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Dysregulation of Glycogen Metabolism with Concomitant Spatial Memory Dysfunction in Type 2 Diabetes: Potential Beneficial Effects of Chronic Exercise. ADVANCES IN NEUROBIOLOGY 2019; 23:363-383. [DOI: 10.1007/978-3-030-27480-1_13] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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52
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The Structure and the Regulation of Glycogen Phosphorylases in Brain. ADVANCES IN NEUROBIOLOGY 2019; 23:125-145. [DOI: 10.1007/978-3-030-27480-1_4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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53
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Abstract
Sleep is a highly conserved phenomenon in endotherms, and therefore it must serve at least one basic function across this wide range of species. What that function is remains one of the biggest mysteries in neurobiology. By using the word neurobiology, we do not mean to exclude possible non-neural functions of sleep, but it is difficult to imagine why the brain must be taken offline if the basic function of sleep did not involve the nervous system. In this chapter we discuss several current hypotheses about sleep function. We divide these hypotheses into two categories: ones that propose higher-order cognitive functions and ones that focus on housekeeping or restorative processes. We also pose four aspects of sleep that any successful functional hypothesis has to account for: why do the properties of sleep change across the life span? Why and how is sleep homeostatically regulated? Why must the brain be taken offline to accomplish the proposed function? And, why are there two radically different stages of sleep?The higher-order cognitive function hypotheses we discuss are essential mechanisms of learning and memory and synaptic plasticity. These are not mutually exclusive hypotheses. Each focuses on specific mechanistic aspects of sleep, and higher-order cognitive processes are likely to involve components of all of these mechanisms. The restorative hypotheses are maintenance of brain energy metabolism, macromolecular biosynthesis, and removal of metabolic waste. Although these three hypotheses seem more different than those related to higher cognitive function, they may each contribute important components to a basic sleep function. Any sleep function will involve specific gene expression and macromolecular biosynthesis, and as we explain there may be important connections between brain energy metabolism and the need to remove metabolic wastes.A deeper understanding of sleep functions in endotherms will enable us to answer whether or not rest behaviors in species other than endotherms are homologous with mammalian and avian sleep. Currently comparisons across the animal kingdom depend on superficial and phenomenological features of rest states and sleep, but investigations of sleep functions would provide more insight into the evolutionary relationships between EEG-defined sleep in endotherms and rest states in ectotherms.
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Affiliation(s)
- Marcos G Frank
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University Spokane, Spokane, WA, USA
| | - H Craig Heller
- Department of Biology, Stanford University, Stanford, CA, USA.
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Wu L, Butler NJM, Swanson RA. Technical and Comparative Aspects of Brain Glycogen Metabolism. ADVANCES IN NEUROBIOLOGY 2019; 23:169-185. [DOI: 10.1007/978-3-030-27480-1_6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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55
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Rothman DL, Dienel GA. Development of a Model to Test Whether Glycogenolysis Can Support Astrocytic Energy Demands of Na +, K +-ATPase and Glutamate-Glutamine Cycling, Sparing an Equivalent Amount of Glucose for Neurons. ADVANCES IN NEUROBIOLOGY 2019; 23:385-433. [PMID: 31667817 DOI: 10.1007/978-3-030-27480-1_14] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Recent studies of glycogen in brain have suggested a much more important role in brain energy metabolism and function than previously recognized, including findings of much higher than previously recognized concentrations, consumption at substantial rates compared with utilization of blood-borne glucose, and involvement in ion pumping and in neurotransmission and memory. However, it remains unclear how glycogenolysis is coupled to neuronal activity and provides support for neuronal as well as astroglial function. At present, quantitative aspects of glycogenolysis in brain functions are very difficult to assess due to its metabolic lability, heterogeneous distributions within and among cells, and extreme sensitivity to physiological stimuli. To begin to address this problem, the present study develops a model based on pathway fluxes, mass balance, and literature relevant to functions and turnover of pathways that intersect with glycogen mobilization. A series of equations is developed to describe the stoichiometric relationships between net glycogen consumption that is predominantly in astrocytes with the rate of the glutamate-glutamine cycle, rates of astrocytic and neuronal glycolytic and oxidative metabolism, and the energetics of sodium/potassium pumping in astrocytes and neurons during brain activation. Literature supporting the assumptions of the model is discussed in detail. The overall conclusion is that astrocyte glycogen metabolism is primarily coupled to neuronal function via fueling glycolytically pumping of Na+ and K+ and sparing glucose for neuronal oxidation, as opposed to previous proposals of coupling neurotransmission via glutamate transport, lactate shuttling, and neuronal oxidation of lactate.
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Affiliation(s)
- Douglas L Rothman
- Magnetic Resonance Research Center and Department of Radiology, Yale University, New Haven, CT, USA.
| | - Gerald A Dienel
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR, USA.,Department of Cell Biology and Physiology, University of New Mexico, Albuquerque, NM, USA
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56
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Regional Distribution of Glycogen in the Mouse Brain Visualized by Immunohistochemistry. ADVANCES IN NEUROBIOLOGY 2019; 23:147-168. [PMID: 31667808 DOI: 10.1007/978-3-030-27480-1_5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Considering that the brain constantly consumes a substantial amount of energy, the nature of its energy reserve is an important issue. Although the brain is rich in lipid content encompassing membranes, myelin sheath, and astrocytic lipid droplets, it is devoid of adipose tissue which serves as an energy reserve. Notably, glycogen represents the major energy store in the brain. While glycogen has been observed mainly in astrocytes for decades by electron microscopy, glycogen distribution in the brain has only been partially documented. The involvement of glycogen metabolism in memory consolidation, demonstrated by several research groups, has reiterated the functional significance of this macromolecule and the need for description of its comprehensive distribution in the brain. The combination of focused microwave-assisted brain fixation and glycogen immunohistochemistry permits assessment of glycogen distribution in the rodent brain. In this article, we describe glycogen distribution in the mouse brain using glycogen immunohistochemistry. We find heterogeneous glycogen storage patterns at multiple spatial scales. The heterogeneous glycogen distribution patterns may underlie local energy metabolism or synaptic activity, and its mechanistic understanding should extend our knowledge on brain metabolism in health and disease.
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Varanoske AN, Wells AJ, Kozlowski GJ, Gepner Y, Frosti CL, Boffey D, Coker NA, Harat I, Hoffman JR. Effects of β-alanine supplementation on physical performance, cognition, endocrine function, and inflammation during a 24 h simulated military operation. Physiol Rep 2018; 6:e13938. [PMID: 30565426 PMCID: PMC6299243 DOI: 10.14814/phy2.13938] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 10/30/2018] [Indexed: 11/24/2022] Open
Abstract
Sustained military operations (SUSOPs) are associated with performance decrements and cognitive dysfunction. β-Alanine (BA) supplementation may have a role in increasing soldier resiliency by enhancing muscle-buffering capacity and reducing oxidative stress. The purpose of this study was to examine the effects of BA on physical performance, cognition, endocrine function, and inflammation during a 24 h simulated SUSOP. Nineteen males were randomized into one of two groups: BA (n = 10) or placebo (n = 9; PLA) (12 g/day) for 14 days preceding the 24 h SUSOP. Assessments were performed at 0 h (0H), 12 h (12H), and 24 h (24H) during the SUSOP. No changes in visual tracking ability, jump power, or upper-body muscular endurance were observed between groups or time points (P's > 0.05). Increases in subjective feelings of soreness and fatigue were noted at 12H compared to 0H (P < 0.05) in PLA, but not in BA. Visual reaction time for PLA was slower at 24H compared to 0H (P = 0.035), and PLA made more errors on reaction time testing at 12H compared to BA (P = 0.048), but motor reaction time was faster (P = 0.016) for PLA. Simulated litter carry and 1 km run completion times increased at 24H compared to 0H in both groups (P < 0.05), however, PLA had a longer 1 km time compared to BA at 24H (P = 0.050). Increases in inflammatory and endocrine markers were observed over the SUSOP, with no differences between groups. BA supplementation appears to maintain some aspects of cognition and physical performance during a 24 h SUSOP, with no effects on endocrine function or inflammation.
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Affiliation(s)
- Alyssa N. Varanoske
- Institute of Exercise Physiology and Wellness, Educational and Human Sciences, Sport and Exercise ScienceUniversity of Central FloridaOrlandoFlorida
| | - Adam J. Wells
- Institute of Exercise Physiology and Wellness, Educational and Human Sciences, Sport and Exercise ScienceUniversity of Central FloridaOrlandoFlorida
| | - Gregory J. Kozlowski
- Institute of Exercise Physiology and Wellness, Educational and Human Sciences, Sport and Exercise ScienceUniversity of Central FloridaOrlandoFlorida
| | - Yftach Gepner
- Institute of Exercise Physiology and Wellness, Educational and Human Sciences, Sport and Exercise ScienceUniversity of Central FloridaOrlandoFlorida
| | - Cheyanne L. Frosti
- Institute of Exercise Physiology and Wellness, Educational and Human Sciences, Sport and Exercise ScienceUniversity of Central FloridaOrlandoFlorida
| | - David Boffey
- Institute of Exercise Physiology and Wellness, Educational and Human Sciences, Sport and Exercise ScienceUniversity of Central FloridaOrlandoFlorida
| | - Nicholas A. Coker
- Institute of Exercise Physiology and Wellness, Educational and Human Sciences, Sport and Exercise ScienceUniversity of Central FloridaOrlandoFlorida
| | - Idan Harat
- Institute of Exercise Physiology and Wellness, Educational and Human Sciences, Sport and Exercise ScienceUniversity of Central FloridaOrlandoFlorida
| | - Jay R. Hoffman
- Institute of Exercise Physiology and Wellness, Educational and Human Sciences, Sport and Exercise ScienceUniversity of Central FloridaOrlandoFlorida
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58
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Bellesi M, de Vivo L, Koebe S, Tononi G, Cirelli C. Sleep and Wake Affect Glycogen Content and Turnover at Perisynaptic Astrocytic Processes. Front Cell Neurosci 2018; 12:308. [PMID: 30254569 PMCID: PMC6141665 DOI: 10.3389/fncel.2018.00308] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 08/23/2018] [Indexed: 12/26/2022] Open
Abstract
Astrocytic glycogen represents the only form of glucose storage in the brain, and one of the outcomes of its breakdown is the production of lactate that can be used by neurons as an alternative energetic substrate. Since brain metabolism is higher in wake than in sleep, it was hypothesized that glycogen stores are depleted during wake and replenished during sleep. Furthermore, it was proposed that glycogen depletion leads to the progressive increase in adenosine levels during wake, providing a homeostatic signal that reflects the buildup of sleep pressure. However, previous studies that measured glycogen dynamics across the sleep/wake cycle obtained inconsistent results, and only measured glycogen in whole tissue. Since most energy in the brain is used to sustain synaptic activity, here we employed tridimensional electron microscopy to quantify glycogen content in the astrocytic processes surrounding the synapse. We studied axon-spine synapses in the frontal cortex of young mice after ~7 h of sleep, 7–8 h of spontaneous or forced wake, or 4.5 days of sleep restriction. Relative to sleep, all wake conditions increased the number of glycogen granules around the synapses to a similar extent. However, progressively longer periods of wake were associated with progressively smaller glycogen granules, suggesting increased turnover. Despite the increased number of granules, in all wake conditions the estimated amount of glucose within the granules was lower than in sleep, indicating that sleep may favor glucose storage. Finally, chronic sleep restriction moved glycogen granules closer to the synaptic cleft. Thus, both short and long wake lead to increased glycogen turnover around cortical synapses, whereas sleep promotes glycogen accumulation.
