1
|
Castillo-Vazquez SK, Massieu L, Rincón-Heredia R, García-delaTorre P, Quiroz-Baez R, Gomez-Verjan JC, Rivero-Segura NA. Glutamatergic Neurotransmission in Aging and Neurodegenerative Diseases: A Potential Target to Improve Cognitive Impairment in Aging. Arch Med Res 2024; 55:103039. [PMID: 38981341 DOI: 10.1016/j.arcmed.2024.103039] [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: 01/11/2024] [Revised: 06/10/2024] [Accepted: 06/26/2024] [Indexed: 07/11/2024]
Abstract
Aging is characterized by the decline in many of the individual's capabilities. It has been recognized that the brain undergoes structural and functional changes during aging that are occasionally associated with the development of neurodegenerative diseases. In this sense, altered glutamatergic neurotransmission, which involves the release, binding, reuptake, and degradation of glutamate (Glu) in the brain, has been widely studied in physiological and pathophysiological aging. In particular, changes in glutamatergic neurotransmission are exacerbated during neurodegenerative diseases and are associated with cognitive impairment, characterized by difficulties in memory, learning, concentration, and decision-making. Thus, in the present manuscript, we aim to highlight the relevance of glutamatergic neurotransmission during cognitive impairment to develop novel strategies to prevent, ameliorate, or delay cognitive decline. To achieve this goal, we provide a comprehensive review of the changes reported in glutamatergic neurotransmission components, such as Glu transporters and receptors during physiological aging and in the most studied neurodegenerative diseases. Finally, we describe the current therapeutic strategies developed to target glutamatergic neurotransmission.
Collapse
Affiliation(s)
- Selma Karime Castillo-Vazquez
- Dirección de Investigación, Instituto Nacional de Geriatría, Mexico City, Mexico; Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Lourdes Massieu
- Departamento de Neuropatología Molecular, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Ruth Rincón-Heredia
- Unidad de Imagenología, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
| | - Paola García-delaTorre
- 4 Unidad de Investigación Epidemiológica y en Servicios de Salud, Área de Envejecimiento, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City Mexico
| | - Ricardo Quiroz-Baez
- Dirección de Investigación, Instituto Nacional de Geriatría, Mexico City, Mexico
| | | | | |
Collapse
|
2
|
McNair LM, Andersen JV, Waagepetersen HS. Stable isotope tracing reveals disturbed cellular energy and glutamate metabolism in hippocampal slices of aged male mice. Neurochem Int 2023; 171:105626. [PMID: 37838084 DOI: 10.1016/j.neuint.2023.105626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/08/2023] [Accepted: 10/05/2023] [Indexed: 10/16/2023]
Abstract
Neurons and astrocytes work in close metabolic collaboration, linking neurotransmission to brain energy and neurotransmitter metabolism. Dysregulated energy metabolism is a hallmark of the aging brain and may underlie the progressive age-dependent cognitive decline. However, astrocyte and neurotransmitter metabolism remains understudied in aging brain research. In particular, how aging affects metabolism of glutamate, being the primary excitatory neurotransmitter, is still poorly understood. Here we investigated critical aspects of cellular energy metabolism in the aging male mouse hippocampus using stable isotope tracing in vitro. Metabolism of [U-13C]glucose demonstrated an elevated glycolytic capacity of aged hippocampal slices, whereas oxidative [U-13C]glucose metabolism in the TCA cycle was significantly reduced with aging. In addition, metabolism of [1,2-13C]acetate, reflecting astrocyte energy metabolism, was likewise reduced in the hippocampal slices of old mice. In contrast, uptake and subsequent metabolism of [U-13C]glutamate was elevated, suggesting increased capacity for cellular glutamate handling with aging. Finally, metabolism of [15N]glutamate was maintained in the aged slices, demonstrating sustained glutamate nitrogen metabolism. Collectively, this study reveals fundamental alterations in cellular energy and neurotransmitter metabolism in the aging brain, which may contribute to age-related hippocampal deficits.
Collapse
Affiliation(s)
- Laura Mikél McNair
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark.
| | - Jens Velde Andersen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Helle Sønderby Waagepetersen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| |
Collapse
|
3
|
Klinger K, del Ángel M, Çalışkan G, Stork O. Increasing NPYergic transmission in the hippocampus rescues aging-related deficits of long-term potentiation in the mouse dentate gyrus. Front Aging Neurosci 2023; 15:1283581. [PMID: 38020778 PMCID: PMC10673643 DOI: 10.3389/fnagi.2023.1283581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Accepted: 10/26/2023] [Indexed: 12/01/2023] Open
Abstract
Loss of neuropeptide Y (NPY)-expressing interneurons in the hippocampus and decaying cholinergic neuromodulation are thought to contribute to impaired cognitive function during aging. However, the interaction of these two neuromodulatory systems in maintaining hippocampal synaptic plasticity during healthy aging has not been explored so far. Here we report profound sex differences in the Neuropeptide-Y (NPY) levels in the dorsal dentate gyrus (DG) with higher NPY concentrations in the male mice compared to their female counterparts and a reduction of NPY levels during aging specifically in males. This change in aged males is accompanied by a deficit in theta burst-induced long-term potentiation (LTP) in the medial perforant path-to-dorsal DG (MPP-DG) synapse, which can be rescued by enhancing cholinergic activation with the acetylcholine esterase blocker, physostigmine. Importantly, NPYergic transmission is required for this rescue of LTP. Moreover, exogenous NPY application alone is sufficient to recover LTP induction in aged male mice, even in the absence of the cholinergic stimulator. Together, our results suggest that in male mice NPYergic neurotransmission is a critical factor for maintaining dorsal DG LTP during aging.
Collapse
Affiliation(s)
- Katharina Klinger
- Department of Genetics and Molecular Neurobiology, Institute of Biology, Otto-von-Guericke University, Magdeburg, Germany
- Research Group “Synapto-Oscillopathies”, Institute of Biology, Otto-von-Guericke-University, Magdeburg, Germany
| | - Miguel del Ángel
- Department of Genetics and Molecular Neurobiology, Institute of Biology, Otto-von-Guericke University, Magdeburg, Germany
| | - Gürsel Çalışkan
- Department of Genetics and Molecular Neurobiology, Institute of Biology, Otto-von-Guericke University, Magdeburg, Germany
- Research Group “Synapto-Oscillopathies”, Institute of Biology, Otto-von-Guericke-University, Magdeburg, Germany
- Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Oliver Stork
- Department of Genetics and Molecular Neurobiology, Institute of Biology, Otto-von-Guericke University, Magdeburg, Germany
- Center for Behavioral Brain Sciences, Magdeburg, Germany
- Center for Intervention and Research on Adaptive and Maladaptive Brain Circuits Underlying Mental Health (C-I-R-C), Magdeburg, Germany
- German Center for Mental Health (DZPG), Magdeburg, Germany
| |
Collapse
|
4
|
Uzay B, Houcek A, Ma ZZ, Konradi C, Monteggia LM, Kavalali ET. Neurotransmitter release progressively desynchronizes in induced human neurons during synapse maturation and aging. Cell Rep 2023; 42:112042. [PMID: 36701235 PMCID: PMC10366341 DOI: 10.1016/j.celrep.2023.112042] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 11/04/2022] [Accepted: 01/13/2023] [Indexed: 01/26/2023] Open
Abstract
Rapid release of neurotransmitters in synchrony with action potentials is considered a key hardwired property of synapses. Here, in glutamatergic synapses formed between induced human neurons, we show that action potential-dependent neurotransmitter release becomes progressively desynchronized as synapses mature and age. In this solely excitatory network, the emergence of NMDAR-mediated transmission elicits endoplasmic reticulum (ER) stress leading to downregulation of key presynaptic molecules, synaptotagmin-1 and cysteine string protein α, that synchronize neurotransmitter release. The emergence of asynchronous release with neuronal maturity and subsequent aging is maintained by the high-affinity Ca2+ sensor synaptotagmin-7 and suppressed by the introduction of GABAergic transmission into the network, inhibition of NMDARs, and ER stress. These results suggest that long-term disruption of excitation-inhibition balance affects the synchrony of excitatory neurotransmission in human synapses.
Collapse
Affiliation(s)
- Burak Uzay
- Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA; Department of Pharmacology, Vanderbilt University, 7130A MRB III 465 21st Avenue South, Nashville, TN 37240-7933, USA
| | - Aiden Houcek
- Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA; Department of Pharmacology, Vanderbilt University, 7130A MRB III 465 21st Avenue South, Nashville, TN 37240-7933, USA
| | - Z Zack Ma
- Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA; Department of Pharmacology, Vanderbilt University, 7130A MRB III 465 21st Avenue South, Nashville, TN 37240-7933, USA
| | - Christine Konradi
- Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA; Department of Pharmacology, Vanderbilt University, 7130A MRB III 465 21st Avenue South, Nashville, TN 37240-7933, USA
| | - Lisa M Monteggia
- Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA; Department of Pharmacology, Vanderbilt University, 7130A MRB III 465 21st Avenue South, Nashville, TN 37240-7933, USA
| | - Ege T Kavalali
- Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA; Department of Pharmacology, Vanderbilt University, 7130A MRB III 465 21st Avenue South, Nashville, TN 37240-7933, USA.
| |
Collapse
|
5
|
Matias I, Diniz LP, Araujo APB, Damico IV, de Moura P, Cabral-Miranda F, Diniz F, Parmeggiani B, de Mello Coelho V, Leite REP, Suemoto CK, Ferreira GC, Kubrusly RCC, Gomes FCA. Age-Associated Upregulation of Glutamate Transporters and Glutamine Synthetase in Senescent Astrocytes In Vitro and in the Mouse and Human Hippocampus. ASN Neuro 2023; 15:17590914231157974. [PMID: 36815213 PMCID: PMC9950616 DOI: 10.1177/17590914231157974] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023] Open
Abstract
Aging is marked by complex and progressive physiological changes, including in the glutamatergic system, that lead to a decline of brain function. Increased content of senescent cells in the brain, such as glial cells, has been reported to impact cognition both in animal models and human tissue during normal aging and in the context of neurodegenerative disease. Changes in the glutamatergic synaptic activity rely on the glutamate-glutamine cycle, in which astrocytes handle glutamate taken up from synapses and provide glutamine for neurons, thus maintaining excitatory neurotransmission. However, the mechanisms of glutamate homeostasis in brain aging are still poorly understood. Herein, we showed that mouse senescent astrocytes in vitro undergo upregulation of GLT-1, GLAST, and glutamine synthetase (GS), along with the increased enzymatic activity of GS and [3H]-D-aspartate uptake. Furthermore, we observed higher levels of GS and increased [3H]-D-aspartate uptake in the hippocampus of aged mice, although the activity of GS was similar between young and old mice. Analysis of a previously available RNAseq dataset of mice at different ages revealed upregulation of GLAST and GS mRNA levels in hippocampal astrocytes during aging. Corroborating these rodent data, we showed an increased number of GS + cells, and GS and GLT-1 levels/intensity in the hippocampus of elderly humans. Our data suggest that aged astrocytes undergo molecular and functional changes that control glutamate-glutamine homeostasis upon brain aging.
