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Guo F, Zhao J, Zhao D, Wang J, Wang X, Feng Z, Vreugdenhil M, Lu C. Dopamine D4 receptor activation restores CA1 LTP in hippocampal slices from aged mice. Aging Cell 2017; 16:1323-1333. [PMID: 28975698 PMCID: PMC5676052 DOI: 10.1111/acel.12666] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/04/2017] [Indexed: 01/22/2023] Open
Abstract
Normal aging is characterized with a decline in hippocampal memory functions that is associated with changes in long-term potentiation (LTP) of the CA3-to-CA1 synapse. Age-related deficit of the dopaminergic system may contribute to impairment of CA1 LTP. Here we assessed how the modulation of CA1 LTP by dopamine is affected by aging and how it is dependent on the Ca2+ source. In slices from adult mice, the initial slope of the field potential showed strong LTP, but in slices from aged mice LTP was impaired. Dopamine did not affect LTP in adult slices, but enhanced LTP in aged slices. The dopamine D1/D5 receptor (D1R/D5R) agonist SKF-81297 did not affect LTP in adult but caused a relative small increase in LTP in aged slices; however, although there was no difference in dopamine D4 receptor (D4R) expression, the D4R agonist PD168077 increased LTP in aged slices to a magnitude similar to that in adult slices. The N-Methyl-D-aspartate receptor antagonist D-AP5 reduced LTP in adult slices, but not in aged slices. However, in the presence of D-AP5, PD168077 completely blocked LTP in aged slices. The voltage-dependent calcium channel (VDCC) blocker nifedipine reduced LTP in adult slices, but surprisingly enhanced LTP in aged slices. Furthermore, in the presence of nifedipine, PD168077 caused a strong enhancement of LTP in aged slices to a magnitude exceeding LTP in adult slices. Our results indicate that the full rescue of impaired LTP in aging by the selective D4R activation and that a large potentiation role on LTP by co-application of D4R agonist and VDCC blocker may provide novel strategies for the intervention of cognitive decline of aging and age-related diseases.
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Affiliation(s)
- Fangli Guo
- Key Lab of Brain Research of Henan ProvinceDepartment of Physiology and NeurobiologyXinxiang Medical UniversityXinxiangChina
| | - Jianhua Zhao
- Department of Neurology1st Affiliated Hospital of Xinxiang Medical UniversityXinxiangChina
| | - Dandan Zhao
- Key Lab of Brain Research of Henan ProvinceDepartment of Physiology and NeurobiologyXinxiang Medical UniversityXinxiangChina
| | - Jiangang Wang
- Key Lab of Brain Research of Henan ProvinceDepartment of Physiology and NeurobiologyXinxiang Medical UniversityXinxiangChina
| | - Xiaofang Wang
- Key Lab of Brain Research of Henan ProvinceDepartment of Physiology and NeurobiologyXinxiang Medical UniversityXinxiangChina
| | - Zhiwei Feng
- Key Lab of Brain Research of Henan ProvinceDepartment of Physiology and NeurobiologyXinxiang Medical UniversityXinxiangChina
| | - Martin Vreugdenhil
- Department of PsychologyXinxiang Medical UniversityXinxiangChina
- Department of Health SciencesBirmingham City UniversityBirminghamUK
| | - Chengbiao Lu
- Key Lab of Brain Research of Henan ProvinceDepartment of Physiology and NeurobiologyXinxiang Medical UniversityXinxiangChina
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Yakovlev AV, Kurmasheva ED, Ishchenko Y, Giniatullin R, Sitdikova GF. Age-Dependent, Subunit Specific Action of Hydrogen Sulfide on GluN1/2A and GluN1/2B NMDA Receptors. Front Cell Neurosci 2017; 11:375. [PMID: 29225568 PMCID: PMC5705612 DOI: 10.3389/fncel.2017.00375] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 11/10/2017] [Indexed: 11/13/2022] Open
Abstract
Hydrogen sulfide (H2S) is an endogenously produced neuroactive gas implicated in many key processes in the peripheral and central nervous system. Whereas the neuroprotective role of H2S has been shown in adult brain, the action of this messenger in newborns remains unclear. One of the known targets of H2S in the nervous system is the N-methyl-D-aspartate (NMDA) glutamate receptor which can be composed of different subunits with distinct functional properties. In the present study, using patch clamp technique, we compared the effects of the H2S donor sodium hydrosulfide (NaHS, 100 μM) on hippocampal NMDA receptor mediated currents in rats of the first and third postnatal weeks. This was supplemented by testing effects of NaHS on recombinant GluN1/2A and GluN1/2B NMDA receptors expressed in HEK293T cells. The main finding is that NaHS action on NMDA currents is age-dependent. Currents were reduced in newborns but increased in older juvenile rats. Consistent with an age-dependent switch in NMDA receptor composition, in HEK239T cells expressing GluN1/2A receptors, NaHS increased NMDA activated currents associated with acceleration of desensitization and decrease of the deactivation rate. In contrast, in GluN1/2B NMDA receptors, which are prevalent in newborns, NaHS decreased currents and reduced receptor deactivation without effect on the desensitization rate. Adenylate cyclase inhibitor MDL-12330A (10 μM) did not prevent the age-dependent effects of NaHS on NMDA evoked currents in pyramidal neurons of hippocampus. The reducing agent dithiothreitol (DTT, 2 mM) applied on HEK293T cells prevented facilitation induced by NaHS on GluN1/2A NMDA receptors, however in GluN1/2B NMDA receptors the inhibitory effect of NaHS was still observed. Our data indicate age-dependent effect of H2S on NMDA receptor mediated currents determined by glutamate receptor subunit composition. While the inhibitory action of H2 on GluN1/2B receptors could limit the excessive activation in early age, the enhanced functionality of GluN1/2A receptor in the presence of this gasotransmitter can enlarge synaptic efficacy and promote synaptic plasticity in adults.
