2+ signaling (Díaz-García et al., 2021a). Since ATP-powered Na+ and Ca2+ pumping activities are increased following stimulation to restore ion gradients and are estimated to consume most neuronal ATP, we aimed to determine if they are coupled to neuronal glycolysis activation. By using two-photon imaging of fluorescent biosensors and dyes in dentate granule cell somas of acute mouse hippocampal slices, we observed that production of cytoplasmic NADH, a byproduct of glycolysis, is strongly coupled to changes in intracellular Na+, while intracellular Ca2+ could only increase NADH production if both forward Na+/Ca2+ exchange and Na+/K+ pump activity were intact. Additionally, antidromic stimulation-induced intracellular [Na+] increases were reduced >50% by blocking Ca2+ entry. These results indicate that neuronal glycolysis activation is predominantly a response to an increase in activity of the Na+/K+ pump, which is strongly potentiated by Na+ influx through the Na+/Ca2+ exchanger during extrusion of Ca2+ following stimulation.
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Affiliation(s)
- Dylan J Meyer
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | | | - Nidhi Nathwani
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Mahia Rahman
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Gary Yellen
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
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8
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Hawrysh PJ, Myrka AM, Buck LT. Review: A history and perspective of mitochondria in the context of anoxia tolerance. Comp Biochem Physiol B Biochem Mol Biol 2022; 260:110733. [PMID: 35288242 DOI: 10.1016/j.cbpb.2022.110733] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 03/07/2022] [Accepted: 03/07/2022] [Indexed: 01/01/2023]
Abstract
Symbiosis is found throughout nature, but perhaps nowhere is it more fundamental than mitochondria in all eukaryotes. Since mitochondria were discovered and mechanisms of oxygen reduction characterized, an understanding gradually emerged that these organelles were involved not just in the combustion of oxygen, but also in the sensing of oxygen. While multiple hypotheses exist to explain the mitochondrial involvement in oxygen sensing, key elements are developing that include potassium channels and reactive oxygen species. To understand how mitochondria contribute to oxygen sensing, it is informative to study a model system which is naturally adapted to survive extended periods without oxygen. Amongst air-breathing vertebrates, the most highly adapted are western painted turtles (Chrysemys picta bellii), which overwinter in ice-covered and anoxic water bodies. Through research of this animal, it was postulated that metabolic rate depression is key to anoxic survival and that mitochondrial regulation is a key aspect. When faced with anoxia, excitatory neurotransmitter receptors in turtle brain are inhibited through mitochondrial calcium release, termed "channel arrest". Simultaneously, inhibitory GABAergic signalling contributes to the "synaptic arrest" of excitatory action potential firing through a pathway dependent on mitochondrial depression of ROS generation. While many pathways are implicated in mitochondrial oxygen sensing in turtles, such as those of adenosine, ATP turnover, and gaseous transmitters, an apparent point of intersection is the mitochondria. In this review we will explore how an organelle that was critical for organismal complexity in an oxygenated world has also become a potentially important oxygen sensor.
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Affiliation(s)
- Peter John Hawrysh
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Alexander Morley Myrka
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Leslie Thomas Buck
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada; Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON M5S 3G5, Canada.
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9
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Sleep deficiency as a driver of cellular stress and damage in neurological disorders. Sleep Med Rev 2022; 63:101616. [PMID: 35381445 PMCID: PMC9177816 DOI: 10.1016/j.smrv.2022.101616] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 12/23/2022]
Abstract
Neurological disorders encompass an extremely broad range of conditions, including those that present early in development and those that progress slowly or manifest with advanced age. Although these disorders have distinct underlying etiologies, the activation of shared pathways, e.g., integrated stress response (ISR) and the development of shared phenotypes (sleep deficits) may offer clues toward understanding some of the mechanistic underpinnings of neurologic dysfunction. While it is incontrovertibly complex, the relationship between sleep and persistent stress in the brain has broad implications in understanding neurological disorders from development to degeneration. The convergent nature of the ISR could be a common thread linking genetically distinct neurological disorders through the dysregulation of a core cellular homeostasis pathway.
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10
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Powers WJ, An H, Diringer MN. Cerebral Blood Flow and Metabolism. Stroke 2022. [DOI: 10.1016/b978-0-323-69424-7.00003-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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11
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Maex R. Effect of extracellular volume on the energy stored in transmembrane concentration gradients. Phys Rev E 2021; 104:044409. [PMID: 34781519 DOI: 10.1103/physreve.104.044409] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 09/30/2021] [Indexed: 11/07/2022]
Abstract
The amount of energy that can be retrieved from a concentration gradient across a membrane separating two compartments depends on the relative size of the compartments. Having a larger low-concentration compartment is in general beneficial. It is shown here analytically that the retrieved energy further increases when the high-concentration compartment shrinks during the mixing process, and a general formula is derived for the energy when the ratio of transported solvent to solute varies. These calculations are then applied to the interstitial compartment of the brain, which is rich in Na^{+} and Cl^{-} ions and poor in K^{+}. The reported shrinkage of this compartment, and swelling of the neurons, during oxygen deprivation is shown to enhance the energy recovered from NaCl entering the neurons. The slight loss of energy on the part of K^{+} can be compensated for by the uptake of K^{+} ions by glial cells. In conclusion, the present study proposes that the reported fluctuations in the size of the interstitial compartment of the brain (expansion during sleep and contraction during oxygen deprivation) optimize the amount of energy that neurons can store in, and retrieve from, their ionic concentration gradients.
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Affiliation(s)
- Reinoud Maex
- Biocomputation Research Group, University of Hertfordshire, Hatfield AL10 9AB, United Kingdom
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12
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Abstract
The susceptibility of the brain to ischaemic injury dramatically limits its viability following interruptions in blood flow. However, data from studies of dissociated cells, tissue specimens, isolated organs and whole bodies have brought into question the temporal limits within which the brain is capable of tolerating prolonged circulatory arrest. This Review assesses cell type-specific mechanisms of global cerebral ischaemia, and examines the circumstances in which the brain exhibits heightened resilience to injury. We suggest strategies for expanding such discoveries to fuel translational research into novel cytoprotective therapies, and describe emerging technologies and experimental concepts. By doing so, we propose a new multimodal framework to investigate brain resuscitation following extended periods of circulatory arrest.
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13
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van Putten MJ, Fahlke C, Kafitz KW, Hofmeijer J, Rose CR. Dysregulation of Astrocyte Ion Homeostasis and Its Relevance for Stroke-Induced Brain Damage. Int J Mol Sci 2021; 22:5679. [PMID: 34073593 PMCID: PMC8198632 DOI: 10.3390/ijms22115679] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/21/2021] [Accepted: 05/22/2021] [Indexed: 12/14/2022] Open
Abstract
Ischemic stroke is a leading cause of mortality and chronic disability. Either recovery or progression towards irreversible failure of neurons and astrocytes occurs within minutes to days, depending on remaining perfusion levels. Initial damage arises from energy depletion resulting in a failure to maintain homeostasis and ion gradients between extra- and intracellular spaces. Astrocytes play a key role in these processes and are thus central players in the dynamics towards recovery or progression of stroke-induced brain damage. Here, we present a synopsis of the pivotal functions of astrocytes at the tripartite synapse, which form the basis of physiological brain functioning. We summarize the evidence of astrocytic failure and its consequences under ischemic conditions. Special emphasis is put on the homeostasis and stroke-induced dysregulation of the major monovalent ions, namely Na+, K+, H+, and Cl-, and their involvement in maintenance of cellular volume and generation of cerebral edema.
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Affiliation(s)
- Michel J.A.M. van Putten
- Department of Clinical Neurophysiology, University of Twente, 7522 NB Enschede, The Netherlands; (M.J.A.M.v.P.); (J.H.)
| | - Christoph Fahlke
- Institut für Biologische Informationsprozesse, Molekular-und Zellphysiologie (IBI-1), Forschungszentrum Jülich, 52425 Jülich, Germany;
| | - Karl W. Kafitz
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany;
| | - Jeannette Hofmeijer
- Department of Clinical Neurophysiology, University of Twente, 7522 NB Enschede, The Netherlands; (M.J.A.M.v.P.); (J.H.)
| | - Christine R. Rose
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany;
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14
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Cao L, Xiong S, Wu Z, Ding L, Zhou Y, Sun H, Zhu M, Lee WT, Nie X, Bian JS. Anti-Na +/K +-ATPase immunotherapy ameliorates α-synuclein pathology through activation of Na +/K +-ATPase α1-dependent autophagy. SCIENCE ADVANCES 2021; 7:7/5/eabc5062. [PMID: 33571110 PMCID: PMC7840131 DOI: 10.1126/sciadv.abc5062] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 12/09/2020] [Indexed: 05/06/2023]
Abstract
Na+/K+-ATPase (NKA) plays important roles in maintaining cellular homeostasis. Conversely, reduced NKA activity has been reported in aging and neurodegenerative diseases. However, little is known about the function of NKA in the pathogenesis of Parkinson's disease (PD). Here, we report that reduction of NKA activity in NKAα1+/- mice aggravates α-synuclein-induced pathology, including a reduction in tyrosine hydroxylase (TH) and deficits in behavioral tests for memory, learning, and motor function. To reverse this effect, we generated an NKA-stabilizing monoclonal antibody, DR5-12D, against the DR region (897DVEDSYGQQWTYEQR911) of the NKAα1 subunit. We demonstrate that DR5-12D can ameliorate α-synuclein-induced TH loss and behavioral deficits by accelerating α-synuclein degradation in neurons. The underlying mechanism for the beneficial effects of DR5-12D involves activation of NKAα1-dependent autophagy via increased AMPK/mTOR/ULK1 pathway signaling. Cumulatively, this work demonstrates that NKA activity is neuroprotective and that pharmacological activation of this pathway represents a new therapeutic strategy for PD.