Collapse
Affiliation(s)
- Isadora Matias
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de
Janeiro, Rio de Janeiro, Brasil, Isadora Matias, Instituto de Ciências
Biomédicas, Universidade Federal do Rio de Janeiro, Centro de Ciências da Saúde,
Bloco F, Ilha do Fundão, 21941-902 - Rio de Janeiro, RJ, Brasil.
| | - Luan Pereira Diniz
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de
Janeiro, Rio de Janeiro, Brasil
| | - Ana Paula Bergamo Araujo
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de
Janeiro, Rio de Janeiro, Brasil
| | - Isabella Vivarini Damico
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de
Janeiro, Rio de Janeiro, Brasil
| | - Pâmella de Moura
- Instituto Biomédico, Universidade Federal
Fluminense, Niterói, Brasil
| | - Felipe Cabral-Miranda
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de
Janeiro, Rio de Janeiro, Brasil
| | - Fabiola Diniz
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de
Janeiro, Rio de Janeiro, Brasil,Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de
Janeiro, Rio de Janeiro, Brasil
| | - Belisa Parmeggiani
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de
Janeiro, Rio de Janeiro, Brasil
| | - Valeria de Mello Coelho
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de
Janeiro, Rio de Janeiro, Brasil
| | - Renata E. P. Leite
- Biobanco para Estudos em Envelhecimento, Faculdade de Medicina da Universidade de
São Paulo, São Paulo, Brasil,Divisão de Geriatria, Faculdade de Medicina da Universidade de São
Paulo, São Paulo, Brasil
| | - Claudia K. Suemoto
- Divisão de Geriatria, Faculdade de Medicina da Universidade de São
Paulo, São Paulo, Brasil
| | - Gustavo Costa Ferreira
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de
Janeiro, Rio de Janeiro, Brasil
| | | | - Flávia Carvalho Alcantara Gomes
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de
Janeiro, Rio de Janeiro, Brasil,Flávia Carvalho Alcantara Gomes. Instituto
de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Centro de
Ciências da Saúde, Bloco F, Ilha do Fundão, 21941-902 - Rio de Janeiro, RJ,
Brasil.
| |
Collapse
|
6
|
Huffels CFM, van Dijk RE, Karst H, Meye FJ, Hol EM, Middeldorp J. Systemic Injection of Aged Blood Plasma in Adult C57BL/6 Mice Induces Neurophysiological Impairments in the Hippocampal CA1. J Alzheimers Dis 2022; 89:283-297. [PMID: 35871343 DOI: 10.3233/jad-220337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Aging is characterized by systemic alterations and forms an important risk factor for Alzheimer's disease. Recently, it has been indicated that blood-borne factors present in the systemic milieu contribute to the aging process. Exposing young mice to aged blood plasma results in impaired neurogenesis and synaptic plasticity in the dentate gyrus, as well as impaired cognition. Vice versa, treating aged mice with young blood plasma rescues impairments associated with aging. OBJECTIVE Whether blood-borne factors are sufficient to drive impairments outside the dentate gyrus, how they impact neurophysiology, and how the functional outcome compares to impairments found in mouse models for AD is still unclear. METHODS Here, we treated adult mice with blood plasma from aged mice and assessed neurophysiological parameters in the hippocampal CA1. RESULTS Mice treated with aged blood plasma show significantly impaired levels of long-term potentiation (LTP), similar to those present in APP/PS1 mice. These impaired levels of LTP in plasma-treated mice are associated with alterations in basic properties of glutamatergic transmission and the enhanced activity of voltage-gated Ca2 + channels. CONCLUSION Together, the data presented in this study show that blood-borne factors are sufficient to drive neurophysiological impairments in the hippocampal CA1.
Collapse
Affiliation(s)
- Christiaan F M Huffels
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| | - Roland E van Dijk
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| | - Henk Karst
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| | - Frank J Meye
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| | - Elly M Hol
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| | - Jinte Middeldorp
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands.,Department of Neurobiology & Aging, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| |
Collapse
|
7
|
Setti SE, Reed MN. Network activity changes in the pathophysiology of Alzheimer's disease: the role of aging and early entorhinal cortex dysfunction. Metab Brain Dis 2022; 37:289-298. [PMID: 34591222 DOI: 10.1007/s11011-021-00848-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 09/23/2021] [Indexed: 11/24/2022]
Abstract
The greatest risk factor for development of the deadly neurodegenerative disorder known as Alzheimer's disease (AD) is advancing age. Currently unknown is what mediates the impact of advanced age on development of AD. Also unknown is what impact activity alterations in the entorhinal cortex (EC) has on the spread of AD pathology such as pathological tau through the brain as AD progresses. This review focuses on evidence in the literature that describes how one potential age-related change, that of glutamate-mediated increases in neuronal activity, may ultimately increase the risk of developing AD and promote the spread of tau pathology in AD-affected brains from the EC to later regions such as the hippocampus and prefrontal cortex. A better understanding of these detrimental alterations may allow for earlier detection of AD, offering a better prognosis for affected individuals.
Collapse
Affiliation(s)
- Sharay E Setti
- Department of Drug Discovery and Development, Auburn University, 720 South Donahue, Auburn, AL, 36849, USA
- Center for Neuroscience Initiative, Auburn University, Auburn, AL, USA
| | - Miranda N Reed
- Department of Drug Discovery and Development, Auburn University, 720 South Donahue, Auburn, AL, 36849, USA.
- Center for Neuroscience Initiative, Auburn University, Auburn, AL, USA.
| |
Collapse
|
8
|
Gasiorowska A, Wydrych M, Drapich P, Zadrozny M, Steczkowska M, Niewiadomski W, Niewiadomska G. The Biology and Pathobiology of Glutamatergic, Cholinergic, and Dopaminergic Signaling in the Aging Brain. Front Aging Neurosci 2021; 13:654931. [PMID: 34326765 PMCID: PMC8315271 DOI: 10.3389/fnagi.2021.654931] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 06/14/2021] [Indexed: 12/12/2022] Open
Abstract
The elderly population is growing worldwide, with important health and socioeconomic implications. Clinical and experimental studies on aging have uncovered numerous changes in the brain, such as decreased neurogenesis, increased synaptic defects, greater metabolic stress, and enhanced inflammation. These changes are associated with cognitive decline and neurobehavioral deficits. Although aging is not a disease, it is a significant risk factor for functional worsening, affective impairment, disease exaggeration, dementia, and general disease susceptibility. Conversely, life events related to mental stress and trauma can also lead to accelerated age-associated disorders and dementia. Here, we review human studies and studies on mice and rats, such as those modeling human neurodegenerative diseases, that have helped elucidate (1) the dynamics and mechanisms underlying the biological and pathological aging of the main projecting systems in the brain (glutamatergic, cholinergic, and dopaminergic) and (2) the effect of defective glutamatergic, cholinergic, and dopaminergic projection on disabilities associated with aging and neurodegenerative disorders, such as Alzheimer's and Parkinson's diseases. Detailed knowledge of the mechanisms of age-related diseases can be an important element in the development of effective ways of treatment. In this context, we briefly analyze which adverse changes associated with neurodegenerative diseases in the cholinergic, glutaminergic and dopaminergic systems could be targeted by therapeutic strategies developed as a result of our better understanding of these damaging mechanisms.
Collapse
Affiliation(s)
- Anna Gasiorowska
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Malgorzata Wydrych
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Patrycja Drapich
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Maciej Zadrozny
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Marta Steczkowska
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Wiktor Niewiadomski
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Grazyna Niewiadomska
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| |
Collapse
|
9
|
Bahadur Patel A, Veeraiah P, Shameem M, Mahesh Kumar J, Saba K. Impaired GABAergic and glutamatergic neurometabolic activity in aged mice brain as measured by 1 H-[ 13 C]-NMR spectroscopy. FASEB J 2021; 35:e21321. [PMID: 33543543 DOI: 10.1096/fj.202001704rr] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 12/07/2020] [Accepted: 12/14/2020] [Indexed: 01/04/2023]
Abstract
Healthy aging is associated with a decline in cognitive function, and is a major risk factor for many neurodegenerative diseases. Although, there are several evidence that brain mitochondrial function is altered with aging its significance at the cellular level is elusive. In this study, we have investigated mitochondrial TCA cycle and neurotransmitter cycle fluxes associated with glutamatergic, GABAergic neurons and astroglia in the cerebral cortex and hippocampus of young (6 months) and aged (24 months) C57BL6 mice by using 1 H-[13 C]-NMR spectroscopy together with timed infusion of 13 C-labeled glucose and acetate. The ratio VCyc /VTCA was determined from a steady-state [2-13 C]acetate experiment. Metabolic fluxes were obtained by fitting a three-compartment metabolic model to 13 C turnover of amino acids from glucose. Levels of glutamate, aspartate and taurine were reduced in the cerebral cortex, while glutamine and choline were elevated in the hippocampus of aged mice. Interestingly, the rate of acetate oxidation increased in the cerebral cortex, while the flux of mitochondrial TCA cycle of glutamatergic neurons decreased in the cerebral cortex (P < .0001) and hippocampus (P = .025) of aged mice. The glutamate-glutamine neurotransmitter cycle flux was reduced in the cerebral cortex (P < .0001). The GABAergic TCA cycle flux was reduced in the cerebral cortex (P = .0008), while GABA-glutamine neurotransmitter cycling flux was also reduced in the cerebral cortex (P = .011) and hippocampus (P = .042) of aged brain. In conclusion, the reduction in excitatory and inhibitory neurotransmitter activity of glutamatergic and GABAergic neurons in the cerebral cortex and hippocampus correlates qualitatively with declined cognitive function in aged mice.
Collapse
Affiliation(s)
- Anant Bahadur Patel
- NMR Microimaging and Spectroscopy, CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Pandichelvam Veeraiah
- NMR Microimaging and Spectroscopy, CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Mohammad Shameem
- NMR Microimaging and Spectroscopy, CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Jerald Mahesh Kumar
- NMR Microimaging and Spectroscopy, CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Kamal Saba
- NMR Microimaging and Spectroscopy, CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| |
Collapse
|
10
|
Sato H, Tsukamoto-Yasui M, Takado Y, Kawasaki N, Matsunaga K, Ueno S, Kanda M, Nishimura M, Karakawa S, Isokawa M, Suzuki K, Nagao K, Higuchi M, Kitamura A. Protein Deficiency-Induced Behavioral Abnormalities and Neurotransmitter Loss in Aged Mice Are Ameliorated by Essential Amino Acids. Front Nutr 2020; 7:23. [PMID: 32219097 PMCID: PMC7079559 DOI: 10.3389/fnut.2020.00023] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 02/25/2020] [Indexed: 12/11/2022] Open
Abstract
Nutritional epidemiology shows that insufficient protein intake is related to senile dementia. The levels of protein intake in aged people are positively associated with memory function, and elderly people with high protein intake have a low risk of mild cognitive impairment. Although the beneficial roles of protein nutrition in maintaining brain function in aged people are well demonstrated, little is known about the mechanism by which dietary intake of protein affects memory and brain conditions. We fed aged mice a low protein diet (LPD) for 2 months, which caused behavioral abnormalities, and examined the nutritional effect of essential amino acid administration under LPD conditions. The passive avoidance test revealed that LPD mice demonstrated learning and memory impairment. Similarly, the LPD mice showed agitation and hyperactive behavior in the elevated plus maze test. Moreover, LPD mice exhibited decreased concentrations of gamma-aminobutyric acid (GABA), glutamate, glycine, dopamine, norepinephrine, serotonin and aspartate in the brain. Interestingly, oral administration of seven essential amino acids (EAAs; valine, leucine, isoleucine, lysine, phenylalanine, histidine, and tryptophan) to LPD mice, which can be a source of neurotransmitters, reversed those behavioral changes. The oral administration of EAAs restored the brain concentration of glutamate, which is involved in learning and memory ability and may be associated with the observed behavioral changes. Although the details of the link between decreased amino acid and neurotransmitter concentrations and behavioral abnormalities must be examined in future studies, these findings suggest the importance of dietary protein and essential amino acids for maintaining brain function.