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Affiliation(s)
- Aleksey V Yakovlev
- Department of Human and Animal Physiology, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Evgeniya D Kurmasheva
- Department of Human and Animal Physiology, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Yevheniia Ishchenko
- Laboratory of Molecular Pain Research, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Rashid Giniatullin
- Laboratory of Molecular Pain Research, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.,Laboratory of Neurobiology, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Guzel F Sitdikova
- Department of Human and Animal Physiology, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
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53
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Li YL, Wu PF, Chen JG, Wang S, Han QQ, Li D, Wang W, Guan XL, Li D, Long LH, Huang JG, Wang F. Activity-Dependent Sulfhydration Signal Controls N-Methyl-D-Aspartate Subtype Glutamate Receptor-Dependent Synaptic Plasticity via Increasing d-Serine Availability. Antioxid Redox Signal 2017; 27:398-414. [PMID: 28051338 DOI: 10.1089/ars.2016.6936] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
AIMS Reactive sulfur species, including hydrogen sulfide (H2S) and its oxydates, have been raised as novel redox signaling molecules. The present study aimed at examining whether endogenous sulfhydration signal is required for long-term potentiation (LTP), a cellular model for memory. RESULTS In this study, we found that increased synaptic activity triggered sulfide generation and protein sulfhydration. Activity-triggered sulfide production was essential for N-methyl-D-aspartate subtype glutamate receptor (NMDAR)-dependent LTP via maintaining the availability of d-serine, a primary coagonist for synaptic NMDARs. Genetic knockdown of cystathionine β-synthase, not cystathionine γ-lyase, impaired LTP. H2S increased NMDAR-dependent LTP via sulfhydration and disinhibition of serine racemase (SR), a main synthetase of d-serine. We found that polysulfides also increased NMDAR-dependent LTP and NMDAR activity. In aged rats, the level of H2S and SR sulfhydration decreased significantly. Exogenous supplement of H2S restored the sulfhydration of SR, followed by the improvement of age-related deficits in LTP. Furthermore, boost of H2S signal in vivo improves hippocampus-dependent memory. Innovation and Conclusion: Our results provide a direct evidence for the biological significance of endogenous sulfhydration signal in synaptic plasticity. Exogenous supplement of H2S could be considered as the new therapeutic approach for the treatment of neurocognitive dysfunction after aging. Antioxid. Redox Signal. 27, 398-414.
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Affiliation(s)
- Yuan-Long Li
- 1 Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology , Wuhan, China
| | - Peng-Fei Wu
- 1 Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology , Wuhan, China .,2 Hubei Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation (Huazhong University of Science and Technology) , Wuhan, China .,3 Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology , Wuhan, China .,4 Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China , Wuhan, China
| | - Jian-Guo Chen
- 1 Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology , Wuhan, China .,2 Hubei Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation (Huazhong University of Science and Technology) , Wuhan, China .,3 Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology , Wuhan, China .,4 Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China , Wuhan, China .,5 The Collaborative Innovation Center for Brain Science , Wuhan, China
| | - Sheng Wang
- 6 School of Life Science and Technology, Huazhong University of Science and Technology , Wuhan, China
| | - Qian-Qian Han
- 1 Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology , Wuhan, China
| | - Dan Li
- 7 Department of Pharmaceutics, College of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology , Wuhan, China
| | - Wen Wang
- 1 Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology , Wuhan, China
| | - Xin-Lei Guan
- 1 Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology , Wuhan, China
| | - Di Li
- 1 Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology , Wuhan, China
| | - Li-Hong Long
- 1 Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology , Wuhan, China .,2 Hubei Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation (Huazhong University of Science and Technology) , Wuhan, China .,3 Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology , Wuhan, China .,4 Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China , Wuhan, China
| | - Jian-Geng Huang
- 7 Department of Pharmaceutics, College of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology , Wuhan, China
| | - Fang Wang
- 1 Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology , Wuhan, China .,2 Hubei Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation (Huazhong University of Science and Technology) , Wuhan, China .,3 Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology , Wuhan, China .,4 Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China , Wuhan, China .,5 The Collaborative Innovation Center for Brain Science , Wuhan, China
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54
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De Domenico E, D'Arcangelo G, Faraoni I, Palmieri M, Tancredi V, Graziani G, Grimaldi P, Tentori L. Modulation of GDF11 expression and synaptic plasticity by age and training. Oncotarget 2017; 8:57991-58002. [PMID: 28938532 PMCID: PMC5601628 DOI: 10.18632/oncotarget.19854] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 07/25/2017] [Indexed: 01/26/2023] Open
Abstract
The Growth Differentiation Factor 11 (GDF11) has been controversially involved in the aging/rejuvenation process. To clarify whether GDF11 is differently expressed during aging, we have evaluated GDF11 levels in skeletal muscles and hippocampi of young and old mice, sedentary or subjected to a 12-weeks triweekly training protocol. The results of real-time PCR and Western blot analyses indicate that skeletal muscles of sedentary old mice express higher levels of GDF11 compared to young animals (p < 0.05). Conversely, in hippocampi no significant differences of GDF11 expression are detected. Analysis of long-term potentiation, a synaptic plasticity phenomenon, reveals that population spikes in response to a tetanic stimulus are significantly higher in sedentary young mice than in old animals (p < 0.01). Training induces a significant improvement of long-term potentiation in both young and old animals (p < 0.05), an increase (p < 0.05) of skeletal muscle GDF11 levels in young mice and a reduction of GDF11 expression in hippocampi of old mice (p < 0.05). Overall, data suggest that GDF11 can be considered an aging biomarker for skeletal muscles. Moreover, physical exercise has a positive impact on long-term potentiation in both young and old mice, while it has variable effects on GDF11 expression depending on age and on the tissue analyzed.