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Affiliation(s)
- Lei Cao
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Siping Xiong
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Zhiyuan Wu
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Lei Ding
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Yebo Zhou
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Haijian Sun
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Mengyuan Zhu
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Wei Thye Lee
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Xiaowei Nie
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
| | - Jin-Song Bian
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
- Department of Pharmacology, School of Medicine, Southern University of Science and Technology, Shenzhen 518055, PR China
- National University of Singapore (Suzhou) Research Institute, Suzhou 215000, China
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15
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Zhu Q, Xiao S, Hua Z, Yang D, Hu M, Zhu YT, Zhong H. Near Infrared (NIR) Light Therapy of Eye Diseases: A Review. Int J Med Sci 2021; 18:109-119. [PMID: 33390779 PMCID: PMC7738953 DOI: 10.7150/ijms.52980] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 10/15/2020] [Indexed: 12/18/2022] Open
Abstract
Near infrared (NIR) light therapy, or photobiomodulation therapy (PBMT), has gained persistent worldwide attention in recent years as a new novel scientific approach for therapeutic applications in ophthalmology. This ongoing therapeutic adoption of NIR therapy is largely propelled by significant advances in the fields of photobiology and bioenergetics, such as the discovery of photoneuromodulation by cytochrome c oxidase and the elucidation of therapeutic biochemical processes. Upon transcranial delivery, NIR light has been shown to significantly increase cytochrome oxidase and superoxide dismutase activities which suggests its role in inducing metabolic and antioxidant beneficial effects. Furthermore, NIR light may also boost cerebral blood flow and cognitive functions in humans without adverse effects. In this review, we highlight the value of NIR therapy as a novel paradigm for treatment of visual and neurological conditions, and provide scientific evidence to support the use of NIR therapy with emphasis on molecular and cellular mechanisms in eye diseases.
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Affiliation(s)
- Qin Zhu
- Department of Ophthalmology, the First Affiliated Hospital of Kunming Medical University, Kunming 650031, China
| | - Shuyuan Xiao
- Department of Ophthalmology, the First Affiliated Hospital of Kunming Medical University, Kunming 650031, China
| | - Zhijuan Hua
- Department of Ophthalmology, the First Affiliated Hospital of Kunming Medical University, Kunming 650031, China
| | - Dongmei Yang
- Department of Ophthalmology, the Second People's Hospital of Yunnan Province, Kunming 650021, China
| | - Min Hu
- Department of Ophthalmology, the Second People's Hospital of Yunnan Province, Kunming 650021, China
| | | | - Hua Zhong
- Department of Ophthalmology, the First Affiliated Hospital of Kunming Medical University, Kunming 650031, China
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16
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Jiang Z, Alamuri TT, Muir ER, Choi DW, Duong TQ. Longitudinal multiparametric MRI study of hydrogen-enriched water with minocycline combination therapy in experimental ischemic stroke in rats. Brain Res 2020; 1748:147122. [DOI: 10.1016/j.brainres.2020.147122] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 09/06/2020] [Accepted: 09/07/2020] [Indexed: 12/11/2022]
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17
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Zhu M, Cao L, Xiong S, Sun H, Wu Z, Bian JS. Na +/K +-ATPase-dependent autophagy protects brain against ischemic injury. Signal Transduct Target Ther 2020; 5:55. [PMID: 32433549 PMCID: PMC7237650 DOI: 10.1038/s41392-020-0153-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 02/19/2020] [Accepted: 03/13/2020] [Indexed: 11/09/2022] Open
Affiliation(s)
- Mengyuan Zhu
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117600, Singapore
| | - Lei Cao
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117600, Singapore
| | - Siping Xiong
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117600, Singapore
| | - Haijian Sun
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117600, Singapore
| | - Zhiyuan Wu
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117600, Singapore
| | - Jin-Song Bian
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117600, Singapore. .,National University of Singapore (Suzhou) Research Institute, Suzhou, China.
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18
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Neurovascular protection by peroxisome proliferator-activated receptor α in ischemic stroke. Exp Neurol 2020; 331:113323. [PMID: 32320699 DOI: 10.1016/j.expneurol.2020.113323] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 04/14/2020] [Accepted: 04/17/2020] [Indexed: 12/11/2022]
Abstract
Ischemic stroke is a leading cause of death and disability worldwide. Currently, the only pharmacological therapy for ischemic stroke is thrombolysis with tissue plasminogen activator that has a narrow therapeutic window and increases the risk of intracerebral hemorrhage. New pharmacological treatments for ischemic stroke are desperately needed, but no neuroprotective drugs have successfully made it through clinical trials. Beneficial effects of peroxisome proliferator-activated receptor alpha (PPARα) activation on vascular integrity and function have been reported, and PPARα agonists have clinically been used for many years to manage cardiovascular disease. Thus, PPARα has gained interest in recent years as a target for neurovascular disease such as ischemic stroke. Accumulating preclinical evidence suggests that PPARα activation modulates several pathophysiological hallmarks of stroke such as oxidative stress, blood-brain barrier (BBB) dysfunction, and neuroinflammation to improve functional recovery. Therefore, this review summarizes the various actions PPARα exerts in neurovascular health and disease and the potential of employing exogenous PPARα agonists for future pharmacological treatment of ischemic stroke.
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19
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Reiffurth C, Alam M, Zahedi-Khorasani M, Major S, Dreier JP. Na +/K +-ATPase α isoform deficiency results in distinct spreading depolarization phenotypes. J Cereb Blood Flow Metab 2020; 40:622-638. [PMID: 30819023 PMCID: PMC7025397 DOI: 10.1177/0271678x19833757] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Compromised Na+/K+-ATPase function is associated with the occurrence of spreading depolarization (SD). Mutations in ATP1A2, the gene encoding the α2 isoform of the Na+/K+-ATPase, were identified in patients with familial hemiplegic migraine type 2 (FHM2), a Mendelian model disease for SD. This suggests a distinct role for the α2 isoform in modulating SD susceptibility and raises questions about underlying mechanisms including the roles of other Na+/K+-ATPase α isoforms. Here, we investigated the effects of genetic ablation and pharmacological inhibition of α1, α2, and α3 on SD using heterozygous knock-out mice. We found that only α2 heterozygous mice displayed higher SD susceptibility when challenged with prolonged extracellular high potassium concentration ([K+]o), a pronounced post SD oligemia and higher SD speed in-vivo. By contrast, under physiological [K+]o, α2 heterozygous mice showed similar SD susceptibility compared to wild-type littermates. Deficiency of α3 resulted in increased resistance against electrically induced SD in-vivo, whereas α1 deficiency did not affect SD. The results support important roles of the α2 isoform in SD. Moreover, they suggest that specific experimental conditions can be necessary to reveal an inherent SD phenotype by driving a (meta-) stable system into decompensation, reminiscent of the episodic nature of SDs in various diseases.
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Affiliation(s)
- Clemens Reiffurth
- Department of Experimental Neurology, Charité-University Medicine Berlin, Berlin, Germany.,Center for Stroke Research, Charité-University Medicine Berlin, Berlin, Germany
| | - Mesbah Alam
- Department of Neurosurgery, Hannover Medical School, Hannover, Germany
| | - Mahdi Zahedi-Khorasani
- Research Center and Department of Physiology, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Sebastian Major
- Department of Experimental Neurology, Charité-University Medicine Berlin, Berlin, Germany.,Center for Stroke Research, Charité-University Medicine Berlin, Berlin, Germany.,Department of Neurology, Charité-University Medicine Berlin, Berlin, Germany
| | - Jens P Dreier
- Department of Experimental Neurology, Charité-University Medicine Berlin, Berlin, Germany.,Center for Stroke Research, Charité-University Medicine Berlin, Berlin, Germany.,Department of Neurology, Charité-University Medicine Berlin, Berlin, Germany.,Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany.,Einstein Center for Neurosciences Berlin, Berlin, Germany
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20
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Major S, Huo S, Lemale CL, Siebert E, Milakara D, Woitzik J, Gertz K, Dreier JP. Direct electrophysiological evidence that spreading depolarization-induced spreading depression is the pathophysiological correlate of the migraine aura and a review of the spreading depolarization continuum of acute neuronal mass injury. GeroScience 2020; 42:57-80. [PMID: 31820363 PMCID: PMC7031471 DOI: 10.1007/s11357-019-00142-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 11/20/2019] [Indexed: 02/07/2023] Open
Abstract
Spreading depolarization is observed as a large negative shift of the direct current potential, swelling of neuronal somas, and dendritic beading in the brain's gray matter and represents a state of a potentially reversible mass injury. Its hallmark is the abrupt, massive ion translocation between intraneuronal and extracellular compartment that causes water uptake (= cytotoxic edema) and massive glutamate release. Dependent on the tissue's energy status, spreading depolarization can co-occur with different depression or silencing patterns of spontaneous activity. In adequately supplied tissue, spreading depolarization induces spreading depression of activity. In severely ischemic tissue, nonspreading depression of activity precedes spreading depolarization. The depression pattern determines the neurological deficit which is either spreading such as in migraine aura or migraine stroke or nonspreading such as in transient ischemic attack or typical stroke. Although a clinical distinction between spreading and nonspreading focal neurological deficits is useful because they are associated with different probabilities of permanent damage, it is important to note that spreading depolarization, the neuronal injury potential, occurs in all of these conditions. Here, we first review the scientific basis of the continuum of spreading depolarizations. Second, we highlight the transition zone of the continuum from reversibility to irreversibility using clinical cases of aneurysmal subarachnoid hemorrhage and cerebral amyloid angiopathy. These illustrate how modern neuroimaging and neuromonitoring technologies increasingly bridge the gap between basic sciences and clinic. For example, we provide direct electrophysiological evidence for the first time that spreading depolarization-induced spreading depression is the pathophysiological correlate of the migraine aura.