Collapse
Affiliation(s)
- Hideaki Sato
- Ajinomoto Co., Inc., Kawasaki, Japan.,Department of Functional Brain Imaging, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Sciences and Technology, Chiba, Japan
| | | | - Yuhei Takado
- Department of Functional Brain Imaging, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Sciences and Technology, Chiba, Japan
| | | | | | | | | | | | | | | | | | | | - Makoto Higuchi
- Department of Functional Brain Imaging, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Sciences and Technology, Chiba, Japan
| | - Akihiko Kitamura
- Ajinomoto Co., Inc., Kawasaki, Japan.,Department of Functional Brain Imaging, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Sciences and Technology, Chiba, Japan
| |
Collapse
|
11
|
Temido-Ferreira M, Coelho JE, Pousinha PA, Lopes LV. Novel Players in the Aging Synapse: Impact on Cognition. J Caffeine Adenosine Res 2019; 9:104-127. [PMID: 31559391 PMCID: PMC6761599 DOI: 10.1089/caff.2019.0013] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
While neuronal loss has long been considered as the main contributor to age-related cognitive decline, these alterations are currently attributed to gradual synaptic dysfunction driven by calcium dyshomeostasis and alterations in ionotropic/metabotropic receptors. Given the key role of the hippocampus in encoding, storage, and retrieval of memory, the morpho- and electrophysiological alterations that occur in the major synapse of this network-the glutamatergic-deserve special attention. We guide you through the hippocampal anatomy, circuitry, and function in physiological context and focus on alterations in neuronal morphology, calcium dynamics, and plasticity induced by aging and Alzheimer's disease (AD). We provide state-of-the art knowledge on glutamatergic transmission and discuss implications of these novel players for intervention. A link between regular consumption of caffeine-an adenosine receptor blocker-to decreased risk of AD in humans is well established, while the mechanisms responsible have only now been uncovered. We review compelling evidence from humans and animal models that implicate adenosine A2A receptors (A2AR) upsurge as a crucial mediator of age-related synaptic dysfunction. The relevance of this mechanism in patients was very recently demonstrated in the form of a significant association of the A2AR-encoding gene with hippocampal volume (synaptic loss) in mild cognitive impairment and AD. Novel pathways implicate A2AR in the control of mGluR5-dependent NMDAR activation and subsequent Ca2+ dysfunction upon aging. The nature of this receptor makes it particularly suited for long-term therapies, as an alternative for regulating aberrant mGluR5/NMDAR signaling in aging and disease, without disrupting their crucial constitutive activity.
Collapse
Affiliation(s)
- Mariana Temido-Ferreira
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Joana E. Coelho
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Paula A. Pousinha
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), CNRS UMR7275, Université Côte d'Azur, Valbonne, France
| | - Luísa V. Lopes
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| |
Collapse
|
12
|
Susceptibility to Aβo and TBOA of LTD and Extrasynaptic NMDAR-Dependent Tonic Current in the Aged Rat Hippocampus. Neurochem Res 2018; 44:692-702. [PMID: 30426348 DOI: 10.1007/s11064-018-2677-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 10/26/2018] [Accepted: 11/02/2018] [Indexed: 12/29/2022]
Abstract
Aging, as the major risk factor of Alzheimer's disease (AD), may increase susceptibility to neurodegenerative diseases through many gradual molecular and biochemical changes. Extracellular glutamate homeostasis and extrasynaptic glutamate N-methyl-D-aspartate receptors (NMDAR) are among early synaptic targets of oligomeric amyloid β (Aβo), one of the AD related synaptotoxic protein species. In this study, we asked for the effects of Aβo on long-term depression (LTD), a form of synaptic plasticity dependent on extrasynaptic NMDAR activation, and on a tonic current (TC) resulting from the activation of extrasynaptic NMDAR by ambient glutamate in hippocampal slices from young (3-6-month-old) and aged (24-28-month-old) Sprague-Dawley rats. Aβo significantly enhanced the magnitude of LTD and the amplitude of TC in aged slices compared to young ones. TBOA, a glutamate transporter inhibitor, also significantly increased LTD magnitude and TC amplitude in slices from aged rats, suggesting either an age-related weakness of the glutamate clearance system and/or a facilitated extrasynaptic NMDAR activation. From our present data, we hypothesize that senescence-related impairment of the extrasynaptic environment may be a vector of vulnerability of the aged hippocampus to neurodegenerative promotors such as Aβo.
Collapse
|
13
|
Wang X, Hu WH, Zhang K, Zhou JJ, Liu DF, Zhang MY, Zhang JG. Acute Fornix Deep Brain Stimulation Improves Hippocampal Glucose Metabolism in Aged Mice. Chin Med J (Engl) 2018; 131:594-599. [PMID: 29483395 PMCID: PMC5850677 DOI: 10.4103/0366-6999.226067] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Background: A beneficial memory effect of acute fornix deep brain stimulation (DBS) has been reported in clinical studies. The aim of this study was to investigate the acute changes in glucose metabolism induced by fornix DBS. Methods: First, the Morris water maze test and novel object recognition memory test were used to confirm declined memory in aged mice (C57BL/6, 20–22 months old). Then, four groups of mice were used as follows: aged mice with stimulation (n = 12), aged mice with sham-stimulation (n = 8), adult mice (3–4 months old) with stimulation (n = 12), and adult mice with sham-stimulation (n = 8). Ipsilateral hippocampal glucose metabolism and glutamate levels were measured in vivo by microdialysis before, during, and after fornix DBS treatment. Histological staining was used to verify the localization of electrodes and mice with inaccurate placement were excluded from subsequent analyses. The effects of fornix DBS on extracellular glucose, lactate, pyruvate, and glutamate levels over time were analyzed by repeated-measures analysis of variance followed by Fisher's least significant difference post hoc test. Results: The aged mice had a higher basal lactate/pyruvate ratio (LPR) and lactate/glucose ratio (LGR) than the adult mice (LPR: 0.34 ± 0.04 vs. 0.13 ± 0.02, t = 4.626, P < 0.0001; LGR: 6.06 ± 0.59 vs. 4.14 ± 0.36, t = 2.823, P < 0.01). Fornix DBS decreased the ipsilateral hippocampal pyruvate and lactate levels (P < 0.05), but the glucose levels were not obviously changed in aged mice. Similarly, the LGR and LPR also decreased in aged mice after fornix DBS treatment (P < 0.05). Glucose metabolism in adult mice was not significantly influenced by fornix DBS. In addition, fornix DBS significantly decreased the ipsilateral hippocampal extracellular levels of glutamate in aged mice (P < 0.05), while significant alterations were not found in the adult mice. Conclusions: The present study provides experimental evidence that fornix DBS could significantly improve hippocampal glucose metabolism in aged mice by promoting cellular aerobic respiration activity.
Collapse
Affiliation(s)
- Xiu Wang
- Department of Neurosurgery, Beijing Tian Tan Hospital, Capital Medical University, Beijing 100050, China
| | - Wen-Han Hu
- Stereotactic and Functional Neurosurgery Laboratory, Beijing Neurosurgical Institute, Capital Medical University; Beijing Key Laboratory of Neurostimulation, Beijing 100050, China
| | - Kai Zhang
- Department of Neurosurgery, Beijing Tian Tan Hospital, Capital Medical University; Beijing Key Laboratory of Neurostimulation, Beijing 100050, China
| | - Jun-Jian Zhou
- Department of Neurosurgery, Beijing Tian Tan Hospital, Capital Medical University, Beijing 100050, China
| | - De-Feng Liu
- Department of Neurosurgery, Beijing Tian Tan Hospital, Capital Medical University, Beijing 100050, China
| | - Mei-Yu Zhang
- Experimental Research Center, China Academy of Traditional Chinese Medicine, Beijing 100700, China
| | - Jian-Guo Zhang
- Department of Neurosurgery, Beijing Tian Tan Hospital, Capital Medical University; Stereotactic and Functional Neurosurgery Laboratory, Beijing Neurosurgical Institute, Capital Medical University; Beijing Key Laboratory of Neurostimulation, Beijing 100050, China
| |
Collapse
|
14
|
Dannenhoffer CA, Varlinskaya EI, Spear LP. Effects of AMPA receptor antagonist, NBQX, and extrasynaptic GABA A agonist, THIP, on social behavior of adolescent and adult rats. Physiol Behav 2018; 194:212-217. [PMID: 29800636 DOI: 10.1016/j.physbeh.2018.05.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 05/15/2018] [Accepted: 05/16/2018] [Indexed: 10/16/2022]
Abstract
Adolescence is characterized by high significance of social interactions, along with a propensity to exhibit social facilitating effects of ethanol while being less sensitive than adults to the inhibition of social behavior that emerges at higher doses of ethanol. Among the neural characteristics of adolescence are generally enhanced levels of glutamatergic (especially NMDA receptor) activity relative to adults, whereas the GABA system is still developmentally immature. Activation of NMDA receptors likely plays a role in modulation of social behavior in adolescent animals as well as in socially facilitating and suppressing effects of ethanol. For instance, adolescent and adult rats differ in their sensitivities to the effects of NMDA antagonists and ethanol on social behavior, with adolescents but not adults demonstrating social facilitation at lower doses of both drugs and adults being more sensitive to the socially suppressing effects evident at higher doses of each. The roles of AMPA and extrasynaptic GABAA receptors in modulation of social behavior during adolescence and in adulthood are still unknown. The present study was designed to assess whether pharmacological blockade of AMPA receptors and/or activation of extrasynaptic GABAA receptors results in age-dependent alterations of social behavior. Adolescent and adult male and female Sprague-Dawley rats were injected with an assigned dose of either a selective AMPA antagonist, NBQX (Experiment 1) or extrasynaptic GABAA agonist, THIP (Experiment 2) and placed into a modified social interaction chamber for a 30-min habituation period prior to a 10-min social interaction test with a novel age- and sex-matched partner. Behaviors such as social investigation, contact behavior and play behavior were scored from video recordings of the interaction tests. In Experiment 1, NBQX produced similar social inhibition at higher doses in both age groups. In Experiment 2, THIP induced inhibition in adolescents, but not adults. No social facilitation was evident following low doses of either drug. Therefore, AMPA and extrasynaptic GABAA receptors appear to play little role if any in modulation of peer-directed social behavior in adolescence and adulthood and not likely to contribute to previously observed age differences in the social effects of acute ethanol.