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Affiliation(s)
- Michele Bellesi
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI, United States.,Department of Experimental and Clinical Medicine, Section of Neuroscience and Cell Biology, Università Politecnica delle Marche, Ancona, Italy
| | - Luisa de Vivo
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI, United States
| | - Samuel Koebe
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI, United States
| | - Giulio Tononi
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI, United States
| | - Chiara Cirelli
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI, United States
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59
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Alhamami HN, Alshamrani A, Briski KP. Inhibition of glycogen phosphorylase stimulates ventromedial hypothalamic nucleus AMP-activated protein kinase: Activity and neuronal nitric oxide synthase protein expression in male rats. Physiol Rep 2018; 5. [PMID: 29199177 PMCID: PMC5727266 DOI: 10.14814/phy2.13484] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 09/28/2017] [Accepted: 10/02/2017] [Indexed: 11/24/2022] Open
Abstract
The glucose polymer glycogen is a vital fuel reserve in the brain. The mediobasal hypothalamic energy sensor AMP‐activated protein kinase (AMPK) maintains glucostasis via neurotransmitter mechanisms that suppress [γ‐aminobutyric acid; GABA] or stimulate [nitric oxide; steroidogenic factor‐1 (SF1)] counter‐regulatory outflow. This study investigated whether glycogen‐derived fuel supply is a critical screened variable in ventromedial hypothalamic nucleus (VMN) monitoring of neuro‐metabolic stability during glucostasis and/or insulin (I)‐induced hypoglycemia. Adult male rats were pretreated by intra‐VMN infusion of the glycogen phosphorylase inhibitor 1,4‐dideoxy‐1,4‐imino‐D‐arabinitol (DAB) before sc vehicle or I injection. Western blot analyses of micropunch‐dissected VMN tissue from euglycemic animals showed DAB augmentation of phosphoAMPK (pAMPK), neuronal nitric oxide synthase (nNOS), and SF‐1, but not glutamate decarboxylase65/67 (GAD) protein. Combinatory DAB/I treatment did not further enhance AMPK activity but significantly amplified nNOS expression relative to DAB alone. Hypoglycemic stimulation of corticosterone, but not glucagon release was prevented by DAB. Results imply that glycogen‐derived substrate fuel provision represses VMN AMPK activity and neurotransmitter signals of metabolic deficiency. Progressive augmentation of nNOS protein by DAB/I versus DAB/V intimates that “fuel‐inhibited” nitrergic neurons may exhibit increasing sensitivity to disrupted glycogen breakdown during glucoprivation versus glucostasis. nNOS and GAD reactivity to DAB/I, but not I implies that acute glycogen utilization during hypoglycemia may be sufficiently robust to avert effects on local metabolic sensory signaling. DAB/I upregulation of GAD alongside prevention of hypercorticosteronemia suggests that indicators of metabolic sufficiency may occur secondary to local compensatory adaptations to severe restriction of glucose‐derived energy.
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Affiliation(s)
- Hussain N Alhamami
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, College of Health and Pharmaceutical Sciences, University of Louisiana at Monroe, Monroe, Louisiana
| | - Ayed Alshamrani
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, College of Health and Pharmaceutical Sciences, University of Louisiana at Monroe, Monroe, Louisiana
| | - Karen P Briski
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, College of Health and Pharmaceutical Sciences, University of Louisiana at Monroe, Monroe, Louisiana
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60
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Abstract
PURPOSE OF REVIEW The goal of the present paper is to review current literature supporting the occurrence of fundamental changes in brain energy metabolism during the transition from wakefulness to sleep. RECENT FINDINGS Latest research in the field indicates that glucose utilization and the concentrations of several brain metabolites consistently change across the sleep-wake cycle. Lactate, a product of glycolysis that is involved in synaptic plasticity, has emerged as a good biomarker of brain state. Sleep-induced changes in cerebral metabolite levels result from a shift in oxidative metabolism, which alters the reliance of brain metabolism upon carbohydrates. We found wide support for the notion that brain energetics is state dependent. In particular, fatty acids and ketone bodies partly replace glucose as cerebral energy source during sleep. This mechanism plausibly accounts for increases in biosynthetic pathways and functional alterations in neuronal activity associated with sleep. A better account of brain energy metabolism during sleep might help elucidate the long mysterious restorative effects of sleep for the whole organism.
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Affiliation(s)
- Nadia Nielsen Aalling
- Center for Translational Neuromedicine, Division of Glial Disease and Therapeutics, Faculty of Health and Medical Sciences, University of Copenhagen, Nørre Allé 14, 2200, Copenhagen N, Denmark
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, Division of Glial Disease and Therapeutics, Faculty of Health and Medical Sciences, University of Copenhagen, Nørre Allé 14, 2200, Copenhagen N, Denmark.,Center for Translational Neuromedicine, University of Rochester Medical School, Rochester, NY, 14640, USA
| | - Mauro DiNuzzo
- Center for Translational Neuromedicine, Division of Glial Disease and Therapeutics, Faculty of Health and Medical Sciences, University of Copenhagen, Nørre Allé 14, 2200, Copenhagen N, Denmark.
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61
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Bak LK, Walls AB, Schousboe A, Waagepetersen HS. Astrocytic glycogen metabolism in the healthy and diseased brain. J Biol Chem 2018; 293:7108-7116. [PMID: 29572349 DOI: 10.1074/jbc.r117.803239] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The brain contains a fairly low amount of glycogen, mostly located in astrocytes, a fact that has prompted the suggestion that glycogen does not have a significant physiological role in the brain. However, glycogen metabolism in astrocytes is essential for several key physiological processes and is adversely affected in disease. For instance, diminished ability to break down glycogen impinges on learning, and epilepsy, Alzheimer's disease, and type 2 diabetes are all associated with abnormal astrocyte glycogen metabolism. Glycogen metabolism supports astrocytic K+ and neurotransmitter glutamate uptake and subsequent glutamine synthesis-three fundamental steps in excitatory signaling at most brain synapses. Thus, there is abundant evidence for a key role of glycogen in brain function. Here, we summarize the physiological brain functions that depend on glycogen, discuss glycogen metabolism in disease, and investigate how glycogen breakdown is regulated at the cellular and molecular levels.
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Affiliation(s)
- Lasse K Bak
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2 Universitetsparken, 2100 Copenhagen, Denmark.
| | - Anne B Walls
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2 Universitetsparken, 2100 Copenhagen, Denmark.
| | - Arne Schousboe
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2 Universitetsparken, 2100 Copenhagen, Denmark
| | - Helle S Waagepetersen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2 Universitetsparken, 2100 Copenhagen, Denmark
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Borniger JC, Ungerleider K, Zhang N, Karelina K, Magalang UJ, Weil ZM. Repetitive Brain Injury of Juvenile Mice Impairs Environmental Enrichment-Induced Modulation of REM Sleep in Adulthood. Neuroscience 2018; 375:74-83. [PMID: 29432885 DOI: 10.1016/j.neuroscience.2018.01.064] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 01/30/2018] [Accepted: 01/31/2018] [Indexed: 10/18/2022]
Abstract
Traumatic brain injuries (TBIs) are a common and costly ongoing public health concern. Injuries that occur during childhood development can have particularly profound and long-lasting effects. One common consequence and potential mediator of negative outcomes of TBI is sleep disruption which occurs in a substantial proportion of TBI patients. These individuals report greater incidences of insomnia and sleep fragmentation combined with a greater overall sleep requirement meaning that many patients are chronically sleep-deprived. We sought to develop an animal model of developmental TBI-induced sleep dysfunction. Specifically, we tested the hypothesis that early (postnatal day 21), repeated closed head injuries in Swiss-Webster mice, would impair basal and homeostatic sleep responses in adulthood. Further, we asked whether environmental enrichment (EE), a manipulation that improves functional recovery following TBI and has been shown to alter sleep physiology, would prevent TBI-induced sleep dysfunction and alter sleep-modulatory peptide expression. In contrast to our hypothesis, the mild, repeated head injury that we used did not significantly alter basal or homeostatic sleep responses in mice housed in standard laboratory conditions. Sham-injured mice housed in enriched environments exhibited enhanced rapid eye movement (REM) sleep and expression of the REM-promoting peptide pro-melanin-concentrating hormone, an effect that was not apparent in TBI mice housed in enriched environments. Thus, TBI blocked the REM-enhancing effects of EE. This work has important implications for the management and rehabilitation of the TBI patient population.
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Affiliation(s)
- Jeremy C Borniger
- Department of Neuroscience, Behavioral Neuroendocrinology Group, Neuroscience Research Institute, Center for Brain and Spinal Cord Repair, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Kyra Ungerleider
- Department of Neuroscience, Behavioral Neuroendocrinology Group, Neuroscience Research Institute, Center for Brain and Spinal Cord Repair, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Ning Zhang
- Department of Neuroscience, Behavioral Neuroendocrinology Group, Neuroscience Research Institute, Center for Brain and Spinal Cord Repair, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Kate Karelina
- Department of Neuroscience, Behavioral Neuroendocrinology Group, Neuroscience Research Institute, Center for Brain and Spinal Cord Repair, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Ulysses J Magalang
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Zachary M Weil
- Department of Neuroscience, Behavioral Neuroendocrinology Group, Neuroscience Research Institute, Center for Brain and Spinal Cord Repair, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.
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Hyper-hippocampal glycogen induced by glycogen loading with exhaustive exercise. Sci Rep 2018; 8:1285. [PMID: 29352196 PMCID: PMC5775355 DOI: 10.1038/s41598-018-19445-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 12/28/2017] [Indexed: 12/29/2022] Open
Abstract
Glycogen loading (GL), a well-known type of sports conditioning, in combination with exercise and a high carbohydrate diet (HCD) for 1 week enhances individual endurance capacity through muscle glycogen supercompensation. This exercise-diet combination is necessary for successful GL. Glycogen in the brain contributes to hippocampus-related memory functions and endurance capacity. Although the effect of HCD on the brain remains unknown, brain supercompensation occurs following exhaustive exercise (EE), a component of GL. We thus employed a rat model of GL and examined whether GL increases glycogen levels in the brain as well as in muscle, and found that GL increased glycogen levels in the hippocampus and hypothalamus, as well as in muscle. We further explored the essential components of GL (exercise and/or diet conditions) to establish a minimal model of GL focusing on the brain. Exercise, rather than a HCD, was found to be crucial for GL-induced hyper-glycogen in muscle, the hippocampus and the hypothalamus. Moreover, EE was essential for hyper-glycogen only in the hippocampus even without HCD. Here we propose the EE component of GL without HCD as a condition that enhances brain glycogen stores especially in the hippocampus, implicating a physiological strategy to enhance hippocampal functions.
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Shima T, Jesmin S, Matsui T, Soya M, Soya H. Differential effects of type 2 diabetes on brain glycometabolism in rats: focus on glycogen and monocarboxylate transporter 2. J Physiol Sci 2018; 68:69-75. [PMID: 27987117 PMCID: PMC10717161 DOI: 10.1007/s12576-016-0508-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 11/23/2016] [Indexed: 12/21/2022]
Abstract
Astrocyte-neuron lactate shuttle (ANLS) is a pathway that supplies glycogen-derived lactate to active neurons via monocarboxylate transporter 2 (MCT2), and is important for maintaining brain functions. Our study revealed alterations of ANLS with hippocampal hyper-glycogen levels and downregulated MCT2 protein levels underlying hippocampal dysfunctions as a complication in type 2 diabetic (T2DM) animals. Since T2DM rats exhibit brain dysfunctions involving several brain regions, we examined whether there might also be T2DM effects on ANLS's disturbances in other brain loci. OLETF rats exhibited significantly higher glycogen levels in the hippocampus, hypothalamus, and cerebral cortex than did LETO rats. MCT2 protein levels in OLETF rats decreased significantly in the hippocampus and hypothalamus compared to their controls, but a significant correlation with glycogen levels was only observed in the hippocampus. This suggests that the hippocampus may be more vulnerable to T2DM compared to other brain regions in the context of ANLS disruption.
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Affiliation(s)
- Takeru Shima
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan
| | - Subrina Jesmin
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan
- Department of Sports Neuroscience, Advanced Research Initiative for Human High Performance (ARIHHP), University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan
| | - Takashi Matsui
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan
- Department of Sports Neuroscience, Advanced Research Initiative for Human High Performance (ARIHHP), University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan
| | - Mariko Soya
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan
| | - Hideaki Soya
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan.
- Department of Sports Neuroscience, Advanced Research Initiative for Human High Performance (ARIHHP), University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan.