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Affiliation(s)
- Sebastian Major
- Center for Stroke Research, Campus Charité Mitte, Charité University Medicine Berlin, Charitéplatz 1, 10117, Berlin, Germany
- Department of Experimental Neurology, Charité-Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Department of Neurology, Charité-Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Shufan Huo
- Center for Stroke Research, Campus Charité Mitte, Charité University Medicine Berlin, Charitéplatz 1, 10117, Berlin, Germany
- Department of Neurology, Charité-Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Coline L Lemale
- Center for Stroke Research, Campus Charité Mitte, Charité University Medicine Berlin, Charitéplatz 1, 10117, Berlin, Germany
- Department of Experimental Neurology, Charité-Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Eberhard Siebert
- Department of Neuroradiology, Charité-Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Denny Milakara
- Solution Centre for Image Guided Local Therapies (STIMULATE), Otto-von-Guericke-University, Magdeburg, Germany
| | - Johannes Woitzik
- Evangelisches Krankenhaus Oldenburg, University of Oldenburg, Oldenburg, Germany
| | - Karen Gertz
- Center for Stroke Research, Campus Charité Mitte, Charité University Medicine Berlin, Charitéplatz 1, 10117, Berlin, Germany
- Department of Experimental Neurology, Charité-Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Department of Neurology, Charité-Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Jens P Dreier
- Center for Stroke Research, Campus Charité Mitte, Charité University Medicine Berlin, Charitéplatz 1, 10117, Berlin, Germany.
- Department of Experimental Neurology, Charité-Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.
- Department of Neurology, Charité-Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.
- Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany.
- Einstein Center for Neurosciences Berlin, Berlin, Germany.
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21
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Bordone MP, Salman MM, Titus HE, Amini E, Andersen JV, Chakraborti B, Diuba AV, Dubouskaya TG, Ehrke E, Espindola de Freitas A, Braga de Freitas G, Gonçalves RA, Gupta D, Gupta R, Ha SR, Hemming IA, Jaggar M, Jakobsen E, Kumari P, Lakkappa N, Marsh APL, Mitlöhner J, Ogawa Y, Paidi RK, Ribeiro FC, Salamian A, Saleem S, Sharma S, Silva JM, Singh S, Sulakhiya K, Tefera TW, Vafadari B, Yadav A, Yamazaki R, Seidenbecher CI. The energetic brain - A review from students to students. J Neurochem 2019; 151:139-165. [PMID: 31318452 DOI: 10.1111/jnc.14829] [Citation(s) in RCA: 132] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 07/03/2019] [Accepted: 07/08/2019] [Indexed: 12/12/2022]
Abstract
The past 20 years have resulted in unprecedented progress in understanding brain energy metabolism and its role in health and disease. In this review, which was initiated at the 14th International Society for Neurochemistry Advanced School, we address the basic concepts of brain energy metabolism and approach the question of why the brain has high energy expenditure. Our review illustrates that the vertebrate brain has a high need for energy because of the high number of neurons and the need to maintain a delicate interplay between energy metabolism, neurotransmission, and plasticity. Disturbances to the energetic balance, to mitochondria quality control or to glia-neuron metabolic interaction may lead to brain circuit malfunction or even severe disorders of the CNS. We cover neuronal energy consumption in neural transmission and basic ('housekeeping') cellular processes. Additionally, we describe the most common (glucose) and alternative sources of energy namely glutamate, lactate, ketone bodies, and medium chain fatty acids. We discuss the multifaceted role of non-neuronal cells in the transport of energy substrates from circulation (pericytes and astrocytes) and in the supply (astrocytes and microglia) and usage of different energy fuels. Finally, we address pathological consequences of disrupted energy homeostasis in the CNS.
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Affiliation(s)
- Melina Paula Bordone
- Facultad de Farmacia y Bioquímica, Instituto de Investigaciones Farmacológicas (ININFA), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Mootaz M Salman
- Department of Cell Biology, Harvard Medical School, and Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Haley E Titus
- Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Elham Amini
- Department of Medicine, University Kebangsaan Malaysia Medical Centre (HUKM), Cheras, Kuala Lumpur, Malaysia
| | - Jens V Andersen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Artem V Diuba
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Tatsiana G Dubouskaya
- Institute of Biophysics and Cell Engineering, National Academy of Sciences of Belarus, Minsk, Belarus
| | - Eric Ehrke
- Centre for Biomolecular Interactions, University of Bremen, Bremen, Germany
| | - Andiara Espindola de Freitas
- Neurobiology Section, Biological Sciences Division, University of California, San Diego, La Jolla, California, USA
| | | | | | | | - Richa Gupta
- CSIR-Indian Institute of Toxicology Research, Lucknow, India
| | - Sharon R Ha
- Baylor College of Medicine, Houston, Texas, USA
| | - Isabel A Hemming
- Brain Growth and Disease Laboratory, The Harry Perkins Institute of Medical Research, Nedlands, Western Australia, Australia.,School of Medicine and Pharmacology, The University of Western Australia, Crawley, Australia
| | - Minal Jaggar
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Emil Jakobsen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Punita Kumari
- Defense Institute of Physiology and allied sciences, Defense Research and Development Organization, Timarpur, Delhi, India
| | - Navya Lakkappa
- Department of Pharmacology, JSS college of Pharmacy, Ooty, India
| | - Ashley P L Marsh
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Jessica Mitlöhner
- Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology Magdeburg, Magdeburg, Germany
| | - Yuki Ogawa
- The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | | | | | - Ahmad Salamian
- Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Suraiya Saleem
- CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Sorabh Sharma
- Department of Pharmacy, Birla Institute of Technology and Science, Pilani, Rajasthan, India
| | - Joana M Silva
- Life and Health Sciences Research Institute (ICVS), Medical School, University of Minho, Braga, Portugal
| | - Shripriya Singh
- CSIR-Indian Institute of Toxicology Research, Lucknow, India
| | - Kunjbihari Sulakhiya
- Department of Pharmacy, Indira Gandhi National Tribal University, Amarkantak, India
| | - Tesfaye Wolde Tefera
- School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Behnam Vafadari
- Institute of environmental medicine, UNIKA-T, Technical University of Munich, Munich, Germany
| | - Anuradha Yadav
- CSIR-Indian Institute of Toxicology Research, Lucknow, India
| | - Reiji Yamazaki
- Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan.,Center for Behavioral Brain Sciences (CBBS), Otto von Guericke University, Magdeburg, Germany
| | - Constanze I Seidenbecher
- Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology Magdeburg, Magdeburg, Germany.,Center for Behavioral Brain Sciences (CBBS), Otto von Guericke University, Magdeburg, Germany
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22
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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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23
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Moura LIF, Lemos C, Ledent C, Carvalho E, Köfalvi A. Chronic insulinopenia/hyperglycemia decreases cannabinoid CB 1 receptor density and impairs glucose uptake in the mouse forebrain. Brain Res Bull 2019; 147:101-109. [PMID: 30721768 DOI: 10.1016/j.brainresbull.2019.01.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 01/18/2019] [Accepted: 01/25/2019] [Indexed: 12/22/2022]
Abstract
Both endocannabinoids and insulin regulate peripheral and cerebral glucose homeostasis via convergent signaling pathways that are impacted by diabetes. Here we asked how glucose metabolism and important facets of insulin signaling are affected in the forebrain of cannabinoid CB1 receptor knockout mice (CB1R-KO) and their wild-type (WT) littermates, seven weeks after the induction of insulinopenia/hyperglycemia (diabetes) with intraperitoneal streptozotocin injection. Sham-injected animals served as control. Diabetes caused milder weight loss in the WT mice compared to the phenotypically ˜11% leaner CB1R-KO, while hyperglycemia was similar. Resting [3H]deoxyglucose uptake was significantly reduced by ˜20% in acute ex vivo frontocortical and hippocampal slices obtained from both the sham-injected CB1R-KO and the diabetic WT mice. Surprisingly, the third cohort, the diabetic CB1R-KO showed no further impairment in glucose uptake, as compared to the sham-injected CB1R-KO. Depolarization-induced [3H]deoxyglucose uptake was proportional to the respective resting values only in the cortex in all four cohorts. The dissipative metabolism of [14C]-U-glucose remained largely unaffected in all cohorts of animals. However, diabetes reduced cortical CB1R density by ˜20%, as assessed by Western blotting. Albeit the changes in insulin signaling did not reflect the glucose uptake profile in each cohort, there were significant interactions between diabetes and genotype. In conclusion, a chronic decrease or lack of CB1R expression reduces glucose uptake in the mouse brain. Additionally, diabetes failed to cause further impairment in cerebral glucose uptake in the CB1R-KO. These suggest that diabetic encephalopathy may be in part associated with lower CB1R expression.