Collapse
Affiliation(s)
- Carol A Dannenhoffer
- Neurobiology of Adolescent Drinking in Adulthood Consortium (NADIA), Center for Development and Behavioral Neuroscience, Department of Psychology, Binghamton University, 4400 Vestal Pkwy E, Binghamton, NY 13902-6000, United States.
| | - Elena I Varlinskaya
- Neurobiology of Adolescent Drinking in Adulthood Consortium (NADIA), Center for Development and Behavioral Neuroscience, Department of Psychology, Binghamton University, 4400 Vestal Pkwy E, Binghamton, NY 13902-6000, United States
| | - Linda Patia Spear
- Neurobiology of Adolescent Drinking in Adulthood Consortium (NADIA), Center for Development and Behavioral Neuroscience, Department of Psychology, Binghamton University, 4400 Vestal Pkwy E, Binghamton, NY 13902-6000, United States
| |
Collapse
|
15
|
Effects of Aging and Tocotrienol-Rich Fraction Supplementation on Brain Arginine Metabolism in Rats. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:6019796. [PMID: 29348790 PMCID: PMC5733770 DOI: 10.1155/2017/6019796] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 10/04/2017] [Accepted: 10/09/2017] [Indexed: 12/31/2022]
Abstract
Accumulating evidence suggests that altered arginine metabolism is involved in the aging and neurodegenerative processes. This study sought to determine the effects of age and vitamin E supplementation in the form of tocotrienol-rich fraction (TRF) on brain arginine metabolism. Male Wistar rats at ages of 3 and 21 months were supplemented with TRF orally for 3 months prior to the dissection of tissue from five brain regions. The tissue concentrations of L-arginine and its nine downstream metabolites were quantified using high-performance liquid chromatography and liquid chromatography tandem mass spectrometry. We found age-related alterations in L-arginine metabolites in the chemical- and region-specific manners. Moreover, TRF supplementation reversed age-associated changes in arginine metabolites in the entorhinal cortex and cerebellum. Multiple regression analysis revealed a number of significant neurochemical-behavioral correlations, indicating the beneficial effects of TRF supplementation on memory and motor function.
Collapse
|
16
|
Hihara H, Kanetaka H, Kanno A, Koeda S, Nakasato N, Kawashima R, Sasaki K. Evaluating age-related change in lip somatosensation using somatosensory evoked magnetic fields. PLoS One 2017; 12:e0179323. [PMID: 28617862 PMCID: PMC5472294 DOI: 10.1371/journal.pone.0179323] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Accepted: 05/26/2017] [Indexed: 12/04/2022] Open
Abstract
Somatosensory evoked fields (SEFs) to electrical stimulation on the right and left sides of the lower lip were measured using magnetoencephalography and compared in the bilateral hemispheres of 31 healthy normal young and 29 healthy normal elderly subjects to evaluate age-related change in lip somatosensation. The initial peak of the response around 13 ms, designated as N13m, and the second peak of the response, designated as P21m, were investigated. The N13m response, which was detected in 22 of 62 hemispheres in young adults and 37 of 58 hemispheres in elderly adults, showed significantly prolonged latency and increased equivalent current dipole (ECD) moment in the elderly adults. The P21m response, which was detected in 56 of 62 hemispheres in young adults and in 52 of 58 hemispheres in elderly adults, showed longer peak latency in the elderly adults. No significant difference was found in the ECD moment for P21m, which suggests that aging affected the SEFs of the lip somatosensation, but the effects of aging on N13m and P21m differed. Prolonged latency and increased ECD moment of N13m might result from decreased peripheral conduction and increased cortical excitation system associated with aging. Therefore, the initial response component might be an objective parameter for investigating change in lip function with age.
Collapse
Affiliation(s)
- Hiroki Hihara
- Division of Advanced Prosthetic Dentistry, Tohoku University Graduate School of Dentistry, Sendai, Miyagi, Japan
| | - Hiroyasu Kanetaka
- Liaison Center for Innovative Dentistry, Tohoku University Graduate School of Dentistry, Sendai, Miyagi, Japan
| | - Akitake Kanno
- Institute of Development, Aging and Cancer, Tohoku University, Sendai, Miyagi, Japan
| | - Satoko Koeda
- Graduate School of Tokyo Medical and Dental University, Oral and Maxillofacial Surgery, Tokyo, Japan
| | - Nobukazu Nakasato
- Department of Epileptology, Tohoku University School of Medicine, Sendai, Miyagi, Japan
| | - Ryuta Kawashima
- Institute of Development, Aging and Cancer, Tohoku University, Sendai, Miyagi, Japan
| | - Keiichi Sasaki
- Division of Advanced Prosthetic Dentistry, Tohoku University Graduate School of Dentistry, Sendai, Miyagi, Japan
| |
Collapse
|
17
|
Glutamate-glutamine and GABA in brain of normal aged and patients with cognitive impairment. Eur Radiol 2016; 27:2698-2705. [DOI: 10.1007/s00330-016-4669-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Revised: 10/28/2016] [Accepted: 11/21/2016] [Indexed: 02/07/2023]
|
18
|
Liguz-Lecznar M, Lehner M, Kaliszewska A, Zakrzewska R, Sobolewska A, Kossut M. Altered glutamate/GABA equilibrium in aged mice cortex influences cortical plasticity. Brain Struct Funct 2016; 220:1681-93. [PMID: 24659256 DOI: 10.1007/s00429-014-0752-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 03/07/2014] [Indexed: 11/25/2022]
Abstract
Age-related molecular changes in the synapse can cause plasticity decline. We found an impairment of experience-dependent cortical plasticity is induced by short lasting sensory conditioning in aged mice. However, extending the training procedure from 3 to 7 days triggered plasticity in the aged cortex of the same range as in young mice. Additionally, GABAergic markers (GABA, GAD67, VGAT) in young and aged groups that showed the plastic changes were upregulated. This effect was absent in the aged group with impaired plasticity, while the expression of Vglut1 increased in all trained groups. This may reflect the inefficiency of inhibitory mechanisms in the aging brain used to control increased excitation after training and to shape proper signal to noise ratio, which is essential for appropriate stimuli processing. HPLC analysis showed that the glutamate/GABA ratio was significantly reduced in aged animals due to a significant decrease in glutamate level. We also observed a decreased expression of several presynaptic markers involved in excitatory (vesicular glutamate transporter-vglut2) and inhibitory (glutamic acid decarboxylase-GAD67, vesicular GABA transporter VGAT) transmission in the aged barrel cortex. These changes may weaken the plasticity potential of neurons and impede the experience-dependent reorganization of cortical connections. We suggest that the imbalance toward inhibition resulting from a decrease of glutamate content in the aging cerebral cortex, together with GABAergic system ineffectiveness in upregulating GABA level after sensory training, contributes to the impairment of learning-dependent cortical plasticity.
Collapse
|
19
|
Choi IY, Lee P, Wang WT, Hui D, Wang X, Brooks WM, Michaelis EK. Metabolism changes during aging in the hippocampus and striatum of glud1 (glutamate dehydrogenase 1) transgenic mice. Neurochem Res 2014; 39:446-55. [PMID: 24442550 DOI: 10.1007/s11064-014-1239-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 01/03/2014] [Accepted: 01/08/2014] [Indexed: 01/31/2023]
Abstract
The decline in neuronal function during aging may result from increases in extracellular glutamate (Glu), Glu-induced neurotoxicity, and altered mitochondrial metabolism. To study metabolic responses to persistently high levels of Glu at synapses during aging, we used transgenic (Tg) mice that over-express the enzyme Glu dehydrogenase (GDH) in brain neurons and release excess Glu in synapses. Mitochondrial GDH is important in amino acid and carbohydrate metabolism and in anaplerotic reactions. We monitored changes in nineteen neurochemicals in the hippocampus and striatum of adult, middle aged, and aged Tg and wild type (wt) mice, in vivo, using proton ((1)H) magnetic resonance spectroscopy. Significant differences between adult Tg and wt were higher Glu, N-acetyl aspartate (NAA), and NAA + NAA-Glu (NAAG) levels, and lower lactate in the Tg hippocampus and striatum than those of wt. During aging, consistent changes in Tg and wt hippocampus and striatum included increases in myo-inositol and NAAG. The levels of glutamine (Gln), a key neurochemical in the Gln-Glu cycle between neurons and astroglia, increased during aging in both the striatum and hippocampus of Tg mice, but only in the striatum of the wt mice. Age-related increases of Glu were observed only in the striatum of the Tg mice.
Collapse
Affiliation(s)
- In-Young Choi
- Hoglund Brain Imaging Center, University of Kansas Medical Center, Kansas City, KS, USA
| | | | | | | | | | | | | |
Collapse
|
20
|
Villa RF, Ferrari F, Gorini A. Functional Proteomics Related to Energy Metabolism of Synaptosomes from Different Neuronal Systems of Rat Hippocampus during Aging. J Proteome Res 2013; 12:5422-35. [DOI: 10.1021/pr400834g] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Roberto F. Villa
- Department of Biology and
Biotechnology - Laboratory of Pharmacology and Molecular Medicine
of Central Nervous System, University of Pavia, Via Ferrata, 9, 27100 Pavia, Italy
| | - Federica Ferrari
- Department of Biology and
Biotechnology - Laboratory of Pharmacology and Molecular Medicine
of Central Nervous System, University of Pavia, Via Ferrata, 9, 27100 Pavia, Italy
| | - Antonella Gorini
- Department of Biology and
Biotechnology - Laboratory of Pharmacology and Molecular Medicine
of Central Nervous System, University of Pavia, Via Ferrata, 9, 27100 Pavia, Italy
| |
Collapse
|
21
|
Omega-3 fatty acids and brain resistance to ageing and stress: body of evidence and possible mechanisms. Ageing Res Rev 2013; 12:579-94. [PMID: 23395782 DOI: 10.1016/j.arr.2013.01.007] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 01/25/2013] [Accepted: 01/28/2013] [Indexed: 12/11/2022]
Abstract
The increasing life expectancy in the populations of rich countries raises the pressing question of how the elderly can maintain their cognitive function. Cognitive decline is characterised by the loss of short-term memory due to a progressive impairment of the underlying brain cell processes. Age-related brain damage has many causes, some of which may be influenced by diet. An optimal diet may therefore be a practical way of delaying the onset of age-related cognitive decline. Nutritional investigations indicate that the ω-3 poyunsaturated fatty acid (PUFA) content of western diets is too low to provide the brain with an optimal supply of docosahexaenoic acid (DHA), the main ω-3 PUFA in cell membranes. Insufficient brain DHA has been associated with memory impairment, emotional disturbances and altered brain processes in rodents. Human studies suggest that an adequate dietary intake of ω-3 PUFA can slow the age-related cognitive decline and may also protect against the risk of senile dementia. However, despite the many studies in this domain, the beneficial impact of ω-3 PUFA on brain function has only recently been linked to specific mechanisms. This review examines the hypothesis that an optimal brain DHA status, conferred by an adequate ω-3 PUFA intake, limits age-related brain damage by optimizing endogenous brain repair mechanisms. Our analysis of the abundant literature indicates that an adequate amount of DHA in the brain may limit the impact of stress, an important age-aggravating factor, and influences the neuronal and astroglial functions that govern and protect synaptic transmission. This transmission, particularly glutamatergic neurotransmission in the hippocampus, underlies memory formation. The brain DHA status also influences neurogenesis, nested in the hippocampus, which helps maintain cognitive function throughout life. Although there are still gaps in our knowledge of the way ω-3 PUFA act, the mechanistic studies reviewed here indicate that ω-3 PUFA may be a promising tool for preventing age-related brain deterioration.