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Affiliation(s)
- Emanuela De Domenico
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | | | - Isabella Faraoni
- Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Mattia Palmieri
- Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Virginia Tancredi
- Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Grazia Graziani
- Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Paola Grimaldi
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Lucio Tentori
- Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
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55
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Bettio LEB, Rajendran L, Gil-Mohapel J. The effects of aging in the hippocampus and cognitive decline. Neurosci Biobehav Rev 2017; 79:66-86. [PMID: 28476525 DOI: 10.1016/j.neubiorev.2017.04.030] [Citation(s) in RCA: 330] [Impact Index Per Article: 47.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 03/15/2017] [Accepted: 04/10/2017] [Indexed: 02/06/2023]
Abstract
Aging is a natural process that is associated with cognitive decline as well as functional and social impairments. One structure of particular interest when considering aging and cognitive decline is the hippocampus, a brain region known to play an important role in learning and memory consolidation as well as in affective behaviours and mood regulation, and where both functional and structural plasticity (e.g., neurogenesis) occur well into adulthood. Neurobiological alterations seen in the aging hippocampus including increased oxidative stress and neuroinflammation, altered intracellular signalling and gene expression, as well as reduced neurogenesis and synaptic plasticity, are thought to be associated with age-related cognitive decline. Non-invasive strategies such as caloric restriction, physical exercise, and environmental enrichment have been shown to counteract many of the age-induced alterations in hippocampal signalling, structure, and function. Thus, such approaches may have therapeutic value in counteracting the deleterious effects of aging and protecting the brain against age-associated neurodegenerative processes.
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Affiliation(s)
- Luis E B Bettio
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Luckshi Rajendran
- Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Joana Gil-Mohapel
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada; UBC Island Medical program, University of Victoria, Victoria, BC, Canada.
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56
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Shivarama Shetty M, Sajikumar S. 'Tagging' along memories in aging: Synaptic tagging and capture mechanisms in the aged hippocampus. Ageing Res Rev 2017; 35:22-35. [PMID: 28065806 DOI: 10.1016/j.arr.2016.12.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 12/12/2016] [Accepted: 12/30/2016] [Indexed: 02/06/2023]
Abstract
Aging is accompanied by a general decline in the physiological functions of the body with the deteriorating organ systems. Brain is no exception to this and deficits in cognitive functions are quite common in advanced aging. Though a variety of age-related alterations are observed in the structure and function throughout the brain, certain regions show selective vulnerability. Medial temporal lobe, especially the hippocampus, is one such preferentially vulnerable region and is a crucial structure involved in the learning and long-term memory functions. Hippocampal synaptic plasticity, such as long-term potentiation (LTP) and depression (LTD), are candidate cellular correlates of learning and memory and alterations in these properties have been well documented in aging. A related phenomenon called synaptic tagging and capture (STC) has been proposed as a mechanism for cellular memory consolidation and to account for temporal association of memories. Mounting evidences from behavioral settings suggest that STC could be a physiological phenomenon. In this article, we review the recent data concerning STC and provide a framework for how alterations in STC-related mechanisms could contribute to the age-associated memory impairments. The enormity of impairment in learning and memory functions demands an understanding of age-associated memory deficits at the fundamental level given its impact in the everyday tasks, thereby in the quality of life. Such an understanding is also crucial for designing interventions and preventive measures for successful brain aging.
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57
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Arias-Cavieres A, Adasme T, Sánchez G, Muñoz P, Hidalgo C. Aging Impairs Hippocampal- Dependent Recognition Memory and LTP and Prevents the Associated RyR Up-regulation. Front Aging Neurosci 2017; 9:111. [PMID: 28484388 PMCID: PMC5402473 DOI: 10.3389/fnagi.2017.00111] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 04/06/2017] [Indexed: 11/21/2022] Open
Abstract
Recognition memory comprises recollection judgment and familiarity, two different processes that engage the hippocampus and the perirhinal cortex, respectively. Previous studies have shown that aged rodents display defective recognition memory and alterations in hippocampal synaptic plasticity. We report here that young rats efficiently performed at short-term (5 min) and long-term (24 h) hippocampus-associated object-location tasks and perirhinal cortex-related novel-object recognition tasks. In contrast, aged rats successfully performed the object-location and the novel-object recognition tasks only at short-term. In addition, aged rats displayed defective long-term potentiation (LTP) and enhanced long-term depression (LTD). Successful long-term performance of object-location but not of novel-object recognition tasks increased the protein levels of ryanodine receptor types-2/3 (RyR2/RyR3) and of IP3R1 in young rat hippocampus. Likewise, sustained LTP induction (1 h) significantly increased RyR2, RyR3 and IP3R1 protein levels in hippocampal slices from young rats. In contrast, LTD induction (1 h) did not modify the levels of these three proteins. Naïve (untrained) aged rats displayed higher RyR2/RyR3 hippocampal protein levels but similar IP3R1 protein content relative to young rats; these levels did not change following exposure to either memory recognition task or after LTP or LTD induction. The perirhinal cortex from young or aged rats did not display changes in the protein contents of RyR2, RyR3, and IP3R1 after exposure at long-term (24 h) to the object-location or the novel-object recognition tasks. Naïve aged rats displayed higher RyR2 channel oxidation levels in the hippocampus compared to naïve young rats. The RyR2/RyR3 up-regulation and the increased RyR2 oxidation levels exhibited by aged rat hippocampus are likely to generate anomalous calcium signals, which may contribute to the well-known impairments in hippocampal LTP and spatial memory that take place during aging.
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Affiliation(s)
| | - Tatiana Adasme
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de ChileSantiago, Chile.,Centro Integrativo de Biología y Química Aplicada, Universidad Bernardo O'HigginsSantiago, Chile
| | - Gina Sánchez
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de ChileSantiago, Chile.,Pathophysiology Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de ChileSantiago, Chile
| | - Pablo Muñoz
- Center for Applied Neurological Sciences and Interdisciplinary Center for Innovation in Health, School of Medicine, Universidad de ValparaísoValparaíso, Chile
| | - Cecilia Hidalgo
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de ChileSantiago, Chile.,Center of Molecular Studies of the Cell and Physiology and Biophysics Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de ChileSantiago, Chile
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58
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Potential synergistic action of 19 schizophrenia risk genes in the thalamus. Schizophr Res 2017; 180:64-69. [PMID: 27645107 PMCID: PMC5263182 DOI: 10.1016/j.schres.2016.09.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 08/31/2016] [Accepted: 09/03/2016] [Indexed: 11/22/2022]
Abstract
A goal of current schizophrenia (SZ) research is to understand how multiple risk genes work together with environmental factors to produce the disease. In schizophrenia, there is elevated delta frequency EEG power in the awake state, an elevation that can be mimicked in rodents by N-methyl-d-aspartate receptor (NMDAR) antagonist action in the thalamus. This thalamic delta can be blocked by dopamine D2 receptor antagonists, agents known to be therapeutic in SZ. Experiments suggest that these oscillations can interfere with brain function and may thus be causal in producing psychosis. Here we evaluate the question of whether well-established schizophrenia risk genes may interact to affect the delta generation process. We identify 19 risk genes that can plausibly work in a synergistic fashion to generate delta oscillations.