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Affiliation(s)
- Liane I F Moura
- CNC, Center for Neuroscience and Cell Biology of Coimbra, University of Coimbra, 3004-504 Coimbra, Portugal
| | - Cristina Lemos
- CNC, Center for Neuroscience and Cell Biology of Coimbra, University of Coimbra, 3004-504 Coimbra, Portugal; Experimental Psychiatry Unit, Center for Psychiatry and Psychotherapy, Medical University Innsbruck, Austria
| | | | - Eugénia Carvalho
- CNC, Center for Neuroscience and Cell Biology of Coimbra, University of Coimbra, 3004-504 Coimbra, Portugal; Arkansas Children's Research Institute, Little Rock, Arkansas 72202, United States; The Portuguese Diabetes Association (APDP), Lisbon, Portugal; Department of Geriatrics, University of Arkansas for Medical Sciences, Arkansas 72205, United States
| | - Attila Köfalvi
- CNC, Center for Neuroscience and Cell Biology of Coimbra, University of Coimbra, 3004-504 Coimbra, Portugal; Institute for Interdisciplinary Research, University of Coimbra, 3030-789 Coimbra, Portugal.
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24
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Mahan VL. Neurointegrity and neurophysiology: astrocyte, glutamate, and carbon monoxide interactions. Med Gas Res 2019; 9:24-45. [PMID: 30950417 PMCID: PMC6463446 DOI: 10.4103/2045-9912.254639] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 02/15/2019] [Indexed: 12/27/2022] Open
Abstract
Astrocyte contributions to brain function and prevention of neuropathologies are as extensive as that of neurons. Astroglial regulation of glutamate, a primary neurotransmitter, is through uptake, release through vesicular and non-vesicular pathways, and catabolism to intermediates. Homeostasis by astrocytes is considered to be of primary importance in determining normal central nervous system health and central nervous system physiology - glutamate is central to dynamic physiologic changes and central nervous system stability. Gasotransmitters may affect diverse glutamate interactions positively or negatively. The effect of carbon monoxide, an intrinsic central nervous system gasotransmitter, in the complex astrocyte homeostasis of glutamate may offer insights to normal brain development, protection, and its use as a neuromodulator and neurotherapeutic. In this article, we will review the effects of carbon monoxide on astrocyte homeostasis of glutamate.
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Affiliation(s)
- Vicki L. Mahan
- Division of Pediatric Cardiothoracic Surgery in the Department of Surgery, St. Christopher's Hospital for Children/Drexel University College of Medicine, Philadelphia, PA, USA
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25
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Abad N, Rosenberg JT, Hike DC, Harrington MG, Grant SC. Dynamic sodium imaging at ultra-high field reveals progression in a preclinical migraine model. Pain 2018; 159:2058-2065. [PMID: 29905652 PMCID: PMC6150813 DOI: 10.1097/j.pain.0000000000001307] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Under the hypothesis that increased extracellular sodium induces sustained neuronal excitability with the onset and progression of migraine, this study evaluates dynamic in vivo Na fluxes in the brain of a preclinical rodent analogue of migraine. Ultra-high field Na magnetic resonance imaging (MRI) at 21.1 T has demonstrated potential to quantify sodium concentrations with good spatial and temporal resolution after the onset of central sensitization. Sprague-Dawley male rats with implanted intraperitoneal lines were studied by MRI before and after an in situ injection of 10 mg/kg of nitroglycerin (NTG) vs vehicle and saline controls. Slice-selective Na images were acquired using a multislice free induction decay-based chemical shift imaging sequence with resolution of 1.1 × 1.1 × 3 mm for a 9-minute acquisition. A total of 27 repeated scans were acquired over 1 hour of baseline scanning and longitudinally up to 3 hours after injection. Increases of Na MRI signal in the brainstem, extracerebral cerebrospinal fluid, and cisterna magna were evident almost immediately after NTG injection, gaining significance from controls in 36 minutes. The cerebellum and third ventricle also showed sustained trends of increased Na, with the former gaining significance at over 2 hours after NTG injection. The data provide evidence of an early change in sodium concentration, markedly in posterior fossa cerebrospinal fluid and brainstem regions. Further study of fluctuations of sodium concentration and their modulation with treatments could help understand the dynamic features of migraine, locate a putative migraine generator, and guide development of therapeutic measures to correct the disturbance of sodium homeostasis.
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Affiliation(s)
- Nastaren Abad
- Center for Interdisciplinary Magnetic Resonance, The National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL, USA
| | - Jens T. Rosenberg
- Center for Interdisciplinary Magnetic Resonance, The National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA
| | - David C. Hike
- Center for Interdisciplinary Magnetic Resonance, The National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL, USA
| | - Michael G. Harrington
- Molecular Neurology Program, Huntington Medical Research Institutes, Pasadena, CA, USA
| | - Samuel C. Grant
- Center for Interdisciplinary Magnetic Resonance, The National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL, USA
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26
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Lanigan S, Corcoran AE, Wall A, Mukandala G, O'Connor JJ. Acute hypoxic exposure and prolyl-hydroxylase inhibition improves synaptic transmission recovery time from a subsequent hypoxic insult in rat hippocampus. Brain Res 2018; 1701:212-218. [PMID: 30244114 DOI: 10.1016/j.brainres.2018.09.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 09/14/2018] [Accepted: 09/18/2018] [Indexed: 01/18/2023]
Abstract
In the CNS short episodes of acute hypoxia can result in a decrease in synaptic transmission which may be fully reversible upon re-oxygenation. Stabilization of hypoxia-inducible factor (HIF) by inhibition of prolyl hydroxylase domain (PHD) enzymes has been shown to regulate the cellular response to hypoxia and confer neuroprotection both in vivo and in vitro. Hypoxic preconditioning has become a novel therapeutic target to induce neuroprotection during hypoxic insults. However, there is little understanding of the effects of repeated hypoxic insults or pharmacological PHD inhibition on synaptic signaling. In this study we have assessed the effects of hypoxic exposure and PHD inhibition on synaptic transmission in the rat CA1 hippocampus. Field excitatory postsynaptic potentials (fEPSPs) were elicited by stimulation of the Schaffer collateral pathway. 30 min hypoxia (gas mixture 95% N2/5% CO2) resulted in a significant and fully reversible decrease in fEPSP slope associated with decreases in partial pressures of tissue oxygen. 15-30 min of hypoxia was sufficient to induce stabilization of HIF in hippocampal slices. Exposure to a second hypoxic insult after 60 min resulted in a similar depression of fEPSP slope but with a significantly greater rate of recovery of the fEPSP. Prior single treatment of slices with the PHD inhibitor, dimethyloxalylglycine (DMOG) also resulted in a significantly greater rate of recovery of fEPSP post hypoxia. These results suggest that hypoxia and 'pseudohypoxia' preconditioning may improve the rate of recovery of hippocampal neurons to a subsequent acute hypoxia.
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Affiliation(s)
- Sinead Lanigan
- UCD School of Biomolecular & Biomedical Science, UCD Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
| | - Alan E Corcoran
- UCD School of Biomolecular & Biomedical Science, UCD Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
| | - Audrey Wall
- UCD School of Biomolecular & Biomedical Science, UCD Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
| | - Gatambwa Mukandala
- College of Natural and Applied Sciences, University of Dar-Es-Salaam (UDSM), P.O Box 35064, Dar-Es-Salaam, Tanzania
| | - John J O'Connor
- UCD School of Biomolecular & Biomedical Science, UCD Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland.
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27
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Abstract
Appraising success in meeting the world's nutritional needs has largely focused on infant mortality and anthropometric measurements with an emphasis on the first 1,000 days (conception to approximately age 2 years). This ignores the unique nutritional needs of the human brain. Although the intrauterine environment and the early postnatal years are important, equally critical periods follow during which the brain's intricate wiring is established for a lifetime of experience-driven remodeling. At the peak of this process during childhood, the human brain may account for 50% of the body's basal nutritional requirement. Thus, the consequences of proper nutritional management of the brain play out over a lifetime. Our motivation in preparing this review was to move the human brain into a more central position in the planning of nutritional programs. Here we review the macro- and micronutrient requirements of the human brain and how they are delivered, from conception to adulthood.
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Affiliation(s)
- Manu S. Goyal
- Mallinckrodt Institute of Radiology and Department of Neurology, Washington University School of Medicine, Washington University, St. Louis, Missouri 63130, USA
| | - Lora L. Iannotti
- Brown School, Institute for Public Health, Washington University, St. Louis, Missouri 63130, USA
| | - Marcus E. Raichle
- Mallinckrodt Institute of Radiology and Department of Neurology, Washington University School of Medicine, Washington University, St. Louis, Missouri 63130, USA
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28
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Yu Y, Herman P, Rothman DL, Agarwal D, Hyder F. Evaluating the gray and white matter energy budgets of human brain function. J Cereb Blood Flow Metab 2018; 38:1339-1353. [PMID: 28589753 PMCID: PMC6092772 DOI: 10.1177/0271678x17708691] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The insatiable appetite for energy to support human brain function is mainly supplied by glucose oxidation (CMRglc(ox)). But how much energy is consumed for signaling and nonsignaling processes in gray/white matter is highly debated. We examined this issue by combining metabolic measurements of gray/white matter and a theoretical calculation of bottom-up energy budget using biophysical properties of neuronal/glial cells in conjunction with species-exclusive electrophysiological and morphological data. We calculated a CMRglc(ox)-derived budget and confirmed it with experimental results measured by PET, autoradiography, 13C-MRS, and electrophysiology. Several conserved principles were observed regarding the energy costs for brain's signaling and nonsignaling components in both human and rat. The awake resting cortical signaling processes and mass-dependent nonsignaling processes, respectively, demand ∼70% and ∼30% of CMRglc(ox). Inhibitory neurons and glia need 15-20% of CMRglc(ox), with the rest demanded by excitatory neurons. Nonsignaling demands dominate in white matter, in near opposite contrast to gray matter demands. Comparison between 13C-MRS data and calculations suggests ∼1.2 Hz glutamatergic signaling rate in the awake human cortex, which is ∼4 times lower than signaling in the rat cortex. Top-down validated bottom-up budgets could allow computation of anatomy-based CMRglc(ox) maps and accurate cellular level interpretation of brain metabolic imaging.