Collapse
|
22
|
Latour A, Grintal B, Champeil-Potokar G, Hennebelle M, Lavialle M, Dutar P, Potier B, Billard JM, Vancassel S, Denis I. Omega-3 fatty acids deficiency aggravates glutamatergic synapse and astroglial aging in the rat hippocampal CA1. Aging Cell 2013; 12:76-84. [PMID: 23113887 DOI: 10.1111/acel.12026] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2012] [Indexed: 11/28/2022] Open
Abstract
Epidemiological data suggest that a poor ω3 status favoured by the low ω3/ω6 polyunsaturated fatty acids ratio in western diets contributes to cognitive decline in the elderly, but mechanistic evidence is lacking. We therefore explored the impact of ω3 deficiency on the evolution of glutamatergic transmission in the CA1 of the hippocampus during aging by comparing 4 groups of rats aged 6-22 months fed ω3-deficient or ω3/ω6-balanced diets from conception to sacrifice: Young ω3 Balanced (YB) or Deficient (YD), Old ω3 Balanced (OB) or Deficient (OD) rats. ω3 Deficiency induced a 65% decrease in the amount of docosahexaenoic acid (DHA, the main ω3 in cell membranes) in brain phospholipids, but had no impact on glutamatergic transmission and astroglial function in young rats. Aging induced a 10% decrease in brain DHA, a 35% reduction of synaptic efficacy (fEPSP/PFV) due to decreased presynaptic glutamate release and a 30% decrease in the astroglial glutamate uptake associated with a marked astrogliosis (+100% GFAP). The ω3 deficiency further decreased these hallmarks of aging (OD vs. OB rats: -35% fEPSP/PFV P < 0.05, -15% astroglial glutamate uptake P < 0.001, +30% GFAP P < 0.01). This cannot be attributed to aggravation of the brain DHA deficit because the brains of OD rats had more DHA than those of YD rats. Thus, ω3 deficiency worsens the age-induced degradation of glutamatergic transmission and its associated astroglial regulation in the hippocampus.
Collapse
Affiliation(s)
| | | | | | | | | | - Patrick Dutar
- Centre de Psychiatrie et Neurosciences; UMR 894; INSERM; Paris; 75014; France
| | - Brigitte Potier
- Centre de Psychiatrie et Neurosciences; UMR 894; INSERM; Paris; 75014; France
| | - Jean-Marie Billard
- Centre de Psychiatrie et Neurosciences; UMR 894; INSERM; Paris; 75014; France
| | | | | |
Collapse
|
23
|
Villa RF, Ferrari F, Gorini A. Effect of CDP-choline on age-dependent modifications of energy- and glutamate-linked enzyme activities in synaptic and non-synaptic mitochondria from rat cerebral cortex. Neurochem Int 2012; 61:1424-32. [PMID: 23099360 DOI: 10.1016/j.neuint.2012.10.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2012] [Revised: 09/14/2012] [Accepted: 10/13/2012] [Indexed: 01/08/2023]
Abstract
The effect of aging and CDP-choline treatment (20 mg kg⁻¹ body weight i.p. for 28 days) on the maximal rates (V(max)) of representative mitochondrial enzyme activities related to Krebs' cycle (citrate synthase, α-ketoglutarate dehydrogenase, malate dehydrogenase), glutamate and related amino acid metabolism (glutamate dehydrogenase, glutamate-oxaloacetate- and glutamate-pyruvate transaminases) were evaluated in non-synaptic and intra-synaptic "light" and "heavy" mitochondria from frontal cerebral cortex of male Wistar rats aged 4, 12, 18 and 24 months. During aging, enzyme activities vary in a complex way respect to the type of mitochondria, i.e. non-synaptic and intra-synaptic. This micro-heterogeneity is an important factor, because energy-related mitochondrial enzyme catalytic properties cause metabolic modifications of physiopathological significance in cerebral tissue in vivo, also discriminating pre- and post-synaptic sites of action for drugs and affecting tissue responsiveness to noxious stimuli. Results show that CDP-choline in vivo treatment enhances cerebral energy metabolism selectively at 18 months, specifically modifying enzyme catalytic activities in non-synaptic and intra-synaptic "light" mitochondrial sub-populations. This confirms that the observed changes in enzyme catalytic activities during aging reflect the bioenergetic state at each single age and the corresponding energy requirements, further proving that in vivo drug treatment is able to interfere with the neuronal energy metabolism.
Collapse
Affiliation(s)
- Roberto Federico Villa
- Laboratory of Pharmacology and Molecular Medicine of Central Nervous System, Department of Biology and Biotechnology, University of Pavia, Via Ferrata 9, 27100 Pavia, Italy.
| | | | | |
Collapse
|
24
|
Villa RF, Ferrari F, Gorini A. Energy metabolism of rat cerebral cortex, hypothalamus and hypophysis during ageing. Neuroscience 2012; 227:55-66. [PMID: 23022213 DOI: 10.1016/j.neuroscience.2012.09.041] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 09/07/2012] [Accepted: 09/19/2012] [Indexed: 11/16/2022]
Abstract
Ageing is one of the main risk factors for brain disorders. According to the neuroendocrine theory, ageing modifies the sensitivity of hypothalamus-pituitary-adrenal axis to homoeostatic signals coming from the cerebral cortex. The relationships between the energy metabolism of these areas have not been considered yet, in particular with respect to ageing. For these reasons, this study was undertaken to systematically investigate in female Sprague-Dawley rats aged 4, 6, 12, 18, 24, 28 months and in 4-month-old male ones, the catalytic properties of energy-linked enzymes of the Krebs' cycle, electron transport chain, glutamate and related amino acids on different mitochondrial subpopulations, i.e. non-synaptic perikaryal and intra-synaptic (two types) mitochondria. The biochemical enzymatic pattern of these mitochondria shows different expression of the above-mentioned enzymatic activities in the investigated brain areas, including frontal cerebral cortex, hippocampus, striatum, hypothalamus and hypophysis. The study shows that: (i) the energy metabolism of the frontal cerebral cortex is poorly affected by physiological ageing; (ii) the biochemical machinery of non-synaptic perikaryal mitochondria is differently expressed in the considered brain areas; (iii) at 4-6 months, hypothalamus and hypophysis possess lower oxidative metabolism with respect to the frontal cerebral cortex while (iv), during ageing, the opposite situation occurs. We hypothesised that these metabolic modifications likely try to grant HPA functionality in response to the incoming external stress stimuli increased during ageing. It is particularly notable that age-related changes in brain bioenergetics and in mitochondrial functionality may be considered as remarkable factors during physiological ageing and should play important roles in predisposing the brain to physiopathological events, tightly related to molecular mechanisms evoked for pharmacological treatments.
Collapse
Affiliation(s)
- R F Villa
- University of Pavia, Department of Biology and Biotechnology, Laboratory of Pharmacology and Molecular Medicine of Central Nervous System, Via Ferrata 9, 27100 Pavia, Italy.
| | | | | |
Collapse
|
25
|
Ruzzoli M, Pirulli C, Brignani D, Maioli C, Miniussi C. Sensory memory during physiological aging indexed by mismatch negativity (MMN). Neurobiol Aging 2012; 33:625.e21-30. [DOI: 10.1016/j.neurobiolaging.2011.03.021] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 03/07/2011] [Accepted: 03/22/2011] [Indexed: 11/15/2022]
|
26
|
Abstract
The literature on the neuroanatomical changes that occur during normal, non-demented aging is reviewed here with an emphasis on the improved accuracy of studies that use stereological techniques. Loss of neural tissue involved in cognition occurs during aging of humans as well as the other mammals that have been examined. There is considerable regional specificity within the cerebral cortex and the hippocampus in both the degree and cellular basis for loss. The anatomy of the prefrontal cortex is especially vulnerable to the effects of aging while the major subfields of the hippocampus are not. A loss of neurons, dendrites and synapses has been documented, as well as changes in neurotransmitter systems, in some regions of the cortex and hippocampus but not others. Species differences are also apparent in the cortical white matter and the corpus callosum where there are indications of loss of myelin in humans, but most evidence favors preservation in rats. The examination of whether the course of neuroanatomical aging is altered by hormone replacement in females is just beginning. When hormone replacement is started close to the time of cycle cessation, there are indications in humans and rats that replacement can preserve neural tissue but there is some variability due to the type of hormones and regimen of administration.
Collapse
Affiliation(s)
- Janice M Juraska
- Department of Psychology and Program in Neuroscience, University of Illinois, 603 E Daniel, Champaign, IL, 61820, USA,
| | | |
Collapse
|
27
|
Potier B, Billard JM, Rivière S, Sinet PM, Denis I, Champeil-Potokar G, Grintal B, Jouvenceau A, Kollen M, Dutar P. Reduction in glutamate uptake is associated with extrasynaptic NMDA and metabotropic glutamate receptor activation at the hippocampal CA1 synapse of aged rats. Aging Cell 2010; 9:722-35. [PMID: 20569241 DOI: 10.1111/j.1474-9726.2010.00593.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
This study aims to determine whether the regulation of extracellular glutamate is altered during aging and its possible consequences on synaptic transmission and plasticity. A decrease in the expression of the glial glutamate transporters GLAST and GLT-1 and reduced glutamate uptake occur in the aged (24-27 months) Sprague-Dawley rat hippocampus. Glutamatergic excitatory postsynaptic potentials recorded extracellularly in ex vivo hippocampal slices from adult (3-5 months) and aged rats are depressed by DL-TBOA, an inhibitor of glutamate transporter activity, in an N-Methyl-d-Aspartate (NMDA)-receptor-dependent manner. In aged but not in young rats, part of the depressing effect of DL-TBOA also involves metabotropic glutamate receptor (mGluRs) activation as it is significantly reduced by the specific mGluR antagonist d-methyl-4-carboxy-phenylglycine (MCPG). The paired-pulse facilitation ratio, a functional index of glutamate release, is reduced by MCPG in aged slices to a level comparable to that in young rats both under control conditions and after being enhanced by DL-TBOA. These results suggest that the age-associated glutamate uptake deficiency favors presynaptic mGluR activation that lowers glutamate release. In parallel, 2 Hz-induced long-term depression is significantly decreased in aged animals and is fully restored by MCPG. All these data indicate a facilitated activation of extrasynaptic NMDAR and mGluRs in aged rats, possibly because of an altered distribution of glutamate in the extrasynaptic space. This in turn affects synaptic transmission and plasticity within the aged hippocampal CA1 network.