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65
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Zhou P, Guan T, Jiang Z, Namaka M, Huang QJ, Kong JM. Monocarboxylate transporter 1 and the vulnerability of oligodendrocyte lineage cells to metabolic stresses. CNS Neurosci Ther 2017; 24:126-134. [PMID: 29205833 DOI: 10.1111/cns.12782] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 11/16/2017] [Accepted: 11/16/2017] [Indexed: 02/03/2023] Open
Abstract
AIMS Oligodendrocytes, especially oligodendrocyte precursor cells, are known to be sensitive to hypoxic and metabolic stresses. Vulnerability of oligodendrocytes is considered a contributing factor to white matter dysfunction. However, little is known about the energy processing characteristics of oligodendrocyte lineage cells under basal and metabolic stress conditions. The aim of this study was to identify the energy requirements and cellular responses of oligodendrocytes at different developmental stages. METHODS We compared the metabolic stress responses between myelinating oligodendrocytes (OLs) and oligodendrocyte precursor cells (OPCs). Differential regulation of cellular response was also investigated. RESULTS We found that, following cerebral ischemia, monocarboxylate transporter 1 (MCT1) expression was upregulated in the peri-infarct striatum but not in the cortex of the brain. In vitro ischemia models were used to induce oligodendrocyte stress as well. An increase in MCT1 expression was detected in OPCs after a mild oxygen-glucose deprivation. Double-labeled immunohistochemical analysis revealed that OPCs and OLs responded differently to metabolic stresses and that the susceptibility to metabolic stresses of OPCs and OLs was associated with their distinct expression profiles of MCT1. CONCLUSION Taken together, this study shows that MCT1 plays a role in the responses of OPCs and OLs to metabolic and ischemic stresses and suggests that redistribution of energy substrates is a determinant in white matter injury.
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Affiliation(s)
- Peng Zhou
- Department of Anatomy, Southern Medical University, Guangzhou, Guangdong, China.,Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, MB, Canada.,Department of Anatomy, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Teng Guan
- Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, MB, Canada
| | - Zhao Jiang
- Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, MB, Canada.,Manitoba-Shantou Joint Laboratory of Biological Psychiatry, Mental Health Center, Shantou University, Shantou, Guangdong, China
| | - Mike Namaka
- Manitoba-Shantou Joint Laboratory of Biological Psychiatry, Mental Health Center, Shantou University, Shantou, Guangdong, China.,College of Pharmacy, University of Manitoba, Winnipeg, MB, Canada
| | - Qing-Jun Huang
- Manitoba-Shantou Joint Laboratory of Biological Psychiatry, Mental Health Center, Shantou University, Shantou, Guangdong, China
| | - Ji-Ming Kong
- Department of Anatomy, Southern Medical University, Guangzhou, Guangdong, China.,Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, MB, Canada.,Manitoba-Shantou Joint Laboratory of Biological Psychiatry, Mental Health Center, Shantou University, Shantou, Guangdong, China
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66
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Hu ZL, Xia HH, Yang YJ, Zheng H, Zhao LC, Chen YC, Zhuge QC, Xia NZ, Gao HC, Chen WJ. Metabolic alterations in the rat cerebellum following acute middle cerebral artery occlusion, as determined by 1H NMR spectroscopy. Mol Med Rep 2017; 17:531-541. [PMID: 29115616 DOI: 10.3892/mmr.2017.7918] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 09/11/2017] [Indexed: 01/06/2023] Open
Abstract
Supratentorial focal ischemia may reduce cerebral blood volume and cerebellar glucose metabolic rate contralateral to the region of ischemia. The present study investigated the effects of middle cerebral artery occlusion (MCAO) on cerebral metabolism in the ischemic cerebral hemisphere and the non‑ischemic cerebellum in rats 1, 3, 9 and 24 h following ischemia using ex vivo proton nuclear magnetic resonance (1H NMR) spectroscopy. The results demonstrated that focal ischemia induced increases in the levels of lactate and alanine, and a decrease in succinate, as early as 1 h following ischemia in the left cerebral hemisphere and the right cerebellum. A continuous increase in lactate levels and decrease in creatine levels were detected in both cerebral areas 3 and 24 h post‑MCAO. The most obvious difference between the two cerebral areas was that there was no statistically significant difference in N‑acetyl aspartate (NAA) levels in the right cerebellum at all time points; however, the amino acid levels of NAA in the left cerebral hemisphere were markedly decreased 3, 9 and 24 h post‑MCAO. In addition, an obvious increase in glutamine was observed in the right and left cerebellum at 3, 9 and 24 h post‑MCAO. Furthermore, the present study demonstrated that γ‑aminobutyric acid levels were decreased at 1 h in the left and right cerebellum and were evidently increased at 24 h in the right cerebellum post‑MCAO. In conclusion, supratentorial ischemia has been indicated to affect the activities of the non‑ischemic contralateral cerebellum. Therefore, these results suggested that an NMR‑based metabonomic approach may be used as a potential means to elucidate cerebral and cerebellar metabolism following MCAO, which may help improve understanding regarding cerebral infarction at a molecular level. Ex vivo 1H NMR analysis may be useful for the assessment of clinical biopsies.
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Affiliation(s)
- Zi-Long Hu
- Department of Radiology, The First Affiliated Hospital of Wenzhou Medical University/Zhejiang Province Key Laboratory of Aging and Neurological Disorder Research, Wenzhou, Zhejiang 325000, P.R. China
| | - Huan-Huan Xia
- Institute of Metabonomics and Medical NMR, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| | - Yun-Jun Yang
- Department of Radiology, The First Affiliated Hospital of Wenzhou Medical University/Zhejiang Province Key Laboratory of Aging and Neurological Disorder Research, Wenzhou, Zhejiang 325000, P.R. China
| | - Hong Zheng
- Institute of Metabonomics and Medical NMR, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| | - Liang-Cai Zhao
- Institute of Metabonomics and Medical NMR, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| | - Yong-Chun Chen
- Department of Radiology, The First Affiliated Hospital of Wenzhou Medical University/Zhejiang Province Key Laboratory of Aging and Neurological Disorder Research, Wenzhou, Zhejiang 325000, P.R. China
| | - Qi-Chuan Zhuge
- Department of Radiology, The First Affiliated Hospital of Wenzhou Medical University/Zhejiang Province Key Laboratory of Aging and Neurological Disorder Research, Wenzhou, Zhejiang 325000, P.R. China
| | - Neng-Zhi Xia
- Department of Radiology, The First Affiliated Hospital of Wenzhou Medical University/Zhejiang Province Key Laboratory of Aging and Neurological Disorder Research, Wenzhou, Zhejiang 325000, P.R. China
| | - Hong-Chang Gao
- Institute of Metabonomics and Medical NMR, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| | - Wei-Jian Chen
- Department of Radiology, The First Affiliated Hospital of Wenzhou Medical University/Zhejiang Province Key Laboratory of Aging and Neurological Disorder Research, Wenzhou, Zhejiang 325000, P.R. China
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67
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Technical and experimental features of Magnetic Resonance Spectroscopy of brain glycogen metabolism. Anal Biochem 2017; 529:117-126. [DOI: 10.1016/j.ab.2016.12.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 08/31/2016] [Accepted: 12/23/2016] [Indexed: 01/20/2023]
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68
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Dworak M, Kim T, McCarley RW, Basheer R. Creatine supplementation reduces sleep need and homeostatic sleep pressure in rats. J Sleep Res 2017; 26:377-385. [PMID: 28397310 PMCID: PMC5435551 DOI: 10.1111/jsr.12523] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 02/11/2017] [Indexed: 01/02/2023]
Abstract
Sleep has been postulated to promote brain energy restoration. It is as yet unknown if increasing the energy availability within the brain reduces sleep need. The guanidine amino acid creatine (Cr) is a well-known energy booster in cellular energy homeostasis. Oral Cr-monohydrate supplementation (CS) increases exercise performance and has been shown to have substantial effects on cognitive performance, neuroprotection and circadian rhythms. The effect of CS on cellular high-energy molecules and sleep-wake behaviour is unclear. Here, we examined the sleep-wake behaviour and brain energy metabolism before and after 4-week-long oral administration of CS in the rat. CS decreased total sleep time and non-rapid eye movement (NREM) sleep significantly during the light (inactive) but not during the dark (active) period. NREM sleep and NREM delta activity were decreased significantly in CS rats after 6 h of sleep deprivation. Biochemical analysis of brain energy metabolites showed a tendency to increase in phosphocreatine after CS, while cellular adenosine triphosphate (ATP) level decreased. Microdialysis analysis showed that the sleep deprivation-induced increase in extracellular adenosine was attenuated after CS. These results suggest that CS reduces sleep need and homeostatic sleep pressure in rats, thereby indicating its potential in the treatment of sleep-related disorders.
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Affiliation(s)
- Markus Dworak
- Laboratory of Neuroscience, Department of Psychiatry, VA Boston Healthcare System and Harvard Medical School, West Roxbury, MA, USA
- Institute of Movement and Neurosciences, German Sport University Cologne, Germany
| | - Tae Kim
- Laboratory of Neuroscience, Department of Psychiatry, VA Boston Healthcare System and Harvard Medical School, West Roxbury, MA, USA
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Robert W. McCarley
- Laboratory of Neuroscience, Department of Psychiatry, VA Boston Healthcare System and Harvard Medical School, West Roxbury, MA, USA
| | - Radhika Basheer
- Laboratory of Neuroscience, Department of Psychiatry, VA Boston Healthcare System and Harvard Medical School, West Roxbury, MA, USA
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69
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Astrocytic glycogen-derived lactate fuels the brain during exhaustive exercise to maintain endurance capacity. Proc Natl Acad Sci U S A 2017; 114:6358-6363. [PMID: 28515312 DOI: 10.1073/pnas.1702739114] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Brain glycogen stored in astrocytes provides lactate as an energy source to neurons through monocarboxylate transporters (MCTs) to maintain neuronal functions such as hippocampus-regulated memory formation. Although prolonged exhaustive exercise decreases brain glycogen, the role of this decrease and lactate transport in the exercising brain remains less clear. Because muscle glycogen fuels exercising muscles, we hypothesized that astrocytic glycogen plays an energetic role in the prolonged-exercising brain to maintain endurance capacity through lactate transport. To test this hypothesis, we used a rat model of exhaustive exercise and capillary electrophoresis-mass spectrometry-based metabolomics to observe comprehensive energetics of the brain (cortex and hippocampus) and muscle (plantaris). At exhaustion, muscle glycogen was depleted but brain glycogen was only decreased. The levels of MCT2, which takes up lactate in neurons, increased in the brain, as did muscle MCTs. Metabolomics revealed that brain, but not muscle, ATP was maintained with lactate and other glycogenolytic/glycolytic sources. Intracerebroventricular injection of the glycogen phosphorylase inhibitor 1,4-dideoxy-1,4-imino-d-arabinitol did not affect peripheral glycemic conditions but suppressed brain lactate production and decreased hippocampal ATP levels at exhaustion. An MCT2 inhibitor, α-cyano-4-hydroxy-cinnamate, triggered a similar response that resulted in lower endurance capacity. These findings provide direct evidence for the energetic role of astrocytic glycogen-derived lactate in the exhaustive-exercising brain, implicating the significance of brain glycogen level in endurance capacity. Glycogen-maintained ATP in the brain is a possible defense mechanism for neurons in the exhausted brain.
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70
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Alaverdashvili M, Hackett MJ, Caine S, Paterson PG. Parallel changes in cortical neuron biochemistry and motor function in protein-energy malnourished adult rats. Neuroimage 2017; 149:275-284. [PMID: 28179168 DOI: 10.1016/j.neuroimage.2017.02.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 11/25/2016] [Accepted: 02/04/2017] [Indexed: 12/30/2022] Open
Abstract
While protein-energy malnutrition in the adult has been reported to induce motor abnormalities and exaggerate motor deficits caused by stroke, it is not known if alterations in mature cortical neurons contribute to the functional deficits. Therefore, we explored if PEM in adult rats provoked changes in the biochemical profile of neurons in the forelimb and hindlimb regions of the motor cortex. Fourier transform infrared spectroscopic imaging using a synchrotron generated light source revealed for the first time altered lipid composition in neurons and subcellular domains (cytosol and nuclei) in a cortical layer and region-specific manner. This change measured by the area under the curve of the δ(CH2) band may indicate modifications in membrane fluidity. These PEM-induced biochemical changes were associated with the development of abnormalities in forelimb use and posture. The findings of this study provide a mechanism by which PEM, if not treated, could exacerbate the course of various neurological disorders and diminish treatment efficacy.
