1
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Shaikh I, Bhatt LK. Targeting Adipokines: A Promising Therapeutic Strategy for Epilepsy. Neurochem Res 2024:10.1007/s11064-024-04219-4. [PMID: 39060767 DOI: 10.1007/s11064-024-04219-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 07/17/2024] [Accepted: 07/22/2024] [Indexed: 07/28/2024]
Abstract
Epilepsy affects 65 million people globally and causes neurobehavioral, cognitive, and psychological defects. Although research on the disease is progressing and a wide range of treatments are available, approximately 30% of people have refractory epilepsy that cannot be managed with conventional medications. This underlines the importance of further understanding the condition and exploring cutting-edge targets for treatment. Adipokines are peptides secreted by adipocyte's white adipose tissue, involved in controlling food intake and metabolism. Their regulatory functions in the central nervous system (CNS) are multifaceted and identified in several physiology and pathologies. Adipokines play a role in oxidative stress and neuroinflammation which are associated with brain degeneration and connected neurological diseases. This review aims to highlight the potential impacts of leptin, adiponectin, apelin, vaspin, visfatin, and chimerin in the pathogenesis of epilepsy.
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Affiliation(s)
- Iqraa Shaikh
- Department of Pharmacology, SVKM's Dr. Bhanuben Nanavati College of Pharmacy, Vile Parle (W), Mumbai, India
| | - Lokesh Kumar Bhatt
- Department of Pharmacology, SVKM's Dr. Bhanuben Nanavati College of Pharmacy, Vile Parle (W), Mumbai, India.
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2
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Milanowski J, Kozerawski K, Falęcka W, Dudek D, Lisewska B, Lisewski P, Nuszkiewicz J, Wesołowski R, Wojtasik J, Mila-Kierzenkowska C, Szewczyk-Golec K. Changes in the Secretion of Melatonin and Selected Adipokines during the Progression of Parkinson's Disease-Preliminary Studies. Metabolites 2023; 13:metabo13050668. [PMID: 37233709 DOI: 10.3390/metabo13050668] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 05/16/2023] [Accepted: 05/17/2023] [Indexed: 05/27/2023] Open
Abstract
Parkinson's disease (PD) is one of the most common neurodegenerative diseases affecting elderly people. Considering the gap in the literature on melatonin and adipokine levels in PD patients at various stages of the disease, we conducted a study to investigate the levels of selected parameters in PD patients at the disease's early (ES) and advanced (AS) stages. Melatonin, leptin, adiponectin, and resistin concentrations were measured in the blood serum of 20 PD patients without dyskinesia (ES), 24 PD patients with dyskinesia (AS), and 20 healthy volunteers as a control group (CG). The data were analyzed using ANOVA. Melatonin was significantly lower in ES (p < 0.05) and higher in AS patients (p < 0.05) compared to CG. The level of leptin was increased both in ES (p < 0.001) and AS (p < 0.001) versus CG, while resistin was increased only in patients with dyskinesia (p < 0.05). Higher melatonin (p < 0.001) and resistin (p < 0.05) and lower leptin (p < 0.05) levels were found in AS versus ES. The main findings of the study include the changes in inflammatory markers' levels during PD and a surprising increase in melatonin level in dyskinesia patients. Further research is necessary, which will be aimed at modulating the secretion of melatonin and adipokines as a treatment target for PD.
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Affiliation(s)
- Jan Milanowski
- Students Research Club of Medical Biology, Department of Medical Biology and Biochemistry, Faculty of Medicine, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 85-092 Bydgoszcz, Poland
| | - Kamil Kozerawski
- Students Research Club of Medical Biology, Department of Medical Biology and Biochemistry, Faculty of Medicine, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 85-092 Bydgoszcz, Poland
| | - Weronika Falęcka
- Students Research Club of Medical Biology, Department of Medical Biology and Biochemistry, Faculty of Medicine, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 85-092 Bydgoszcz, Poland
| | - Dominik Dudek
- Students Research Club of Medical Biology, Department of Medical Biology and Biochemistry, Faculty of Medicine, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 85-092 Bydgoszcz, Poland
| | | | | | - Jarosław Nuszkiewicz
- Department of Medical Biology and Biochemistry, Faculty of Medicine, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 85-092 Bydgoszcz, Poland
| | - Roland Wesołowski
- Department of Medical Biology and Biochemistry, Faculty of Medicine, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 85-092 Bydgoszcz, Poland
| | - Jakub Wojtasik
- Centre for Statistical Analysis, Nicolaus Copernicus University in Toruń, Chopina 12/18 St., 87-100 Toruń, Poland
| | - Celestyna Mila-Kierzenkowska
- Department of Medical Biology and Biochemistry, Faculty of Medicine, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 85-092 Bydgoszcz, Poland
| | - Karolina Szewczyk-Golec
- Department of Medical Biology and Biochemistry, Faculty of Medicine, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 85-092 Bydgoszcz, Poland
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3
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Grasso P. Harnessing the Power of Leptin: The Biochemical Link Connecting Obesity, Diabetes, and Cognitive Decline. Front Aging Neurosci 2022; 14:861350. [PMID: 35527735 PMCID: PMC9072663 DOI: 10.3389/fnagi.2022.861350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/21/2022] [Indexed: 12/02/2022] Open
Abstract
In this review, the current understanding of leptin’s role in energy balance, glycemic regulation, and cognitive function is examined, and its involvement in maintaining the homeostatic “harmony” of these physiologies is explored. The effects of exercise on circulating leptin levels are summarized, and the results of clinical application of leptin to metabolic disease and neurologic dysfunction are reviewed. Finally, pre-clinical evidence is presented which suggests that synthetic peptide leptin mimetics may be useful in resolving not only the leptin resistance associated with common obesity and other elements of metabolic syndrome, but also the peripheral insulin resistance characterizing type 2 diabetes mellitus, and the central insulin resistance associated with certain neurologic deficits in humans.
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Affiliation(s)
- Patricia Grasso
- Department of Medicine, Albany Medical College, Albany, NY, United States
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, United States
- *Correspondence: Patricia Grasso,
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4
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Harvey J. Leptin regulation of synaptic function at hippocampal TA-CA1 and SC-CA1 synapses. VITAMINS AND HORMONES 2022; 118:315-336. [PMID: 35180931 DOI: 10.1016/bs.vh.2021.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Increasing evidence indicates that the metabolic hormone, leptin markedly influences the functioning of the hippocampus. In particular, exposure to leptin results in persistent changes in synaptic efficacy at both temporoammonic (TA) and Schaffer Collateral (SC) inputs to hippocampal CA1 neurons. The ability of leptin to regulate TA-CA1 and SC-CA1 synapses has important functional implications, as both synaptic connections play important roles in hippocampal-dependent learning and memory. Here we review the modulatory actions of the hormone leptin at these hippocampal CA1 synapses and explore the impact on learning and memory processes.
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Affiliation(s)
- Jenni Harvey
- Division of Systems Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom.
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5
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David CD, Wyrosdic BN, Wan H, Lapp HE, Bartlett AA, Yitbarek S, Park JH. B6D2F1 mice that retain sexual behavior long term after castration outperform those that cease in the radial arm maze. Psychoneuroendocrinology 2022; 136:105627. [PMID: 34923212 DOI: 10.1016/j.psyneuen.2021.105627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 12/07/2021] [Accepted: 12/09/2021] [Indexed: 11/25/2022]
Abstract
In rodents, gonadal steroids play a critical yet variable role in behaviors such as social interaction and cognitive performance. Gonadal steroids organize sex differences observed in spatial working memory, while the absence of activational effects induced by castration generally impedes spatial learning and memory. Although male sexual behavior is typically inhibited following castration, a significant proportion of gonadectomized B6D2F1 hybrid males retains the complete repertoire of male reproductive behavior. In a prior study, amyloid precursor protein and tau, proteins involved in cognitive behavior, facilitated steroid-independent male sex behavior in B6D2F1 hybrid male mice. We used this strain to investigate the relationship between gonadal steroid-independent male sexual behavior and cognition. After identifying "maters" (animals retaining steroid-independent male sex behavior) and "non-maters," we tested spatial memory in an 8-arm radial arm maze. Although neither group demonstrated a decrease in errors as a function of time, maters committed fewer errors compared to non-maters overall (p < 0.05). Maters also completed the maze more quickly than non-maters (p < 0.05). We measured mRNA expression of APP and MAPT as well as LEPR and D2R to probe potential roles of metabolism and motivation. Uniquely among maters, increased relative expression of D2R and LEPR in the hippocampus was associated with a longer latency to complete the maze during the last 3 or across all trials, respectively. These data demonstrate that maters outperform non-maters in the radial arm maze, warranting further study of potential differences in acquisition of spatial memory tasks or learning strategy between these groups.
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Affiliation(s)
- Caroline D David
- Department of Psychology, University of Massachusetts Boston, Boston, MA 02125, USA.
| | - Brianna N Wyrosdic
- Department of Psychology, University of Massachusetts Boston, Boston, MA 02125, USA
| | - HoYin Wan
- Department of Psychology, University of Massachusetts Boston, Boston, MA 02125, USA
| | - Hannah E Lapp
- Department of Psychology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Andrew A Bartlett
- Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, MA 02478, USA
| | - Shewit Yitbarek
- Department of Psychology, University of Massachusetts Boston, Boston, MA 02125, USA
| | - Jin Ho Park
- Department of Psychology, University of Massachusetts Boston, Boston, MA 02125, USA
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6
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Zarza-Rebollo JA, Molina E, Rivera M. The role of the FTO gene in the relationship between depression and obesity. A systematic review. Neurosci Biobehav Rev 2021; 127:630-637. [PMID: 34019853 DOI: 10.1016/j.neubiorev.2021.05.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 05/12/2021] [Accepted: 05/13/2021] [Indexed: 12/23/2022]
Abstract
Depression and obesity are major global health problems that frequently co-occur. The FTO gene has one of the strongest links with obesity and high body mass index (BMI) in humans. Besides, this gene is highly expressed in the brain, may play a role in the nervous system, and could confer risk for depression, although scarce literature is available in this respect. We perform a systematic review of the relationship between FTO and both conditions. We selected original articles with observational design or reviews, where depression was assessed with ICD-10, DSM-5 or previous versions, published from 2012 (when the first related paper was published) to November 2020, performed in adults, in English or Spanish and having an optimal methodological quality (evaluated with SIGN checklist). Five original studies were finally included. The results regarding the role of FTO in depression-obesity comorbidity were inconclusive. This leads us to endorse further research covering the role of this gene on both conditions, emphasising a more precise characterization of depression, in order to confirm this role.
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Affiliation(s)
- Juan Antonio Zarza-Rebollo
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, University of Granada, Spain; Institute of Neurosciences 'Federico Olóriz', Biomedical Research Centre (CIBM), University of Granada, Spain
| | - Esther Molina
- Institute of Neurosciences 'Federico Olóriz', Biomedical Research Centre (CIBM), University of Granada, Spain; Department of Nursing, Faculty of Health Sciences, University of Granada, Spain.
| | - Margarita Rivera
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, University of Granada, Spain; Institute of Neurosciences 'Federico Olóriz', Biomedical Research Centre (CIBM), University of Granada, Spain
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7
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Irving A, Harvey J. Regulation of hippocampal synaptic function by the metabolic hormone leptin: Implications for health and disease. Prog Lipid Res 2021; 82:101098. [PMID: 33895229 DOI: 10.1016/j.plipres.2021.101098] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 04/16/2021] [Accepted: 04/20/2021] [Indexed: 10/21/2022]
Abstract
Significant advances have been made in our understanding of the hormone, leptin and its CNS actions in recent years. It is now evident that leptin has a multitude of brain functions, that extend beyond its established role in the hypothalamic control of energy balance. Additional brain regions including the hippocampus are important targets for leptin, with a high density of leptin receptors (LepRs) expressed in specific hippocampal regions and localised to CA1 synapses. Extensive evidence indicates that leptin has pro-cognitive actions, as it rapidly modifies synaptic efficacy at excitatory Schaffer collateral (SC)-CA1 and temporoammonic (TA)-CA1 synapses and enhances performance in hippocampal-dependent memory tasks. There is a functional decline in hippocampal responsiveness to leptin with age, with significant reductions in the modulatory effects of leptin at SC-CA1 and TA-CA1 synapses in aged, compared to adult hippocampus. As leptin has pro-cognitive effects, this decline in leptin sensitivity is likely to have negative consequences for cognitive function during the aging process. Here we review how evaluation of the hippocampal actions of leptin has improved our knowledge of the regulatory brain functions of leptin in health and provided significant insight into the impact of leptin in age-related neurodegenerative disorders linked to cognitive decline.