Collapse
Affiliation(s)
- Brigitte Potier
- Université Paris Descartes, Centre de Psychiatrie et de Neurosciences, UMR, Paris, France.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Ahmad AS, Ahmad M, Maruyama T, Narumiya S, Doré S. Prostaglandin D2 DP1 receptor is beneficial in ischemic stroke and in acute exicitotoxicity in young and old mice. AGE (DORDRECHT, NETHERLANDS) 2010; 32:271-282. [PMID: 20640551 PMCID: PMC2926852 DOI: 10.1007/s11357-010-9135-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Accepted: 01/29/2010] [Indexed: 05/29/2023]
Abstract
The cardiovascular complications reported to be associated with cyclooxygenase inhibitor use have shifted our focus toward prostaglandins and their respective receptors. Prostaglandin D(2) and its DP1 receptor have been implicated in various normal and pathologic conditions, but their role in stroke is still poorly defined. Here, we tested whether DP1 deletion aggravates N-methyl-D: -aspartic acid (NMDA)-induced acute toxicity and whether DP1 pharmacologic activation protects mice from acute excitotoxicity and transient cerebral ischemia. Moreover, since the elderly are more vulnerable to stroke-related damage than are younger patients, we tested the susceptibility of aged DP1 knockout (DP1(-/-)) mice to brain damage. We found that intrastriatal injection of 15 nmol NMDA caused significantly larger lesion volumes (27.2 +/- 6.4%) in young adult DP1(-/-) mice than in their wild-type counterparts. Additionally, intracerebroventricular pretreatment of wild-type mice with 10, 25, and 50 nmol of the DP1-selective agonist BW245C significantly attenuated the NMDA-induced lesion size by 19.5 +/- 5.0%, 39.6 +/- 7.7%, and 28.9 +/- 7.0%, respectively. The lowest tested dose of BW245C also was able to reduce middle cerebral artery occlusion-induced brain infarction size significantly (21.0 +/- 5.7%). Interestingly, the aggravated NMDA-induced brain damage was persistent in older DP1(-/-) mice as well. We conclude that the DP1 receptor plays an important role in attenuating brain damage and that selective targeting of this receptor could be considered as an adjunct therapeutic tool to minimize stroke damage.
Collapse
Affiliation(s)
- Abdullah Shafique Ahmad
- Department of Anesthesiology/Critical Care Medicine, Johns Hopkins University School of Medicine, 720 Rutland Ave., Ross 364, Baltimore, MD 21205 USA
| | - Muzamil Ahmad
- Department of Anesthesiology/Critical Care Medicine, Johns Hopkins University School of Medicine, 720 Rutland Ave., Ross 364, Baltimore, MD 21205 USA
| | - Takayuki Maruyama
- Pharmacological Research Laboratories, Ono Pharmaceutical Co. Ltd., Mishima-gun, Osaka, Japan
| | - Shuh Narumiya
- Department of Pharmacology, Kyoto University Faculty of Medicine, Kyoto, Japan
| | - Sylvain Doré
- Department of Anesthesiology/Critical Care Medicine, Johns Hopkins University School of Medicine, 720 Rutland Ave., Ross 364, Baltimore, MD 21205 USA
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD USA
| |
Collapse
|
29
|
Differential response of AMPA and NMDA glutamate receptors of Purkinje cells to aging of the chicken cerebellum. Neurosci Lett 2010; 478:146-9. [DOI: 10.1016/j.neulet.2010.05.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2009] [Revised: 04/19/2010] [Accepted: 05/04/2010] [Indexed: 11/19/2022]
|
30
|
Liguz-Lecznar M, Siucinska E, Zakrzewska R, Kossut M. Impairment of experience-dependent cortical plasticity in aged mice. Neurobiol Aging 2009; 32:1896-905. [PMID: 20005597 DOI: 10.1016/j.neurobiolaging.2009.11.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2009] [Revised: 11/10/2009] [Accepted: 11/13/2009] [Indexed: 11/15/2022]
Abstract
This study addresses the relationship between aging and experience-dependent plasticity in the mouse somatosensory cortex. Plasticity in the cortical representation of vibrissae (whiskers) was investigated in young (3 months), mature (14 months) and old (2 years) mice using [14C]2-deoxyglucose (2-DG) autoradiography. Plastic changes were evoked using two experimental paradigms. The deprivation-based protocol included unilateral deprivation of all but one row of whiskers for a week. In the conditioning protocol the animals were subjected to classical conditioning, where tactile stimulation of one row of whiskers was paired with an aversive stimulus. Both procedures evoked functional plasticity in the young group, expressed as a widening of the functional cortical representation of the spared or conditioned row. Aging had a differential effect on these two forms of plasticity. Conditioning-related plasticity was more vulnerable to aging: the plastic change was not detectable in mature animals, even though they acquired the behavioral response. Deprivation-induced plasticity also declined with age, but some effects were persistent in the oldest animals.
Collapse
Affiliation(s)
- Monika Liguz-Lecznar
- Dept. of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology, 3 Pasteur Street, 02-093 Warsaw, Poland.
| | | | | | | |
Collapse
|
31
|
Increased cortical plasticity in the elderly: changes in the somatosensory cortex after paired associative stimulation. Neuroscience 2009; 163:266-76. [PMID: 19524024 DOI: 10.1016/j.neuroscience.2009.06.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Revised: 05/20/2009] [Accepted: 06/06/2009] [Indexed: 02/08/2023]
|
32
|
Stephens ML, Quintero JE, Pomerleau F, Huettl P, Gerhardt GA. Age-related changes in glutamate release in the CA3 and dentate gyrus of the rat hippocampus. Neurobiol Aging 2009; 32:811-20. [PMID: 19535175 DOI: 10.1016/j.neurobiolaging.2009.05.009] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2009] [Revised: 05/01/2009] [Accepted: 05/08/2009] [Indexed: 12/31/2022]
Abstract
The present studies employed a novel microelectrode array recording technology to study glutamate release and uptake in the dentate gyrus, CA3 and CA1 hippocampal subregions in anesthetized young, late-middle aged and aged male Fischer 344 rats. The mossy fiber terminals in CA3 showed a significantly decreased amount of KCl-evoked glutamate release in aged rats compared to both young and late-middle-aged rats. Significantly more KCl-evoked glutamate release was seen from perforant path terminals in the DG of late-middle-aged rats compared young and aged rats. The DG of aged rats developed an increased glutamate uptake rate compared to the DG of young animals, indicating a possible age-related change in glutamate regulation to deal with increased glutamate release that occurred in late-middle age. No age-related changes in resting levels of glutamate were observed in the DG, CA3 and CA1. Taken together, these data support dynamic changes to glutamate regulation during aging in subregions of the mammalian hippocampus that are critical for learning and memory.
Collapse
Affiliation(s)
- Michelle L Stephens
- Department of Anatomy and Neurobiology, Center for Microelectrode Technology, Morris K. Udall Parkinson's Disease Research Center of Excellence, University of Kentucky Chandler Medical Center, Lexington, KY 40536-0098, USA
| | | | | | | | | |
Collapse
|
33
|
Oja SS, Saransaari P. Release of Endogenous Amino Acids from the Hippocampus and Brain Stem from Developing and Adult Mice in Ischemia. Neurochem Res 2009; 34:1668-76. [DOI: 10.1007/s11064-009-9961-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Accepted: 03/18/2009] [Indexed: 11/29/2022]
|
34
|
Pal S, Poddar MK. Long-term exposure of variable dietary protein-to-carbohydrate ratio: effect on brain regional glutamatergic activity with age. Neurochem Res 2007; 33:952-61. [PMID: 17763947 DOI: 10.1007/s11064-007-9460-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2007] [Accepted: 07/23/2007] [Indexed: 10/22/2022]
Abstract
Glutamatergic activity of hypothalamus and hippocampus of young (3 months) male albino rats having normal diet [protein (20%)-carbohydrate (68%)] was increased with the increase of age. Long-term (60 consecutive days) feeding of low protein (8%)-high carbohydrate (80%) diet (LP-HC) increased glutamatergic activity in these brain regions of young rats and decreased that in aged (18 months). On the contrary, supplementation of high protein (50%)-low carbohydrate (38%) diet (HP-LC) under similar condition decreased glutamatergic activity in those brain regions of young and increased that in aged brain regions. Thus, prolonged exposure of LP-HC diet may damage young brain; whereas, HP-LC diet under similar condition causes excitotoxicity to aged brain. Therefore, considering the present scenario in relation to metabolism and receptor activity of glutamatergic system, it may be suggested that long-term consumption of LP-HC and HP-LC diets modulate the brain regional glutamatergic activity reversibly with age.
Collapse
Affiliation(s)
- Sudipta Pal
- Neuroscience Division, Department of Biochemistry, University of Calcutta, 35 B. C. Road, Kolkata 700 019, India
| | | |
Collapse
|
35
|
Zappasodi F, Pasqualetti P, Tombini M, Ercolani M, Pizzella V, Rossini PM, Tecchio F. Hand cortical representation at rest and during activation: Gender and age effects in the two hemispheres. Clin Neurophysiol 2006; 117:1518-28. [PMID: 16740403 DOI: 10.1016/j.clinph.2006.03.016] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2005] [Revised: 03/16/2006] [Accepted: 03/21/2006] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To characterize the age- and gender- dependence of sensory hand cortical representation in the two hemispheres in healthy population. METHODS In 57 adults, the cerebral activity from rolandic areas as detected by magnetoencephalography was considered both in a resting state (spectral power properties) and in response to the electrical stimulation of the contralateral median nerve (M20 and M30 cortical sources). RESULTS We found a dependence of rest and evoked activity on age (alpha rhythm slowing, high frequency power increase, M20 latency increase, M20 strength increase, no change in M30) and on gender (higher alpha frequency, higher beta power, higher spectral entropy, lower M20 amplitude in women). These changes were quite symmetrical in the two hemispheres, making the interhemispheric differences non-dependent on age and gender. Moreover, lower total power and faster alpha rhythm appeared in the dominant hemisphere. CONCLUSIONS Age and gender have a significant effect on spontaneous and evoked activity at the primary sensorimotor cortex. SIGNIFICANCE The results consolidate the reference base in healthy population, to study pathological conditions. Inter-hemispheric asymmetries are confirmed as a sensitive indicator for the early identification of possible neuronal rearrangements due to unilateral brain injuries.