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Affiliation(s)
- Yuguo Yu
- 1 School of Life Science and the Collaborative Innovation Center for Brain Science, the Center for Computational Systems Biology, Fudan University, Shanghai, China
| | - Peter Herman
- 2 Department of Radiology and Biomedical Imaging Yale University, New Haven, CT, USA.,3 Magnetic Resonance Research Center, Yale University, New Haven, CT, USA.,4 Quantitative Neuroscience with Magnetic Resonance Core Center, Yale University, New Haven, CT, USA
| | - Douglas L Rothman
- 2 Department of Radiology and Biomedical Imaging Yale University, New Haven, CT, USA.,3 Magnetic Resonance Research Center, Yale University, New Haven, CT, USA.,4 Quantitative Neuroscience with Magnetic Resonance Core Center, Yale University, New Haven, CT, USA.,5 Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Divyansh Agarwal
- 3 Magnetic Resonance Research Center, Yale University, New Haven, CT, USA.,4 Quantitative Neuroscience with Magnetic Resonance Core Center, Yale University, New Haven, CT, USA.,6 Currently at Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Fahmeed Hyder
- 2 Department of Radiology and Biomedical Imaging Yale University, New Haven, CT, USA.,3 Magnetic Resonance Research Center, Yale University, New Haven, CT, USA.,4 Quantitative Neuroscience with Magnetic Resonance Core Center, Yale University, New Haven, CT, USA.,5 Department of Biomedical Engineering, Yale University, New Haven, CT, USA
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29
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Mitra A, Raichle ME. How networks communicate: propagation patterns in spontaneous brain activity. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0546. [PMID: 27574315 DOI: 10.1098/rstb.2015.0546] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/09/2016] [Indexed: 12/18/2022] Open
Abstract
Initially regarded as 'noise', spontaneous (intrinsic) activity accounts for a large portion of the brain's metabolic cost. Moreover, it is now widely known that infra-slow (less than 0.1 Hz) spontaneous activity, measured using resting state functional magnetic resonance imaging of the blood oxygen level-dependent (BOLD) signal, is correlated within functionally defined resting state networks (RSNs). However, despite these advances, the temporal organization of spontaneous BOLD fluctuations has remained elusive. By studying temporal lags in the resting state BOLD signal, we have recently shown that spontaneous BOLD fluctuations consist of remarkably reproducible patterns of whole brain propagation. Embedded in these propagation patterns are unidirectional 'motifs' which, in turn, give rise to RSNs. Additionally, propagation patterns are markedly altered as a function of state, whether physiological or pathological. Understanding such propagation patterns will likely yield deeper insights into the role of spontaneous activity in brain function in health and disease.This article is part of the themed issue 'Interpreting blood oxygen level-dependent: a dialogue between cognitive and cellular neuroscience'.
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Affiliation(s)
- Anish Mitra
- Department of Radiology, Washington University, St Louis, MO 63110, USA
| | - Marcus E Raichle
- Department of Radiology, Washington University, St Louis, MO 63110, USA Department of Neurology, Washington University, St Louis, MO 63110, USA
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30
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Chen J, Wang J, Zhang J, Pu C. 3- n-Butylphthalide reduces the oxidative damage of muscles in an experimental autoimmune myositis animal model. Exp Ther Med 2017; 14:2085-2093. [PMID: 28962128 PMCID: PMC5609169 DOI: 10.3892/etm.2017.4766] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 03/23/2017] [Indexed: 01/18/2023] Open
Abstract
3-n-Butylphthalide (NBP) protects the mitochondria and reduces apoptosis in multiple disease models. However, it remains to be determined whether NBP can protect muscle cells from oxidative stress, lipid peroxidation and apoptosis in myositis. In the present study, a myosin immunization protocol was applied to induce experimental autoimmune myositis (EAM) in guinea pigs. After 4 weeks, a low- or high-dose NBP solution was injected intraperitoneally into the guinea pigs, with saline solution serving as the negative control. After 10 days, the guinea pigs were sacrificed and muscle cells were isolated for analysis. The results revealed that NBP increased the superoxide dismutase and catalase activity, and reduced malondialdehyde activity in the EAM model. Furthermore, NBP enhanced ATPase activity in muscle mitochondrial membranes and muscle fiber membranes, reduced the number of apoptotic cells, and differentially regulated the Bcl-2, Bax and BAD mRNA and protein expression levels in muscle tissues and sera. NBP directly protects muscle mitochondria and muscle cells from oxidative damage. Notably, NBP reduced muscle cell apoptosis. Thus, it is speculated that, as an antioxidant treatment, NBP may benefit individuals with myopathy.
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Affiliation(s)
- Juan Chen
- Department of Neurology, Chinese PLA Medical School, Beijing 100853, P.R. China.,Department of Neurology, The 309th Hospital of PLA, Beijing 100091, P.R. China
| | - Jingyang Wang
- Department of Neurology, Chinese PLA Medical School, Beijing 100853, P.R. China
| | - Jiyan Zhang
- Laboratory of Immunology, Academy of Military Medical Sciences, Beijing 100850, P.R. China
| | - Chuanqiang Pu
- Department of Neurology, Chinese PLA Medical School, Beijing 100853, P.R. China
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31
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Engl E, Jolivet R, Hall CN, Attwell D. Non-signalling energy use in the developing rat brain. J Cereb Blood Flow Metab 2017; 37:951-966. [PMID: 27170699 PMCID: PMC5322833 DOI: 10.1177/0271678x16648710] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 03/30/2016] [Accepted: 04/05/2016] [Indexed: 11/26/2022]
Abstract
Energy use in the brain constrains its information processing power, but only about half the brain's energy consumption is directly related to information processing. Evidence for which non-signalling processes consume the rest of the brain's energy has been scarce. For the first time, we investigated the energy use of the brain's main non-signalling tasks with a single method. After blocking each non-signalling process, we measured oxygen level changes in juvenile rat brain slices with an oxygen-sensing microelectrode and calculated changes in oxygen consumption throughout the slice using a modified diffusion equation. We found that the turnover of the actin and microtubule cytoskeleton, followed by lipid synthesis, are significant energy drains, contributing 25%, 22% and 18%, respectively, to the rate of oxygen consumption. In contrast, protein synthesis is energetically inexpensive. We assess how these estimates of energy expenditure relate to brain energy use in vivo, and how they might differ in the mature brain.
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Affiliation(s)
- Elisabeth Engl
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK
| | - Renaud Jolivet
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK
- CERN, and Département de physique nucléaire et corpusculaire (DPNC), University of Geneva, Geneva, Switzerland
| | | | - David Attwell
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK
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32
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Koçak OM, Kale E, Çiçek M. Default Mode Network Connectivity Differences in Obsessive-compulsive Disorder. ACTA ACUST UNITED AC 2017. [DOI: 10.1007/bf03379589] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Abstract
Recent evidence suggests that the brain intrinsic activity during rest might be as significant as task evoked activities and consumes considerable energy linked to neural signaling processes. We performed an fMRI study recently aiming to compare the differences in brain activity between patients with obsessive-compulsive disorder and healthy volunteers during a simple suppression paradigm. We hypothesized that the patients with obsessive-compulsive disorder would show default mode network (DMN) connectivity dissociations from healthy individuals. OcD patients had higher connectivity (p < 0.05) than controls between right inferior parietal lobe (IPL) and left ventral medial prefrontal cortex (MPFC).