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Affiliation(s)
- Mariam Alaverdashvili
- Neuroscience Research Group, Department of Anatomy and Cell Biology and College of Pharmacy and Nutrition University of Saskatchewan, D Wing GD30 (Box 1) Health Sciences, 107 Wiggins Road, Saskatoon, SK, Canada, S7N 5E5; College of Pharmacy and Nutrition, Canada; Department of Anatomy and Cell Biology, Canada; Cameco MS Neuroscience Center, University of Saskatchewan, Saskatoon, Canada.
| | - Mark J Hackett
- Neuroscience Research Group, Department of Anatomy and Cell Biology and College of Pharmacy and Nutrition University of Saskatchewan, D Wing GD30 (Box 1) Health Sciences, 107 Wiggins Road, Saskatoon, SK, Canada, S7N 5E5; Department of Geological Sciences, Canada
| | - Sally Caine
- Neuroscience Research Group, Department of Anatomy and Cell Biology and College of Pharmacy and Nutrition University of Saskatchewan, D Wing GD30 (Box 1) Health Sciences, 107 Wiggins Road, Saskatoon, SK, Canada, S7N 5E5; Department of Anatomy and Cell Biology, Canada; Cameco MS Neuroscience Center, University of Saskatchewan, Saskatoon, Canada
| | - Phyllis G Paterson
- Neuroscience Research Group, Department of Anatomy and Cell Biology and College of Pharmacy and Nutrition University of Saskatchewan, D Wing GD30 (Box 1) Health Sciences, 107 Wiggins Road, Saskatoon, SK, Canada, S7N 5E5; College of Pharmacy and Nutrition, Canada; Cameco MS Neuroscience Center, University of Saskatchewan, Saskatoon, Canada.
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71
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Shima T, Matsui T, Jesmin S, Okamoto M, Soya M, Inoue K, Liu YF, Torres-Aleman I, McEwen BS, Soya H. Moderate exercise ameliorates dysregulated hippocampal glycometabolism and memory function in a rat model of type 2 diabetes. Diabetologia 2017; 60:597-606. [PMID: 27928614 DOI: 10.1007/s00125-016-4164-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 11/03/2016] [Indexed: 12/15/2022]
Abstract
AIMS/HYPOTHESIS Type 2 diabetes is likely to be an independent risk factor for hippocampal-based memory dysfunction, although this complication has yet to be investigated in detail. As dysregulated glycometabolism in peripheral tissues is a key symptom of type 2 diabetes, it is hypothesised that diabetes-mediated memory dysfunction is also caused by hippocampal glycometabolic dysfunction. If so, such dysfunction should also be ameliorated with moderate exercise by normalising hippocampal glycometabolism, since 4 weeks of moderate exercise enhances memory function and local hippocampal glycogen levels in normal animals. METHODS The hippocampal glycometabolism in OLETF rats (model of human type 2 diabetes) was assessed and, subsequently, the effects of exercise on memory function and hippocampal glycometabolism were investigated. RESULTS OLETF rats, which have memory dysfunction, exhibited higher levels of glycogen in the hippocampus than did control rats, and breakdown of hippocampal glycogen with a single bout of exercise remained unimpaired. However, OLETF rats expressed lower levels of hippocampal monocarboxylate transporter 2 (MCT2, a transporter for lactate to neurons). Four weeks of moderate exercise improved spatial memory accompanied by further increase in hippocampal glycogen levels and restoration of MCT2 expression independent of neurotrophic factor and clinical symptoms in OLETF rats. CONCLUSIONS/INTERPRETATION Our findings are the first to describe detailed profiles of glycometabolism in the type 2 diabetic hippocampus and to show that 4 weeks of moderate exercise improves memory dysfunction in type 2 diabetes via amelioration of dysregulated hippocampal glycometabolism. Dysregulated hippocampal lactate-transport-related glycometabolism is a possible aetiology of type-2-diabetes-mediated memory dysfunction.
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Affiliation(s)
- Takeru Shima
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan
| | - Takashi Matsui
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan
- Department of Sports Neuroscience, Advanced Research Initiative for Human High Performance (ARIHHP), University of Tsukuba, Tsukuba, Ibaraki, Japan
- Cajal Institute, CSIC, Madrid, Spain
| | - Subrina Jesmin
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan
- Department of Sports Neuroscience, Advanced Research Initiative for Human High Performance (ARIHHP), University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Masahiro Okamoto
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan
- Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY, USA
| | - Mariko Soya
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan
| | - Koshiro Inoue
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan
| | - Yu-Fan Liu
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan
| | | | - Bruce S McEwen
- Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY, USA
| | - Hideaki Soya
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan.
- Department of Sports Neuroscience, Advanced Research Initiative for Human High Performance (ARIHHP), University of Tsukuba, Tsukuba, Ibaraki, Japan.
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Decreased Glycogen Content Might Contribute to Chronic Stress-Induced Atrophy of Hippocampal Astrocyte volume and Depression-like Behavior in Rats. Sci Rep 2017; 7:43192. [PMID: 28233800 PMCID: PMC5324119 DOI: 10.1038/srep43192] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 01/20/2017] [Indexed: 01/08/2023] Open
Abstract
The involvement of brain glycogen in the progress of chronic stress-induced impairment of hippocampal astrocyte structural plasticity and depression-like behavior is yet to be clarified. The present study designed three experiments to determine the role of brain glycogen in the plasticity and behavioral consequences of chronic stress. Time course studies on brain glycogen, astrocytes, and behavioral responses to stress were conducted in Experiment 1. Chronic stress decreased the hippocampal glycogen levels, reduced astrocytic size and protrusion length in the hippocampus, and induced depression-like behavior. Glycogen synthase 1 mRNA in the hippocampus was silenced by lentiviral vector-based RNA interference (RNAi) in Experiment 2. This RNAi produced a lack of glycogen in the hippocampus, decreased the hippocampal astrocyte size, and induced depressive behavior in rats. The mechanisms of chronic stress-induced brain glycogen decrease were investigated in Experiment 3. Chronic stress promoted hippocampal glycogen breakdown and increased hippocampal glycogen synthesis. Results suggest that decreased glycogen content was associated with chronic stress-induced atrophy of hippocampal astrocyte size and depression-like behavior. Furthermore, the decrease of glycogen content in the hippocampus might be due to the compensation of glycogen synthesis for breakdown in an insufficient manner.
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73
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Ichihara Y, Doi T, Ryu Y, Nagao M, Sawada Y, Ogata T. Oligodendrocyte Progenitor Cells Directly Utilize Lactate for Promoting Cell Cycling and Differentiation. J Cell Physiol 2016; 232:986-995. [PMID: 27861886 PMCID: PMC5299506 DOI: 10.1002/jcp.25690] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 11/11/2016] [Indexed: 12/17/2022]
Abstract
Oligodendrocyte progenitor cells (OPCs) undergo marked morphological changes to become mature oligodendrocytes, but the metabolic resources for this process have not been fully elucidated. Although lactate, a metabolic derivative of glycogen, has been reported to be consumed in oligodendrocytes as a metabolite, and to ameliorate hypomyelination induced by low glucose conditions, it is not clear about the direct contribution of lactate to cell cycling and differentiation of OPCs, and the source of lactate for remyelination. Therefore, we evaluated the effect of 1,4‐dideoxy‐1,4‐imino‐d‐arabinitol (DAB), an inhibitor of the glycogen catabolic enzyme glycogen phosphorylase, in a mouse cuprizone model. Cuprizone induced demyelination in the corpus callosum and remyelination occurred after cuprizone treatment ceased. This remyelination was inhibited by the administration of DAB. To further examine whether lactate affects proliferation or differentiation of OPCs, we cultured mouse primary OPC‐rich cells and analyzed the effect of lactate. Lactate rescued the slowed cell cycling induced by 0.4 mM glucose, as assessed by the BrdU‐positive cell ratio. Lactate also promoted OPC differentiation detected by monitoring the mature oligodendrocyte marker myelin basic protein, in the presence of both 36.6 mM and 0.4 mM glucose. Furthermore, these lactate‐mediated effects were suppressed by the reported monocarboxylate transporter inhibitor, α‐cyano‐4‐hydroxy‐cinnamate. These results suggest that lactate directly promotes the cell cycling rate and differentiation of OPCs, and that glycogen, one of the sources of lactate, contributes to remyelination in vivo. J. Cell. Physiol. 232: 986–995, 2017. © 2016 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Yoshinori Ichihara
- Department of Rehabilitation for Movement Functions, National Rehabilitation Center for Persons With Disabilities, Saitama, Japan
| | - Toru Doi
- Department of Rehabilitation for Movement Functions, National Rehabilitation Center for Persons With Disabilities, Saitama, Japan
| | - Youngjae Ryu
- Department of Rehabilitation for Movement Functions, National Rehabilitation Center for Persons With Disabilities, Saitama, Japan
| | - Motoshi Nagao
- Department of Rehabilitation for Movement Functions, National Rehabilitation Center for Persons With Disabilities, Saitama, Japan
| | - Yasuhiro Sawada
- Department of Rehabilitation for Movement Functions, National Rehabilitation Center for Persons With Disabilities, Saitama, Japan
| | - Toru Ogata
- Department of Rehabilitation for Movement Functions, National Rehabilitation Center for Persons With Disabilities, Saitama, Japan
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74
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Hackett MJ, Sylvain NJ, Hou H, Caine S, Alaverdashvili M, Pushie MJ, Kelly ME. Concurrent Glycogen and Lactate Imaging with FTIR Spectroscopy To Spatially Localize Metabolic Parameters of the Glial Response Following Brain Ischemia. Anal Chem 2016; 88:10949-10956. [DOI: 10.1021/acs.analchem.6b02588] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Mark J. Hackett
- Nanochemistry
Research Institute, Department of Chemistry, Curtin University, GPO Box U1987, Perth, Western Australia 6845, Australia
| | - Nicole J. Sylvain
- Department
of Surgery, Division of Neurosurgery, College of Medicine, University of Saskatchewan, 107 Wiggins Road, Suite B419 Health
Sciences Building, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Huishu Hou
- Department
of Surgery, Division of Neurosurgery, College of Medicine, University of Saskatchewan, 107 Wiggins Road, Suite B419 Health
Sciences Building, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Sally Caine
- College
of Pharmacy and Nutrition, College of Medicine, University of Saskatchewan, 107 Wiggins
Road, Suite B221 Health Sciences Building, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Mariam Alaverdashvili
- College
of Pharmacy and Nutrition, College of Medicine, University of Saskatchewan, 107 Wiggins
Road, Suite B221 Health Sciences Building, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Michael J. Pushie
- Department
of Surgery, Division of Neurosurgery, College of Medicine, University of Saskatchewan, 107 Wiggins Road, Suite B419 Health
Sciences Building, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Michael E. Kelly
- Department
of Surgery, Division of Neurosurgery, College of Medicine, University of Saskatchewan, 107 Wiggins Road, Suite B419 Health
Sciences Building, Saskatoon, Saskatchewan S7N 5E5, Canada
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Perciavalle V, Marchetta NS, Giustiniani S, Borbone C, Perciavalle V, Petralia MC, Buscemi A, Coco M. Attentive processes, blood lactate and CrossFit ®. PHYSICIAN SPORTSMED 2016; 44:403-406. [PMID: 27556548 DOI: 10.1080/00913847.2016.1222852] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
OBJECTIVES To analyze the influences of blood lactate produced during a specific session of CrossFit® on intensity and selectivity of attention. The first was evaluated by measuring the reaction time and the second by analyzing divided attention with a dual task. METHODS Fifteen male professionals of CrossFit® volunteered in the study. The training session was the Workout Of the Day (WOD) called 15.5, marked as: 27-21-15-9 repetitions (without recovery) in term of calories measured by using a rowing ergometer (e.g. 27 rowed calories) and in term of barbell full squats (raising a weight of 43 kg for men and of 29.5 kg for women). Blood lactate, blood glucose, reaction time, execution time of a dual task, number of errors and number of omissions were measured at rest, at the conclusion of the session and 15 minutes after its end. RESULTS The levels of the blood lactate before the start of the session were considerably higher than those which normally occur at rest (<2 mmol /L), with a mean value of 4.5 mmol /l (± 1.99 SD). At the end of the workout session the blood lactate exhibited a significant increase, reaching a mean value of 13.8 mmol /l (± 1.18 SD) and then returning to values similar to the initial ones after 15 minutes. Blood glucose did not exhibit any statistically significant differences during the session. Reaction time, execution time, number of errors and number of omissions exhibited a significant worsening concomitantly with the increase in blood lactate. CONCLUSION Athletes practicing CrossFit®, with high levels of blood lactate even at rest, should consequently have attentional performances somewhat limited.