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Affiliation(s)
- Andrew Irving
- School of Biomolecular and Biomedical Science, The Conway Institute, University College Dublin, Dublin, Ireland
| | - Jenni Harvey
- Division of Systems Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, United Kingdom.
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8
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Mansur RB, Subramaniapillai M, Lee Y, Pan Z, Carmona NE, Shekotikhina M, Iacobucci M, Rodrigues N, Nasri F, Rashidian H, Rosenblat JD, Brietzke E, Cosgrove VE, Kramer NE, Suppes T, McIntyre RS. Leptin mediates improvements in cognitive function following treatment with infliximab in adults with bipolar depression. Psychoneuroendocrinology 2020; 120:104779. [PMID: 32603956 DOI: 10.1016/j.psyneuen.2020.104779] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/16/2020] [Accepted: 06/16/2020] [Indexed: 11/18/2022]
Abstract
A potential role for leptin in the pathophysiology of bipolar disorder (BD) has been proposed. We recently investigated the effects of the tumor necrosis factor-alpha (TNF-α) antagonist infliximab in individuals with bipolar depression. Leptin is known to interact with the TNF-α system. Herein, we aimed to explore infliximab's effects on leptin and its relationship with brain structure and function. Sixty adults with bipolar depression were enrolled in this randomized, double-blind, 12-week clinical trial of adjunctive infliximab (n = 29) and saline control (n = 31), which were administered intravenously at weeks 0, 2, and 6. Plasma concentrations of leptin, TNF-α and soluble TNF receptors (sTNFR) 1 and 2 were assessed at weeks 0, 2, 6, and 12. We observed a significant decrease in leptin levels in infliximab-treated patients, relative to placebo. Infliximab treatment also significantly reduced TNF-α and sTNFR2, but not sTNFR1 levels. Changes in sTNR2 levels at week 6 significantly determined changes in leptin at week 12 in infliximab-, but not placebo-treated participants. Improvements in verbal memory and increases in global cortical volume were associated with reduction in leptin levels in the treatment group. Mediation analysis indicated that cognitive improvement in infliximab-treated patients was mediated by reductions in leptin levels, which in its turn were determined by decreases in sTNR2 levels. In conclusion, infliximab treatment reduced plasma leptin levels in individuals with BD, through modulation of sTNFR2. Decreases in leptin signaling were associated with an increase in global cortical volume and better performance in a verbal memory task.
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Affiliation(s)
- Rodrigo B Mansur
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada.
| | | | - Yena Lee
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, ON, Canada; Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Zihang Pan
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, ON, Canada
| | - Nicole E Carmona
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, ON, Canada; Department of Psychology, Ryerson University, Toronto, ON, Canada
| | - Margarita Shekotikhina
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, ON, Canada; University of Ottawa, Department of Psychiatry, Ottawa, ON, Canada
| | - Michelle Iacobucci
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, ON, Canada
| | - Nelson Rodrigues
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, ON, Canada
| | - Flora Nasri
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, ON, Canada
| | - Houman Rashidian
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Joshua D Rosenblat
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Elisa Brietzke
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, ON, Canada; Kingston General Hospital, Providence Care Hospital, Department of Psychiatry, Queen's University School of Medicine, Kingston, ON, Canada
| | - Victoria E Cosgrove
- Department of Psychiatry & Behavioral Sciences, Stanford University, School of Medicine, Palo Alto, CA, USA
| | - Nicole E Kramer
- Department of Psychiatry & Behavioral Sciences, Stanford University, School of Medicine, Palo Alto, CA, USA
| | - Trisha Suppes
- Department of Psychiatry & Behavioral Sciences, Stanford University, School of Medicine, Palo Alto, CA, USA
| | - Roger S McIntyre
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada; Institute of Medical Science, University of Toronto, Toronto, ON, Canada
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9
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Effects of intrahippocampal injection of Leptin on seizure-induced cognitive impairment in male rats. LEARNING AND MOTIVATION 2020. [DOI: 10.1016/j.lmot.2020.101612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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10
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Cortés-Álvarez NY, Vuelvas-Olmos CR, Pinto-González MF, Guzmán-Muñiz J, Gonzalez-Perez O, Moy-López NA. A high-fat diet during pregnancy impairs memory acquisition and increases leptin receptor expression in the hippocampus of rat offspring. Nutr Neurosci 2020; 25:146-158. [DOI: 10.1080/1028415x.2020.1728473] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Nadia Yanet Cortés-Álvarez
- Laboratory of Neuroscience, School of Psychology, University of Colima, Colima, Mexico
- Medical Sciences Program, School of Medicine, University of Colima, Colima, Mexico
| | - César Rubén Vuelvas-Olmos
- Laboratory of Neuroscience, School of Psychology, University of Colima, Colima, Mexico
- Medical Sciences Program, School of Medicine, University of Colima, Colima, Mexico
| | - María Fernanda Pinto-González
- Laboratory of Neuroscience, School of Psychology, University of Colima, Colima, Mexico
- Medical Sciences Program, School of Medicine, University of Colima, Colima, Mexico
| | - Jorge Guzmán-Muñiz
- Laboratory of Neuroscience, School of Psychology, University of Colima, Colima, Mexico
| | - Oscar Gonzalez-Perez
- Laboratory of Neuroscience, School of Psychology, University of Colima, Colima, Mexico
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11
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Bland T, Zhu M, Dillon C, Sahin GS, Rodriguez-Llamas JL, Appleyard SM, Wayman GA. Leptin Controls Glutamatergic Synaptogenesis and NMDA-Receptor Trafficking via Fyn Kinase Regulation of NR2B. Endocrinology 2020; 161:5678106. [PMID: 31840160 PMCID: PMC7015580 DOI: 10.1210/endocr/bqz030] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 12/10/2019] [Indexed: 01/13/2023]
Abstract
Activation of the leptin receptor, LepRb, by the adipocytokine/neurotrophic factor leptin in the central nervous system has procognitive and antidepressive effects. Leptin has been shown to increase glutamatergic synaptogenesis in multiple brain regions. In contrast, mice that have a mutation in the LepRb gene show abnormal synapse development in the hippocampus as well as deficits in cognition and increased depressive-like symptoms. Leptin increases glutamatergic synaptogenesis, in part, through enhancement of N-methyl-D-aspartic acid (NMDA) receptor function; yet the underlying signaling pathway is not known. In this study, we examine how leptin regulates surface expression of NR2B-containing NMDA receptors in hippocampal neurons. Leptin stimulation increases NR2BY1472 phosphorylation, which is inhibited by the Src family kinase inhibitor, PP1. Moreover, we show that Fyn, a member of the Src family kinases, is required for leptin-stimulated NR2BY1472 phosphorylation. Furthermore, inhibiting Y1472 phosphorylation with either a dominant negative Fyn mutant or an NR2B mutant that lacks the phosphorylation site (NR2BY1472F) blocks leptin-stimulated synaptogenesis. Additionally, we show that LepRb forms a complex with NR2B and Fyn. Taken together, these findings expand our knowledge of the LepRb interactome and the mechanisms by which leptin stimulates glutamatergic synaptogenesis in the developing hippocampus. Comprehending these mechanisms is key for understanding dendritic spine development and synaptogenesis, alterations of which are associated with many neurological disorders.
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Affiliation(s)
- Tyler Bland
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington
| | - Mingyan Zhu
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington
| | - Crystal Dillon
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington
| | - Gulcan Semra Sahin
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington
| | - Jose Luis Rodriguez-Llamas
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington
| | - Suzanne M Appleyard
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington
| | - Gary A Wayman
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington
- Correspondence: Gary A. Wayman, Department of Integrative Physiology and Neuroscience, Program in Neuroscience, Washington State University, Pullman Washington 99164. E-mail:
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12
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Bland T, Sahin GS, Zhu M, Dillon C, Impey S, Appleyard SM, Wayman GA. USP8 Deubiquitinates the Leptin Receptor and Is Necessary for Leptin-Mediated Synapse Formation. Endocrinology 2019; 160:1982-1998. [PMID: 31199479 PMCID: PMC6660906 DOI: 10.1210/en.2019-00107] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 06/08/2019] [Indexed: 11/19/2022]
Abstract
Leptin has neurotrophic actions in the hippocampus to increase synapse formation and stimulate neuronal plasticity. Leptin also enhances cognition and has antidepressive and anxiolytic-like effects, two hippocampal-dependent behaviors. In contrast, mice lacking leptin or the long form of the leptin receptor (LepRb) have lower cortical volume and decreased memory and exhibit depressive-like behaviors. A number of the signaling pathways regulated by LepRb are known, but how membrane LepRb levels are regulated in the central nervous system is not well understood. Here, we show that the lysosomal inhibitor chloroquine increases LepRb expression in hippocampal cultures, suggesting that LepRb is degraded in the lysosome. Furthermore, we show that leptin increases surface expression of its own receptor by decreasing the level of ubiquitinated LepRbs. This decrease is mediated by the deubiquitinase ubiquitin-specific protease 8 (USP8), which we show is in complex with LepRb. Acute leptin stimulation increases USP8 activity. Moreover, leptin stimulates USP8 gene expression through cAMP response element-binding protein (CREB)-dependent transcription, an effect blocked by expression of a dominant-negative CREB or with short hairpin RNA knockdown of CREB. Increased expression of USP8 causes increased surface localization of LepRb, which in turn enhances leptin-mediated activation of the MAPK kinase/extracellular signal-regulated kinase pathway and CREB activation. Lastly, increased USP8 expression increases glutamatergic synapse formation in hippocampal cultures, an effect dependent on expression of LepRbs. Leptin-stimulated synapse formation also requires USP8. In conclusion, we show that USP8 deubiquitinates LepRb, thus inhibiting lysosomal degradation and enhancing surface localization of LepRb, which are essential for leptin-stimulated synaptogenesis in the hippocampus.