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59
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Márquez Loza A, Elias V, Wong CP, Ho E, Bermudez M, Magnusson KR. Effects of ibuprofen on cognition and NMDA receptor subunit expression across aging. Neuroscience 2017; 344:276-292. [PMID: 28057539 DOI: 10.1016/j.neuroscience.2016.12.041] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Revised: 12/13/2016] [Accepted: 12/22/2016] [Indexed: 11/28/2022]
Abstract
Age-related declines in long- and short-term memory show relationships to decreases in N-methyl-d-aspartate (NMDA) receptor expression, which may involve inflammation. This study was designed to determine effects of an anti-inflammatory drug, ibuprofen, on cognitive function and NMDA receptor expression across aging. Male C57BL/6 mice (ages 5, 14, 20, and 26months) were fed ibuprofen (375ppm) in NIH31 diet or diet alone for 6weeks prior to testing. Behavioral testing using the Morris water maze showed that older mice performed significantly worse than younger in spatial long-term memory, reversal, and short-term memory tasks. Ibuprofen enhanced overall performance in the short-term memory task, but this appeared to be more related to improved executive function than memory. Ibuprofen induced significant decreases over all ages in the mRNA densities for GluN2B subunit, all GluN1 splice variants, and GluN1-1 splice forms in the frontal cortex and in protein expression of GluN2A, GluN2B and GluN1 C2' cassettes in the hippocampus. GluN1-3 splice form mRNA and C2' cassette protein were significantly increased across ages in frontal lobes of ibuprofen-treated mice. Ibuprofen did not alter expression of pro-inflammatory cytokines IL-1β and TNFα, but did reduce the area of reactive astrocyte immunostaining in frontal cortex of aged mice. Enhancement in executive function showed a relationship to increased GluN1-3 mRNA and decreased gliosis. These findings suggest that inflammation may play a role in executive function declines in aged animals, but other effects of ibuprofen on NMDA receptors appeared to be unrelated to aging or inflammation.
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Affiliation(s)
- Alejandra Márquez Loza
- Department of Biomedical Sciences, Oregon State University, Corvallis, OR 97331, USA; Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA.
| | - Valerie Elias
- Department of Biomedical Sciences, Oregon State University, Corvallis, OR 97331, USA; Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA.
| | - Carmen P Wong
- School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331, USA.
| | - Emily Ho
- Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA; School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331, USA.
| | - Michelle Bermudez
- Department of Biomedical Sciences, Oregon State University, Corvallis, OR 97331, USA; Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA.
| | - Kathy R Magnusson
- Department of Biomedical Sciences, Oregon State University, Corvallis, OR 97331, USA; Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA.
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60
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Ambrogini P, Betti M, Galati C, Di Palma M, Lattanzi D, Savelli D, Galli F, Cuppini R, Minelli A. α-Tocopherol and Hippocampal Neural Plasticity in Physiological and Pathological Conditions. Int J Mol Sci 2016; 17:E2107. [PMID: 27983697 PMCID: PMC5187907 DOI: 10.3390/ijms17122107] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 12/01/2016] [Accepted: 12/09/2016] [Indexed: 12/25/2022] Open
Abstract
Neuroplasticity is an "umbrella term" referring to the complex, multifaceted physiological processes that mediate the ongoing structural and functional modifications occurring, at various time- and size-scales, in the ever-changing immature and adult brain, and that represent the basis for fundamental neurocognitive behavioral functions; in addition, maladaptive neuroplasticity plays a role in the pathophysiology of neuropsychiatric dysfunctions. Experiential cues and several endogenous and exogenous factors can regulate neuroplasticity; among these, vitamin E, and in particular α-tocopherol (α-T), the isoform with highest bioactivity, exerts potent effects on many plasticity-related events in both the physiological and pathological brain. In this review, the role of vitamin E/α-T in regulating diverse aspects of neuroplasticity is analyzed and discussed, focusing on the hippocampus, a brain structure that remains highly plastic throughout the lifespan and is involved in cognitive functions. Vitamin E-mediated influences on hippocampal synaptic plasticity and related cognitive behavior, on post-natal development and adult hippocampal neurogenesis, as well as on cellular and molecular disruptions in kainate-induced temporal seizures are described. Besides underscoring the relevance of its antioxidant properties, non-antioxidant functions of vitamin E/α-T, mainly involving regulation of cell signaling molecules and their target proteins, have been highlighted to help interpret the possible mechanisms underlying the effects on neuroplasticity.
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Affiliation(s)
- Patrizia Ambrogini
- Department of Biomolecular Sciences, University of Urbino, 61029 Urbino, Italy.
| | - Michele Betti
- Department of Biomolecular Sciences, University of Urbino, 61029 Urbino, Italy.
| | - Claudia Galati
- Department of Biomolecular Sciences, University of Urbino, 61029 Urbino, Italy.
| | - Michael Di Palma
- Department of Biomolecular Sciences, University of Urbino, 61029 Urbino, Italy.
| | - Davide Lattanzi
- Department of Biomolecular Sciences, University of Urbino, 61029 Urbino, Italy.
| | - David Savelli
- Department of Biomolecular Sciences, University of Urbino, 61029 Urbino, Italy.
| | - Francesco Galli
- Department of Pharmaceutical Sciences, University of Perugia, 06123 Perugia, Italy.
| | - Riccardo Cuppini
- Department of Biomolecular Sciences, University of Urbino, 61029 Urbino, Italy.
| | - Andrea Minelli
- Department of Biomolecular Sciences, University of Urbino, 61029 Urbino, Italy.