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Affiliation(s)
| | | | - Salvatore Giustiniani
- b Department of Biomedical and Biotechnological Sciences , University of Catania , Catania , Italy
| | - Carlo Borbone
- b Department of Biomedical and Biotechnological Sciences , University of Catania , Catania , Italy
| | - Vincenzo Perciavalle
- b Department of Biomedical and Biotechnological Sciences , University of Catania , Catania , Italy
| | - Maria Cristina Petralia
- b Department of Biomedical and Biotechnological Sciences , University of Catania , Catania , Italy
| | - Andrea Buscemi
- b Department of Biomedical and Biotechnological Sciences , University of Catania , Catania , Italy
| | - Marinella Coco
- b Department of Biomedical and Biotechnological Sciences , University of Catania , Catania , Italy
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Kim LJ, Coelho FM, Araujo P, Tedesco RC, Souza RB, Tufik S, Andersen ML. Sleep restriction reduces the survival time and aggravates the neurological dysfunction and memory impairments in an animal model of cerebral hypoperfusion. Brain Res 2016; 1644:213-21. [DOI: 10.1016/j.brainres.2016.05.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 05/02/2016] [Accepted: 05/05/2016] [Indexed: 11/30/2022]
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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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78
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Oe Y, Baba O, Ashida H, Nakamura KC, Hirase H. Glycogen distribution in the microwave-fixed mouse brain reveals heterogeneous astrocytic patterns. Glia 2016; 64:1532-45. [PMID: 27353480 PMCID: PMC5094520 DOI: 10.1002/glia.23020] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 05/26/2016] [Accepted: 06/01/2016] [Indexed: 01/05/2023]
Abstract
In the brain, glycogen metabolism has been implied in synaptic plasticity and learning, yet the distribution of this molecule has not been fully described. We investigated cerebral glycogen of the mouse by immunohistochemistry (IHC) using two monoclonal antibodies that have different affinities depending on the glycogen size. The use of focused microwave irradiation yielded well-defined glycogen immunoreactive signals compared with the conventional periodic acid-Schiff method. The IHC signals displayed a punctate distribution localized predominantly in astrocytic processes. Glycogen immunoreactivity (IR) was high in the hippocampus, striatum, cortex, and cerebellar molecular layer, whereas it was low in the white matter and most of the subcortical structures. Additionally, glycogen distribution in the hippocampal CA3-CA1 and striatum had a 'patchy' appearance with glycogen-rich and glycogen-poor astrocytes appearing in alternation. The glycogen patches were more evident with large-molecule glycogen in young adult mice but they were hardly observable in aged mice (1-2 years old). Our results reveal brain region-dependent glycogen accumulation and possibly metabolic heterogeneity of astrocytes. GLIA 2016;64:1532-1545.
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Affiliation(s)
- Yuki Oe
- Laboratory for Neuron-Glia Circuitry, RIKEN Brain Science Institute, Wako, Saitama, Japan
| | - Otto Baba
- Oral and Maxillofacial Anatomy, Graduate School of Oral Sciences, Tokushima University, Tokushima, Japan
| | - Hitoshi Ashida
- Laboratory of Biochemistry Frontiers, Graduate School of Agricultural Science, Kobe University, Hyogo, Japan
| | - Kouichi C Nakamura
- Department of Morphological Brain Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hajime Hirase
- Laboratory for Neuron-Glia Circuitry, RIKEN Brain Science Institute, Wako, Saitama, Japan.,Saitama University Brain Science Institute, Saitama, Japan
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79
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Lucas SJE, Helge JW, Schütz UHW, Goldman RF, Cotter JD. Moving in extreme environments: extreme loading; carriage versus distance. EXTREME PHYSIOLOGY & MEDICINE 2016; 5:6. [PMID: 27110357 PMCID: PMC4840901 DOI: 10.1186/s13728-016-0047-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2016] [Accepted: 04/01/2016] [Indexed: 12/17/2022]
Abstract
This review addresses human capacity for movement in the context of extreme loading and with it the combined effects of metabolic, biomechanical and gravitational stress on the human body. This topic encompasses extreme duration, as occurs in ultra-endurance competitions (e.g. adventure racing and transcontinental races) and expeditions (e.g. polar crossings), to the more gravitationally limited load carriage (e.g. in the military context). Juxtaposed to these circumstances is the extreme metabolic and mechanical unloading associated with space travel, prolonged bedrest and sedentary lifestyle, which may be at least as problematic, and are therefore included as a reference, e.g. when considering exposure, dangers and (mal)adaptations. As per the other reviews in this series, we describe the nature of the stress and the associated consequences; illustrate relevant regulations, including why and how they are set; present the pros and cons for self versus prescribed acute and chronic exposure; describe humans' (mal)adaptations; and finally suggest future directions for practice and research. In summary, we describe adaptation patterns that are often U or J shaped and that over time minimal or no load carriage decreases the global load carrying capacity and eventually leads to severe adverse effects and manifest disease under minimal absolute but high relative loads. We advocate that further understanding of load carrying capacity and the inherent mechanisms leading to adverse effects may advantageously be studied in this perspective. With improved access to insightful and portable technologies, there are some exciting possibilities to explore these questions in this context.
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Affiliation(s)
- Samuel J. E. Lucas
- />School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, B15 2TT UK
- />Department of Physiology, University of Otago, Dunedin, New Zealand
| | - Jørn W. Helge
- />Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Uwe H. W. Schütz
- />Department of Diagnostic and Interventional Radiology, University Hospital of Ulm, Ulm, Germany
- />Orthopaedic Consulting Office at the Green Tower and Medical Pain Centre Lake Constance–Upper Swabia, Ravensburg, Germany
| | | | - James D. Cotter
- />School of Physical Education, Sport and Exercise Sciences, University of Otago, Dunedin, New Zealand
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80
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Wickwire EM, Williams SG, Roth T, Capaldi VF, Jaffe M, Moline M, Motamedi GK, Morgan GW, Mysliwiec V, Germain A, Pazdan RM, Ferziger R, Balkin TJ, MacDonald ME, Macek TA, Yochelson MR, Scharf SM, Lettieri CJ. Sleep, Sleep Disorders, and Mild Traumatic Brain Injury. What We Know and What We Need to Know: Findings from a National Working Group. Neurotherapeutics 2016; 13:403-17. [PMID: 27002812 PMCID: PMC4824019 DOI: 10.1007/s13311-016-0429-3] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Disturbed sleep is one of the most common complaints following traumatic brain injury (TBI) and worsens morbidity and long-term sequelae. Further, sleep and TBI share neurophysiologic underpinnings with direct relevance to recovery from TBI. As such, disturbed sleep and clinical sleep disorders represent modifiable treatment targets to improve outcomes in TBI. This paper presents key findings from a national working group on sleep and TBI, with a specific focus on the testing and development of sleep-related therapeutic interventions for mild TBI (mTBI). First, mTBI and sleep physiology are briefly reviewed. Next, essential empirical and clinical questions and knowledge gaps are addressed. Finally, actionable recommendations are offered to guide active and efficient collaboration between academic, industry, and governmental stakeholders.
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Affiliation(s)
- Emerson M Wickwire
- Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA.
- Sleep Disorders Center, Division of Pulmonary and Critical Care, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Scott G Williams
- Department of Medicine, Walter Reed National Military Medical Center, Bethesda, MD, USA
- Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Thomas Roth
- Sleep Disorders and Research Center, Henry Ford Hospital, Detroit, MI, USA
| | - Vincent F Capaldi
- Department of Behavioral Biology, Walter Reed Army Institute of Research, Center for Military Psychiatry and Neuroscience Research, Silver Spring, MD, USA
| | - Michael Jaffe
- Department of Neurology, University of Florida, Gainesville, FL, USA
- Concussion and Sports Program, University of Florida Trauma, Gainesville, FL, USA
- UF Health Sleep Disorders Center, Gainesville, FL, USA
| | | | - Gholam K Motamedi
- Department of Neurology, Georgetown University Hospital, Washington, DC, USA
| | - Gregory W Morgan
- Sleep Disorders Center, National Intrepid Center of Excellence, Bethesda, MD, USA
| | - Vincent Mysliwiec
- Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
- Department of Sleep Medicine, San Antonio Military Medical Center, San Antonio, TX, USA
| | - Anne Germain
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | | | | | - Thomas J Balkin
- Department of Behavioral Biology, Walter Reed Army Institute of Research, Center for Military Psychiatry and Neuroscience Research, Silver Spring, MD, USA
| | - Margaret E MacDonald
- Defense and Veterans Brain Injury Center, (Contractor, General Dynamics Health Solutions), Evans Army Community Hospital, Fort Carson, CO, USA
| | - Thomas A Macek
- Department of Clinical Science, CNS, Takeda Development Center - Americas, Deerfield, IL, USA
| | - Michael R Yochelson
- Medstar National Rehabilitation Network, Washington, DC, USA
- Departments of Neurology and Rehabilitation Medicine, Georgetown University School of Medicine, Washington, DC, USA
| | - Steven M Scharf
- Sleep Disorders Center, Division of Pulmonary and Critical Care, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Christopher J Lettieri
- Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
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81
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Koivisto H, Leinonen H, Puurula M, Hafez HS, Barrera GA, Stridh MH, Waagepetersen HS, Tiainen M, Soininen P, Zilberter Y, Tanila H. Chronic Pyruvate Supplementation Increases Exploratory Activity and Brain Energy Reserves in Young and Middle-Aged Mice. Front Aging Neurosci 2016; 8:41. [PMID: 27014054 PMCID: PMC4794631 DOI: 10.3389/fnagi.2016.00041] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 02/15/2016] [Indexed: 01/09/2023] Open
Abstract
Numerous studies have reported neuroprotective effects of pyruvate when given in systemic injections. Impaired glucose uptake and metabolism are found in Alzheimer's disease (AD) and in AD mouse models. We tested whether dietary pyruvate supplementation is able to provide added energy supply to brain and thereby attenuate aging- or AD-related cognitive impairment. Mice received ~800 mg/kg/day Na-pyruvate in their chow for 2-6 months. In middle-aged wild-type mice and in 6.5-month-old APP/PS1 mice, pyruvate facilitated spatial learning and increased exploration of a novel odor. However, in passive avoidance task for fear memory, the treatment group was clearly impaired. Independent of age, long-term pyruvate increased explorative behavior, which likely explains the paradoxical impairment in passive avoidance. We also assessed pyruvate effects on body weight, muscle force, and endurance, and found no effects. Metabolic postmortem assays revealed increased energy compounds in nuclear magnetic resonance spectroscopy as well as increased brain glycogen storages in the pyruvate group. Pyruvate supplementation may counteract aging-related behavioral impairment, but its beneficial effect seems related to increased explorative activity rather than direct memory enhancement.