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Affiliation(s)
- Tyler Bland
- Department of Integrated Physiology and Neuroscience, Washington State University, Pullman, Washington
| | - Gulcan Semra Sahin
- Department of Integrated Physiology and Neuroscience, Washington State University, Pullman, Washington
| | - Mingyan Zhu
- Department of Integrated Physiology and Neuroscience, Washington State University, Pullman, Washington
| | - Crystal Dillon
- Department of Integrated Physiology and Neuroscience, Washington State University, Pullman, Washington
| | - Soren Impey
- Oregon Stem Cell Center, Oregon Health and Sciences University, Portland, Oregon
| | - Suzanne M Appleyard
- Department of Integrated Physiology and Neuroscience, Washington State University, Pullman, Washington
| | - Gary A Wayman
- Department of Integrated Physiology and Neuroscience, Washington State University, Pullman, Washington
- Correspondence: Gary A. Wayman, PhD, Department of Integrative Physiology and Neuroscience, Program in Neuroscience, Washington State University, Pullman, Washington 99164. E-mail:
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13
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Suarez AN, Noble EE, Kanoski SE. Regulation of Memory Function by Feeding-Relevant Biological Systems: Following the Breadcrumbs to the Hippocampus. Front Mol Neurosci 2019; 12:101. [PMID: 31057368 PMCID: PMC6482164 DOI: 10.3389/fnmol.2019.00101] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 04/03/2019] [Indexed: 12/15/2022] Open
Abstract
The hippocampus (HPC) controls fundamental learning and memory processes, including memory for visuospatial navigation (spatial memory) and flexible memory for facts and autobiographical events (declarative memory). Emerging evidence reveals that hippocampal-dependent memory function is regulated by various peripheral biological systems that are traditionally known for their roles in appetite and body weight regulation. Here, we argue that these effects are consistent with a framework that it is evolutionarily advantageous to encode and recall critical features surrounding feeding behavior, including the spatial location of a food source, social factors, post-absorptive processing, and other episodic elements of a meal. We review evidence that gut-to-brain communication from the vagus nerve and from feeding-relevant endocrine systems, including ghrelin, insulin, leptin, and glucagon-like peptide-1 (GLP-1), promote hippocampal-dependent spatial and declarative memory via neurotrophic and neurogenic mechanisms. The collective literature reviewed herein supports a model in which various stages of feeding behavior and hippocampal-dependent memory function are closely linked.
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Affiliation(s)
| | | | - Scott E. Kanoski
- Human and Evolutionary Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, United States
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McGregor G, Harvey J. Leptin Regulation of Synaptic Function at Hippocampal TA-CA1 and SC-CA1 Synapses: Implications for Health and Disease. Neurochem Res 2019; 44:650-660. [PMID: 28819795 PMCID: PMC6420429 DOI: 10.1007/s11064-017-2362-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 07/05/2017] [Accepted: 07/21/2017] [Indexed: 12/16/2022]
Abstract
Growing evidence indicates that the endocrine hormone leptin regulates hippocampal synaptic function in addition to its established role as a hypothalamic satiety signal. Indeed, numerous studies show that leptin facilitates the cellular events that underlie hippocampal learning and memory including activity-dependent synaptic plasticity and glutamate receptor trafficking, indicating that leptin may be a potential cognitive enhancer. Although there has been extensive investigation into the modulatory role of leptin at hippocampal Schaffer collateral (SC)-CA1 synapses, recent evidence indicates that leptin also potently regulates excitatory synaptic transmission at the anatomically distinct temporoammonic (TA) input to hippocampal CA1 neurons. The cellular mechanisms underlying activity-dependent synaptic plasticity at TA-CA1 synapses differ from those at SC-CA1 synapses and the TA input is implicated in spatial and episodic memory formation. Furthermore, the TA input is an early target for neurodegeneration in Alzheimer's disease (AD) and aberrant leptin function is linked to AD. Here, we review the evidence that leptin regulates hippocampal synaptic function at both SC- and TA-CA1 synapses and discuss the consequences for neurodegenerative disorders like AD.
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Affiliation(s)
- Gemma McGregor
- Division of Neuroscience, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, DD1 9SY, UK
| | - Jenni Harvey
- Division of Neuroscience, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, DD1 9SY, UK.
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15
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McGregor G, Clements L, Farah A, Irving AJ, Harvey J. Age-dependent regulation of excitatory synaptic transmission at hippocampal temporoammonic-CA1 synapses by leptin. Neurobiol Aging 2018; 69:76-93. [PMID: 29860205 PMCID: PMC6075472 DOI: 10.1016/j.neurobiolaging.2018.05.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 04/17/2018] [Accepted: 05/04/2018] [Indexed: 12/15/2022]
Abstract
The hippocampus is a key target for the hormone leptin and leptin regulation of excitatory synaptic transmission at Schaffer-collateral-CA1 synapses during aging are well documented. However, little is known about the age-dependent actions of leptin at the temporoammonic (TA) input to CA1 neurons. Here we show that leptin induces a novel form of N-methyl-D-aspartate receptor-dependent long-term depression (LTD) at adult (12-24 weeks old) TA-CA1 synapses. Leptin-induced LTD requires activation of canonical Janus tyrosine kinase 2- signal transducer and activator of transcription signaling and removal of GluA1-containing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors from synapses. Moreover, leptin-induced LTD is occluded by activity-dependent LTD at TA-CA1 synapses. By contrast, leptin has no effect on excitatory synaptic transmission at aged (12-14 months old) TA-CA1 synapses, and low-frequency stimulation also fails to induce LTD at this age. These findings demonstrate clear age-related alterations in the leptin sensitivity of TA-CA1 synapses and provide valuable information on how the leptin system alters with age. As leptin has been linked to Alzheimer's disease, these findings have important implications for understanding of age-related disorders such as Alzheimer's disease.
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Affiliation(s)
- Gemma McGregor
- Division of Neuroscience, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
| | - Leigh Clements
- Division of Neuroscience, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
| | - Adham Farah
- Division of Neuroscience, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
| | - Andrew J Irving
- School of Biomolecular and Biomedical Science, The Conway Institute, University College Dublin, Dublin, Ireland
| | - Jenni Harvey
- Division of Neuroscience, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK.
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16
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Perissinotti PP, Rivero-Echeto MC, Garcia-Rill E, Bisagno V, Urbano FJ. Leptin alters somatosensory thalamic networks by decreasing gaba release from reticular thalamic nucleus and action potential frequency at ventrobasal neurons. Brain Struct Funct 2018. [PMID: 29520482 DOI: 10.1007/s00429-018-1645-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Leptin is an adipose-derived hormone that controls appetite and energy expenditure. Leptin receptors are expressed on extra-hypothalamic ventrobasal (VB) and reticular thalamic (RTN) nuclei from embryonic stages. Here, we studied the effects of pressure-puff, local application of leptin on both synaptic transmission and action potential properties of thalamic neurons in thalamocortical slices. We used whole-cell patch-clamp recordings of thalamocortical VB neurons from wild-type (WT) and leptin-deficient obese (ob/ob) mice. We observed differences in VB neurons action potentials and synaptic currents kinetics when comparing WT vs. ob/ob. Leptin reduced GABA release onto VB neurons throughout the activation of a JAK2-dependent pathway, without affecting excitatory glutamate transmission. We observed a rapid and reversible reduction by leptin of the number of action potentials of VB neurons via the activation of large conductance Ca2+-dependent potassium channels. These leptin effects were observed in thalamocortical slices from up to 5-week-old WT but not in leptin-deficient obese mice. Results described here suggest the existence of a leptin-mediated trophic modulation of thalamocortical excitability during postnatal development. These findings could contribute to a better understanding of leptin within the thalamocortical system and sleep deficits in obesity.
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Affiliation(s)
- Paula P Perissinotti
- Departamento de Fisiología, Facultad de Ciencias Exactas y Naturales, Biología Molecular y Celular "Dr. Héctor Maldonado", Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET-Universidad de Buenos Aires, Intendente Güiraldes 2160, Ciudad Universitaria, C1428EGA, Ciudad Autónoma de Buenos Aires, Argentina
| | - María Celeste Rivero-Echeto
- Departamento de Fisiología, Facultad de Ciencias Exactas y Naturales, Biología Molecular y Celular "Dr. Héctor Maldonado", Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET-Universidad de Buenos Aires, Intendente Güiraldes 2160, Ciudad Universitaria, C1428EGA, Ciudad Autónoma de Buenos Aires, Argentina
| | - Edgar Garcia-Rill
- Department of Neurobiology and Developmental Sciences, Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Verónica Bisagno
- Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina
- Instituto de Investigaciones Farmacológicas (ININFA), CONICET-Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina
| | - Francisco J Urbano
- Departamento de Fisiología, Facultad de Ciencias Exactas y Naturales, Biología Molecular y Celular "Dr. Héctor Maldonado", Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina.
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET-Universidad de Buenos Aires, Intendente Güiraldes 2160, Ciudad Universitaria, C1428EGA, Ciudad Autónoma de Buenos Aires, Argentina.
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17
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Peineau S, Rabiant K, Pierrefiche O, Potier B. Synaptic plasticity modulation by circulating peptides and metaplasticity: Involvement in Alzheimer's disease. Pharmacol Res 2018; 130:385-401. [PMID: 29425728 DOI: 10.1016/j.phrs.2018.01.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 01/23/2018] [Accepted: 01/26/2018] [Indexed: 10/18/2022]
Abstract
Synaptic plasticity is a cellular process involved in learning and memory whose alteration in its two main forms (Long Term Depression (LTD) and Long Term Potentiation (LTP)), is observed in most brain pathologies, including neurodegenerative disorders such as Alzheimer's disease (AD). In humans, AD is associated at the cellular level with neuropathological lesions composed of extracellular deposits of β-amyloid (Aβ) protein aggregates and intracellular neurofibrillary tangles, cellular loss, neuroinflammation and a general brain homeostasis dysregulation. Thus, a dramatic synaptic environment perturbation is observed in AD patients, involving changes in brain neuropeptides, cytokines, growth factors or chemokines concentration and diffusion. Studies performed in animal models demonstrate that these circulating peptides strongly affect synaptic functions and in particular synaptic plasticity. Besides this neuromodulatory action of circulating peptides, other synaptic plasticity regulation mechanisms such as metaplasticity are altered in AD animal models. Here, we will review new insights into the study of synaptic plasticity regulatory/modulatory mechanisms which could influence the process of synaptic plasticity in the context of AD with a particular attention to the role of metaplasticity and peptide dependent neuromodulation.
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Affiliation(s)
- Stéphane Peineau
- GRAP UMR1247, INSERM, Centre Universitaire de Recherche en Santé, Université de Picardie Jules Verne, Amiens, France; Centre for Synaptic Plasticity, School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, UK.
| | - Kevin Rabiant
- GRAP UMR1247, INSERM, Centre Universitaire de Recherche en Santé, Université de Picardie Jules Verne, Amiens, France
| | - Olivier Pierrefiche
- GRAP UMR1247, INSERM, Centre Universitaire de Recherche en Santé, Université de Picardie Jules Verne, Amiens, France.
| | - Brigitte Potier
- Laboratoire Aimé Cotton, CNRS-ENS UMR9188, Université Paris-Sud, Orsay, France.
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18
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Pousti F, Ahmadi R, Mirahmadi F, Hosseinmardi N, Rohampour K. Adiponectin modulates synaptic plasticity in hippocampal dentate gyrus. Neurosci Lett 2017; 662:227-232. [PMID: 29079430 DOI: 10.1016/j.neulet.2017.10.042] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Revised: 10/17/2017] [Accepted: 10/20/2017] [Indexed: 12/15/2022]
Abstract
Recent studies have suggested the involvement of some metabolic hormones in memory formation and synaptic plasticity. Insulin dysfunction is known as an essential process in the pathogenesis of sporadic Alzheimer's disease (AD). In this study we examined whether adiponectin (ADN), as an insulin-sensitizing adipokine, could affect hippocampal synaptic plasticity. Field potential recordings were performed on intracerebroventricular (icv) cannulated urethane anesthetized rats. After baseline recording from dentate gyrus (DG) and 10min prior to high/low frequency stimulation (HFS/LFS), 10μl icv ADN (600nm) were injected. The slope of field excitatory postsynaptic potentials (fEPSP) and the amplitude of population spikes (PS) were recorded in response to perforanth path (PP) stimulation. Paired pulse stimuli and ADN injection without any stimulation protocols were also evaluated. Application of ADN before HFS increased PS amplitude recorded in DG significantly (P≤0.05) in comparison to HFS only group. ADN suppressed the potency of LFS to induce long-term depression (LTD), causing a significant difference between fEPSP slope (P≤0.05) and PS amplitude (P≤0.01) between ADN+LFS and ADN group. Paired pulse stimuli applied at 20ms intervals showed more paired pulse facilitation (PPF), when applied after ADN (P≤0.05). ADN induced a chemical long-term potentiation (LTP) in which fEPSP slope and PS amplitude increased significantly (P≤0.01 and P≤0.05, respectively). It is concluded that ADN is able to potentiate the HFS-induced LTP and suppress LFS-induced LTD. ADN caused a chemical LTP, when applied without any tetanic protocol. ADN may enhance the presynaptic release probability.
