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Rojas R, Griñán-Ferré C, Castellanos A, Griego E, Martínez M, Navarro-López JDD, Jiménez-Díaz L, Rodríguez-Álvarez J, Del Cerro DS, Castillo PE, Pallàs M, Fadó R, Casals N. BETA-HYDROXYBUTYRATE COUNTERACTS THE DELETERIOUS EFFECTS OF A SATURATED HIGH-FAT DIET ON SYNAPTIC AMPA RECEPTORS AND COGNITIVE PERFORMANCE. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.23.576931. [PMID: 39091837 PMCID: PMC11291009 DOI: 10.1101/2024.01.23.576931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
The ketogenic diet, characterized by high fat and low carbohydrates, has gained popularity not only as a strategy for managing body weight but also for its efficacy in delaying cognitive decline associated with neurodegenerative diseases and the aging process. Since this dietary approach stimulates the liver's production of ketone bodies, primarily β-hydroxybutyrate (BHB), which serves as an alternative energy source for neurons, we investigated whether BHB could mitigate impaired AMPA receptor trafficking, synaptic dysfunction, and cognitive decline induced by metabolic challenges such as saturated fatty acids. Here, we observe that, in cultured primary cortical neurons, exposure to palmitic acid (200μM) decreased surface levels of glutamate GluA1-containing AMPA receptors, whereas unsaturated fatty acids, such as oleic acid and ω-3 docosahexaenoic acid (200μM), and BHB (5mM) increased them. Furthermore, BHB countered the adverse effects of palmitic acid on synaptic GluA1 levels in hippocampal neurons, as well as excitability and plasticity in hippocampal slices. Additionally, daily intragastric administration of BHB (100 mg/kg/day) for two months reversed cognitive impairment induced by a saturated high-fat diet (49% of calories from fat) in a mouse experimental model of obesity. In summary, our findings underscore the significant impact of fatty acids and ketone bodies on AMPA receptors abundance, synaptic function and neuroplasticity, shedding light on the potential use of BHB to delay cognitive impairments associated with metabolic diseases.
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Fadó R, Molins A, Rojas R, Casals N. Feeding the Brain: Effect of Nutrients on Cognition, Synaptic Function, and AMPA Receptors. Nutrients 2022; 14:nu14194137. [PMID: 36235789 PMCID: PMC9572450 DOI: 10.3390/nu14194137] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 09/29/2022] [Accepted: 09/30/2022] [Indexed: 11/05/2022] Open
Abstract
In recent decades, traditional eating habits have been replaced by a more globalized diet, rich in saturated fatty acids and simple sugars. Extensive evidence shows that these dietary factors contribute to cognitive health impairment as well as increase the incidence of metabolic diseases such as obesity and diabetes. However, how these nutrients modulate synaptic function and neuroplasticity is poorly understood. We review the Western, ketogenic, and paleolithic diets for their effects on cognition and correlations with synaptic changes, focusing mainly (but not exclusively) on animal model studies aimed at tracing molecular alterations that may contribute to impaired human cognition. We observe that memory and learning deficits mediated by high-fat/high-sugar diets, even over short exposure times, are associated with reduced arborization, widened synaptic cleft, narrowed post-synaptic zone, and decreased activity-dependent synaptic plasticity in the hippocampus, and also observe that these alterations correlate with deregulation of the AMPA-type glutamate ionotropic receptors (AMPARs) that are crucial to neuroplasticity. Furthermore, we explored which diet-mediated mechanisms modulate synaptic AMPARs and whether certain supplements or nutritional interventions could reverse deleterious effects, contributing to improved learning and memory in older people and patients with Alzheimer’s disease.