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Affiliation(s)
| | - Henri Leinonen
- A. I. Virtanen Institute, University of Eastern Finland , Kuopio , Finland
| | - Mari Puurula
- A. I. Virtanen Institute, University of Eastern Finland , Kuopio , Finland
| | - Hani Sayed Hafez
- Biology Department, Faculty of Science, Suez University , Suez , Egypt
| | | | - Malin H Stridh
- Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Helle S Waagepetersen
- Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Mika Tiainen
- NMR Metabolomics Laboratory, School of Pharmacy, University of Eastern Finland , Kuopio , Finland
| | - Pasi Soininen
- NMR Metabolomics Laboratory, School of Pharmacy, University of Eastern Finland , Kuopio , Finland
| | - Yuri Zilberter
- Institut national de la santé et de la recherche médicale UMR_S 1106, Institut de Neurosciences des Systèmes, Aix-Marseille Université , Marseille , France
| | - Heikki Tanila
- A. I. Virtanen Institute, University of Eastern Finland , Kuopio , Finland
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82
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DiNuzzo M. Astrocyte-Neuron Interactions during Learning May Occur by Lactate Signaling Rather than Metabolism. Front Integr Neurosci 2016; 10:2. [PMID: 26858613 PMCID: PMC4731513 DOI: 10.3389/fnint.2016.00002] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 01/11/2016] [Indexed: 12/25/2022] Open
Affiliation(s)
- Mauro DiNuzzo
- Museo Storico della Fisica e Centro Studi e Ricerche "Enrico Fermi,"Rome, Italy; Dipartimento di Fisica, Sapienza Università di RomaRome, Italy
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83
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Pace M, Baracchi F, Gao B, Bassetti C. Identification of Sleep-Modulated Pathways Involved in Neuroprotection from Stroke. Sleep 2015; 38:1707-18. [PMID: 26085290 DOI: 10.5665/sleep.5148] [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: 01/09/2015] [Accepted: 04/13/2015] [Indexed: 12/21/2022] Open
Abstract
STUDY OBJECTIVES Sleep deprivation (SDp) performed before stroke induces an ischemic tolerance state as observed in other forms of preconditioning. As the mechanisms underlying this effect are not well understood, we used DNA oligonucleotide microarray analysis to identify the genes and the gene-pathways underlying SDp preconditioning effects. DESIGN Gene expression was analyzed 3 days after stroke in 4 experimental groups: (i) SDp performed before focal cerebral ischemia (IS) induction; (ii) SDp performed before sham surgery; (iii) IS without SDp; and (iv) sham surgery without SDp. SDp was performed by gentle handling during the last 6 h of the light period, and ischemia was induced immediately after. SETTINGS Basic sleep research laboratory. MEASUREMENTS AND RESULTS Stroke induced a massive alteration in gene expression both in sleep deprived and non-sleep deprived animals. However, compared to animals that underwent ischemia alone, SDp induced a general reduction in transcriptional changes with a reduction in the upregulation of genes involved in cell cycle regulation and immune response. Moreover, an upregulation of a new neuroendocrine pathway which included melanin concentrating hormone, glycoprotein hormones-α-polypeptide and hypocretin was observed exclusively in rats sleep deprived before stroke. CONCLUSION Our data indicate that sleep deprivation before stroke reprogrammed the signaling response to injury. The inhibition of cell cycle regulation and inflammation are neuroprotective mechanisms reported also for other forms of preconditioning treatment, whereas the implication of the neuroendocrine function is novel and has never been described before. These results therefore provide new insights into neuroprotective mechanisms involved in ischemic tolerance mechanisms.
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Affiliation(s)
- Marta Pace
- ZEN - Zentrum für Experimentelle Neurologie, Inselspital, Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Francesca Baracchi
- ZEN - Zentrum für Experimentelle Neurologie, Inselspital, Bern, Switzerland
| | - Bo Gao
- ZEN - Zentrum für Experimentelle Neurologie, Inselspital, Bern, Switzerland
| | - Claudio Bassetti
- ZEN - Zentrum für Experimentelle Neurologie, Inselspital, Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
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84
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Falkowska A, Gutowska I, Goschorska M, Nowacki P, Chlubek D, Baranowska-Bosiacka I. Energy Metabolism of the Brain, Including the Cooperation between Astrocytes and Neurons, Especially in the Context of Glycogen Metabolism. Int J Mol Sci 2015; 16:25959-81. [PMID: 26528968 PMCID: PMC4661798 DOI: 10.3390/ijms161125939] [Citation(s) in RCA: 177] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 09/27/2015] [Accepted: 10/16/2015] [Indexed: 01/15/2023] Open
Abstract
Glycogen metabolism has important implications for the functioning of the brain, especially the cooperation between astrocytes and neurons. According to various research data, in a glycogen deficiency (for example during hypoglycemia) glycogen supplies are used to generate lactate, which is then transported to neighboring neurons. Likewise, during periods of intense activity of the nervous system, when the energy demand exceeds supply, astrocyte glycogen is immediately converted to lactate, some of which is transported to the neurons. Thus, glycogen from astrocytes functions as a kind of protection against hypoglycemia, ensuring preservation of neuronal function. The neuroprotective effect of lactate during hypoglycemia or cerebral ischemia has been reported in literature. This review goes on to emphasize that while neurons and astrocytes differ in metabolic profile, they interact to form a common metabolic cooperation.
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Affiliation(s)
- Anna Falkowska
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University, Powstańców Wlkp. 72, 70-111 Szczecin, Poland.
| | - Izabela Gutowska
- Department of Biochemistry and Human Nutrition, Pomeranian Medical University, Broniewskiego 24, 71-460 Szczecin, Poland.
| | - Marta Goschorska
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University, Powstańców Wlkp. 72, 70-111 Szczecin, Poland.
| | - Przemysław Nowacki
- Department of Neurology, Pomeranian Medical University, Unii Lubelskiej 1, 71-225 Szczecin, Poland.
| | - Dariusz Chlubek
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University, Powstańców Wlkp. 72, 70-111 Szczecin, Poland.
| | - Irena Baranowska-Bosiacka
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University, Powstańców Wlkp. 72, 70-111 Szczecin, Poland.
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85
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Zhang HY, Zhao YN, Wang ZL, Huang YF. Chronic corticosterone exposure reduces hippocampal glycogen level and induces depression-like behavior in mice. J Zhejiang Univ Sci B 2015; 16:62-9. [PMID: 25559957 DOI: 10.1631/jzus.b1400166] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Long-term exposure to stress or high glucocorticoid levels leads to depression-like behavior in rodents; however, the cause remains unknown. Increasing evidence shows that astrocytes, the most abundant cells in the central nervous system (CNS), are important to the nervous system. Astrocytes nourish and protect the neurons, and serve as glycogen repositories for the brain. The metabolic process of glycogen, which is closely linked to neuronal activity, can supply sufficient energy substrates for neurons. The research team probed into the effects of chronic corticosterone (CORT) exposure on the glycogen level of astrocytes in the hippocampal tissues of male C57BL/6N mice in this study. The results showed that chronic CORT injection reduced hippocampal neurofilament light protein (NF-L) and synaptophysin (SYP) levels, induced depression-like behavior in male mice, reduced hippocampal glycogen level and glycogen synthase activity, and increased glycogen phosphorylase activity. The results suggested that the reduction of the hippocampal glycogen level may be the mechanism by which chronic CORT treatment damages hippocampal neurons and induces depression-like behavior in male mice.
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Affiliation(s)
- Hui-yu Zhang
- Laboratory of Pathological Sciences, Basic Medical College, Nanjing University of Chinese Medicine, Nanjing 210023, China; Department of Pathology, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou 511436, China
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86
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Duran J, Guinovart JJ. Brain glycogen in health and disease. Mol Aspects Med 2015; 46:70-7. [PMID: 26344371 DOI: 10.1016/j.mam.2015.08.007] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 08/21/2015] [Indexed: 12/18/2022]
Abstract
Glycogen is present in the brain at much lower concentrations than in muscle or liver. However, by characterizing an animal depleted of brain glycogen, we have shown that the polysaccharide plays a key role in learning capacity and in activity-dependent changes in hippocampal synapse strength. Since glycogen is essentially found in astrocytes, the diverse roles proposed for this polysaccharide in the brain have been attributed exclusively to these cells. However, we have demonstrated that neurons have an active glycogen metabolism that contributes to tolerance to hypoxia. However, these cells can store only minute amounts of glycogen, since the progressive accumulation of this molecule leads to neuronal loss. Loss-of-function mutations in laforin and malin cause Lafora disease. This condition is characterized by the presence of high numbers of insoluble polyglucosan bodies, known as Lafora bodies, in neuronal cells. Our findings reveal that the accumulation of this aberrant glycogen accounts for the neurodegeneration and functional consequences, as well as the impaired autophagy, observed in models of this disease. Similarly glycogen synthase is responsible for the accumulation of corpora amylacea, which are polysaccharide-based aggregates present in the neurons of aged human brains. Our findings change the current view of the role of glycogen in the brain and reveal that endogenous neuronal glycogen metabolism is important under stress conditions and that neuronal glycogen accumulation contributes to neurodegenerative diseases and to aging-related corpora amylacea formation.
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Affiliation(s)
- Jordi Duran
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Spain
| | - Joan J Guinovart
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Spain; Department of Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Spain.
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87
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Abstract
Glycogen provides an important glucose reservoir in the brain since the concentration of glucosyl units stored in glycogen is several fold higher than free glucose available in brain tissue. We have previously reported 3-4 µmol/g brain glycogen content using in vivo (13)C magnetic resonance spectroscopy (MRS) in conjunction with [1-(13)C]glucose administration in healthy humans, while higher levels were reported in the rodent brain. Due to the slow turnover of bulk brain glycogen in humans, complete turnover of the glycogen pool, estimated to take 3-5 days, was not observed in these prior studies. In an attempt to reach complete turnover and thereby steady state (13)C labeling in glycogen, here we administered [1-(13)C]glucose to healthy volunteers for 80 h. To eliminate any net glycogen synthesis during this period and thereby achieve an accurate estimate of glycogen concentration, volunteers were maintained at euglycemic blood glucose levels during [1-(13)C]glucose administration and (13)C-glycogen levels in the occipital lobe were measured by (13)C MRS approximately every 12 h. Finally, we fitted the data with a biophysical model that was recently developed to take into account the tiered structure of the glycogen molecule and additionally incorporated blood glucose levels and isotopic enrichments as input function in the model. We obtained excellent fits of the model to the (13)C-glycogen data, and glycogen content in the healthy human brain tissue was found to be 7.8 ± 0.3 µmol/g, a value substantially higher than previous estimates of glycogen content in the human brain.
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Affiliation(s)
- Gülin Öz
- Department of Radiology, Center for Magnetic Resonance Research, University of Minnesota, 2021 6th St. S.E., Minneapolis, MN, 55455, USA.
| | - Mauro DiNuzzo
- Museo storico della fisica e Centro di studi e ricerche Enrico Fermi, Rome, Italy
| | - Anjali Kumar
- Department of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Amir Moheet
- Department of Medicine, University of Minnesota, Minneapolis, MN, USA
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88
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Matsui T, Soya S, Kawanaka K, Soya H. Brain Glycogen Decreases During Intense Exercise Without Hypoglycemia: The Possible Involvement of Serotonin. Neurochem Res 2015; 40:1333-40. [PMID: 26037553 DOI: 10.1007/s11064-015-1594-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Revised: 04/21/2015] [Accepted: 04/28/2015] [Indexed: 11/25/2022]
Abstract
Brain glycogen stored in astrocytes, a source of lactate as a neuronal energy source, decreases during prolonged exercise with hypoglycemia. However, brain glycogen dynamics during exercise without hypoglycemia remain unknown. Since intense exercise increases brain noradrenaline and serotonin as known inducers for brain glycogenolysis, we hypothesized that brain glycogen decreases with intense exercise not accompanied by hypoglycemia. To test this hypothesis, we employed a well-established acute intense exercise model of swimming in rats. Rats swam for fourteen 20 s bouts with a weight equal to 8 % of their body mass and were sacrificed using high-power (10 kW) microwave irradiation to inactivate brain enzymes for accurate detection of brain glycogen and monoamines. Intense exercise did not alter blood glucose, but did increase blood lactate levels. Immediately after exercise, brain glycogen decreased and brain lactate increased in the hippocampus, cerebellum, cortex, and brainstem. Simultaneously, serotonin turnover in the hippocampus and brainstem mutually increased and were associated with decreased brain glycogen. Intense swimming exercise that does not induce hypoglycemia decreases brain glycogen associated with increased brain lactate, implying an importance of glycogen in brain energetics during intense exercise even without hypoglycemia. Activated serotonergic regulation is a possible underlying mechanism for intense exercise-induced glycogenolysis at least in the hippocampus and brainstem.