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Affiliation(s)
- Farideh Pousti
- Department of Biology, Islamic Azad University, Qom Branch, Qom, Iran
| | - Ramesh Ahmadi
- Department of Biology, Islamic Azad University, Qom Branch, Qom, Iran
| | - Fatemeh Mirahmadi
- Department of Biology, Islamic Azad University, Qom Branch, Qom, Iran
| | - Narges Hosseinmardi
- Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Kambiz Rohampour
- Cellular and Molecular Research Center, Qom University of Medical Sciences, Qom, Iran.
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19
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20
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Van Doorn C, Macht VA, Grillo CA, Reagan LP. Leptin resistance and hippocampal behavioral deficits. Physiol Behav 2017; 176:207-213. [PMID: 28267584 PMCID: PMC10538552 DOI: 10.1016/j.physbeh.2017.03.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 03/02/2017] [Accepted: 03/02/2017] [Indexed: 01/05/2023]
Abstract
The adipocyte-derived hormone leptin is an important regulator of body weight and metabolism through activation of brain leptin receptors expressed in regions such as the hypothalamus. Beyond these well described and characterized activities of leptin in the hypothalamus, it is becoming increasingly clear that the central activities of leptin extend to the hippocampus. Indeed, leptin receptors are expressed in the hippocampus where these receptors are proposed to mediate various aspects of hippocampal synaptic plasticity that ultimately impact cognitive function. This concept is supported by studies demonstrating that leptin promotes hippocampal-dependent learning and memory, as well as studies indicating that leptin resistance is associated with deficits in hippocampal-dependent behaviors and in the induction of depressive-like behaviors. The effects of leptin on cognitive/behavioral plasticity in the hippocampus may be regulated by direct activation of leptin receptors expressed in the hippocampus; additionally, leptin-mediated activation of synaptic networks that project to the hippocampus may also impact hippocampal-mediated behaviors. In view of these previous observations, the goal of this review will be to discuss the mechanisms through which leptin facilitates cognition and behavior, as well as to dissect the loci at which leptin resistance leads to impairments in hippocampal synaptic plasticity, including the development of cognitive deficits and increased risk of depressive illness in metabolic disorders such as obesity and type 2 diabetes mellitus (T2DM).
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Affiliation(s)
- Catherine Van Doorn
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC 29208, United States
| | - Victoria A Macht
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC 29208, United States
| | - Claudia A Grillo
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC 29208, United States
| | - Lawrence P Reagan
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC 29208, United States; W.J.B. Dorn VA Medical Center, Columbia, SC 29208, United States.
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21
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Letra L, Santana I. The Influence of Adipose Tissue on Brain Development, Cognition, and Risk of Neurodegenerative Disorders. ADVANCES IN NEUROBIOLOGY 2017; 19:151-161. [PMID: 28933064 DOI: 10.1007/978-3-319-63260-5_6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The brain is a highly metabolic organ and thus especially vulnerable to changes in peripheral metabolism, including those induced by obesity-associated adipose tissue dysfunction. In this context, it is likely that the development and maturation of neurocognitive circuits may also be affected and modulated by metabolic environmental factors, beginning in utero. It is currently recognized that maternal obesity, either pre-gestational or gestational, negatively influences fetal brain development and elevates the risk of cognitive impairment and neuropsychiatric disorders in the offspring. During infancy and adolescence, obesity remains a limiting factor for healthy neurodevelopment, especially affecting executive functions but also attention, visuospatial ability, and motor skills. In middle age, obesity seems to induce an accelerated brain aging and thus may increase the risk of age-related neurodegenerative diseases such as Alzheimer's disease. In this chapter we review and discuss experimental and clinical evidence focusing on the influence of adipose tissue dysfunction on neurodevelopment and cognition across lifespan, as well as some possible mechanistic links, namely the role of the most well studied adipokines.
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Affiliation(s)
- Liliana Letra
- Institute of Physiology, Institute for Biomedical Imaging and Life Sciences-IBILI, Faculty of Medicine, University of Coimbra, Coimbra, Portugal. .,Neurology Department, Centro Hospitalar do Baixo Vouga, Aveiro, Portugal.
| | - Isabel Santana
- Neurology Department, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
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22
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Salameh TS, Rhea EM, Banks WA, Hanson AJ. Insulin resistance, dyslipidemia, and apolipoprotein E interactions as mechanisms in cognitive impairment and Alzheimer's disease. Exp Biol Med (Maywood) 2016; 241:1676-83. [PMID: 27470930 PMCID: PMC4999626 DOI: 10.1177/1535370216660770] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
An increased risk for Alzheimer's disease is associated with dyslipidemia and insulin resistance. A separate literature shows the genetic risk for developing Alzheimer's disease is strongly correlated to the presence of the E4 isoform of the apolipoprotein E carrier protein. Understanding how apolipoprotein E carrier protein, lipids, amyloid β peptides, glucose, central nervous system insulin, and peripheral insulin interact with one another in Alzheimer's disease is an area of increasing interest. Here, we will review the evidence relating apolipoprotein E carrier protein, lipids, and insulin action to Alzheimer's disease and Aβ peptides and then propose mechanisms as to how these factors might interact with one another to impair cognition and promote Alzheimer's disease.
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Affiliation(s)
- Therese S Salameh
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Elizabeth M Rhea
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - William A Banks
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Angela J Hanson
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
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23
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Azab SF, Abdalhady MA, Almalky MAA, Amin EK, Sarhan DT, Elhindawy EM, Allah MAN, Elhewala AA, Salam MMA, Hashem MIA, Soliman AA, Akeel NE, Abdellatif SH, Elsamad NA, Rass AA, Arafat MS. Serum and CSF adiponectin, leptin, and interleukin 6 levels as adipocytokines in Egyptian children with febrile seizures: a cross-sectional study. Ital J Pediatr 2016; 42:38. [PMID: 27068222 PMCID: PMC4828849 DOI: 10.1186/s13052-016-0250-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 04/04/2016] [Indexed: 12/20/2022] Open
Abstract
Background A febrile seizure (FS) is the most common convulsive disorder in children. Activation of cytokine network is involved in FS pathogenesis. Adiponectin, leptin and IL-6 are the major adipocytokines secreted by fat cells. To date, only a few studies concerned the association of adipocytokines with febrile seizures. In this study, we tried to investigate serum and CSF levels of adiponectin, leptin, and interleukin-6 (IL-6); as adipocytokines, for the first time in Egyptian children with febrile seizures. Methods This was a prospective cross-sectional study included one hundred patients with febrile seizure, and matched with age, gender, 100 children with febrile illness without seizures (febrile control, FC) and 100 healthy control group (HC). Serum and cerebrospinal fluid (CSF) levels of adiponectin, leptin, and (IL-6) were measured by enzyme-linked immunosorbent assay (ELISA) method. Results Serum adiponectin was significantly higher in children with FS (16.8 ± 3.7 ug/ml) and the FC group (18.3 ± 4.3 ug/ml) compared to the HC group (9.5 ± 2.2 ug/ml); P < 0.05, respectively. Serum leptin was significantly lower in children with FS (0.9 ± 0.3 ng/ml) compared to both the FC group (4.7 ± 1.2 ng/ml) and the HC group (1.8 ± 0.4 ng/ml); P < 0.01, respectively. Children with FS had significantly higher serum IL-6 levels (43.7 ± 11.7 ng/ml) than the FC group (21.9 ± 4.5 ng/ml) and the HC group (6.5 ± 1.8 ng/ml); P < 0.01, respectively. Patients with simple febrile seizures (SFS) had serum and CSF adiponectin levels similar to those with complex febrile seizures (CFS); (P > 0.05). Serum and CSF leptin levels were significantly lower in patients with CFS compared to the SFS group (P < 0.05). Serum and CSF IL-6 levels were significantly higher in patients with CFS compared to the SFS group (P < 0.01). On multivariate logistic regression analysis, the high serum IL-6 levels was the most significant risk factor associated with febrile seizures among studied children (OR: 6.2; 95 % CI: 3.58 –10.57; P = 0.0001). Conclusion Our data brought a novel observation that some adipocytokines like leptin and IL-6 could be, at least in part, an aetiopathogenetic factor in the manifestation of febrile seizures in susceptible Egyptian children. Moreover, we observed a significant association between high CSF IL-6 levels and susceptibility to complex febrile seizures as did the low CSF leptin levels.
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Affiliation(s)
- Seham F Azab
- Faculty of Medicine, Zagazig University, 18 Omar Bin Elkhattab St, Al Qawmia, Zagazig City, AlSharqia Governorate, Egypt.
| | - Mohamed A Abdalhady
- Faculty of Medicine, Zagazig University, 18 Omar Bin Elkhattab St, Al Qawmia, Zagazig City, AlSharqia Governorate, Egypt
| | - Mohamed A A Almalky
- Faculty of Medicine, Zagazig University, 18 Omar Bin Elkhattab St, Al Qawmia, Zagazig City, AlSharqia Governorate, Egypt
| | - Ezzat K Amin
- Faculty of Medicine, Zagazig University, 18 Omar Bin Elkhattab St, Al Qawmia, Zagazig City, AlSharqia Governorate, Egypt
| | - Dina T Sarhan
- Faculty of Medicine, Zagazig University, 18 Omar Bin Elkhattab St, Al Qawmia, Zagazig City, AlSharqia Governorate, Egypt
| | - Eman M Elhindawy
- Faculty of Medicine, Zagazig University, 18 Omar Bin Elkhattab St, Al Qawmia, Zagazig City, AlSharqia Governorate, Egypt
| | - Mayy A N Allah
- Faculty of Medicine, Zagazig University, 18 Omar Bin Elkhattab St, Al Qawmia, Zagazig City, AlSharqia Governorate, Egypt
| | - Ahmed A Elhewala
- Faculty of Medicine, Zagazig University, 18 Omar Bin Elkhattab St, Al Qawmia, Zagazig City, AlSharqia Governorate, Egypt
| | - Mohamed M A Salam
- Faculty of Medicine, Zagazig University, 18 Omar Bin Elkhattab St, Al Qawmia, Zagazig City, AlSharqia Governorate, Egypt
| | - Mustafa I A Hashem
- Faculty of Medicine, Zagazig University, 18 Omar Bin Elkhattab St, Al Qawmia, Zagazig City, AlSharqia Governorate, Egypt
| | - Attia A Soliman
- Faculty of Medicine, Zagazig University, 18 Omar Bin Elkhattab St, Al Qawmia, Zagazig City, AlSharqia Governorate, Egypt
| | - Nagwa E Akeel
- Faculty of Medicine, Zagazig University, 18 Omar Bin Elkhattab St, Al Qawmia, Zagazig City, AlSharqia Governorate, Egypt
| | - Sawsan H Abdellatif
- Faculty of Medicine, Zagazig University, 18 Omar Bin Elkhattab St, Al Qawmia, Zagazig City, AlSharqia Governorate, Egypt
| | - Nahla A Elsamad
- Faculty of Medicine, Zagazig University, 18 Omar Bin Elkhattab St, Al Qawmia, Zagazig City, AlSharqia Governorate, Egypt
| | - Anwar A Rass
- Faculty of Medicine, Zagazig University, 18 Omar Bin Elkhattab St, Al Qawmia, Zagazig City, AlSharqia Governorate, Egypt
| | - Manal S Arafat
- M.D. Clinical Pathology, Mansoura Student Hospital, Mansoura, Egypt
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Gavello D, Carbone E, Carabelli V. Leptin-mediated ion channel regulation: PI3K pathways, physiological role, and therapeutic potential. Channels (Austin) 2016; 10:282-96. [PMID: 27018500 DOI: 10.1080/19336950.2016.1164373] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Leptin is produced by adipose tissue and identified as a "satiety signal," informing the brain when the body has consumed enough food. Specific areas of the hypothalamus express leptin receptors (LEPRs) and are the primary site of leptin action for body weight regulation. In response to leptin, appetite is suppressed and energy expenditure allowed. Beside this hypothalamic action, leptin targets other brain areas in addition to neuroendocrine cells. LEPRs are expressed also in the hippocampus, neocortex, cerebellum, substantia nigra, pancreatic β-cells, and chromaffin cells of the adrenal gland. It is intriguing how leptin is able to activate different ionic conductances, thus affecting excitability, synaptic plasticity and neurotransmitter release, depending on the target cell. Most of the intracellular pathways activated by leptin and directed to ion channels involve PI3K, which in turn phosphorylates different downstream substrates, although parallel pathways involve AMPK and MAPK. In this review we will describe the effects of leptin on BK, KATP, KV, CaV, TRPC, NMDAR and AMPAR channels and clarify the landscape of pathways involved. Given the ability of leptin to influence neuronal excitability and synaptic plasticity by modulating ion channels activity, we also provide a short overview of the growing potentiality of leptin as therapeutic agent for treating neurological disorders.