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61
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Islam S, Shajib MS, Ahmed T. Antinociceptive effect of methanol extract of Celosia cristata Linn. in mice. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2016; 16:400. [PMID: 27770773 PMCID: PMC5075210 DOI: 10.1186/s12906-016-1393-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Accepted: 10/11/2016] [Indexed: 11/10/2022]
Abstract
BACKGROUND Celosia cristata Linn. (Amaranthaceae) is used in traditional medicine for the treatment of headache, sores, ulcers, eye inflammations, skin eruption, painful menstruation and carpal tunnel syndrome. This study was performed to evaluate the antinociceptive activity of methanol extract of the whole plant of C. cristata (MECC). METHODS The evaluation of the antinociceptive effect of MECC was performed using thermal (hot plate, tail immersion test) and chemical (acetic acid, formalin, and glutamate-induced nociception test) pain models in mice at four different doses (50, 100, 200, 400 mg/kg; p.o.). Involvement of opioid receptors mediated central antinociceptive mechanism of MECC was evaluated using naloxone. Furthermore, the association of ATP-sensitive K+ channel and cGMP pathway were evaluated using glibenclamide and methylene blue respectively. RESULTS Oral treatment of MECC produced significant, strong and dose-dependent central and peripheral antinociceptive effect in experimental pain models. MECC significantly increased the latency time of thermal threshold in both hot plate and tail immersion test. The inhibition of writhing syndrome by the extract in the acetic acid-induced writhing test was remarkable. MECC significantly reduced the formalin-induced neurogenic and inflammatory pain. In addition, the inhibition of glutamate-induced paw licking and edema by MECC was significant. The antinociceptive effect was significantly reversed by naloxone and glibenclamide, suggesting the association of opioid and ATP-sensitive K+ channel system respectively. In addition, MECC also demonstrated the involvement of cGMP pathway in the antinociceptive action. CONCLUSION The study suggests that C. cristata possess significant antinociceptive effect which is associated with both central and peripheral mechanisms and provides a rationale for its extensive use at different painful conditions in traditional medicine.
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Affiliation(s)
- Shanta Islam
- Department of Pharmacy, Stamford University Bangladesh, 51 Siddeswari Road, 1217 Dhaka, Bangladesh
| | - Md Shafiullah Shajib
- Department of Pharmacy, Stamford University Bangladesh, 51 Siddeswari Road, 1217 Dhaka, Bangladesh
| | - Tajnin Ahmed
- Department of Pharmacy, Stamford University Bangladesh, 51 Siddeswari Road, 1217 Dhaka, Bangladesh
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LeVault KR, Tischkau SA, Brewer GJ. Circadian Disruption Reveals a Correlation of an Oxidative GSH/GSSG Redox Shift with Learning and Impaired Memory in an Alzheimer's Disease Mouse Model. J Alzheimers Dis 2016; 49:301-16. [PMID: 26484899 DOI: 10.3233/jad-150026] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
It is unclear whether pre-symptomatic Alzheimer's disease (AD) causes circadian disruption or whether circadian disruption accelerates AD pathogenesis. In order to examine the sensitivity of learning and memory to circadian disruption, we altered normal lighting phases by an 8 h shortening of the dark period every 3 days (jet lag) in the APPSwDI NOS2-/- model of AD (AD-Tg) at a young age (4-5 months), when memory is not yet affected compared to non-transgenic (non-Tg) mice. Analysis of activity in 12-12 h lighting or constant darkness showed only minor differences between AD-Tg and non-Tg mice. Jet lag greatly reduced activity in both genotypes during the normal dark time. Learning on the Morris water maze was significantly impaired only in the AD-Tg mice exposed to jet lag. However, memory 3 days after training was impaired in both genotypes. Jet lag caused a decrease of glutathione (GSH) levels that tended to be more pronounced in AD-Tg than in non-Tg brains and an associated increase in NADH levels in both genotypes. Lower brain GSH levels after jet lag correlated with poor performance on the maze. These data indicate that the combination of the environmental stress of circadian disruption together with latent stress of the mutant amyloid and NOS2 knockout contributes to cognitive deficits that correlate with lower GSH levels.
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Affiliation(s)
- Kelsey R LeVault
- Department of Medical Microbiology, Immunology and Cell Biology, Southern Illinois University School Medicine, Springfield, Illinois, USA
| | - Shelley A Tischkau
- Department of Pharmacology, Southern Illinois University School Medicine, Springfield, Illinois, USA
| | - Gregory J Brewer
- Department of Medical Microbiology, Immunology and Cell Biology, Southern Illinois University School Medicine, Springfield, Illinois, USA.,Department of Neurology, Southern Illinois University School Medicine, Springfield, Illinois, USA.,Institute for Memory Impairment and Neurological Disorders (MIND), Department of Biomedical Engineering, University of California Irvine, Irvine, California, USA (current)
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63
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Beckhauser TF, Francis-Oliveira J, De Pasquale R. Reactive Oxygen Species: Physiological and Physiopathological Effects on Synaptic Plasticity. J Exp Neurosci 2016; 10:23-48. [PMID: 27625575 PMCID: PMC5012454 DOI: 10.4137/jen.s39887] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 08/09/2016] [Accepted: 08/13/2016] [Indexed: 12/18/2022] Open
Abstract
In the mammalian central nervous system, reactive oxygen species (ROS) generation is counterbalanced by antioxidant defenses. When large amounts of ROS accumulate, antioxidant mechanisms become overwhelmed and oxidative cellular stress may occur. Therefore, ROS are typically characterized as toxic molecules, oxidizing membrane lipids, changing the conformation of proteins, damaging nucleic acids, and causing deficits in synaptic plasticity. High ROS concentrations are associated with a decline in cognitive functions, as observed in some neurodegenerative disorders and age-dependent decay of neuroplasticity. Nevertheless, controlled ROS production provides the optimal redox state for the activation of transductional pathways involved in synaptic changes. Since ROS may regulate neuronal activity and elicit negative effects at the same time, the distinction between beneficial and deleterious consequences is unclear. In this regard, this review assesses current research and describes the main sources of ROS in neurons, specifying their involvement in synaptic plasticity and distinguishing between physiological and pathological processes implicated.