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Affiliation(s)
- Takashi Matsui
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Institute for Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan
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89
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Blanco AM, Gómez-Boronat M, Pérez-Maceira J, Mancebo MJ, Aldegunde M. Brain glycogen supercompensation after different conditions of induced hypoglycemia and sustained swimming in rainbow trout (Oncorhynchus mykiss). Comp Biochem Physiol A Mol Integr Physiol 2015; 187:55-60. [PMID: 25956213 DOI: 10.1016/j.cbpa.2015.04.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 04/27/2015] [Accepted: 04/28/2015] [Indexed: 11/17/2022]
Abstract
Brain glycogen is depleted when used as an emergency energy substrate. In mammals, brain glycogen levels rebound to higher than normal levels after a hypoglycemic episode and a few hours after refeeding or administration of glucose. This phenomenon is called glycogen supercompensation. However, this mechanism has not been investigated in lower vertebrates. The aim of this study was therefore to determine whether brain glycogen supercompensation occurs in the rainbow trout brain. For this purpose, short-term brain glucose and glycogen contents were determined in rainbow trout after being subjected to the following experimental conditions: i) a 5-day or 10-day fasting period and refeeding; ii) a single injection of insulin (4 mg kg(-1)) and refeeding; and iii) sustained swimming and injection of glucose (500 mg kg(-1)). Food deprivation during the fasting periods and insulin administration both induced a decrease in glucose and glycogen levels in the brain. However, only refeeding after 10 days of fasting significantly increased the brain glycogen content above control levels, in a clear short-term supercompensation response. Unlike in mammals, prolonged exercise did not alter brain glucose or glycogen levels. Furthermore, brain glycogen supercompensation was not observed after glucose administration in fish undergoing sustained swimming. To our knowledge, this is the first study providing direct experimental evidence for the existence of a short-term glycogen supercompensation response in a teleost brain, although the response was only detectable after prolonged fasting.
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Affiliation(s)
- A M Blanco
- Laboratorio de Fisiología Animal (Instituto de Acuicultura), Facultad de Biología, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - M Gómez-Boronat
- Laboratorio de Fisiología Animal (Instituto de Acuicultura), Facultad de Biología, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - J Pérez-Maceira
- Laboratorio de Fisiología Animal (Instituto de Acuicultura), Facultad de Biología, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - M J Mancebo
- Laboratorio de Fisiología Animal (Instituto de Acuicultura), Facultad de Biología, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - M Aldegunde
- Laboratorio de Fisiología Animal (Instituto de Acuicultura), Facultad de Biología, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
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90
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He J, Luo Z, Huang L, He J, Chen Y, Rong X, Jia S, Tang F, Wang X, Zhang R, Zhang J, Shi J, Abliz Z. Ambient mass spectrometry imaging metabolomics method provides novel insights into the action mechanism of drug candidates. Anal Chem 2015; 87:5372-9. [PMID: 25874739 DOI: 10.1021/acs.analchem.5b00680] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Elucidation of the mechanism of action for drug candidates is fundamental to drug development, and it is strongly facilitated by metabolomics. Herein, we developed an imaging metabolomics method based on air-flow-assisted desorption electrospray ionization mass spectrometry imaging (AFADESI-MSI) under ambient conditions. This method was subsequently applied to simultaneously profile a novel anti-insomnia drug candidate, N(6)-(4-hydroxybenzyl)-adenosine (NHBA), and various endogenous metabolites in rat whole-body tissue sections after the administration of NHBA. The principal component analysis (PCA) represented by an intuitive color-coding scheme based on hyperspectral imaging revealed in situ molecular profiling alterations in response to stimulation of NHBA, which are in a very low intensity and hidden in massive interferential peaks. We found that the abundance of six endogenous metabolites changed after drug administration. The spatiotemporal distribution indicated that five altered molecules—including neurotransmitter γ-aminobutyric acid, neurotransmitter precursors choline and glycerophosphocholine, energy metabolism-related molecules adenosine (an endogenous sleep factor), and creatine—are closely associated with insomnia or other neurological disorders. These findings not only provide insights into a deep understanding on the mechanism of action of NHBA, but also demonstrate that the AFADESI-MSI-based imaging metabolomics is a powerful technique to investigate the molecular mechanism of drug action, especially for drug candidates with multitarget or undefined target in the preclinical study stage.
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Affiliation(s)
- Jingjing He
- †State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China
| | - Zhigang Luo
- †State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China
| | - Lan Huang
- §Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, People's Republic of China
| | - Jiuming He
- †State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China
| | - Yi Chen
- ‡State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments and Mechanology, Tsinghua University, Beijing 100084, People's Republic of China
| | - Xianfang Rong
- †State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China
| | - Shaobo Jia
- †State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China
| | - Fei Tang
- ‡State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments and Mechanology, Tsinghua University, Beijing 100084, People's Republic of China
| | - Xiaohao Wang
- ‡State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments and Mechanology, Tsinghua University, Beijing 100084, People's Republic of China
| | - Ruiping Zhang
- †State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China
| | - Jianjun Zhang
- †State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China
| | - Jiangong Shi
- †State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China
| | - Zeper Abliz
- †State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China
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91
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Kaczor P, Rakus D, Mozrzymas JW. Neuron-astrocyte interaction enhance GABAergic synaptic transmission in a manner dependent on key metabolic enzymes. Front Cell Neurosci 2015; 9:120. [PMID: 25914620 PMCID: PMC4391237 DOI: 10.3389/fncel.2015.00120] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 03/17/2015] [Indexed: 11/21/2022] Open
Abstract
Gamma aminobutric acid (GABA) is the major inhibitory neurotransmitter in the adult brain and mechanisms of GABAergic inhibition have been intensely investigated in the past decades. Recent studies provided evidence for an important role of astrocytes in shaping GABAergic currents. One of the most obvious, but yet poorly understood, mechanisms of the cross-talk between GABAergic currents and astrocytes is metabolism including neurotransmitter homeostasis. In particular, how modulation of GABAergic currents by astrocytes depends on key enzymes involved in cellular metabolism remains largely unknown. To address this issue, we have considered two simple models of neuronal culture (NC): nominally astrocyte-free NC and neuronal-astrocytic co-cultures (ANCC). Miniature Inhibitory Postsynaptic Currents (mIPSCs) were recorded in control conditions and in the presence of different enzyme blockers. We report that enrichment of NC with astrocytes results in a marked increase in mIPSC frequency. This enhancement of GABAergic activity was accompanied by increased number of GAD65 and vGAT puncta, indicating that at least a part of the frequency enhancement was due to increased number of synaptic contacts. Inhibition of glutamine synthetase (Glns) (with MSO) strongly reduced mIPSC frequency in ANCC but had no effect in NC. Moreover, treatment of ANCC with inhibitor of glycogen phosphorylase (Gys) (BAYU6751) or with selective inhibitor of astrocytic Krebs cycle, fluoroacetate, resulted in a marked reduction of mIPSC frequency in ANCC having no effect in NC. We conclude that GABAergic synaptic transmission strongly depends on neuron-astrocyte interaction in a manner dependent on key metabolic enzymes as well as on the Krebs cycle.
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Affiliation(s)
- Przemysław Kaczor
- Department of Animal Molecular Physiology, Wroclaw University Wroclaw, Poland
| | - Dariusz Rakus
- Department of Animal Molecular Physiology, Wroclaw University Wroclaw, Poland
| | - Jerzy W Mozrzymas
- Department of Animal Molecular Physiology, Wroclaw University Wroclaw, Poland ; Laboratory of Neuroscience, Department of Biophysics, Wroclaw Medical University Wroclaw, Poland
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92
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Muhič M, Vardjan N, Chowdhury HH, Zorec R, Kreft M. Insulin and Insulin-like Growth Factor 1 (IGF-1) Modulate Cytoplasmic Glucose and Glycogen Levels but Not Glucose Transport across the Membrane in Astrocytes. J Biol Chem 2015; 290:11167-76. [PMID: 25792745 DOI: 10.1074/jbc.m114.629063] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Indexed: 01/21/2023] Open
Abstract
Astrocytes contain glycogen, an energy buffer, which can bridge local short term energy requirements in the brain. Glycogen levels reflect a dynamic equilibrium between glycogen synthesis and glycogenolysis. Many factors that include hormones and neuropeptides, such as insulin and insulin-like growth factor 1 (IGF-1) likely modulate glycogen stores in astrocytes, but detailed mechanisms at the cellular level are sparse. We used a glucose nanosensor based on Förster resonance energy transfer to monitor cytosolic glucose concentration with high temporal resolution and a cytochemical approach to determine glycogen stores in single cells. The results show that after glucose depletion, glycogen stores are replenished. Insulin and IGF-1 boost the process of glycogen formation. Although astrocytes appear to express glucose transporter GLUT4, glucose entry across the astrocyte plasma membrane is not affected by insulin. Stimulation of cells with insulin and IGF-1 decreased cytosolic glucose concentration, likely because of elevated glucose utilization for glycogen synthesis.
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Affiliation(s)
- Marko Muhič
- From the Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
| | - Nina Vardjan
- From the Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia, Celica Biomedical, 1000 Ljubljana, Slovenia, and
| | - Helena H Chowdhury
- From the Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia, Celica Biomedical, 1000 Ljubljana, Slovenia, and
| | - Robert Zorec
- From the Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia, Celica Biomedical, 1000 Ljubljana, Slovenia, and
| | - Marko Kreft
- From the Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia, Celica Biomedical, 1000 Ljubljana, Slovenia, and the Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia
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93
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Rattray B, Argus C, Martin K, Northey J, Driller M. Is it time to turn our attention toward central mechanisms for post-exertional recovery strategies and performance? Front Physiol 2015; 6:79. [PMID: 25852568 PMCID: PMC4362407 DOI: 10.3389/fphys.2015.00079] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 02/27/2015] [Indexed: 11/23/2022] Open
Abstract
Key PointsCentral fatigue is accepted as a contributor to overall athletic performance, yet little research directly investigates post-exercise recovery strategies targeting the brain Current post-exercise recovery strategies likely impact on the brain through a range of mechanisms, but improvements to these strategies is needed Research is required to optimize post-exercise recovery with a focus on the brain
Post-exercise recovery has largely focused on peripheral mechanisms of fatigue, but there is growing acceptance that fatigue is also contributed to through central mechanisms which demands that attention should be paid to optimizing recovery of the brain. In this narrative review we assemble evidence for the role that many currently utilized recovery strategies may have on the brain, as well as potential mechanisms for their action. The review provides discussion of how common nutritional strategies as well as physical modalities and methods to reduce mental fatigue are likely to interact with the brain, and offer an opportunity for subsequent improved performance. We aim to highlight the fact that many recovery strategies have been designed with the periphery in mind, and that refinement of current methods are likely to provide improvements in minimizing brain fatigue. Whilst we offer a number of recommendations, it is evident that there are many opportunities for improving the research, and practical guidelines in this area.