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Affiliation(s)
- Daniela Gavello
- a Department of Drug Science , Lab of Cellular Physiology and Molecular Neuroscience, NIS Center of Excellence, University of Torino , Torino , Italy
| | - Emilio Carbone
- a Department of Drug Science , Lab of Cellular Physiology and Molecular Neuroscience, NIS Center of Excellence, University of Torino , Torino , Italy
| | - Valentina Carabelli
- a Department of Drug Science , Lab of Cellular Physiology and Molecular Neuroscience, NIS Center of Excellence, University of Torino , Torino , Italy
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25
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McGregor G, Malekizadeh Y, Harvey J. Minireview: Food for thought: regulation of synaptic function by metabolic hormones. Mol Endocrinol 2016; 29:3-13. [PMID: 25470238 DOI: 10.1210/me.2014-1328] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The peripheral actions of the metabolic hormones, leptin and insulin, are well documented. However, the functions of these hormones are not restricted to the periphery because evidence is growing that both leptin and insulin can readily cross the blood-brain barrier and have widespread central actions. The hippocampus in particular expresses high levels of both insulin and leptin receptors as well as key components of their associated signaling cascades. Moreover, recent studies indicate that both hormones are potential cognitive enhancers. Indeed, it has been demonstrated that both leptin and insulin markedly influence key cellular events that underlie hippocampal learning and memory including activity-dependent synaptic plasticity and the trafficking of glutamate receptors to and away from hippocampal synapses. The hippocampal formation is also a prime site for the neurodegenerative processes that occur during Alzheimer's disease, and impairments in either leptin or insulin function have been linked to central nervous system-driven diseases like Alzheimer's disease. Thus, the capacity of the metabolic hormones, leptin and insulin, to regulate hippocampal synaptic function has significant implications for normal brain function and also central nervous system-driven disease.
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Affiliation(s)
- Gemma McGregor
- Division of Neuroscience, Medical Research Institute, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, United Kingdom
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McGuire MJ, Ishii M. Leptin Dysfunction and Alzheimer's Disease: Evidence from Cellular, Animal, and Human Studies. Cell Mol Neurobiol 2016; 36:203-17. [PMID: 26993509 DOI: 10.1007/s10571-015-0282-7] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 10/01/2015] [Indexed: 12/13/2022]
Abstract
There is accumulating evidence from epidemiological studies that changes in body weight are associated with Alzheimer's disease (AD) from mid-life obesity increasing the risk of developing AD to weight loss occurring at the earliest stages of AD. Therefore, factors that regulate body weight are likely to influence the development and progression of AD. The adipocyte-derived hormone leptin has emerged as a major regulator of body weight mainly by activating hypothalamic neural circuits. Leptin also has several pleotropic effects including regulating cognitive function and having neuroprotective effects, suggesting a potential link between leptin and AD. Here, we will examine the relationship between leptin and AD by reviewing the recent evidence from cellular and animal models to human studies. We present a model where leptin has a bidirectional role in AD. Not only can alterations in leptin levels and function worsen cognitive decline and progression of AD pathology, but AD pathology, in of itself, can disrupt leptin signaling, which together would lead to a downward spiral of progressive neurodegeneration and worsening body weight and systemic metabolic deficits. Collectively, these studies serve as a framework to highlight the importance of understanding the molecular mechanisms underlying the body weight and systemic metabolic deficits in AD, which has the potential to open new avenues that may ultimately lead to novel therapeutic targets and diagnostic tools.
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Affiliation(s)
- Matthew J McGuire
- Feil Family Brain and Mind Research Institute, Joan and Sanford I. Weill Medical College of Cornell University, New York, NY, 10065, USA
| | - Makoto Ishii
- Feil Family Brain and Mind Research Institute, Joan and Sanford I. Weill Medical College of Cornell University, New York, NY, 10065, USA.
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Juan De Solis A, Baquero AF, Bennett CM, Grove KL, Zeltser LM. Postnatal undernutrition delays a key step in the maturation of hypothalamic feeding circuits. Mol Metab 2016; 5:198-209. [PMID: 26977392 PMCID: PMC4770263 DOI: 10.1016/j.molmet.2016.01.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 01/06/2016] [Accepted: 01/11/2016] [Indexed: 01/20/2023] Open
Abstract
OBJECTIVE Humans and animals exposed to undernutrition (UN) during development often experience accelerated "catch-up" growth when food supplies are plentiful. Little is known about the mechanisms regulating early growth rates. We previously reported that actions of leptin and presynaptic inputs to orexigenic NPY/AgRP/GABA (NAG) neurons in the arcuate nucleus of the hypothalamus are almost exclusively excitatory during the lactation period, since neuronal and humoral inhibitory systems do not develop until after weaning. Moreover, we identified a critical step that regulates the maturation of electrophysiological responses of NAG neurons at weaning - the onset of genes encoding ATP-dependent potassium (KATP) channel subunits. We explored the possibility that UN promotes subsequent catch-up growth, in part, by delaying the maturation of negative feedback systems to neuronal circuits driving food intake. METHODS We used the large litter (LL) size model to study the impacts of postnatal UN followed by catch-up growth. We evaluated the maturation of presynaptic and postsynaptic inhibitory systems in NAG neurons using a combination of electrophysiological and molecular criteria, in conjunction with leptin's ability to suppress fasting-induced hyperphagia. RESULTS The onset of KATP channel subunit expression and function, the switch in leptin's effect on NAG neurons, the ingrowth of inhibitory inputs to NAG neurons, and the development of homeostatic feedback to feeding circuits were delayed in LL offspring relative to controls. The development of functional KATP channels and the establishment of leptin-mediated suppression of food intake in the peri-weaning period were tightly linked and were not initiated until growth and adiposity of LL offspring caught up to controls. CONCLUSIONS Our data support the idea that initiation of KATP channel subunit expression in NAG neurons serves as a molecular gatekeeper for the maturation of homeostatic feeding circuits.
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Key Words
- ARH, arcuate nucleus of the hypothalamus
- AgRP
- AgRP, agouti-related peptide
- EPSC, excitatory postsynaptic current
- Feeding circuits
- GABA, gamma-aminobutyric acid
- IPSC, inhibitory postsynaptic current
- KATP channel
- KATP, ATP-sensitive potassium channel
- Kir, potassium inward rectifiying channel subunit
- LL, large litter
- Lepr, leptin receptor
- Leptin
- NAG, NPY, AgRP, GABA, NPY, neuropeptide Y
- NPY
- P, postnatal day
- PVH, paraventricular nucleus of the hypothalamus
- Pomc, pro-opiomelanocortin
- SUR, sulfonylurea receptor
- UN, undernutrition
- Undernutrition
- pSTAT3, phosphorylated signal transducer and activator of transcription 3
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Affiliation(s)
- Alain Juan De Solis
- Division of Molecular Genetics, Naomi Berrie Diabetes Center, Columbia University, New York, NY 10032, USA.
| | - Arian F Baquero
- Division of Diabetes, Obesity & Metabolism, Oregon National Primate Research Center, Beaverton, OR 97006, USA.
| | - Camdin M Bennett
- Division of Diabetes, Obesity & Metabolism, Oregon National Primate Research Center, Beaverton, OR 97006, USA.
| | - Kevin L Grove
- Division of Diabetes, Obesity & Metabolism, Oregon National Primate Research Center, Beaverton, OR 97006, USA.
| | - Lori M Zeltser
- Division of Molecular Genetics, Naomi Berrie Diabetes Center, Columbia University, New York, NY 10032, USA; Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA.
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28
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Leptin as a Neuroprotector and a Central Nervous System Functional Stability Factor. ACTA ACUST UNITED AC 2015. [DOI: 10.1007/s11055-015-0120-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Leptin Induces a Novel Form of NMDA Receptor-Dependent LTP at Hippocampal Temporoammonic-CA1 Synapses. eNeuro 2015; 2:eN-NWR-0007-15. [PMID: 26464986 PMCID: PMC4586932 DOI: 10.1523/eneuro.0007-15.2015] [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: 01/27/2015] [Revised: 05/12/2015] [Accepted: 05/15/2015] [Indexed: 01/08/2023] Open
Abstract
Hippocampal CA1 pyramidal neurons receive two anatomically distinct glutamatergic inputs that have distinct roles in learning and memory. The hormone leptin markedly influences excitatory synaptic transmission at the indirect Schaffer-collateral pathway to CA1 neurons. It is well documented that the hormone leptin regulates many central functions and that hippocampal CA1 pyramidal neurons are a key target for leptin action. Indeed, leptin modulates excitatory synaptic transmission and synaptic plasticity at the Schaffer-collateral input to CA1 neurons. However the impact of leptin on the direct temporoammonic (TA) input to CA1 neurons is not known. Here we show that leptin evokes a long-lasting increase [long-term potentiation (LTP)] in excitatory synaptic transmission at TA-CA1 synapses in rat juvenile hippocampus. Leptin-induced LTP was NMDA receptor-dependent and specifically involved the activation of GluN2B subunits. The signaling pathways underlying leptin-induced LTP involve the activation of phosphoinositide 3-kinase, but were independent of the ERK signaling cascade. Moreover, insertion of GluA2-lacking AMPA receptors was required for leptin-induced LTP as prior application of philanthotoxin prevented the effects of leptin. In addition, synaptic-induced LTP occluded the persistent increase in synaptic efficacy induced by leptin. In conclusion, these data indicate that leptin induces a novel form of NMDA receptor-dependent LTP at juvenile TA-CA1 synapses, which has important implications for the role of leptin in modulating hippocampal synaptic function in health and disease.