Collapse
|
36
|
Miccheli A, Puccetti C, Capuani G, Di Cocco ME, Giardino L, Calzà L, Battaglia A, Battistin L, Conti F. [1-13C]Glucose entry in neuronal and astrocytic intermediary metabolism of aged rats. A study of the effects of nicergoline treatment by 13C NMR spectroscopy. Brain Res 2003; 966:116-25. [PMID: 12646315 DOI: 10.1016/s0006-8993(02)04217-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Age-related changes in glucose utilization through the TCA cycle were studied using [1-13C]glucose and 13C, 1H NMR spectroscopy on rat brain extracts. Significant increases in lactate levels, as well as in creatine/phosphocreatine ratios (Cr/PCr), and a decrease in N-acetyl-aspartate (NAA) and aspartate levels were observed in aged rat brains as compared to adult animals following glucose administration. The total amount of 13C from [1-13C]glucose incorporated in glutamate, glutamine, aspartate and GABA was significantly decreased in control aged rat brains as compared to adult brains. The results showed a decrease in oxidative glucose utilization of control aged rat brains. The long-term nicergoline treatment increased NAA and glutamate levels, and decreased the lactate levels as well as the Cr/PCr ratios in aged rat brains as compared to adult rats. The total amount of 13C incorporated in glutamate, glutamine, aspartate, NAA and GABA was increased by nicergoline treatment, showing an improvement in oxidative glucose metabolism in aged brains. A significant increase in pyruvate carboxylase/pyruvate dehydrogenase activity (PC/PDH) in the synthesis of glutamate in nicergoline-treated aged rats is consistent with an increase in the transport of glutamine from glia to neurons for conversion into glutamate. In adult rat brains, no effect of nicergoline on glutamate PC/PDH activity was observed, although an increase in PC/PDH activity in glutamine was, suggesting that nicergoline affects the glutamate/glutamine cycle between neurons and glia in different ways depending on the age of animals. These results provide new insights into the effects of nicergoline on the CNS.
Collapse
Affiliation(s)
- Alfredo Miccheli
- Department of Chemistry, 'La Sapienza' University of Rome, P le A Moro 5, 00185 Rome, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Astrocytes and microgliain Alzheimer's disease. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s1569-2558(03)31039-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
38
|
Gottfried C, Tramontina F, Gonçalves D, Gonçalves CA, Moriguchi E, Dias RD, Wofchuk ST, Souza DO. Glutamate uptake in cultured astrocytes depends on age: a study about the effect of guanosine and the sensitivity to oxidative stress induced by H(2)O(2). Mech Ageing Dev 2002; 123:1333-40. [PMID: 12297336 DOI: 10.1016/s0047-6374(02)00069-6] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Relatively few studies have been conducted to investigate the relationship between glutamate and development and/or aging. Rat cortical astrocyte cultures were used as a model to investigate glutamate uptake during development. The immunocontent of the markers glial fibrillary acidic protein (GFAP) and S100B increased, while basal secretion of S100B decreased, in astrocytes from 10 to 40 days in vitro (DIV). Basal glutamate uptake increased with age. Exposure to hydrogen peroxide decreased glutamate uptake more potently at 40 than 10 DIV. Moreover, 40 DIV astrocytes showed earlier loss of integrity (at 6 h) than 10 DIV astrocytes (at 24 h) after H(2)O(2) exposure. Addition of guanosine stimulated glutamate uptake only in 10 DIV astrocytes. The present work shows that mature astrocytes in culture present some neurochemical alterations also observed in astrocytes of aged animals. These results can contribute to the understanding of some consequences of the excitotoxicity and oxidative stress during brain aging.
Collapse
Affiliation(s)
- Carmem Gottfried
- Departamento de Ciências Fisiológicas, Faculdade de Biociências, Pontifi;cia Universidade Católica do Rio Grande do Sul, PUCRS, RS, Porto Alegre, Brazil.
| | | | | | | | | | | | | | | |
Collapse
|
39
|
Chakrabarti L, Bandyopadhyay BC, Poddar MK. Is age-induced decline in immune response associated with hypothalamic glutamate receptor density and dietary protein? Nutr Neurosci 2002; 4:375-87. [PMID: 11842914 DOI: 10.1080/1028415x.2001.11747374] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Manipulation of dietary protein has been found to be the most useful dictator in the age-associated decline of neuroimmune activity in mammals. In the present study, we sought to clarify the effect of dietary protein on age-induced alterations of hypothalamic glutamatergic activity and immune response. The hypothalamic glutamatergic activity and immune response were found to increase and decrease, respectively, with the increase in age of rats from young (3 months) to old (18 months) maintained with normal (20%) protein diet. Intake of low (5%) protein diet (LPD) and high (40%) protein diet (HPD) under short-term period (7 days) failed to alter the age-associated loss of immune response and increase in hypothalamic glutamatergic activity. However, long-term (30 days) supplementation of LPD retarded the age-induced decline in immune response and increase in hypothalamic glutamatergic activity, whereas, HPD consumption under similar condition potentiated the age-related immunosuppression and increase in hypothalamic glutamatergic activity. These results suggest that (a) the age-associated immunosuppression may be inversely related to the hypothalamic glutamatergic activity and (b) consumption of diets having variable quantity of protein without variation of calorie content modulates immune response and hypothalamic glutamatergic activity depending upon age and duration of dietary supplementation.
Collapse
Affiliation(s)
- L Chakrabarti
- Department of Biochemistry, University of Calcutta, India
| | | | | |
Collapse
|
40
|
Segovia G, Porras A, Del Arco A, Mora F. Glutamatergic neurotransmission in aging: a critical perspective. Mech Ageing Dev 2001; 122:1-29. [PMID: 11163621 DOI: 10.1016/s0047-6374(00)00225-6] [Citation(s) in RCA: 248] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The effects of aging on glutamate neurotransmission in the brain is reviewed and evaluated. Glutamate is the neurotransmitter in most of the excitatory synapses and appears to be involved in functions such as motor behaviour, cognition and emotion, which alter with age. However, relatively few studies have been conducted to study the relationship between glutamate and aging of the brain. The studies presented here indicate the existence of a number of changes in the glutamatergic system during the normal process of aging. First, an age-related decrease of glutamate content in tissue from cerebral cortex and hippocampus has been reported, although it may be mainly a consequence of changes in metabolic activity rather than glutamatergic neurotransmission. On the other hand, studies in vitro and in vivo have shown no changes in glutamate release during aging. Since glutamate sampled in most of these studies is the result of a balance between release and uptake processes, the lack of changes in glutamate release may be due to compensatory changes in glutamate uptake. In fact, a reduced glutamate uptake capacity, as well as a loss in the number of high affinity glutamate transporters in glutamatergic terminals of aged rats, have been described. However, the most significant and consistent finding is the decrease in the density of glutamatergic NMDA receptors with age. A new perspective, in which glutamate interacts with other neurotransmitters to conform the substrates of specific circuits of the brain and its relevance to aging, is included in this review. In particular, studies from our laboratory suggest the existence of age-related changes in the interaction between glutamate and other neurotransmitters, e.g. dopamine and GABA, which are regionally specific.
Collapse
Affiliation(s)
- G Segovia
- Department of Physiology, Faculty of Medicine, Complutense University of Madrid, Av. Complutense s/n, 28040, Madrid, Spain
| | | | | | | |
Collapse
|
41
|
Lovell MA, Xie C, Markesbery WR. Acrolein, a product of lipid peroxidation, inhibits glucose and glutamate uptake in primary neuronal cultures. Free Radic Biol Med 2000; 29:714-20. [PMID: 11053772 DOI: 10.1016/s0891-5849(00)00346-4] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Oxidative stress has been implicated in the pathogenesis of several neurodegenerative disorders including Alzheimer's disease (AD). Increased lipid peroxidation, decreased levels of polyunsaturated fatty acids, and increased levels of 4-hydroxynonenal (HNE), F(2)-isoprostanes, and F(4)-neuroprostanes are present in the brain in patients with AD. Acrolein, an alpha,beta-unsaturated aldehydic product of lipid peroxidation has been demonstrated to be approximately 100 times more reactive than HNE and is present in neurofibrillary tangles in the brain in AD. We recently demonstrated statistically significant elevated concentrations of extractable acrolein in the hippocampus/parahippocampal gyrus and amygdala in AD compared with age-matched control subjects. Concentrations of acrolein were two to five times those of HNE in the same samples. Treatment of hippocampal cultures with acrolein led to a time- and concentration-dependent decrease in cell survival as well as a concentration-dependent increase in intracellular calcium. In cortical neuron cultures, we now report that acrolein causes a concentration-dependent impairment of glutamate uptake and glucose transport in cortical neuron cultures. Treatment of cortical astrocyte cultures with acrolein led to the same pattern of impairment of glutamate uptake as observed in cortical neuron cultures. Collectively, these data demonstrate neurotoxicity mechanisms of arolein that might be important in the pathogenesis of neuron degeneration in AD.
Collapse
Affiliation(s)
- M A Lovell
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536-0230, USA
| | | | | |
Collapse
|
42
|
Perron JT, Tyson RL, Sutherland GR. Maintenance of tricarboxylic acid cycle kinetics in Brown-Norway Fischer 344 rats may translate to longevity. Neurosci Lett 2000; 281:91-4. [PMID: 10704750 DOI: 10.1016/s0304-3940(00)00825-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Glucose metabolism and tricarboxylic acid cycle (TCA) kinetics have been shown to decline in brain with age in various animal species. This study examined TCA cycle kinetics and age in Brown-Norway Fischer 344 rats. Using [1-(13)C]glucose infused over 10, 30, 60 or 100 min, and following the label through the TCA cycle using (1)H¿(13)C¿ spin-echo difference magnetic resonance spectroscopy, groups of 2 (n=18), 12 (n=16), and 24 (n=16) month old rats were evaluated. Unexpectedly, TCA cycle kinetics did not change with age. Observed decreases in glutamate, glutamine and N-acetyl aspartate levels are consistent with an age-related decrease in neuronal numbers. The possible link between this observation and increased longevity, together with a decreased incidence of neoplasia in the Brown-Norway Fischer 344 rat is discussed.
Collapse
Affiliation(s)
- J T Perron
- Seaman Family MR Research Center and the Department of Clinical Neurosciences, University of Calgary, Foothills Hospital, 1403-29 Street NW, Calgary, Alberta, Canada
| | | | | |
Collapse
|
43
|
Huttunen J, Wikström H, Salonen O, Ilmoniemi RJ. Human somatosensory cortical activation strengths: comparison between males and females and age-related changes. Brain Res 1999; 818:196-203. [PMID: 10082804 DOI: 10.1016/s0006-8993(98)01215-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The amplitudes of many scalp-recorded evoked potential (EP) deflections are higher in females than in males, and in elderly than in young subjects. Since EPs critically depend on the electric conductivity of the cranium, it is not known whether these differences reflect age- and gender-dependent changes in the intensity of neuronal activation, or changes in the volume conductor. Evoked magnetic fields are not significantly affected by the conductivities of the cranial tissues and therefore reflect more directly the neuronal activation than EPs. We report here on the effects of age and gender on somatosensory evoked fields (SEFs) from the primary somatosensory cortex (SI) in 43 healthy subjects (21 males) aged from 20 to 73 years (males 51+/-18 years, females 51+/-14 years). The intensity of neuronal activation was estimated with equivalent current dipoles (ECDs) found at the peaks of the N20m, P35m and P60m deflections from the left SI after right median nerve stimulation. The peak latencies of N20m and P35m (but not of P60m) were shorter in females than in males. The N20m latency was positively correlated with age in males, but otherwise the latencies did not correlate with age. The ECD amplitudes did not differ between males and females for any of the deflections. The N20m ECD strength showed a significant positive correlation (r=0.39, p<0.01) with age while P35m and P60m ECD strengths did not. The results thus did not disclose gender differences in the activation strengths of the somatosensory cortex, implying that such differences in evoked potentials may possibly be due to gender differences in the volume conductor. On the other hand, the results suggest a slight age-related increase in cortical excitability.