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33
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Gerkau NJ, Rakers C, Petzold GC, Rose CR. Differential effects of energy deprivation on intracellular sodium homeostasis in neurons and astrocytes. J Neurosci Res 2017; 95:2275-2285. [PMID: 28150887 DOI: 10.1002/jnr.23995] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 11/10/2016] [Accepted: 11/10/2016] [Indexed: 12/11/2022]
Abstract
The maintenance of a low intracellular sodium concentration by the Na+ /K+ -ATPase (NKA) is critical for brain function. In both neurons and glial cells, NKA activity is required to counteract changes in the sodium gradient due to opening of voltage- and ligand-gated channels and/or activation of sodium-dependent secondary active transporters. Because NKA consumes about 50% of cellular ATP, sodium homeostasis is strictly dependent on an intact cellular energy metabolism. Despite the high energetic costs of electrical signaling, neurons do not contain significant energy stores themselves, but rely on a close metabolic interaction with surrounding astrocytes. A disruption of energy supply as observed during focal ischemia causes a rapid drop in ATP in both neurons and astrocytes. There is accumulating evidence that dysregulation of intracellular sodium is an inherent consequence of a reduction in cellular ATP, triggering secondary failure of extra- and intracellular homeostasis of other ions -in particular potassium, calcium, and protons- and thereby promoting excitotoxicity. The characteristics, cellular mechanisms and direct consequences of harmful sodium influx, however, differ between neurons and astrocytes. Moreover, recent work has shown that an intact astrocyte metabolism and sodium homeostasis are critical to maintain the sodium homeostasis of surrounding neurons as well as their capacity to recover from imposed sodium influx. Understanding the mechanisms of sodium increases upon metabolic failure and the differential responses of neurons and glial cells as well as their metabolic interactions will be critical to fully unravel the events causing cellular malfunction, failure and cell death following energy depletion. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Niklas J Gerkau
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Universitätsstrasse 1, D-40225, Düsseldorf, Germany
| | - Cordula Rakers
- German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Strasse 27, 53127, Bonn, Germany
| | - Gabor C Petzold
- German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Strasse 27, 53127, Bonn, Germany
| | - Christine R Rose
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Universitätsstrasse 1, D-40225, Düsseldorf, Germany
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34
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Neuronal energy consumption: biophysics, efficiency and evolution. Curr Opin Neurobiol 2016; 41:129-135. [DOI: 10.1016/j.conb.2016.09.004] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 08/25/2016] [Accepted: 09/05/2016] [Indexed: 12/20/2022]
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35
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Sanganalmath SK, Gopal P, Parker JR, Downs RK, Parker JC, Dawn B. Global cerebral ischemia due to circulatory arrest: insights into cellular pathophysiology and diagnostic modalities. Mol Cell Biochem 2016; 426:111-127. [PMID: 27896594 DOI: 10.1007/s11010-016-2885-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 11/08/2016] [Indexed: 02/07/2023]
Abstract
Circulatory arrest (CA) remains a major unresolved public health problem in the United States; the annual incidence of which is ~0.50 to 0.55 per 1000 population. Despite seminal advances in therapeutic approaches over the past several decades, brain injury continues to be the leading cause of morbidity and mortality after CA. In brief, CA typically results in global cerebral ischemia leading to delayed neuronal death in the hippocampal pyramidal cells as well as in the cortical layers. The dynamic changes occurring in neurons after CA are still unclear, and predicting these neurological changes in the brain still remains a difficult issue. It is hypothesized that the "no-flow" period produces a cytotoxic cascade of membrane depolarization, Ca2+ ion influx, glutamate release, acidosis, and resultant activation of lipases, nucleases, and proteases. Furthermore, during reperfusion injury, neuronal death occurs due to the generation of free radicals by interfering with the mitochondrial respiratory chain. The efficacy of many pharmacological agents for CA patients has often been disappointing, reflecting our incomplete understanding of this enigmatic disease. The primary obstacles to the development of a neuroprotective therapy in CA include uncertainties with regard to the precise cause(s) of neuronal dysfunction and what to target. In this review, we summarize our knowledge of the pathophysiology as well as specific cellular changes in brain after CA and revisit the most important neurofunctional, neuroimaging techniques, and serum biomarkers as potent predictors of neurologic outcome in CA patients.
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Affiliation(s)
- Santosh K Sanganalmath
- Division of Cardiovascular Diseases, Department of Medicine, University of Kansas Medical Center, 3901 Rainbow Blvd, Kansas City, KS, 66160, USA.
| | - Purva Gopal
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA
| | - John R Parker
- Division of Neuropathology, Department of Pathology and Laboratory Medicine, University of Louisville, Louisville, KY, USA
| | - Richard K Downs
- Division of Neuroradiology, Department of Radiology, University of Louisville, Louisville, KY, USA
| | - Joseph C Parker
- Division of Neuropathology, Department of Pathology and Laboratory Medicine, University of Louisville, Louisville, KY, USA
| | - Buddhadeb Dawn
- Division of Cardiovascular Diseases, Department of Medicine, University of Kansas Medical Center, 3901 Rainbow Blvd, Kansas City, KS, 66160, USA
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36
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Roberts BR, Doecke JD, Rembach A, Yévenes LF, Fowler CJ, McLean CA, Lind M, Volitakis I, Masters CL, Bush AI, Hare DJ. Rubidium and potassium levels are altered in Alzheimer's disease brain and blood but not in cerebrospinal fluid. Acta Neuropathol Commun 2016; 4:119. [PMID: 27842602 PMCID: PMC5109650 DOI: 10.1186/s40478-016-0390-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 10/29/2016] [Indexed: 12/21/2022] Open
Abstract
Loss of intracellular compartmentalization of potassium is a biochemical feature of Alzheimer's disease indicating a loss of membrane integrity and mitochondrial dysfunction. We examined potassium and rubidium (a biological proxy for potassium) in brain tissue, blood fractions and cerebrospinal fluid from Alzheimer's disease and healthy control subjects to investigate the diagnostic potential of these two metal ions. We found that both potassium and rubidium levels were significantly decreased across all intracellular compartments in the Alzheimer's disease brain. Serum from over 1000 participants in the Australian Imaging, Biomarkers and Lifestyle Flagship Study of Ageing (AIBL), showed minor changes according to disease state. Potassium and rubidium levels in erythrocytes and cerebrospinal fluid were not significantly different according to disease state, and rubidium was slightly decreased in Alzheimer's disease patients compared to healthy controls. Our data provides evidence that contrasts the hypothesized disruption of the blood-brain barrier in Alzheimer's disease, with the systemic decrease in cortical potassium and rubidium levels suggesting influx of ions from the blood is minimal and that the observed changes are more likely indicative of an internal energy crisis within the brain. These findings may be the basis for potential diagnostic imaging studies using radioactive potassium and rubidium tracers.
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37
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Mondragão MA, Schmidt H, Kleinhans C, Langer J, Kafitz KW, Rose CR. Extrusion versus diffusion: mechanisms for recovery from sodium loads in mouse CA1 pyramidal neurons. J Physiol 2016; 594:5507-27. [PMID: 27080107 PMCID: PMC5043027 DOI: 10.1113/jp272431] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 04/07/2016] [Indexed: 12/20/2022] Open
Abstract
KEY POINTS Neuronal activity causes local or global sodium signalling in neurons, depending on the pattern of synaptic activity. Recovery from global sodium loads critically relies on Na(+) /K(+) -ATPase and an intact energy metabolism in both somata and dendrites. For recovery from local sodium loads in dendrites, Na(+) /K(+) -ATPase activity is not required per se. Instead, recovery is predominately mediated by lateral diffusion, exhibiting rates that are 10-fold higher than for global sodium signals. Recovery from local dendritic sodium increases is still efficient during short periods of energy deprivation, indicating that fast diffusion of sodium to non-stimulated regions strongly reduces local energy requirements. ABSTRACT Excitatory activity is accompanied by sodium influx into neurones as a result of the opening of voltage- and ligand-activated channels. Recovery from resulting sodium transients has mainly been attributed to Na(+) /K(+) -ATPase (NKA). Because sodium ions are highly mobile, diffusion could provide an additional pathway. We tested this in hippocampal neurones using whole-cell patch-clamp recordings and sodium imaging. Somatic sodium transients induced by local glutamate application recovered at a maximum rate of 8 mm min(-1) (∼0.03 mm min(-1 ) μm(-2) ). Somatic sodium extrusion was accelerated at higher temperature and blocked by ouabain, emphasizing its dependence on NKA. Moreover, it was slowed down during inhibition of glycolysis by sodium fluoride (NaF). Local glutamate application to dendrites revealed a 10-fold higher apparent dendritic sodium extrusion rate compared to somata. Recovery was almost unaltered by increased temperature, ouabain or NaF. We found that sodium diffused along primary dendrites with a diffusion coefficient of ∼330 μm²/s. During global glutamate application, impeding substantial net diffusion, apparent dendritic extrusion rates were reduced to somatic rates and also affected by NaF. Numerical simulations confirmed the essential role of NKA for the recovery of somatic, but not dendritic sodium loads. Our data show that sodium export upon global sodium increases is largely mediated by NKA and depends on an intact energy metabolism. For recovery from local dendritic sodium increases, diffusion dominates over extrusion, operating efficiently even during short periods of energy deprivation. Although sodium will eventually be extruded by the NKA, its diffusion-based fast dissemination to non-stimulated regions might reduce local energy requirements.
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Affiliation(s)
- Miguel A Mondragão
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Hartmut Schmidt
- Carl-Ludwig-Institute for Physiology, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Christian Kleinhans
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Julia Langer
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Karl W Kafitz
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Christine R Rose
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
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38
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Krueger JM, Frank MG, Wisor JP, Roy S. Sleep function: Toward elucidating an enigma. Sleep Med Rev 2016; 28:46-54. [PMID: 26447948 PMCID: PMC4769986 DOI: 10.1016/j.smrv.2015.08.005] [Citation(s) in RCA: 223] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 07/16/2015] [Accepted: 08/19/2015] [Indexed: 01/11/2023]
Abstract
Sleep function remains controversial. Individual perspectives frame the issue of sleep function differently. We briefly illustrate how sleep measurement and the evolution, tissue organization levels, molecular mechanisms, and regulation of sleep could influence one's view of sleep function. Then we discuss six viable theories of sleep function. Sleep serves host-defense mechanisms and conserves caloric expenditures, but these functions likely are opportunistic functions evolving later in evolution. That sleep replenishes brain energy stores and that sleep serves a glymphatic function by removing toxic byproducts of waking activity are attractive ideas, but lack extensive supporting experimental evidence. That sleep restores performance is experimentally demonstrated and has obvious evolutionary value. However, this hypothesis lacks experimentally verified mechanisms although ideas relating to this issue are presented. Finally, the ideas surrounding the broad hypothesis that sleep serves a connectivity/plasticity function are many and attractive. There is experimental evidence that connectivity changes with sleep, sleep loss, and with changing afferent input, and that those changes are linked to sleep regulatory mechanisms. In our view, this is the leading contender for the primordial function of sleep. However, much refinement of ideas and innovative experimental approaches are needed to clarify the sleep-connectivity relationship.