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Wang W, Liu SL, Li K, Chen Y, Jiang B, Li YK, Xiao JL, Yang S, Chen T, Chen JG, Li JG, Wang F. Leptin: a potential anxiolytic by facilitation of fear extinction. CNS Neurosci Ther 2015; 21:425-34. [PMID: 25645604 DOI: 10.1111/cns.12375] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 11/26/2014] [Accepted: 12/08/2014] [Indexed: 01/22/2023] Open
Abstract
AIMS Anxiety disorders are characterized by a deficient extinction of fear memory. Evidence is growing that leptin influences numerous neuronal functions. The aims of this study were to investigate the effects and the mechanism of leptin on fear extinction. METHODS AND RESULTS Leptin (1 mg/kg, i.p) was applied to evaluate the anxiolytic effect in rat behavioral tests. Field potentials recording were used to investigate the changes in synaptic transmission in the thalamic-lateral amygadala (LA) pathway of rat. We found that leptin produced strong anxiolytic effects under basal condition and after acute stress. Systemic administration and intra-LA infusions of leptin facilitated extinction of conditioned fear responses. The antagonist of NMDA receptor, MK-801, blocked the effect of leptin on fear extinction completely. Furthermore, these effects of leptin on fear extinction were accompanied by a reversal of conditioning-induced synaptic potentiation in the LA. Leptin facilitated NMDA receptor-mediated synaptic transmission, and reversed amygdala long-term potentiation (LTP) in a dose-dependent manner in vitro, and this LTP depotentiation effect was mediated by NMDA receptor and MAPK signaling pathway. CONCLUSIONS These results identify a key role of leptin in dampening fear conditioning-induced synaptic potentiation in the LA through NMDA receptor and indicate a new strategy for treating anxiety disorders.
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Affiliation(s)
- Wei Wang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Farr OM, Tsoukas MA, Mantzoros CS. Leptin and the brain: influences on brain development, cognitive functioning and psychiatric disorders. Metabolism 2015; 64:114-30. [PMID: 25092133 DOI: 10.1016/j.metabol.2014.07.004] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 06/16/2014] [Accepted: 07/05/2014] [Indexed: 12/20/2022]
Abstract
Receptors of leptin, the prototypical adipokine, are expressed throughout the cortex and several other areas of the brain. Although typically studied for its role in energy intake and expenditure, leptin plays a critical role in many other neurocognitive processes and interacts with various other hormones and neurotransmitters to perform these functions. Here, we review the literature on how leptin influences brain development, neural degradation, Alzheimer's disease, psychiatric disorders, and more complicated cognitive functioning and feeding behaviors. We also discuss modulators of leptin and the leptin receptor as they relate to normal cognitive functioning and may mediate some of the actions of leptin in the brain. Although we are beginning to better understand the critical role leptin plays in normal cognitive functioning, there is much to be discovered.
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Affiliation(s)
- Olivia M Farr
- Division of Endocrinology, Boston VA Healthcare System/Harvard Medical School, Boston, MA 02215.
| | - Michael A Tsoukas
- Division of Endocrinology, Boston VA Healthcare System/Harvard Medical School, Boston, MA 02215
| | - Christos S Mantzoros
- Division of Endocrinology, Boston VA Healthcare System/Harvard Medical School, Boston, MA 02215
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32
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Dong S, Yasui N, Negishi H, Gao M, Yamori Y, Ikeda K, Sun J. 3,4-Oxo-isopropylidene-shikimic acid promotes adiopkine expression during murine 3T3-L1 fibroblast differentiation into adipocytes. JOURNAL OF TRADITIONAL CHINESE MEDICAL SCIENCES 2014. [DOI: 10.1016/j.jtcms.2014.09.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Letra L, Santana I, Seiça R. Obesity as a risk factor for Alzheimer's disease: the role of adipocytokines. Metab Brain Dis 2014; 29:563-8. [PMID: 24553879 DOI: 10.1007/s11011-014-9501-z] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2013] [Accepted: 02/03/2014] [Indexed: 12/11/2022]
Abstract
Alzheimer's disease is the leading cause of dementia and the most prevalent neurodegenerative disease. It is an aging-related multi-factorial disorder and growing evidence support the contribution of metabolic factors to what was formerly thought to be a centrally mediated process. Obesity has already been recognized as an important player in the pathogenesis of this type of dementia, independently of insulin resistance or other vascular risk factors. Although the exact underlying mechanisms are still unknown, adipocyte dysfunction and concomitant alteration in adipocyte-derived protein secretion seem to be involved, since these adipocytokines can cross the blood-brain barrier and influence cognitive-related structures. Very few studies have assessed the role of adipocytokines dysfunction on cognitive impaired patients and yielded contradictory results. Interestingly, extensive research on the central effects of leptin in Alzheimer's disease-transgenic mice has demonstrated its capacity to enhance synaptic plasticity and strength, as well as to prevent beta-amyloid deposition and tau phosphorylation. In addition, adiponectin, the most abundant adipocytokine whose levels are inversely correlated to adiposity, has shown to be neuroprotective to hippocampal cells. Many other adipose-derived cytokines have mainly pro-inflammatory properties, being able to trigger and/or enhance central inflammatory cascades and also to influence the secretion of other adipocytokines involved in cognition. This paper pretends to review the existing evidence on the contribution of adipocytokines dysfunction to the increased risk of dementia associated with mid-life obesity, unraveling its insulin-independent effects on cognition.
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Affiliation(s)
- Liliana Letra
- Serviço de Neurologia, Centro Hospitalar e Universitário de Coimbra, Portugal, Av. Bissaya Barreto - Praceta Prof Mota Pinto, 3000-075, Coimbra, Portugal,
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Guimond D, Diabira D, Porcher C, Bader F, Ferrand N, Zhu M, Appleyard SM, Wayman GA, Gaiarsa JL. Leptin potentiates GABAergic synaptic transmission in the developing rodent hippocampus. Front Cell Neurosci 2014; 8:235. [PMID: 25177272 PMCID: PMC4133691 DOI: 10.3389/fncel.2014.00235] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 07/26/2014] [Indexed: 12/17/2022] Open
Abstract
It is becoming increasingly clear that leptin is not only a hormone regulating energy homeostasis but also a neurotrophic factor impacting a number of brain regions, including the hippocampus. Although leptin promotes the development of GABAergic transmission in the hypothalamus, little is known about its action on the GABAergic system in the hippocampus. Here we show that leptin modulates GABAergic transmission onto developing CA3 pyramidal cells of newborn rats. Specifically, leptin induces a long-lasting potentiation (LLP-GABAA) of miniature GABAA receptor-mediated postsynaptic current (GABAA-PSC) frequency. Leptin also increases the amplitude of evoked GABAA-PSCs in a subset of neurons along with a decrease in the coefficient of variation and no change in the paired-pulse ratio, pointing to an increased recruitment of functional synapses. Adding pharmacological blockers to the recording pipette showed that the leptin-induced LLP-GABAA requires postsynaptic calcium released from internal stores, as well as postsynaptic MAPK/ERK kinases 1 and/or 2 (MEK1/2), phosphoinositide 3 kinase (PI3K) and calcium-calmodulin kinase kinase (CaMKK). Finally, study of CA3 pyramidal cells in leptin-deficient ob/ob mice revealed a reduction in the basal frequency of miniature GABAA-PSCs compared to wild type littermates. In addition, presynaptic GAD65 immunostaining was reduced in the CA3 stratum pyramidale of mutant animals, both results converging to suggest a decreased number of functional GABAergic synapses in ob/ob mice. Overall, these results show that leptin potentiates and promotes the development of GABAergic synaptic transmission in the developing hippocampus likely via an increase in the number of functional synapses, and provide insights into the intracellular pathways mediating this effect. This study further extends the scope of leptin's neurotrophic action to a key regulator of hippocampal development and function, namely GABAergic transmission.
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Affiliation(s)
- Damien Guimond
- Parc Scientifique de Luminy, Aix-Marseille Université Marseille, France ; Unité 901, Institut National de la Santé et de la Recherche Médicale Marseille, France ; Institut de Neurobiologie de la Méditerranée Marseille, France ; Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University Pullman, WA, USA
| | - Diabe Diabira
- Parc Scientifique de Luminy, Aix-Marseille Université Marseille, France ; Unité 901, Institut National de la Santé et de la Recherche Médicale Marseille, France ; Institut de Neurobiologie de la Méditerranée Marseille, France
| | - Christophe Porcher
- Parc Scientifique de Luminy, Aix-Marseille Université Marseille, France ; Unité 901, Institut National de la Santé et de la Recherche Médicale Marseille, France ; Institut de Neurobiologie de la Méditerranée Marseille, France
| | - Francesca Bader
- Parc Scientifique de Luminy, Aix-Marseille Université Marseille, France ; Unité 901, Institut National de la Santé et de la Recherche Médicale Marseille, France ; Institut de Neurobiologie de la Méditerranée Marseille, France
| | - Nadine Ferrand
- Parc Scientifique de Luminy, Aix-Marseille Université Marseille, France ; Unité 901, Institut National de la Santé et de la Recherche Médicale Marseille, France ; Institut de Neurobiologie de la Méditerranée Marseille, France
| | - Mingyan Zhu
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University Pullman, WA, USA
| | - Suzanne M Appleyard
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University Pullman, WA, USA
| | - Gary A Wayman
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University Pullman, WA, USA
| | - Jean-Luc Gaiarsa
- Parc Scientifique de Luminy, Aix-Marseille Université Marseille, France ; Unité 901, Institut National de la Santé et de la Recherche Médicale Marseille, France ; Institut de Neurobiologie de la Méditerranée Marseille, France
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35
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Leptin reverses corticosterone-induced inhibition of neural stem cell proliferation through activating the NR2B subunits of NMDA receptors. Biochem Biophys Res Commun 2014; 447:95-100. [DOI: 10.1016/j.bbrc.2014.03.112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 03/22/2014] [Indexed: 12/31/2022]
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Sharieh Hosseini SG, Khatamsaz S, Shariati M. The effects of losartan on memory performance and leptin resistance induced by obesity and high-fat diet in adult male rats. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2014; 17:41-8. [PMID: 24592306 PMCID: PMC3938885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2013] [Accepted: 10/02/2013] [Indexed: 11/01/2022]
Abstract
OBJECTIVE(S) Leptin is a hormone secreted by adipose tissue and is involved not only in the regulation of feeding and energy expenditure, but also its role in memory enhancement has been demonstrated as well. The partial transfer of leptin across the blood-brain barrier in obese individuals causes leptin resistance and prevents leptin reaching brain. On the other hand, studies have shown that angiotensin antagonists such as losartan can improve memory and learning abilities. The aim of this study was to evaluate the effects of losartan on improving memory and leptin resistance induced by high fat diet in obese rats. MATERIALS AND METHODS 40 Wistar male rats were divided in 4 groups: control (C), losartan (LOS), high-fat diet (HFD) and high-fat diet and losartan (HFD and LOS). The spatial memory performances of the rats were assessed in the Morris water maze after 2 months of treatment. Then they were weighed and serum levels of leptin and triglyceride were measured. RESULTS In spite of receiving high-fat diet, no significant differences in body weight were observed in the (HFD & LOS) group. In the Morris water maze trial, the (LOS) and (HFD & LOS) groups also showed a significant reduction (P <0.05) in latency and path length. In addition, a significant decrease (P <0.05) in serum levels of leptin and no significant difference in serum levels of triglyceride was observed in the (HFD & LOS) group. CONCLUSION Losartan can improve leptin resistance induced by obesity and high fat diet. At the same time, it modulates body weight and enhances learning and memory.