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Affiliation(s)
- Rut Fadó
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, E-08195 Sant Cugat del Vallès, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, E-28029 Madrid, Spain
- Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, E-08193 Cerdanyola del Vallès, Spain
- Correspondence: ; Tel.: +34-93-504-20-00
| | - Anna Molins
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, E-08195 Sant Cugat del Vallès, Spain
| | - Rocío Rojas
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, E-08195 Sant Cugat del Vallès, Spain
| | - Núria Casals
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, E-08195 Sant Cugat del Vallès, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, E-28029 Madrid, Spain
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Gorina YV, Salmina AB, Erofeev AI, Can Z, Bolshakova AV, Balaban PM, Bezprozvanny IB, Vlasova OL. Metabolic Plasticity of Astrocytes. J EVOL BIOCHEM PHYS+ 2021. [DOI: 10.1134/s0022093021060016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Greco T, Vespa PM, Prins ML. Alternative substrate metabolism depends on cerebral metabolic state following traumatic brain injury. Exp Neurol 2020; 329:113289. [PMID: 32247790 PMCID: PMC8168752 DOI: 10.1016/j.expneurol.2020.113289] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 03/25/2020] [Accepted: 03/28/2020] [Indexed: 12/13/2022]
Abstract
Decreases in energy metabolism following traumatic brain injury (TBI) are attributed to impairment of glycolytic flux and oxidative phosphorylation. Glucose utilization post-TBI is decreased while administration of alternative substrates has been shown to be neuroprotective. Changes in energy metabolism following TBI happens in two phases; a period of hyper-metabolism followed by prolonged hypo-metabolism. It is not understood how different cerebral metabolic states may impact substrate metabolism and ultimately mitochondrial function. Adult male or female Sprague Dawley rats were given sham surgery or controlled cortical impact (CCI) and were assigned one of two administration schemes. Glucose, lactate or beta-hydroxybutyrate (BHB) were infused i.v. either starting immediately after injury or beginning 6 h post-injury for 3 h to reflect the hyper- and hypo-metabolic stages. Animals were euthanized 24 h post-injury. The peri-contusional cortex was collected and assayed for mitochondrial respiration peroxide production, and citrate synthase activity. Tissue acetyl-CoA, ATP, glycogen and HMGB1 were also quantified. Sex differences were observed in injury pattern. Administration based on cerebral metabolic state identified that only early lactate and late BHB improved mitochondrial function and peroxide production and TCA cycle intermediates in males. In contrast, both early and late BHB had deleterious effects on all aspects of metabolic measurements in females. These data stress there is no one optimal alternative substrate, but rather the fuel type used should be guided by both cerebral metabolic state and sex.
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Affiliation(s)
- Tiffany Greco
- UCLA Department of Neurosurgery, USA; UCLA Brain Injury Research Center, USA.
| | - Paul M Vespa
- UCLA Department of Neurosurgery, USA; UCLA Department of Neurology, USA
| | - Mayumi L Prins
- UCLA Department of Neurosurgery, USA; UCLA Interdepartmental Program for Neuroscience, USA; UCLA Brain Injury Research Center, USA
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Weber DD, Aminzadeh-Gohari S, Tulipan J, Catalano L, Feichtinger RG, Kofler B. Ketogenic diet in the treatment of cancer - Where do we stand? Mol Metab 2020; 33:102-121. [PMID: 31399389 PMCID: PMC7056920 DOI: 10.1016/j.molmet.2019.06.026] [Citation(s) in RCA: 221] [Impact Index Per Article: 55.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 06/17/2019] [Accepted: 06/28/2019] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Cancer is one of the greatest public health challenges worldwide, and we still lack complementary approaches to significantly enhance the efficacy of standard anticancer therapies. The ketogenic diet, a high-fat, low-carbohydrate diet with adequate amounts of protein, appears to sensitize most cancers to standard treatment by exploiting the reprogramed metabolism of cancer cells, making the diet a promising candidate as an adjuvant cancer therapy. SCOPE OF REVIEW To critically evaluate available preclinical and clinical evidence regarding the ketogenic diet in the context of cancer therapy. Furthermore, we highlight important mechanisms that could explain the potential antitumor effects of the ketogenic diet. MAJOR CONCLUSIONS The ketogenic diet probably creates an unfavorable metabolic environment for cancer cells and thus can be regarded as a promising adjuvant as a patient-specific multifactorial therapy. The majority of preclinical and several clinical studies argue for the use of the ketogenic diet in combination with standard therapies based on its potential to enhance the antitumor effects of classic chemo- and radiotherapy, its overall good safety and tolerability and increase in quality of life. However, to further elucidate the mechanisms of the ketogenic diet as a therapy and evaluate its application in clinical practice, more molecular studies as well as uniformly controlled clinical trials are needed.
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Affiliation(s)
- Daniela D Weber
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Müllner Hauptstraße 48, 5020, Salzburg, Austria.
| | - Sepideh Aminzadeh-Gohari
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Müllner Hauptstraße 48, 5020, Salzburg, Austria.
| | - Julia Tulipan
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Müllner Hauptstraße 48, 5020, Salzburg, Austria.
| | - Luca Catalano
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Müllner Hauptstraße 48, 5020, Salzburg, Austria.
| | - René G Feichtinger
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Müllner Hauptstraße 48, 5020, Salzburg, Austria.
| | - Barbara Kofler
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Müllner Hauptstraße 48, 5020, Salzburg, Austria.