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Affiliation(s)
- Thiago Fernando Beckhauser
- Physiology and Biophysics Department, Biomedical Sciences Institute, Sao Paulo University (USP), Butanta, Sao Paulo, Brazil
| | - José Francis-Oliveira
- Physiology and Biophysics Department, Biomedical Sciences Institute, Sao Paulo University (USP), Butanta, Sao Paulo, Brazil
| | - Roberto De Pasquale
- Physiology and Biophysics Department, Biomedical Sciences Institute, Sao Paulo University (USP), Butanta, Sao Paulo, Brazil
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Steullet P, Cabungcal JH, Monin A, Dwir D, O'Donnell P, Cuenod M, Do KQ. Redox dysregulation, neuroinflammation, and NMDA receptor hypofunction: A "central hub" in schizophrenia pathophysiology? Schizophr Res 2016; 176:41-51. [PMID: 25000913 PMCID: PMC4282982 DOI: 10.1016/j.schres.2014.06.021] [Citation(s) in RCA: 171] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 06/06/2014] [Accepted: 06/08/2014] [Indexed: 12/18/2022]
Abstract
Accumulating evidence points to altered GABAergic parvalbumin-expressing interneurons and impaired myelin/axonal integrity in schizophrenia. Both findings could be due to abnormal neurodevelopmental trajectories, affecting local neuronal networks and long-range synchrony and leading to cognitive deficits. In this review, we present data from animal models demonstrating that redox dysregulation, neuroinflammation and/or NMDAR hypofunction (as observed in patients) impairs the normal development of both parvalbumin interneurons and oligodendrocytes. These observations suggest that a dysregulation of the redox, neuroimmune, and glutamatergic systems due to genetic and early-life environmental risk factors could contribute to the anomalies of parvalbumin interneurons and white matter in schizophrenia, ultimately impacting cognition, social competence, and affective behavior via abnormal function of micro- and macrocircuits. Moreover, we propose that the redox, neuroimmune, and glutamatergic systems form a "central hub" where an imbalance within any of these "hub" systems leads to similar anomalies of parvalbumin interneurons and oligodendrocytes due to the tight and reciprocal interactions that exist among these systems. A combination of vulnerabilities for a dysregulation within more than one of these systems may be particularly deleterious. For these reasons, molecules, such as N-acetylcysteine, that possess antioxidant and anti-inflammatory properties and can also regulate glutamatergic transmission are promising tools for prevention in ultra-high risk patients or for early intervention therapy during the first stages of the disease.
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Affiliation(s)
- P Steullet
- Center for Psychiatric Neuroscience, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Site de Cery, 1008 Prilly-Lausanne, Switzerland
| | - J H Cabungcal
- Center for Psychiatric Neuroscience, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Site de Cery, 1008 Prilly-Lausanne, Switzerland
| | - A Monin
- Center for Psychiatric Neuroscience, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Site de Cery, 1008 Prilly-Lausanne, Switzerland
| | - D Dwir
- Center for Psychiatric Neuroscience, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Site de Cery, 1008 Prilly-Lausanne, Switzerland
| | - P O'Donnell
- Neuroscience Research Unit, Pfizer, Inc., 700 Main Street, Cambridge, MA 02139, USA
| | - M Cuenod
- Center for Psychiatric Neuroscience, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Site de Cery, 1008 Prilly-Lausanne, Switzerland
| | - K Q Do
- Center for Psychiatric Neuroscience, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Site de Cery, 1008 Prilly-Lausanne, Switzerland.
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65
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Han J, Zhang H, Wang S, Zhou J, Luo Y, Long LH, Hu ZL, Wang F, Chen JG, Wu PF. Potentiation of Surface Stability of AMPA Receptors by Sulfhydryl Compounds: A Redox-Independent Effect by Disrupting Palmitoylation. Neurochem Res 2016; 41:2890-2903. [PMID: 27426946 DOI: 10.1007/s11064-016-2006-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 07/04/2016] [Accepted: 07/12/2016] [Indexed: 02/07/2023]
Abstract
Sulfhydryl compounds such as dithiothreitol (DTT) and β-mercaptoethanol (β-ME) are widely used as redox agents. Previous studies in our group and other laboratory have reported the effect of sulfhydryl compounds on the function of glutamate receptor, including plasticity. Most of these findings have focused on the N-methyl-D-aspartic acid receptor, in contrast, very little is known about the effect of sulfhydryl compounds on α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor (AMPAR). Here, we observed that DTT (100 μM), β-ME (200 μM) and L-cysteine (200 μM) significantly elevated the surface expression of AMPARs via reducing their palmitoylation in rat hippocampal slices in vitro. Increased surface stability of AMPARs was not be correlated with the altered redox status, because the chemical entities containing mercapto group such as penicillamine (200 μM) and 2-mercapto-1-methylimidazole (200 μM) exhibited little effects on the surface expression of AMPARs. Computing results of Asp-His-His-Cys (DHHC) 3, the main enzyme for palmitoylation of AMPARs, indicated that only the alkyl mercaptans with chain-like configuration, such as DTT and β-ME, can enter the pocket of DHHC3 and disrupt the catalytic activity via inhibiting DHHC3 auto-palmitoylation. Collectively, our findings indicate a novel redox-independent mechanism underlay the multiple effects of thiol reductants on synaptic function.