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Affiliation(s)
- Seyydeh Gohar Sharieh Hosseini
- Islamic Azad University, Kazerun Branch, Department of Physiology, Kazerun, Iran,Corresponding author: Seyydeh Gohar Sharieh Hosseini. Islamic Azad University, Kazerun Branch, Department of Physiology, Kazerun, Iran. Tel: +98-711-8238047;
| | | | - Mehrdad Shariati
- Islamic Azad University, Kazerun Branch, Department of Physiology, Kazerun, Iran
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Irving AJ, Harvey J. Leptin regulation of hippocampal synaptic function in health and disease. Philos Trans R Soc Lond B Biol Sci 2013; 369:20130155. [PMID: 24298156 DOI: 10.1098/rstb.2013.0155] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The endocrine hormone leptin plays a key role in regulating food intake and body weight via its actions in the hypothalamus. However, leptin receptors are highly expressed in many extra-hypothalamic brain regions and evidence is growing that leptin influences many central processes including cognition. Indeed, recent studies indicate that leptin is a potential cognitive enhancer as it markedly facilitates the cellular events underlying hippocampal-dependent learning and memory, including effects on glutamate receptor trafficking, neuronal morphology and activity-dependent synaptic plasticity. However, the ability of leptin to regulate hippocampal synaptic function markedly declines with age and aberrant leptin function has been linked to neurodegenerative disorders such as Alzheimer's disease (AD). Here, we review the evidence supporting a cognitive enhancing role for the hormone leptin and discuss the therapeutic potential of using leptin-based agents to treat AD.
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Affiliation(s)
- Andrew J Irving
- Division of Neuroscience, Medical Research Institute, Ninewells Hospital and Medical School, University of Dundee, , Dundee DD1 9SY, UK
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Harvey J. Leptin regulation of neuronal morphology and hippocampal synaptic function. Front Synaptic Neurosci 2013; 5:3. [PMID: 23964236 PMCID: PMC3734345 DOI: 10.3389/fnsyn.2013.00003] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 07/12/2013] [Indexed: 12/14/2022] Open
Abstract
The central actions of the hormone leptin in regulating energy homeostasis via the hypothalamus are well documented. However, evidence is growing that this hormone can also modify the structure and function of synapses throughout the CNS. The hippocampus is a region of the forebrain that plays a crucial role in associative learning and memory and is an area also highly vulnerable to neurodegenerative processes. Recent studies indicate that leptin is a potential cognitive enhancer as it modulates the cellular processes underlying hippocampal-dependent learning and memory including dendritic morphology, glutamate receptor trafficking and activity-dependent synaptic plasticity. Here, we review the recent evidence implicating the hormone leptin as a key regulator of hippocampal synaptic function and discuss the role of leptin receptor-driven lipid signaling pathways involved in this process.
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Affiliation(s)
- Jenni Harvey
- Division of Neuroscience, Medical Research Institute, Ninewells Hospital and Medical School, University of Dundee Dundee, UK
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Beck P, Urbano FJ, Williams DK, Garcia-Rill E. Effects of leptin on pedunculopontine nucleus (PPN) neurons. J Neural Transm (Vienna) 2013; 120:1027-38. [PMID: 23263542 PMCID: PMC3618992 DOI: 10.1007/s00702-012-0957-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 12/10/2012] [Indexed: 12/24/2022]
Abstract
Leptin, a hormone that regulates appetite and energy expenditure, is increased in obese individuals, although these individuals often exhibit leptin resistance. Obesity is characterized by sleep/wake disturbances, such as excessive daytime sleepiness, increased REM sleep, increased nighttime arousals, and decreased percentage of total sleep time. Several studies have shown that short sleep duration is highly correlated with decreased leptin levels in both animal and human models. Arousal and rapid eye movement (REM) sleep are regulated by the cholinergic arm of the reticular activating system, the pedunculopontine nucleus (PPN). The goal of this project was to determine the role of leptin in the PPN, and thus in obesity-related sleep disorders. Whole-cell patch-clamp recordings were conducted on PPN neurons in 9- to 17-day-old rat brainstem slices. Leptin decreased action potential (AP) amplitude, AP frequency, and h-current (I(H)). These findings suggest that leptin causes a blockade of Na⁺ channels. Therefore, we conducted an experiment to test the effects of leptin on Na⁺ conductance. To determine the average voltage dependence of this conductance, results from each cell were equally weighted by expressing conductance as a fraction of the maximum conductance in each cell. I Na amplitude was decreased in a dose-dependent manner, suggesting a direct effect of leptin on these channels. The average decrease in Na⁺ conductance by leptin was ~40 %. We hypothesize that leptin normally decreases activity in the PPN by reducing I(H) and I(Na) currents, and that in states of leptin dysregulation (i.e., leptin resistance) this effect may be blunted, therefore causing increased arousal and REM sleep drive, and ultimately leading to sleep-related disorders.
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Affiliation(s)
- Paige Beck
- Center for Translational Neuroscience, Dept. Neurobiology & Dev. Sci., University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | | | - D. Keith Williams
- Center for Translational Neuroscience, Dept. Neurobiology & Dev. Sci., University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Edgar Garcia-Rill
- Center for Translational Neuroscience, Dept. Neurobiology & Dev. Sci., University of Arkansas for Medical Sciences, Little Rock, AR, USA
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Beck P, Mahaffey S, Urbano FJ, Garcia-Rill E. Role of G-proteins in the effects of leptin on pedunculopontine nucleus neurons. J Neurochem 2013; 126:705-14. [PMID: 23692342 DOI: 10.1111/jnc.12312] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 05/14/2013] [Accepted: 05/15/2013] [Indexed: 12/25/2022]
Abstract
The pedunculopontine nucleus (PPN), the cholinergic arm of the reticular activating system, regulates waking and rapid eye movement sleep. Here, we demonstrate immunohistochemical labeling of the leptin receptor signaling isoform in PPN neurons, and investigated the effects of G-protein modulation and the leptin triple antagonist (TA) on the action of leptin in the PPN. Whole-cell patch clamp recordings were performed in rat brainstem slices from 9 to 17 day old pups. Previous results showed that leptin caused a partial blockade of sodium (I(Na)) and h-current (I(H)) in PPN neurons. TA (100 nM) reduced the blockade of I(Na) (~ 50% reduction) and I(H) (~ 93% reduction) caused by leptin. Intracellular guanosine 5'-[β-thio]diphosphate trilithium salt (a G-protein inhibitor) significantly reduced the effect of leptin on I(Na) (~ 60% reduction) but not on I(H) (~ 25% reduction). Intracellular GTPγS (a G-protein activator) reduced the effect of leptin on both I(Na) (~ 80% reduction) and I(H) (~ 90% reduction). These results suggest that the effects of leptin on the intrinsic properties of PPN neurons are leptin receptor- and G-protein dependent. We also found that leptin enhanced NMDA receptor-mediated responses in single neurons and in the PPN population as a whole, an effect blocked by TA. These experiments further strengthen the association between leptin dysregulation and sleep disturbances. Beck et al. investigated the effects of leptin on the intrinsic properties of neurons from the pedunculopontine nucleus (PPN). Leptin reduced the amplitude of voltage-gated sodium (I(Na)) and hyperpolarization-activated cyclic nucleotide-gated HCN (I(H)) channels. These effects were antagonized by a leptin receptor (OB-R) antagonist and by the G-protein antagonist GDPβ.
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Affiliation(s)
- Paige Beck
- Department of Neurobiology and Development Science, Center for Translational Neuroscience, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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Fadel JR, Jolivalt CG, Reagan LP. Food for thought: the role of appetitive peptides in age-related cognitive decline. Ageing Res Rev 2013; 12:764-76. [PMID: 23416469 DOI: 10.1016/j.arr.2013.01.009] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2012] [Revised: 01/22/2013] [Accepted: 01/25/2013] [Indexed: 01/25/2023]
Abstract
Through their well described actions in the hypothalamus, appetitive peptides such as insulin, orexin and leptin are recognized as important regulators of food intake, body weight and body composition. Beyond these metabolic activities, these peptides also are critically involved in a wide variety of activities ranging from modulation of immune and neuroendocrine function to addictive behaviors and reproduction. The neurological activities of insulin, orexin and leptin also include facilitation of hippocampal synaptic plasticity and enhancement of cognitive performance. While patients with metabolic disorders such as obesity and diabetes have greater risk of developing cognitive deficits, dementia and Alzheimer's disease (AD), the underlying mechanisms that are responsible for, or contribute to, age-related cognitive decline are poorly understood. In view of the importance of these peptides in metabolic disorders, it is not surprising that there is a greater focus on their potential role in cognitive deficits associated with aging. The goal of this review is to describe the evidence from clinical and pre-clinical studies implicating insulin, orexin and leptin in the etiology and progression of age-related cognitive decline. Collectively, these studies support the hypothesis that leptin and insulin resistance, concepts normally associated with the hypothalamus, are also applicable to the hippocampus.
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Affiliation(s)
- Jim R Fadel
- Department of Pharmacology, Physiology and Neuroscience, School of Medicine, University of South Carolina, 6439 Garners Ferry Road, Columbia, SC 29208, USA
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42
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Thompson JL, Borgland SL. Presynaptic leptin action suppresses excitatory synaptic transmission onto ventral tegmental area dopamine neurons. Biol Psychiatry 2013; 73:860-8. [PMID: 23305991 DOI: 10.1016/j.biopsych.2012.10.026] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2012] [Revised: 10/31/2012] [Accepted: 10/31/2012] [Indexed: 12/28/2022]
Abstract
BACKGROUND Leptin is an adipocyte-derived cytokine that can act in the brain to suppress feeding and maintain energy homeostasis. Additionally, leptin activates its receptors in the ventral tegmental area (VTA), a critical site for neuroadaptations to rewarding stimuli, to modulate reward-seeking behaviors. Although leptin can decrease intrinsic excitability of dopamine neurons in the VTA, it is unknown whether leptin can modulate excitatory synaptic transmission in this brain region. Because plasticity of glutamatergic synapses onto VTA neurons can encode predictive information about reward, we hypothesized that leptin can decrease excitatory synaptic transmission onto dopamine neurons. METHODS Using whole-cell patch clamp electrophysiology in mouse midbrain slices, we tested the effects of leptin on evoked α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) or N-methyl-D-aspartate receptor (NMDAR)-mediated excitatory postsynaptic currents (EPSCs) onto VTA dopamine neurons. RESULTS Leptin depressed both AMPAR and NMDAR EPSCs in VTA dopamine neurons and reduced frequency but not amplitude of mini EPSCs. Bath application of the MEK1/2 inhibitor U0126 did not alter leptin-induced suppression of AMPAR EPSCs. However, external, but not internal, application of the phosphoinositol 3-kinase (PI3K) or Janus kinase 2 (Jak2) tyrosine kinase inhibitors abolished leptin-induced synaptic depression. CONCLUSIONS This study demonstrates that leptin causes a presynaptic inhibition of the probability of glutamate release onto VTA dopamine neurons. This synaptic inhibition requires Jak2 and PI3K activation. Leptin-induced weakening of synaptic strength onto dopamine cells may underlie its inhibitory effects on appetitive behavior for rewarding stimuli.
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Affiliation(s)
- Jennifer L Thompson
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, Canada
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43
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Regulation of synaptic functions in central nervous system by endocrine hormones and the maintenance of energy homoeostasis. Biosci Rep 2013; 32:423-32. [PMID: 22582733 PMCID: PMC3804927 DOI: 10.1042/bsr20120026] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Energy homoeostasis, a co-ordinated balance of food intake and energy expenditure, is regulated by the CNS (central nervous system). The past decade has witnessed significant advances in our understanding of metabolic processes and brain circuitry which responds to a broad range of neural, nutrient and hormonal signals. Accumulating evidence demonstrates altered synaptic plasticity in the CNS in response to hormone signals. Moreover, emerging observations suggest that synaptic plasticity underlies all brain functions, including the physiological regulation of energy homoeostasis, and that impaired synaptic constellation and plasticity may lead to pathological development and conditions. Here, we summarize the current knowledge on the regulation of postsynaptic receptors such as AMPA (α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid), NMDA (N-methyl-D-aspartate) and GABA (γ-aminobutyric acid) receptors, and the presynaptic components by hormone signals. A detailed understanding of the neurobiological mechanisms by which hormones regulate energy homoeostasis may lead to novel strategies in treating metabolic disorders.