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Johnson SC, Pan A, Sun GX, Freed A, Stokes JC, Bornstein R, Witkowski M, Li L, Ford JM, Howard CRA, Sedensky MM, Morgan PG. Relevance of experimental paradigms of anesthesia induced neurotoxicity in the mouse. PLoS One 2019; 14:e0213543. [PMID: 30897103 PMCID: PMC6428290 DOI: 10.1371/journal.pone.0213543] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 02/24/2019] [Indexed: 11/30/2022] Open
Abstract
Routine general anesthesia is considered to be safe in healthy individuals. However, pre-clinical studies in mice, rats, and monkeys have repeatedly demonstrated that exposure to anesthetic agents during early post-natal periods can lead to acute neurotoxicity. More concerning, later-life defects in cognition, assessed by behavioral assays for learning and memory, have been reported. Although the potential for anesthetics to damage the neonatal brain is well-documented, the clinical significance of the pre-clinical models in which damage is induced remains quite unclear. Here, we systematically evaluate critical physiological parameters in post-natal day 7 neonatal mice exposed to 1.5% isoflurane for 2–4 hours, the most common anesthesia induced neurotoxicity paradigm in this animal model. We find that 2 or more hours of anesthesia exposure results in dramatic respiratory and metabolic changes that may limit interpretation of this paradigm to the clinical situation. Our data indicate that neonatal mouse models of AIN are not necessarily appropriate representations of human exposures.
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Affiliation(s)
- Simon C. Johnson
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, United States of America
- Department of Neurology, University of Washington, Seattle, WA, United States of America
- * E-mail:
| | - Amanda Pan
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, United States of America
| | - Grace X. Sun
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, United States of America
| | - Arielle Freed
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, United States of America
- University of Washington School of Dentistry, Seattle, WA, United States of America
| | - Julia C. Stokes
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, United States of America
| | - Rebecca Bornstein
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, United States of America
- Department of Pathology, University of Washington, Seattle, WA, United States of America
| | - Michael Witkowski
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, United States of America
| | - Li Li
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, United States of America
| | - Jeremy M. Ford
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, United States of America
- Seattle Children's Imagination Lab, Seattle Children’s Research Institute, Seattle, WA, United States of America
| | - Christopher R. A. Howard
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, United States of America
- Seattle Children's Imagination Lab, Seattle Children’s Research Institute, Seattle, WA, United States of America
| | - Margaret M. Sedensky
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, United States of America
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA, United States of America
| | - Philip G. Morgan
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, United States of America
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA, United States of America
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Bonnet U, Bingmann D, Speckmann EJ, Wiemann M. Small intraneuronal acidification via short-chain monocarboxylates: First evidence of an inhibitory action on over-excited human neocortical neurons. Life Sci 2018; 204:65-70. [PMID: 29730171 DOI: 10.1016/j.lfs.2018.05.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 05/01/2018] [Accepted: 05/02/2018] [Indexed: 10/17/2022]
Abstract
AIMS In cortical mammalian neurons, small fluctuations of intracellular pH (pHi) play a crucial role for inter- and intracellular signaling as well as for cellular and synaptic plasticity. Yet, there have been no respective data about humans. Thus, we investigated the interrelation of pHi and excitability of human cortical neurons. MATERIALS AND METHODS Intracellular electrophysiological and pH-recordings were made in neurons in slices taken from brain tissue resected from the middle temporal gyrus of two male children (26 months and 35 months old) who suffered from pharmacotherapy-resistant temporal lobe epilepsy. To excite the tissue (n = 13), we used the 0-Mg2+/high-K+-in vitro epilepsy model producing robust epileptiform discharges (ED). To evoke an intracellular acidification (n = 12), we used the well-established propionate-model and applied 10 mM propionate to the bath solutions. In addition, we recorded the effects of other strongly related short-chain monocarboxylates (l-lactate (10 mM) and the ketone body DL-β-hydroxybutyrate (10 mM)) on ED and pHi. KEY FINDINGS The ED-frequency was reversibly reduced by propionate (n = 5), l-lactate (n = 5), or DL-β-hydroxybutyrate (n = 3), while the durations of EDs and their after-depolarizations increased. In parallel experiments, all three short-chain monocarboxylates (each n = 4) lowered the pHi of the neurons (n = 12) by 0.05-0.07 pH units which was temporally related to the reported changes in bioelectric activity. SIGNIFICANCE A mild drop of the intraneuronal pH was associated with the control of even over-excited human neocortical tissue. This is identical with prior observations in non-human mammalian cortical neurons. Possible implications for neuroplasticity and the treatment of neuropsychiatric disorders are discussed.