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Affiliation(s)
- Jun Han
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030, Hubei, China
| | - Hai Zhang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030, Hubei, China
| | - Sheng Wang
- School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Jun Zhou
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030, Hubei, China
| | - Yi Luo
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030, Hubei, China
| | - Li-Hong Long
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030, Hubei, China.,Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, 430030, Hubei, China.,The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, 430030, Hubei, China.,Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Zhuang-Li Hu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030, Hubei, China.,Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, 430030, Hubei, China.,The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, 430030, Hubei, China.,Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Fang Wang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030, Hubei, China.,Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, 430030, Hubei, China.,The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, 430030, Hubei, China.,Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Jian-Guo Chen
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030, Hubei, China.,Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, 430030, Hubei, China.,The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, 430030, Hubei, China.,Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Peng-Fei Wu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030, Hubei, China. .,Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, 430030, Hubei, China. .,The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, 430030, Hubei, China. .,Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China.
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66
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Febo M, Foster TC. Preclinical Magnetic Resonance Imaging and Spectroscopy Studies of Memory, Aging, and Cognitive Decline. Front Aging Neurosci 2016; 8:158. [PMID: 27468264 PMCID: PMC4942756 DOI: 10.3389/fnagi.2016.00158] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Accepted: 06/16/2016] [Indexed: 01/14/2023] Open
Abstract
Neuroimaging provides for non-invasive evaluation of brain structure and activity and has been employed to suggest possible mechanisms for cognitive aging in humans. However, these imaging procedures have limits in terms of defining cellular and molecular mechanisms. In contrast, investigations of cognitive aging in animal models have mostly utilized techniques that have offered insight on synaptic, cellular, genetic, and epigenetic mechanisms affecting memory. Studies employing magnetic resonance imaging and spectroscopy (MRI and MRS, respectively) in animal models have emerged as an integrative set of techniques bridging localized cellular/molecular phenomenon and broader in vivo neural network alterations. MRI methods are remarkably suited to longitudinal tracking of cognitive function over extended periods permitting examination of the trajectory of structural or activity related changes. Combined with molecular and electrophysiological tools to selectively drive activity within specific brain regions, recent studies have begun to unlock the meaning of fMRI signals in terms of the role of neural plasticity and types of neural activity that generate the signals. The techniques provide a unique opportunity to causally determine how memory-relevant synaptic activity is processed and how memories may be distributed or reconsolidated over time. The present review summarizes research employing animal MRI and MRS in the study of brain function, structure, and biochemistry, with a particular focus on age-related cognitive decline.
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Affiliation(s)
- Marcelo Febo
- Department of Psychiatry, William L. and Evelyn F. McKnight Brain Institute, University of Florida Gainesville, FL, USA
| | - Thomas C Foster
- Department of Neuroscience, William L. and Evelyn F. McKnight Brain Institute, University of Florida Gainesville, FL, USA
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67
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Stein LR, O'Dell KA, Funatsu M, Zorumski CF, Izumi Y. Short-term environmental enrichment enhances synaptic plasticity in hippocampal slices from aged rats. Neuroscience 2016; 329:294-305. [PMID: 27208617 DOI: 10.1016/j.neuroscience.2016.05.020] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2015] [Revised: 05/11/2016] [Accepted: 05/12/2016] [Indexed: 12/26/2022]
Abstract
Age-associated changes in cognition are mirrored by impairments in cellular models of memory and learning, such as long-term potentiation (LTP) and long-term depression (LTD). In young rodents, environmental enrichment (EE) can enhance memory, alter LTP and LTD, as well as reverse cognitive deficits induced by aging. Whether short-term EE can benefit cognition and synaptic plasticity in aged rodents is unclear. Here, we tested if short-term EE could overcome age-associated impairments in induction of LTP and LTD. LTP and LTD could not be induced in the CA1 region of hippocampal slices in control, aged rats using standard stimuli that are highly effective in young rats. However, exposure of aged littermates to EE for three weeks enabled successful induction of LTP and LTD. EE-facilitated LTP was dependent upon N-methyl-d-aspartate receptors (NMDARs). These alterations in synaptic plasticity occurred with elevated levels of phosphorylated cAMP response element-binding protein and vascular endothelial growth factor, but in the absence of changes in several other synaptic and cellular markers. Importantly, our study suggests that even a relatively short period of EE is sufficient to alter synaptic plasticity and molecular markers linked to cognitive function in aged animals.
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Affiliation(s)
- Liana R Stein
- Department of Psychiatry, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
| | - Kazuko A O'Dell
- Department of Psychiatry, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA; The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
| | - Michiyo Funatsu
- Department of Psychiatry, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
| | - Charles F Zorumski
- Department of Psychiatry, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA; The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA; Center for Brain Research in Mood Disorders, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA; Department of Neuroscience, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
| | - Yukitoshi Izumi
- Department of Psychiatry, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA; The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA; Center for Brain Research in Mood Disorders, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
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68
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Foster TC, Kyritsopoulos C, Kumar A. Central role for NMDA receptors in redox mediated impairment of synaptic function during aging and Alzheimer's disease. Behav Brain Res 2016; 322:223-232. [PMID: 27180169 DOI: 10.1016/j.bbr.2016.05.012] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 04/15/2016] [Accepted: 05/05/2016] [Indexed: 01/07/2023]
Abstract
Increased human longevity has magnified the negative impact that aging can have on cognitive integrity of older individuals experiencing some decline in cognitive function. Approximately 30% of the elderly will have cognitive problems that influence their independence. Impaired executive function and memory performance are observed in normal aging and yet can be an early sign of a progressive cognitive impairment of Alzheimer's disease (AD), the most common form of dementia. Brain regions that are vulnerable to aging exhibit the earliest pathology of AD. Senescent synaptic function is observed as a shift in Ca2+-dependent synaptic plasticity and similar mechanisms are thought to contribute to the early cognitive deficits associated with AD. In the case of aging, intracellular redox state mediates a shift in Ca2+ regulation including N-methyl-d-aspartate (NMDA) receptor hypofunction and increased Ca2+ release from intracellular stores to alter synaptic plasticity. AD can interact with these aging processes such that molecules linked to AD, β-amyloid (Aβ) and mutated presenilin 1 (PS1), can also degrade NMDA receptor function, promote Ca2+ release from intracellular stores, and may increase oxidative stress. Thus, age is one of the most important predictors of AD and brain aging likely contributes to the onset of AD. The focus of this review article is to provide an update on mechanisms that contribute to the senescent synapse and possible interactions with AD-related molecules, with special emphasis on regulation of NMDA receptors.