Collapse
Affiliation(s)
- J Huttunen
- BioMag Laboratory, Medical Engineering Centre, Helsinki University Central Hospital, Helsinki, Finland.
| | | | | | | |
Collapse
|
44
|
De la Fuente M, Miñano M, Manuel Victor V, Del Rio M, Ferrández MD, Díez A, Miquel J. Relation between exploratory activity and immune function in aged mice: a preliminary study. Mech Ageing Dev 1998; 102:263-77. [PMID: 9720657 DOI: 10.1016/s0047-6374(98)00015-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Previous studies show that fast exploration of a T-shaped maze by mature mice may predict an above average longevity. Since the nervous and the immune systems work in a coordinated fashion, and it seems that these two homeostatic systems both influence organismic aging and suffer a senescent decline, we have performed a comparative study of the above behavioral parameter and different functions of three representative immune cells: lymphocytes, macrophages and natural killer (NK) cells obtained from old (76 +/- 1 weeks of age) female OF1-Swiss mice. At 70 weeks of age the mice were divided into a 'fast' and a 'slow' group, containing 100 and 0%, respectively, of animals able to explore the 50 cm-long first arm of the maze in 20 s or less. At 76 +/- 1 weeks of age the animals were sacrificed, the peritoneal cell suspensions were obtained and the immune organs (axillary nodes, spleen and thymus) were isolated. The following leukocyte functions were studied in peritoneal macrophages: adherence to substrate, mobility (spontaneous and chemotaxis), ingestion of particles and superoxide anion production whereas mobility, lymphoproliferative response to the mitogen Con A and NK activity were studied in the immune-organ leukocyte suspensions. The results show that the aged fast mice have better immune functions than the aged slow mice.
Collapse
Affiliation(s)
- M De la Fuente
- Department of Animal Physiology, Faculty of Biological Sciences, Complutense University, Madrid, Spain.
| | | | | | | | | | | | | |
Collapse
|
45
|
Roberts EL, Wisotzky D, Chih CP. Aging and the effects of MK-801 on anoxic damage in rat hippocampal slices. Brain Res 1998; 791:321-4. [PMID: 9593969 DOI: 10.1016/s0006-8993(98)00141-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We examined whether age-related differences in N-methyl-D-aspartate (NMDA) receptor-mediated neurotoxicity contribute to the increased vulnerability of the aged brain to anoxic damage. In both adult and aged hippocampal slices, NMDA receptor blockade with MK-801 did not affect the onset of anoxic depolarization. MK-801 improved the postanoxic recovery of synaptic transmission by the same percentage in both age groups. Thus, the faster onset of anoxic depolarization and diminished postanoxic recovery of synaptic transmission seen in aged hippocampal slices cannot be attributed to age-related differences in NMDA receptor-mediated neurotoxicity.
Collapse
Affiliation(s)
- E L Roberts
- Geriatric Research, Education, and Clinical Center, Miami VA Medical Center, Miami, FL 33125, USA
| | | | | |
Collapse
|
46
|
Liachenko S, Tang P, Somogyi GT, Xu Y. Comparison of anaesthetic and non-anaesthetic effects on depolarization-evoked glutamate and GABA release from mouse cerebrocortical slices. Br J Pharmacol 1998; 123:1274-80. [PMID: 9559915 PMCID: PMC1565278 DOI: 10.1038/sj.bjp.0701728] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
1. Investigation with substances that are similar in structure, but different in anaesthetic properties, may lead to further understanding of the mechanisms of general anaesthesia. 2. We have studied the effects of two cyclobutane derivatives, the anaesthetic, 1-chloro-1,2,2-trifluorocyclobutane (F3), and the non-anaesthetic, 1,2-dichlorohexafluorocyclobutane (F6), on K+-evoked glutamate and gamma-aminobutyric acid (GABA) release from isolated, superfused, cerebrocortical slices from mice, by use of h.p.l.c. with fluorescence detection for quantitative analysis. 3. At clinically relevant concentrations, the anaesthetic, F3, inhibited 40 mM K+-evoked glutamate and GABA release by 72% and 47%, respectively, whereas the structurally similar non-anaesthetic, F6, suppressed evoked glutamate release by 70% but had no significant effects on evoked GABA release. A second exposure to 40 mM KCl after a approximately 30 min washout of F3 or F6 showed recovery of K+-evoked release, suggesting that F3 and F6 did not cause any non-specific or irreversible changes in the brain slices. 4. Our findings suggest that suppression of excitatory neurotransmitter release may not be directly relevant to the primary action of general anaesthetics. A mechanism involving inhibitory postsynaptic action is implicated, in which a moderate suppression of depolarization-evoked GABA release by the anaesthetic may be consistent with the enhancement of postsynaptic GABAergic activities.
Collapse
Affiliation(s)
- S Liachenko
- Department of Anaesthesiology and Critical Care Medicine, University of Pittsburgh, Pennsylvania 15261, USA
| | | | | | | |
Collapse
|
47
|
Blanc EM, Keller JN, Fernandez S, Mattson MP. 4-hydroxynonenal, a lipid peroxidation product, impairs glutamate transport in cortical astrocytes. Glia 1998; 22:149-60. [PMID: 9537835 DOI: 10.1002/(sici)1098-1136(199802)22:2<149::aid-glia6>3.0.co;2-2] [Citation(s) in RCA: 119] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Astrocytes possess plasma membrane glutamate transporters that rapidly remove glutamate from the extracellular milieu and thereby prevent excitotoxic injury to neurons. Cellular oxidative stress is increased in neural tissues in a variety of acute and chronic neurodegenerative conditions. Recent findings suggest that oxidative stress increases neuronal vulnerability to excitotoxicity and that membrane lipid peroxidation plays a key role in this process. We now report that 4-hydroxynonenal (HNE), an aldehydic product of membrane lipid peroxidation, impairs glutamate transport in cultured cortical astrocytes. Impairment of glutamate transport occurred within 1-3 h of exposure to HNE; FeSO4, an inducer of membrane lipid peroxidation, also impaired glutamate transport. Vitamin E prevented impairment of glutamate transport induced by FeSO4, but not that induced by HNE, consistent with HNE acting as an effector of lipid peroxidation-induced impairment of glutamate transport. Glutathione, which binds and thereby detoxifies HNE, prevented HNE from impairing glutamate transport. Western blot, immunoprecipitation, and immunocytochemical analyses using an antibody against HNE-protein conjugates provided evidence that HNE covalently binds to many different astrocytic proteins including the glutamate transporter GLT-1. Data further suggest that HNE promotes intermolecular cross-linking of GLT-1 monomers to form dimers. HNE also induced mitochondrial dysfunction and accumulation of peroxides in astrocytes. Impairment of glutamate transport and mitochondrial function occurred with sublethal concentrations of HNE, concentrations known to be generated in cells exposed to various oxidative insults. Collectively, our data suggest that HNE may be an important mediator of oxidative stress-induced impairment of astrocytic glutamate transport and may thereby play a role in promoting neuronal excitotoxicity.
Collapse
Affiliation(s)
- E M Blanc
- Sanders-Brown Research Center on Aging, University of Kentucky, Lexington 40536-0230, USA
| | | | | | | |
Collapse
|
48
|
Vaccari A, Saba PL, Mocci I, Ruiu S. Is increased neurotoxicity a burden of the ageing brain? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1997; 429:221-34. [PMID: 9413577 DOI: 10.1007/978-1-4757-9551-6_16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- A Vaccari
- Department of Neuroscience B. Brodie, Neurotoxicology Unit, Cagliari, Italy
| | | | | | | |
Collapse
|
49
|
Porras A, Sanz B, Mora F. Dopamine-glutamate interactions in the prefrontal cortex of the conscious rat: studies on ageing. Mech Ageing Dev 1997; 99:9-17. [PMID: 9430101 DOI: 10.1016/s0047-6374(97)00084-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The effects of apomorphine, a D1-D2 dopamine receptor agonist, on the extracellular concentration of glutamate were investigated in the medial prefrontal cortex of young, middle-aged and aged rats. In vivo intracerebral perfusions were undertaken in the conscious rat using a concentric push-pull cannula system. Glutamate concentration in the samples were determined by HPLC with fluorometric detection. Apomorphine produced an increase in extracellular concentration of glutamate in medial prefrontal cortex of young rats (178% of baseline) only at 10 microM, but not at 5 and 20 microM. This increase in glutamate concentration induced by apomorphine was significantly attenuated by blockade of D1-D2 dopamine receptors with haloperidol. Apomorphine, at 10 microM, failed to induce an increase in extracellular concentration of glutamate in the prefrontal cortex of middle-aged and aged rats. However, at 20 microM, apomorphine induced an increase in glutamate concentration in the prefrontal cortex of middle-aged rats, but not in aged rats. These data indicate that an interaction between dopamine and glutamate exists in the medial prefrontal cortex and that this interaction deteriorates with age.
Collapse
Affiliation(s)
- A Porras
- Department of Physiology, Faculty of Medicine, Complutense University of Madrid, Spain
| | | | | |
Collapse
|
50
|
Saransaari P, Oja SS. Dizocilpine binding to cerebral cortical membranes from developing and ageing mice. Mech Ageing Dev 1995; 85:171-81. [PMID: 8786663 DOI: 10.1016/0047-6374(95)01665-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The binding of [3H]dizocilpine (MK-801) to the N-methyl-D-aspartate (NMDA)-gated ion channel was characterized in cerebral cortical membranes during the major portion of the mouse life-span (from 7-day- to 22-month-olds). The binding was saturable, consisting of only one component at all ages studied. The maximal binding capacity Bmax was very substantial in 14-day-old mice when compared to adults (3-month-olds), decreasing thereafter during ageing. The binding constant KD remained unchanged during development and increased only slightly in aged mice. Glutamate and glycine potentiated dizocilpine binding concentration-dependently. Their efficacy varied markedly with age. Both glutamate and glycine had considerably less effect on the immature cerebral cortex and in the oldest group of mice (22-month-old) than in young adults. The marked increase in dizocilpine binding sites at the age of 2 weeks coincides with the previously reported transient increase in NMDA binding sites in the cerebral cortex. The weak potentiation of dizocilpine binding by glutamate and glycine in the immature brain could be a factor which protects neurons during this period from excitotoxicity and increased susceptibility to seizures induced by acidic amino acids. The decrease in the number of dizocilpine binding sites during ageing could result partly from the loss of cortical neurons.
Collapse
Affiliation(s)
- P Saransaari
- Department of Physiology, University of Tampere School of Medicine, Finland
| | | |
Collapse
|