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Affiliation(s)
- Udo Bonnet
- Department of Psychiatry, Psychotherapy, and Psychosomatic Medicine, Evangelisches Krankenhaus Castrop-Rauxel, Academic Teaching Hospital of the University Duisburg-Essen, Castrop-Rauxel, Germany; Department of Psychiatry and Psychotherapy, Faculty of Medicine, LVR-Hospital Essen, University of Duisburg-Essen, Essen, Germany.
| | - Dieter Bingmann
- Institute of Physiology, University of Duisburg-Essen, Essen, Germany
| | | | - Martin Wiemann
- Institute of Physiology, University of Duisburg-Essen, Essen, Germany; IBE R&D gGmbH, Institute for Lung Health, D-48149 Münster, Germany
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Simeone TA, Simeone KA, Stafstrom CE, Rho JM. Do ketone bodies mediate the anti-seizure effects of the ketogenic diet? Neuropharmacology 2018; 133:233-241. [PMID: 29325899 PMCID: PMC5858992 DOI: 10.1016/j.neuropharm.2018.01.011] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Revised: 11/27/2017] [Accepted: 01/07/2018] [Indexed: 01/01/2023]
Abstract
Although the mechanisms underlying the anti-seizure effects of the high-fat ketogenic diet (KD) remain unclear, a long-standing question has been whether ketone bodies (i.e., β-hydroxybutyrate, acetoacetate and acetone), either alone or in combination, contribute mechanistically. The traditional belief has been that while ketone bodies reflect enhanced fatty acid oxidation and a general shift toward intermediary metabolism, they are not likely to be the key mediators of the KD's clinical effects, as blood levels of β-hydroxybutyrate do not correlate consistently with improved seizure control. Against this unresolved backdrop, new data support ketone bodies as having anti-seizure actions. Specifically, β-hydroxybutyrate has been shown to interact with multiple novel molecular targets such as histone deacetylases, hydroxycarboxylic acid receptors on immune cells, and the NLRP3 inflammasome. Clearly, as a diet-based therapy is expected to render a broad array of biochemical, molecular, and cellular changes, no single mechanism can explain how the KD works. Specific metabolic substrates or enzymes are only a few of many important factors influenced by the KD that can collectively influence brain hyperexcitability and hypersynchrony. This review summarizes recent novel experimental findings supporting the anti-seizure and neuroprotective properties of ketone bodies.
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Affiliation(s)
- Timothy A Simeone
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Kristina A Simeone
- Department of Pharmacology, Creighton University School of Medicine, Omaha, NE, USA
| | - Carl E Stafstrom
- Department of Neurology, and Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jong M Rho
- Department of Pediatrics, Department of Clinical Neurosciences, and Department of Physiology and Pharmacology, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
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Brownlow ML, Jung SH, Moore RJ, Bechmann N, Jankord R. Nutritional Ketosis Affects Metabolism and Behavior in Sprague-Dawley Rats in Both Control and Chronic Stress Environments. Front Mol Neurosci 2017; 10:129. [PMID: 28555095 PMCID: PMC5430035 DOI: 10.3389/fnmol.2017.00129] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 04/18/2017] [Indexed: 12/19/2022] Open
Abstract
Nutritional ketosis may enhance cerebral energy metabolism and has received increased interest as a way to improve or preserve performance and resilience. Most studies to date have focused on metabolic or neurological disorders while anecdotal evidence suggests that ketosis may enhance performance in the absence of underlying dysfunction. Moreover, decreased availability of glucose in the brain following stressful events is associated with impaired cognition, suggesting the need for more efficient energy sources. We tested the hypotheses that ketosis induced by endogenous or exogenous ketones could: (a) augment cognitive outcomes in healthy subjects; and (b) prevent stress-induced detriments in cognitive parameters. Adult, male, Sprague Dawley rats were used to investigate metabolic and behavioral outcomes in 3 dietary conditions: ketogenic (KD), ketone supplemented (KS), or NIH-31 control diet in both control or chronic stress conditions. Acute administration of exogenous ketones resulted in reduction in blood glucose and sustained ketosis. Chronic experiments showed that in control conditions, only KD resulted in pronounced metabolic alterations and improved performance in the novel object recognition test. The hypothalamic-pituitary-adrenal (HPA) axis response revealed that KD-fed rats maintained peripheral ketosis despite increases in glucose whereas no diet effects were observed in ACTH or CORT levels. Both KD and KS-fed rats decreased escape latencies on the third day of water maze, whereas only KD prevented stress-induced deficits on the last testing day and improved probe test performance. Stress-induced decrease in hippocampal levels of β-hydroxybutyrate was attenuated in KD group while both KD and KS prevented stress effects on BDNF levels. Mitochondrial enzymes associated with ketogenesis were increased in both KD and KS hippocampal samples and both endothelial and neuronal glucose transporters were affected by stress but only in the control diet group. Our results highlight the complex relationship between peripheral metabolism, behavioral performance and biochemical changes in the hippocampus. Endogenous ketosis improved behavioral and metabolic parameters associated with energy metabolism and cognition while ketone supplementation replicated the biochemical effects within the hippocampus but only showed modest effects on behavioral improvements.