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Affiliation(s)
- James M Krueger
- College of Medical Sciences, Washington State University-Spokane, WA, USA.
| | - Marcos G Frank
- College of Medical Sciences, Washington State University-Spokane, WA, USA
| | - Jonathan P Wisor
- College of Medical Sciences, Washington State University-Spokane, WA, USA
| | - Sandip Roy
- Department of Electrical Engineering, Washington State University-Pullman, WA, USA
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39
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Lim H, Ahn HW, Kornijcuk V, Kim G, Seok JY, Kim I, Hwang CS, Jeong DS. Relaxation oscillator-realized artificial electronic neurons, their responses, and noise. NANOSCALE 2016; 8:9629-9640. [PMID: 27103542 DOI: 10.1039/c6nr01278g] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A proof-of-concept relaxation oscillator-based leaky integrate-and-fire (ROLIF) neuron circuit is realized by using an amorphous chalcogenide-based threshold switch and non-ideal operational amplifier (op-amp). The proposed ROLIF neuron offers biologically plausible features such as analog-type encoding, signal amplification, unidirectional synaptic transmission, and Poisson noise. The synaptic transmission between pre- and postsynaptic neurons is achieved through a passive synapse (simple resistor). The synaptic resistor coupled to the non-ideal op-amp realizes excitatory postsynaptic potential (EPSP) evolution that evokes postsynaptic neuron spiking. In an attempt to generalize our proposed model, we theoretically examine ROLIF neuron circuits adopting different non-ideal op-amps having different gains and slew rates. The simulation results indicate the importance of gain in postsynaptic neuron spiking, irrespective of the slew rate (as long as the rate exceeds a particular value), providing the basis for the ROLIF neuron circuit design. Eventually, the behavior of a postsynaptic neuron in connection to multiple presynaptic neurons via synapses is highlighted in terms of EPSP evolution amid simultaneously incident asynchronous presynaptic spikes, which in fact reveals an important role of the random noise in spatial integration.
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Affiliation(s)
- Hyungkwang Lim
- Center for Electronic Materials, Korea Institute of Science and Technology, 5 Hwarang-ro 14-gil, Seongbuk-gu, 02792 Seoul, Republic of Korea.
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40
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Loewendorf AI, Matynia A, Saribekyan H, Gross N, Csete M, Harrington M. Roads Less Traveled: Sexual Dimorphism and Mast Cell Contributions to Migraine Pathology. Front Immunol 2016; 7:140. [PMID: 27148260 PMCID: PMC4836167 DOI: 10.3389/fimmu.2016.00140] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 03/31/2016] [Indexed: 12/30/2022] Open
Abstract
Migraine is a common, little understood, and debilitating disease. It is much more prominent in women than in men (~2/3 are women) but the reasons for female preponderance are not clear. Migraineurs frequently experience severe comorbidities, such as allergies, depression, irritable bowel syndrome, and others; many of the comorbidities are more common in females. Current treatments for migraine are not gender specific, and rarely are migraine and its comorbidities considered and treated by the same specialist. Thus, migraine treatments represent a huge unmet medical need, which will only be addressed with greater understanding of its underlying pathophysiology. We discuss the current knowledge about sex differences in migraine and its comorbidities, and focus on the potential role of mast cells (MCs) in both. Sex-based differences in pain recognition and drug responses, fluid balance, and the blood–brain barrier are recognized but their impact on migraine is not well studied. Furthermore, MCs are well recognized for their prominent role in allergies but much less is known about their contributions to pain pathways in general and migraine specifically. MC-neuron bidirectional communication uniquely positions these cells as potential initiators and/or perpetuators of pain. MCs can secrete nociceptor sensitizing and activating agents, such as serotonin, prostaglandins, histamine, and proteolytic enzymes that can also activate the pain-mediating transient receptor potential vanilloid channels. MCs express receptors for both estrogen and progesterone that induce degranulation upon binding. Furthermore, environmental estrogens, such as Bisphenol A, activate MCs in preclinical models but their impact on pain pathways or migraine is understudied. We hope that this discussion will encourage scientists and physicians alike to bridge the knowledge gaps linking sex, MCs, and migraine to develop better, more comprehensive treatments for migraine patients.
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Affiliation(s)
| | - Anna Matynia
- Department of Ophthalmology, Jules Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA; Brain Research Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | | | - Noah Gross
- Huntington Medical Research Institutes , Pasadena, CA , USA
| | - Marie Csete
- Huntington Medical Research Institutes , Pasadena, CA , USA
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Rose CR, Verkhratsky A. Principles of sodium homeostasis and sodium signalling in astroglia. Glia 2016; 64:1611-27. [DOI: 10.1002/glia.22964] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 12/21/2015] [Indexed: 12/22/2022]
Affiliation(s)
- Christine R. Rose
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences; Heinrich Heine University Düsseldorf; Düsseldorf Germany
| | - Alexei Verkhratsky
- Faculty of Life Sciences; the University of Manchester; Manchester United Kingdom
- Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
- Department of Neurosciences; University of the Basque Country UPV/EHU and CIBERNED; Leioa Spain
- University of Nizhny Novgorod; Nizhny Novgorod Russia
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Killing Me Softly: Connotations to Unfolded Protein Response and Oxidative Stress in Alzheimer's Disease. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:1805304. [PMID: 26881014 PMCID: PMC4736771 DOI: 10.1155/2016/1805304] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 11/28/2015] [Accepted: 12/07/2015] [Indexed: 11/18/2022]
Abstract
This review is focused on the possible causes of mitochondrial dysfunction in AD, underlying molecular mechanisms of this malfunction, possible causes and known consequences of APP, Aβ, and hyperphosphorylated tau presence in mitochondria, and the contribution of altered lipid metabolism (nonsterol isoprenoids) to pathological processes leading to increased formation and accumulation of the aforementioned hallmarks of AD. Abnormal protein folding and unfolded protein response seem to be the outcomes of impaired glycosylation due to metabolic disturbances in geranylgeraniol intermediary metabolism. The origin and consecutive fate of APP, Aβ, and tau are emphasized on intracellular trafficking apparently influenced by inaccurate posttranslational modifications. We hypothesize that incorrect intracellular processing of APP determines protein translocation to mitochondria in AD. Similarly, without obvious reasons, the passage of Aβ and tau to mitochondria is observed. APP targeted to mitochondria blocks the activity of protein translocase complex resulting in poor import of proteins central to oxidative phosphorylation. Besides, APP, Aβ, and neurofibrillary tangles of tau directly or indirectly impair mitochondrial biochemistry and bioenergetics, with concomitant generation of oxidative/nitrosative stress. Limited protective mechanisms are inadequate to prevent the free radical-mediated lesions. Finally, neuronal loss is observed in AD-affected brains typically by pathologic apoptosis.
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Cerebral Blood Flow and Metabolism. Stroke 2016. [DOI: 10.1016/b978-0-323-29544-4.00003-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Zsurka G, Kunz WS. Mitochondrial dysfunction and seizures: the neuronal energy crisis. Lancet Neurol 2015; 14:956-66. [PMID: 26293567 DOI: 10.1016/s1474-4422(15)00148-9] [Citation(s) in RCA: 159] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 06/19/2015] [Accepted: 06/24/2015] [Indexed: 12/21/2022]
Abstract
Seizures are often the key manifestation of neurological diseases caused by pathogenic mutations in 169 of the genes that have so far been identified to affect mitochondrial function. Mitochondria are the main producers of ATP needed for normal electrical activities of neurons and synaptic transmission. Additionally, they have a central role in neurotransmitter synthesis, calcium homoeostasis, redox signalling, production and modulation of reactive oxygen species, and neuronal death. Hypotheses link mitochondrial failure to seizure generation through changes in calcium homoeostasis, oxidation of ion channels and neurotransmitter transporters by reactive oxygen species, a decrease in neuronal plasma membrane potential, and reduced network inhibition due to interneuronal dysfunction. Seizures, irrespective of their origin, represent an excessive acute energy demand in the brain. Accordingly, secondary mitochondrial dysfunction has been described in various epileptic disorders, including disorders that are mainly of non-mitochondrial origin. An understanding of the reciprocal relation between mitochondrial dysfunction and epilepsy is crucial to select appropriate anticonvulsant treatment and has the potential to open up new therapeutic approaches in the subset of epileptic disorders caused by mitochondrial dysfunction.
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Affiliation(s)
- Gábor Zsurka
- Division of Neurochemistry, Department of Epileptology, and Life & Brain Center, University of Bonn, Bonn, Germany
| | - Wolfram S Kunz
- Division of Neurochemistry, Department of Epileptology, and Life & Brain Center, University of Bonn, Bonn, Germany.
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Nirujogi RS, Wright JD, Manda SS, Zhong J, Na CH, Meyerhoff J, Benton B, Jabbour R, Willis K, Kim MS, Pandey A, Sekowski JW. Phosphoproteomic analysis reveals compensatory effects in the piriform cortex of VX nerve agent exposed rats. Proteomics 2015; 15:487-99. [PMID: 25403869 DOI: 10.1002/pmic.201400371] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 10/01/2014] [Accepted: 11/12/2014] [Indexed: 01/15/2023]
Abstract
To gain insights into the toxicity induced by the nerve agent VX, an MS-based phosphoproteomic analysis was carried out on the piriform cortex region of brains from VX-treated rats. Using isobaric tag based TMT labeling followed by titanium dioxide enrichment strategy, we identified 9975 unique phosphosites derived from 3287 phosphoproteins. Temporal changes in the phosphorylation status of peptides were observed over a time period of 24 h in rats exposed to a 1× LD50, intravenous (i.v.) dose with the most notable changes occurring at the 1 h postexposure time point. Five major functional classes of proteins exhibited changes in their phosphorylation status: (i) ion channels/transporters, including ATPases, (ii) kinases/phosphatases, (iii) GTPases, (iv) structural proteins, and (v) transcriptional regulatory proteins. This study is the first quantitative phosphoproteomic analysis of VX toxicity in the brain. Understanding the toxicity and compensatory signaling mechanisms will improve the understanding of the complex toxicity of VX in the brain and aid in the elucidation of novel molecular targets that would be important for development of improved countermeasures. All MS data have been deposited in the ProteomeXchange with identifier PXD001184 (http://proteomecentral.proteomexchange.org/dataset/PXD001184).