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Affiliation(s)
- Ben Rattray
- Discipline of Sport and Exercise Science, Faculty of Health, University of Canberra Canberra, ACT, Australia ; University of Canberra Research Institute for Sport and Exercise, University of Canberra Canberra, ACT, Australia
| | - Christos Argus
- University of Canberra Research Institute for Sport and Exercise, University of Canberra Canberra, ACT, Australia
| | - Kristy Martin
- Discipline of Sport and Exercise Science, Faculty of Health, University of Canberra Canberra, ACT, Australia ; University of Canberra Research Institute for Sport and Exercise, University of Canberra Canberra, ACT, Australia
| | - Joseph Northey
- Discipline of Sport and Exercise Science, Faculty of Health, University of Canberra Canberra, ACT, Australia ; University of Canberra Research Institute for Sport and Exercise, University of Canberra Canberra, ACT, Australia
| | - Matthew Driller
- Department of Sport and Leisure Studies, The University of Waikato Hamilton, New Zealand
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94
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95
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Dienel GA, Cruz NF. Contributions of glycogen to astrocytic energetics during brain activation. Metab Brain Dis 2015; 30:281-98. [PMID: 24515302 PMCID: PMC4130810 DOI: 10.1007/s11011-014-9493-8] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 01/21/2014] [Indexed: 12/11/2022]
Abstract
Glycogen is the major store of glucose in brain and is mainly in astrocytes. Brain glycogen levels in unstimulated, carefully-handled rats are 10-12 μmol/g, and assuming that astrocytes account for half the brain mass, astrocytic glycogen content is twice as high. Glycogen turnover is slow under basal conditions, but it is mobilized during activation. There is no net increase in incorporation of label from glucose during activation, whereas label release from pre-labeled glycogen exceeds net glycogen consumption, which increases during stronger stimuli. Because glycogen level is restored by non-oxidative metabolism, astrocytes can influence the global ratio of oxygen to glucose utilization. Compensatory increases in utilization of blood glucose during inhibition of glycogen phosphorylase are large and approximate glycogenolysis rates during sensory stimulation. In contrast, glycogenolysis rates during hypoglycemia are low due to continued glucose delivery and oxidation of endogenous substrates; rates that preserve neuronal function in the absence of glucose are also low, probably due to metabolite oxidation. Modeling studies predict that glycogenolysis maintains a high level of glucose-6-phosphate in astrocytes to maintain feedback inhibition of hexokinase, thereby diverting glucose for use by neurons. The fate of glycogen carbon in vivo is not known, but lactate efflux from brain best accounts for the major metabolic characteristics during activation of living brain. Substantial shuttling coupled with oxidation of glycogen-derived lactate is inconsistent with available evidence. Glycogen has important roles in astrocytic energetics, including glucose sparing, control of extracellular K(+) level, oxidative stress management, and memory consolidation; it is a multi-functional compound.
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Affiliation(s)
- Gerald A Dienel
- Department of Neurology, University of Arkansas for Medical Sciences, Slot 500, 4301 W. Markham St., Little Rock, AR, 72205, USA,
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96
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Khowaja A, Choi IY, Seaquist ER, Öz G. In vivo Magnetic Resonance Spectroscopy of cerebral glycogen metabolism in animals and humans. Metab Brain Dis 2015; 30:255-61. [PMID: 24676563 PMCID: PMC4392006 DOI: 10.1007/s11011-014-9530-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 03/12/2014] [Indexed: 01/31/2023]
Abstract
Glycogen serves as an important energy reservoir in the human body. Despite the abundance of glycogen in the liver and skeletal muscles, its concentration in the brain is relatively low, hence its significance has been questioned. A major challenge in studying brain glycogen metabolism has been the lack of availability of non-invasive techniques for quantification of brain glycogen in vivo. Invasive methods for brain glycogen quantification such as post mortem extraction following high energy microwave irradiation are not applicable in the human brain. With the advent of (13)C Magnetic Resonance Spectroscopy (MRS), it has been possible to measure brain glycogen concentrations and turnover in physiological conditions, as well as under the influence of stressors such as hypoglycemia and visual stimulation. This review presents an overview of the principles of the (13)C MRS methodology and its applications in both animals and humans to further our understanding of glycogen metabolism under normal physiological and pathophysiological conditions such as hypoglycemia unawareness.
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Affiliation(s)
- Ameer Khowaja
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, University of Minnesota, 420 Delaware Street, SE, Minneapolis, MN 55455, USA
| | - In-Young Choi
- Hoglund Brain Imaging Center, Department of Neurology, Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Elizabeth R. Seaquist
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, University of Minnesota, 420 Delaware Street, SE, Minneapolis, MN 55455, USA
| | - Gülin Öz
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN 55455, USA
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97
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Petit JM, Burlet-Godinot S, Magistretti PJ, Allaman I. Glycogen metabolism and the homeostatic regulation of sleep. Metab Brain Dis 2015; 30:263-79. [PMID: 25399336 PMCID: PMC4544655 DOI: 10.1007/s11011-014-9629-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 11/04/2014] [Indexed: 12/19/2022]
Abstract
In 1995 Benington and Heller formulated an energy hypothesis of sleep centered on a key role of glycogen. It was postulated that a major function of sleep is to replenish glycogen stores in the brain that have been depleted during wakefulness which is associated to an increased energy demand. Astrocytic glycogen depletion participates to an increase of extracellular adenosine release which influences sleep homeostasis. Here, we will review some evidence obtained by studies addressing the question of a key role played by glycogen metabolism in sleep regulation as proposed by this hypothesis or by an alternative hypothesis named "glycogenetic" hypothesis as well as the importance of the confounding effect of glucocorticoïds. Even though actual collected data argue in favor of a role of sleep in brain energy balance-homeostasis, they do not support a critical and direct involvement of glycogen metabolism on sleep regulation. For instance, glycogen levels during the sleep-wake cycle are driven by different physiological signals and therefore appear more as a marker-integrator of brain energy status than a direct regulator of sleep homeostasis. In support of this we provide evidence that blockade of glycogen mobilization does not induce more sleep episodes during the active period while locomotor activity is reduced. These observations do not invalidate the energy hypothesis of sleep but indicate that underlying cellular mechanisms are more complex than postulated by Benington and Heller.
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Affiliation(s)
- Jean-Marie Petit
- Laboratory of Neuroenergetics and Cellular Dynamics, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, 1015, Switzerland,
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98
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DiNuzzo M, Mangia S, Maraviglia B, Giove F. Does abnormal glycogen structure contribute to increased susceptibility to seizures in epilepsy? Metab Brain Dis 2015; 30:307-16. [PMID: 24643875 PMCID: PMC4169361 DOI: 10.1007/s11011-014-9524-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 03/05/2014] [Indexed: 12/22/2022]
Abstract
Epilepsy is a family of brain disorders with a largely unknown etiology and high percentage of pharmacoresistance. The clinical manifestations of epilepsy are seizures, which originate from aberrant neuronal synchronization and hyperexcitability. Reactive astrocytosis, a hallmark of the epileptic tissue, develops into loss-of-function of glutamine synthetase, impairment of glutamate-glutamine cycle and increase in extracellular and astrocytic glutamate concentration. Here, we argue that chronically elevated intracellular glutamate level in astrocytes is instrumental to alterations in the metabolism of glycogen and leads to the synthesis of polyglucosans. Unaccessibility of glycogen-degrading enzymes to these insoluble molecules compromises the glycogenolysis-dependent reuptake of extracellular K(+) by astrocytes, thereby leading to increased extracellular K(+) and associated membrane depolarization. Based on current knowledge, we propose that the deterioration in structural homogeneity of glycogen particles is relevant to disruption of brain K(+) homeostasis and increased susceptibility to seizures in epilepsy.
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Affiliation(s)
- Mauro DiNuzzo
- MARBILab, Museo storico della fisica e Centro di studi e ricerche "Enrico Fermi", Rome, Italy,
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99
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Sickmann HM, Waagepetersen HS. Effects of diabetes on brain metabolism--is brain glycogen a significant player? Metab Brain Dis 2015; 30:335-43. [PMID: 24771109 DOI: 10.1007/s11011-014-9546-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 04/10/2014] [Indexed: 10/25/2022]
Abstract
Brain glycogen, being an intracellular glucose reservoir, contributes to maintain energy and neurotransmitter homeostasis under physiological as well as pathological conditions. Under conditions with a disturbance in systemic glucose metabolism such as in diabetes, the supply of glucose to the brain may be affected and have important impacts on brain metabolism and neurotransmission. This also implies that brain glycogen may serve an essential role in the diabetic state to sustain appropriate brain function. There are two main types of diabetes; type 1 and type 2 diabetes and both types may be associated with brain impairments e.g. cognitive decline and dementia. It is however, not clear how these impairments on brain function are linked to alterations in brain energy and neurotransmitter metabolism. In this review, we will illuminate how rodent diabetes models have contributed to a better understanding of how brain energy and neurotransmitter metabolism is affected in diabetes. There will be a particular focus on the role of brain glycogen to support glycolytic and TCA cycle activity as well as glutamate-glutamine cycle in type 1 and type 2 diabetes.
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Affiliation(s)
- Helle M Sickmann
- Dept. of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark,
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100
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Elliott AS, Huber JD, O'Callaghan JP, Rosen CL, Miller DB. A review of sleep deprivation studies evaluating the brain transcriptome. SPRINGERPLUS 2014; 3:728. [PMID: 25932362 PMCID: PMC4409616 DOI: 10.1186/2193-1801-3-728] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 11/25/2014] [Indexed: 12/14/2022]
Abstract
Epidemiological studies show a positive association between adequate sleep and good health. Further, disrupted sleep may increase the risk for CNS diseases, such as stroke and Alzheimer’s disease. However, there has been limited progress in determining how sleep is linked to brain health or how sleep disruption may increase susceptibility to brain insult and disease. Animal studies can aid in understanding these links. In reviewing the animal literature related to the effects of sleep disruption on the brain, we found most of the work was directed toward investigating and characterizing the role of various brain areas or structures in initiating and regulating sleep. In contrast, limited effort has been directed towards understanding how sleep disruption alters the brain’s health or susceptibility to insult. We also note many current studies have determined the changes in the brain following compromised sleep by examining, for example, the brain transcriptome or to a more limited extent the proteome. However, these studies have utilized almost exclusively total sleep deprivation (e.g., 24 out of 24 hours) paradigms or single short periods of limited acute sleep deprivation (e.g., 3 out of 24 hours). While such strategies are beneficial in understanding how sleep is controlled, they may not have much translational value for determining links between sleep and brain health or for determining how sleep disruption may increase brain susceptibility to insult. Surprisingly, few studies have determined how the duration and recurrence of sleep deprivation influence the effects seen after sleep deprivation. Our aim in this review was to identify relevant rodent studies from 1980 through 2012 and analyze those that use varying durations of sleep deprivation or restriction in their effort to evaluate the effects of sleep deprivation on the brain transcriptome and to a more limited extent the proteome. We examined how differences in the duration of sleep deprivation affect gene and protein expression to better understand the full consequences of repeated sleep disruption on the brain. Future research needs to consider and emphasize how the type and extent of the sleep deprivation exposure impacts the conclusions reached concerning the influence of sleep disruption on the brain. We identified relevant studies between 1980 and 2012 by searching the electronic databases of PubMed, Medline (Ovid), Embase (Ovid), and Web of Science using the terms “sleep” AND “disrupt”, “deprivation”, “restrict”, “fragment”, “loss”, “disturb”, “disorder”, “dysfunction”, “brain”, “cortex”, striatum”, hypothalamus”, “hippocampus”, “gene”, “protein”, “genomics”, “proteomics”, “polymerase chain reaction”, “pcr”, “microarray”, “molecular”, “rodent” “rat”, “rats”, “mouse”, “mice”. All searches were limited to rodent studies in English and the reference lists of retrieved articles were searched for additional pertinent studies.
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Affiliation(s)
- Alisa S Elliott
- School of Medicine, West Virginia University, Morgantown, WV USA
| | - Jason D Huber
- School of Pharmacy, West Virginia University, Morgantown, WV USA
| | - James P O'Callaghan
- Toxicology and Molecular Biology Branch, CDC-NIOSH, 1095 Willowdale Rd, Morgantown, WV 26505 USA
| | - Charles L Rosen
- School of Medicine, West Virginia University, Morgantown, WV USA
| | - Diane B Miller
- Toxicology and Molecular Biology Branch, CDC-NIOSH, 1095 Willowdale Rd, Morgantown, WV 26505 USA
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