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Affiliation(s)
- Milene L Brownlow
- Applied Neuroscience Branch, Warfighter Interface Division, Air Force Research Laboratory, Wright-Patterson Air Force BaseDayton, OH, USA.,Research Associateship Program, National Research Council, National Academies of ScienceWashington DC, USA
| | - Seung H Jung
- Applied Neuroscience Branch, Warfighter Interface Division, Air Force Research Laboratory, Wright-Patterson Air Force BaseDayton, OH, USA.,Research Associateship Program, National Research Council, National Academies of ScienceWashington DC, USA
| | - Raquel J Moore
- Applied Neuroscience Branch, Warfighter Interface Division, Air Force Research Laboratory, Wright-Patterson Air Force BaseDayton, OH, USA.,Infoscitex, Inc.Dayton, OH, USA
| | - Naomi Bechmann
- Applied Neuroscience Branch, Warfighter Interface Division, Air Force Research Laboratory, Wright-Patterson Air Force BaseDayton, OH, USA.,Infoscitex, Inc.Dayton, OH, USA
| | - Ryan Jankord
- Applied Neuroscience Branch, Warfighter Interface Division, Air Force Research Laboratory, Wright-Patterson Air Force BaseDayton, OH, USA
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Kawamura MJ, Ruskin DN, Masino SA. Metabolic Therapy for Temporal Lobe Epilepsy in a Dish: Investigating Mechanisms of Ketogenic Diet using Electrophysiological Recordings in Hippocampal Slices. Front Mol Neurosci 2016; 9:112. [PMID: 27847463 PMCID: PMC5088211 DOI: 10.3389/fnmol.2016.00112] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 10/17/2016] [Indexed: 11/13/2022] Open
Abstract
The hippocampus is prone to epileptic seizures and is a key brain region and experimental platform for investigating mechanisms associated with the abnormal neuronal excitability that characterizes a seizure. Accordingly, the hippocampal slice is a common in vitro model to study treatments that may prevent or reduce seizure activity. The ketogenic diet is a metabolic therapy used to treat epilepsy in adults and children for nearly 100 years; it can reduce or eliminate even severe or refractory seizures. New insights into its underlying mechanisms have been revealed by diverse types of electrophysiological recordings in hippocampal slices. Here we review these reports and their relevant mechanistic findings. We acknowledge that a major difficulty in using hippocampal slices is the inability to reproduce precisely the in vivo condition of ketogenic diet feeding in any in vitro preparation, and progress has been made in this in vivo/in vitro transition. Thus far at least three different approaches are reported to reproduce relevant diet effects in the hippocampal slices: (1) direct application of ketone bodies; (2) mimicking the ketogenic diet condition during a whole-cell patch-clamp technique; and (3) reduced glucose incubation of hippocampal slices from ketogenic diet–fed animals. Significant results have been found with each of these methods and provide options for further study into short- and long-term mechanisms including Adenosine triphosphate (ATP)-sensitive potassium (KATP) channels, vesicular glutamate transporter (VGLUT), pannexin channels and adenosine receptors underlying ketogenic diet and other forms of metabolic therapy.
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Affiliation(s)
| | - David N Ruskin
- Department of Psychology and Neuroscience Program, Trinity College Hartford, CT, USA
| | - Susan A Masino
- Department of Psychology and Neuroscience Program, Trinity College Hartford, CT, USA
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