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Khoshdel A, Parvin N, Abbasi M. Selenium and leptin levels in febrile seizure: a case-control study in children. KOREAN JOURNAL OF PEDIATRICS 2013; 56:80-5. [PMID: 23482826 PMCID: PMC3589595 DOI: 10.3345/kjp.2013.56.2.80] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 09/11/2012] [Accepted: 10/25/2012] [Indexed: 11/27/2022]
Abstract
PURPOSE Febrile seizures (FS) are seizures that occur between the age of 6 and 60 months, but its pathophysiology still is not fully understood. There is limited information about the correlation between levels of selenium and leptin with FS. This study aimed to determine the relationship between serum levels of selenium and leptin in children with FS. METHODS This case-control study was conducted in a University Hospital in Shahrekord, Iran, in 2011. The serum levels of selenium and leptin of 25 children with simple febrile seizure (case group) were compared with 25 febrile children without seizure (control group) in acute phase and after three months. The levels of serum selenium and leptin were measured by flame atomic absorption spectrophotometer and enzyme-linked immunosorbent assay method, respectively. RESULTS In acute phase, the mean serum level of selenium in case and control groups were 95.88±42.55 and 113.25±54.43 µg/dL, respectively, and difference was not significant (P=0.415), but after three months, this level had a significant increase in both groups (P<0.001). In acute phase, the mean serum leptin level in case and control groups were 0.94±0.5 and 0.98±0.84 ng/mL, respectively, but difference was not significant (P=0.405). After three months, serum leptin level had no significant change in both groups (P=0.882). CONCLUSION These observations suggest that serum levels of selenium and leptin have not specific relation with FS but overllay is lower, however, further study is recommended. Also selenium level in stress and acute phase was significantly lower than recovery phase.
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Affiliation(s)
- Abolfazl Khoshdel
- Department of Pediatrics, Shahrekord University of Medical Sciences, Shahrekord, Iran
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Marwarha G, Ghribi O. Leptin signaling and Alzheimer's disease. AMERICAN JOURNAL OF NEURODEGENERATIVE DISEASE 2012; 1:245-265. [PMID: 23383396 PMCID: PMC3560472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 11/09/2012] [Indexed: 06/01/2023]
Abstract
Leptin, an adipocytokine produced in the peripheral system as well as in the brain, is implicated in obesity, food intake, glucose homeostasis, and energy expenditure. Leptin expression levels and signaling pathways may also be linked to the pathophysiology of neurodegenerative diseases including Alzheimer's disease. Epidemiological studies have demonstrated that higher circulating leptin levels are associated with lower risk of dementia including Alzheimer's disease, and lower circulating levels of leptin have been reported in patients with Alzheimer's disease. Leptin receptors are highly expressed in the hippocampus, a brain area involved in learning and memory and severely affected during the course of Alzheimer's disease. In laboratory studies, several in vivo and in vitro studies have shown that leptin supplementation decreases amyloid-β (Aβ) production and tau phosphorylation, two major biochemical events that play a key role in the pathogenesis of Alzheimer's disease. In this review, we will review the structure of leptin, the type of receptors of leptin in the brain, the various biological functions attributed to this adipocytokine, the signaling pathways that govern leptin actions, and the potential role of leptin in the pathophysiology of Alzheimer's disease. Leptin exerts its functions by binding to the leptin receptor (ObR). This binding can involve several signaling pathways including JAK/STAT pathway, ERK pathway and the PI3K/Akt/mTOR Pathway. Modulation of these pathways leads to the regulation of a multitude of functions that define the intricate involvement of leptin in various physiological tasks. In this review, we will specifically relate the potential involvement of leptin signaling in Alzheimer's disease based on work published by several laboratories including ours. All this work points to leptin as a possible target for developing supplementation therapies for reducing the progression of Alzheimer's disease.
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Affiliation(s)
- Gurdeep Marwarha
- Department of Pharmacology, Physiology and Therapeutics, University of North Dakota, School of Medicine and Health Sciences Grand Forks, North Dakota, 58202
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Pan W, Hsuchou H, Jayaram B, Khan RS, Huang EYK, Wu X, Chen C, Kastin AJ. Leptin action on nonneuronal cells in the CNS: potential clinical applications. Ann N Y Acad Sci 2012; 1264:64-71. [PMID: 22530983 PMCID: PMC3407332 DOI: 10.1111/j.1749-6632.2012.06472.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Leptin, an adipocyte-derived cytokine, crosses the blood–brain barrier to act on many regions of the central nervous system (CNS). It participates in the regulation of energy balance, inflammatory processes, immune regulation, synaptic formation, memory condensation, and neurotrophic activities. This review focuses on the newly identified actions of leptin on astrocytes. We first summarize the distribution of leptin receptors in the brain, with a focus on the hypothalamus, where the leptin receptor is known to mediate essential feeding suppression activities, and on the hippocampus, where leptin facilitates memory, reduces neurodegeneration, and plays a dual role in seizures. We will then discuss regulation of the nonneuronal leptin system in obesity. Its relationship with neuronal leptin signaling is illustrated by in vitro assays in primary astrocyte culture and by in vivo studies on mice after pretreatment with a glial metabolic inhibitor or after cell-specific deletion of intracellular signaling leptin receptors. Overall, the glial leptin system shows robust regulation and plays an essential role in obesity. Strategies to manipulate this nonneuronal leptin signaling may have major clinical impact.
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Affiliation(s)
- Weihong Pan
- Blood-Brain Barrier Group, Pennington Biomedical Research Center, Baton Rouge, Lousiana 70808, USA.
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Valladolid-Acebes I, Merino B, Principato A, Fole A, Barbas C, Lorenzo MP, García A, Del Olmo N, Ruiz-Gayo M, Cano V. High-fat diets induce changes in hippocampal glutamate metabolism and neurotransmission. Am J Physiol Endocrinol Metab 2012; 302:E396-402. [PMID: 22114023 DOI: 10.1152/ajpendo.00343.2011] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Obesity and high-fat (HF) diets have a deleterious impact on hippocampal function and lead to impaired synaptic plasticity and learning deficits. Because all of these processes need an adequate glutamatergic transmission, we have hypothesized that nutritional imbalance triggered by these diets might eventually concern glutamate (Glu) neural pathways within the hippocampus. Glu is withdrawn from excitatory synapses by specific uptake mechanisms involving neuronal (EAAT-3) and glial (GLT-1, GLAST) transporters, which regulate the time that synaptically released Glu remains in the extracellular space and, consequently, the duration and location of postsynaptic receptor activation. The goal of the present study was to evaluate in mouse hippocampus the effect of a short-term high-fat dietary treatment on 1) Glu uptake kinetics, 2) the density of Glu carriers and Glu-degrading enzymes, 3) the density of Glu receptor subunits, and 4) synaptic transmission and plasticity. Here, we show that HF diet triggers a 50% decrease of the Michaelis-Menten constant together with a 300% increase of the maximal velocity of the uptake process. Glial Glu carriers GLT-1 and GLAST were upregulated in HF mice (32 and 27%, respectively), whereas Glu-degrading enzymes glutamine synthase and GABA-decarboxilase appeared to be downregulated in these animals. In addition, HF diet hippocampus displayed diminished basal synaptic transmission and hindered NMDA-induced long-term depression (NMDA-LTD). This was coincident with a reduced density of the NR2B subunit of NMDA receptors. All of these results are compatible with the development of leptin resistance within the hippocampus. Our data show that HF diets upregulate mechanisms involved in Glu clearance and simultaneously impair Glu metabolism. Neurochemical changes occur concomitantly with impaired basal synaptic transmission and reduced NMDA-LTD. Taken together, our results suggest that HF diets trigger neurochemical changes, leading to a desensitization of NMDA receptors within the hippocampus, which might account for cognitive deficits.
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Affiliation(s)
- Ismael Valladolid-Acebes
- Departamento de Ciencias Farmacéuticas y de la Alimentación, Facultad de Farmacia, Universidad CEU-San Pablo, Madrid, Spain
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Obesity and the ageing brain: could leptin play a role in neurodegeneration? Curr Gerontol Geriatr Res 2011; 2011:708154. [PMID: 22013440 PMCID: PMC3195276 DOI: 10.1155/2011/708154] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Accepted: 08/15/2011] [Indexed: 01/19/2023] Open
Abstract
Obesity and ageing are both characteristics of the human population that are on the increase across the globe. It has long been established that ageing is the major risk factor for neurodegenerative conditions such as Alzheimer's disease, and it is becoming increasingly evident that obesity is another such factor. Leptin resistance or insensitivity has been uncovered as a cause of obesity, and in addition the leptin signalling system is less potent in the elderly. Taken together, these findings reveal that this molecule may be a link between neurodegeneration and obesity or ageing. It is now known that leptin has beneficial effects on both the survival and neurophysiology of the neurons that are lost in Alzheimer's disease suggesting that it may be an important research target in the quest for strategies to prevent, halt, or cure this condition.
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Shan X, Yeo GSH. Central leptin and ghrelin signalling: comparing and contrasting their mechanisms of action in the brain. Rev Endocr Metab Disord 2011; 12:197-209. [PMID: 21331644 DOI: 10.1007/s11154-011-9171-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In the past two decades, two major discoveries have greatly contributed to our current knowledge on the central control of food intake and body-weight; the discovery of the anorexigenic adipocyte derived hormone leptin in 1994 and the orexigenic gut derived hormone ghrelin in 1999. Both hormones act as crucial signals to indicate nutritional status as well as to modulate feeding behaviour through a variety of distinct pathways. They target overlapping CNS regions in order to mediate their obvious opposing effects on energy balance. Here we depict the integral picture of leptin and ghrelin on central regulation of food intake by reviewing their actions across the CNS, in regions of the hypothalamus, brainstem, mesolimbic reward pathway and other higher brain areas.
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Affiliation(s)
- Xiaoye Shan
- University of Cambridge Metabolic Research Labs, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK
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50
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Kanoski SE, Hayes MR, Greenwald HS, Fortin SM, Gianessi CA, Gilbert JR, Grill HJ. Hippocampal leptin signaling reduces food intake and modulates food-related memory processing. Neuropsychopharmacology 2011; 36:1859-70. [PMID: 21544068 PMCID: PMC3154104 DOI: 10.1038/npp.2011.70] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The increase in obesity prevalence highlights the need for a more comprehensive understanding of the neural systems controlling food intake; one that extends beyond food intake driven by metabolic need and considers that driven by higher-order cognitive factors. The hippocampus, a brain structure involved in learning and memory function, has recently been linked with food intake control. Here we examine whether administration of the adiposity hormone leptin to the dorsal and ventral sub-regions of the hippocampus influences food intake and memory for food. Leptin (0.1 μg) delivered bilaterally to the ventral hippocampus suppressed food intake and body weight measured 24 h after administration; a higher dose (0.4 μg) was needed to suppress intake following dorsal hippocampal delivery. Leptin administration to the ventral but not dorsal hippocampus blocked the expression of a conditioned place preference for food and increased the latency to run for food in an operant runway paradigm. Additionally, ventral but not dorsal hippocampal leptin delivery suppressed memory consolidation for the spatial location of food, whereas hippocampal leptin delivery had no effect on memory consolidation in a non-spatial appetitive response paradigm. Collectively these findings indicate that ventral hippocampal leptin signaling contributes to the inhibition of food-related memories elicited by contextual stimuli. To conclude, the results support a role for hippocampal leptin signaling in the control of food intake and food-related memory processing.
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Affiliation(s)
- Scott E Kanoski
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA.
| | - Matthew R Hayes
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA,Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA
| | - Holly S Greenwald
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA
| | - Samantha M Fortin
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA
| | - Carol A Gianessi
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA
| | - Jennifer R Gilbert
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA
| | - Harvey J Grill
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA
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