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Affiliation(s)
- Raja Sekhar Nirujogi
- Institute of Bioinformatics, International Tech Park, Bangalore, India; School of Life Sciences, Centre for Bioinformatics, Pondicherry University, Puducherry, India; Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
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Engl E, Attwell D. Non-signalling energy use in the brain. J Physiol 2015; 593:3417-29. [PMID: 25639777 PMCID: PMC4560575 DOI: 10.1113/jphysiol.2014.282517] [Citation(s) in RCA: 137] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 01/27/2015] [Indexed: 01/19/2023] Open
Abstract
Energy use limits the information processing power of the brain. However, apart from the ATP used to power electrical signalling, a significant fraction of the brain's energy consumption is not directly related to information processing. The brain spends just under half of its energy on non-signalling processes, but it remains poorly understood which tasks are so energetically costly for the brain. We review existing experimental data on subcellular processes that may contribute to this non-signalling energy use, and provide modelling estimates, to try to assess the magnitude of their ATP consumption and consider how their changes in pathology may compromise neuronal function. As a main result, surprisingly little consensus exists on the energetic cost of actin treadmilling, with estimates ranging from < 1% of the brain's global energy budget up to one-half of neuronal energy use. Microtubule treadmilling and protein synthesis have been estimated to account for very small fractions of the brain's energy budget, whereas there is stronger evidence that lipid synthesis and mitochondrial proton leak are energetically expensive. Substantial further research is necessary to close these gaps in knowledge about the brain's energy-expensive non-signalling tasks.
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Affiliation(s)
- Elisabeth Engl
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, WC1E 6BT, UK
| | - David Attwell
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, WC1E 6BT, UK
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Zhang LN, Sun YJ, Wang LX, Gao ZB. Glutamate Transporters/Na(+), K(+)-ATPase Involving in the Neuroprotective Effect as a Potential Regulatory Target of Glutamate Uptake. Mol Neurobiol 2015; 53:1124-1131. [PMID: 25586061 DOI: 10.1007/s12035-014-9071-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Accepted: 12/29/2014] [Indexed: 02/05/2023]
Abstract
The glutamate (Glu) transporters GLAST and GLT-1, as the two most important transporters in brain tissue, transport Glu from the extracellular space into the cell protecting against Glu toxicity. Furthermore, GLAST and GLT-1 are sodium-dependent Glu transporters (GluTs) that rely on sodium and potassium gradients generated principally by Na(+), K(+)-ATPase to generate ion gradients that drive Glu uptake. There is an interaction between Na(+), K(+)-ATPase and GluTs to modulate Glu uptake, and Na(+), K(+)-ATPase α, β or γ subunit can be directly coupled to GluTs, co-localizing with GLAST or GLT-1 in vivo to form a macromolecular complex and operate as a functional unit to regulate glutamatergic neurotransmission. Therefore, GluTs/Na(+), K(+)-ATPase may be involved in the neuroprotective effect as a potential regulatory target of Glu uptake in neurodegenerative diseases induced by Glu-mediated neurotoxicity as the final common pathway.
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Affiliation(s)
- Li-Nan Zhang
- Department of Pharmacy, Hebei University of Science and Technology, 70 Yuhua East Road, Shijiazhuang, Hebei, 050018, People's Republic of China
| | - Yong-Jun Sun
- Department of Pharmacy, Hebei University of Science and Technology, 70 Yuhua East Road, Shijiazhuang, Hebei, 050018, People's Republic of China
| | - Li-Xue Wang
- Cadre Ward, Capital Medical University Electric Power Teaching Hospital, Compound A1, Taiping Bridge Xili, Beijing, 100073, People's Republic of China
| | - Zi-Bin Gao
- Department of Pharmacy, Hebei University of Science and Technology, 70 Yuhua East Road, Shijiazhuang, Hebei, 050018, People's Republic of China. .,State Key Laboratory Breeding Base-Hebei Province Key Laboratory of Molecular Chemistry for Drug, 70 Yuhua East Road, Shijiazhuang, 050018, People's Republic of China.
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Greene JG. Causes and consequences of degeneration of the dorsal motor nucleus of the vagus nerve in Parkinson's disease. Antioxid Redox Signal 2014; 21:649-67. [PMID: 24597973 DOI: 10.1089/ars.2014.5859] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
SIGNIFICANCE Parkinson's disease (PD) is no longer considered merely a movement disorder caused by degeneration of dopamine neurons in the midbrain. It is now recognized as a widespread neuropathological syndrome accompanied by a variety of motor and nonmotor clinical symptoms. As such, any hypothesis concerning PD pathogenesis and pathophysiology must account for the entire spectrum of disease and not solely focus on the dopamine system. RECENT ADVANCES Based on its anatomy and the intrinsic properties of its neurons, the dorsal motor nucleus of the vagus nerve (DMV) is uniquely vulnerable to damage from PD. Fibers in the vagus nerve course throughout the gastrointestinal (GI) tract to and from the brainstem forming a close link between the peripheral and central nervous systems and a point of proximal contact between the environment and areas where PD pathology is believed to start. In addition, DMV neurons are under high levels of oxidative stress due to their high level of α-synuclein expression, fragile axons, and specific neuronal physiology. Moreover, several consequences of DMV damage, namely, GI dysfunction and unrestrained inflammation, may propagate a vicious cycle of injury affecting vulnerable brain regions. CRITICAL ISSUES Current evidence to suggest the vagal system plays a pivotal role in PD pathogenesis is circumstantial, but given the current state of the field, the time is ripe to obtain direct experimental evidence to better delineate it. FUTURE DIRECTIONS Better understanding of the DMV and vagus nerve may provide insight into PD pathogenesis and a neural highway with direct brain access that could be harnessed for novel therapeutic interventions.
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Affiliation(s)
- James G Greene
- Department of Neurology, Emory University , Atlanta, Georgia
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Gao J, Yao H, Pan XD, Xie AM, Zhang L, Song JH, Ma AJ, Liu ZC. Alteration of mitochondrial function and ultrastructure in the hippocampus of pilocarpine-treated rat. Epilepsy Res 2014; 108:162-70. [DOI: 10.1016/j.eplepsyres.2013.11.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 09/17/2013] [Accepted: 11/21/2013] [Indexed: 11/26/2022]
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50
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Araujo B, Torres L, Stein M, Cabral FR, Herai R, Okamoto O, Cavalheiro E. Decreased expression of proteins involved in energy metabolism in the hippocampal granular layer of rats submitted to the pilocarpine epilepsy model. Neurosci Lett 2013; 561:46-51. [PMID: 24373985 DOI: 10.1016/j.neulet.2013.12.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 12/01/2013] [Accepted: 12/17/2013] [Indexed: 11/18/2022]
Abstract
Long-term structural and functional changes in the hippocampus have been identified as the primary physiopathological basis for temporal lobe epilepsy. These changes include reactive gliosis and granule cell axonal sprouting within the dentate gyrus. The intimate mechanisms of these changes are beginning to be revealed. Here, we show the possibility of using laser capture microdissection (LCM) to isolate the dentate granular cell layer of Wistar rats submitted to the pilocarpine model of epilepsy. Using two-dimensional gel electrophoresis (2-D PAGE) and mass spectrometry for laser-captured cells, we identified molecular events that could be altered as part of the epileptic pathogenic process. According to our results, eight proteins related to energy metabolism were differentially expressed between both the control and pilocarpine-treated animals. These results provide, for the first time, new molecular insights into the altered protein profile of the epileptogenic dentate gyrus and can contribute to a better understanding of the phenomena involved in the genesis and maintenance of the epileptic state.
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Affiliation(s)
- Bruno Araujo
- Neurologia Experimental - Escola Paulista de Medicina/Universidade Federal de São Paulo, São Paulo, SP, Brazil; University of California San Diego, School of Medicine, Department of Pediatrics/Rady Children's Hospital San Diego, Department of Cellular & Molecular Medicine, Stem Cell Program, La Jolla, CA, USA.
| | - Laila Torres
- Neurologia Experimental - Escola Paulista de Medicina/Universidade Federal de São Paulo, São Paulo, SP, Brazil; Hospital Israelita Albert Einstein - Instituto do Cérebro, São Paulo, SP, Brazil; University of California San Diego, School of Medicine, Department of Pediatrics/Rady Children's Hospital San Diego, Department of Cellular & Molecular Medicine, Stem Cell Program, La Jolla, CA, USA
| | - Mariana Stein
- Laboratório de Biologia Molecular de Parasitas - Escola Paulista de Medicina/Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Francisco Romero Cabral
- Hospital Israelita Albert Einstein - Instituto do Cérebro, São Paulo, SP, Brazil; Faculdade de Ciências Médicas da Santa Casa de São Paulo, São Paulo, SP, Brazil
| | - Roberto Herai
- University of California San Diego, School of Medicine, Department of Pediatrics/Rady Children's Hospital San Diego, Department of Cellular & Molecular Medicine, Stem Cell Program, La Jolla, CA, USA
| | - Oswaldo Okamoto
- Departamento de Genética e Biologia Evolutiva, Universidade de São Paulo, USP, Instituto de Biociências, São Paulo, SP, Brazil
| | - Esper Cavalheiro
- Neurologia Experimental - Escola Paulista de Medicina/Universidade Federal de São Paulo, São Paulo, SP, Brazil
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