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Affiliation(s)
- T C Foster
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL 32611, United States of America.
| | - C Kyritsopoulos
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL 32611, United States of America
| | - A Kumar
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL 32611, United States of America.
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Hidalgo C, Arias-Cavieres A. Calcium, Reactive Oxygen Species, and Synaptic Plasticity. Physiology (Bethesda) 2016; 31:201-15. [DOI: 10.1152/physiol.00038.2015] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
In this review article, we address how activity-dependent Ca2+ signaling is crucial for hippocampal synaptic/structural plasticity and discuss how changes in neuronal oxidative state affect Ca2+ signaling and synaptic plasticity. We also analyze current evidence indicating that oxidative stress and abnormal Ca2+ signaling contribute to age-related synaptic plasticity deterioration.
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Affiliation(s)
- Cecilia Hidalgo
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile; and
- Center of Molecular Studies of the Cell and Physiology and Biophysics Program, ICBM, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Alejandra Arias-Cavieres
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile; and
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Abstract
UNLABELLED A decline in estradiol (E2)-mediated cognitive benefits denotes a critical window for the therapeutic effects of E2, but the mechanism for closing of the critical window is unknown. We hypothesized that upregulating the expression of estrogen receptor α (ERα) or estrogen receptor β (ERβ) in the hippocampus of aged animals would restore the therapeutic potential of E2 treatments and rejuvenate E2-induced hippocampal plasticity. Female rats (15 months) were ovariectomized, and, 14 weeks later, adeno-associated viral vectors were used to express ERα, ERβ, or green fluorescent protein (GFP) in the CA1 region of the dorsal hippocampus. Animals were subsequently treated for 5 weeks with cyclic injections of 17β-estradiol-3-benzoate (EB, 10 μg) or oil vehicle. Spatial memory was examined 48 h after EB/oil treatment. EB treatment in the GFP (GFP + EB) and ERβ (ERβ + EB) groups failed to improve episodic spatial memory relative to oil-treated animals, indicating closing of the critical window. Expression of ERβ failed to improve cognition and was associated with a modest learning impairment. Cognitive benefits were specific to animals expressing ERα that received EB treatment (ERα + EB), such that memory was improved relative to ERα + oil and GFP + EB. Similarly, ERα + EB animals exhibited enhanced NMDAR-mediated synaptic transmission compared with the ERα + oil and GFP + EB groups. This is the first demonstration that the window for E2-mediated benefits on cognition and hippocampal E2 responsiveness can be reinstated by increased expression of ERα. SIGNIFICANCE STATEMENT Estradiol is neuroprotective, promotes synaptic plasticity in the hippocampus, and protects against cognitive decline associated with aging and neurodegenerative diseases. However, animal models and clinical studies indicate a critical window for the therapeutic treatment such that the beneficial effects are lost with advanced age and/or with extended hormone deprivation. We used gene therapy to upregulate expression of the estrogen receptors ERα and ERβ and demonstrate that the window for estradiol's beneficial effects on memory and hippocampal synaptic function can be reinstated by enhancing the expression of ERα. Our findings suggest that the activity of ERα controls the therapeutic window by regulating synaptic plasticity mechanisms involved in memory.
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71
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Patel R, Sesti F. Oxidation of ion channels in the aging nervous system. Brain Res 2016; 1639:174-85. [PMID: 26947620 DOI: 10.1016/j.brainres.2016.02.046] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Revised: 02/24/2016] [Accepted: 02/25/2016] [Indexed: 12/19/2022]
Abstract
Ion channels are integral membrane proteins that allow passive diffusion of ions across membranes. In neurons and in other excitable cells, the harmonious coordination between the numerous types of ion channels shape and propagate electrical signals. Increased accumulation of reactive oxidative species (ROS), and subsequent oxidation of proteins, including ion channels, is a hallmark feature of aging and may contribute to cell failure as a result. In this review we discuss the effects of ROS on three major types of ion channels of the central nervous system, namely the potassium (K(+)), calcium (Ca(2+)) and sodium (Na(+)) channels. We examine two general mechanisms through which ROS affect ion channels: via direct oxidation of specific residues and via indirect interference of pathways that regulate the channels. The overall status of the present studies indicates that the interaction of ion channels with ROS is multimodal and pervasive in the central nervous system and likely constitutes a general mechanism of aging susceptibility.
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Affiliation(s)
- Rahul Patel
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, 683 Hoes Lane West, Piscataway, NJ 08854, USA
| | - Federico Sesti
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, 683 Hoes Lane West, Piscataway, NJ 08854, USA.
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Effects of pre-natal alcohol exposure on hippocampal synaptic plasticity: Sex, age and methodological considerations. Neurosci Biobehav Rev 2016; 64:12-34. [PMID: 26906760 DOI: 10.1016/j.neubiorev.2016.02.014] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 01/14/2016] [Accepted: 02/18/2016] [Indexed: 12/28/2022]
Abstract
The consumption of alcohol during gestation is detrimental to the developing central nervous system (CNS). The severity of structural and functional brain alterations associated with alcohol intake depends on many factors including the timing and duration of alcohol consumption. The hippocampal formation, a brain region implicated in learning and memory, is highly susceptible to the effects of developmental alcohol exposure. Some of the observed effects of alcohol on learning and memory may be due to changes at the synaptic level, as this teratogen has been repeatedly shown to interfere with hippocampal synaptic plasticity. At the molecular level alcohol interferes with receptor proteins and can disrupt hormones that are important for neuronal signaling and synaptic plasticity. In this review we examine the consequences of prenatal and early postnatal alcohol exposure on hippocampal synaptic plasticity and highlight the numerous factors that can modulate the effects of alcohol. We also discuss some potential mechanisms responsible for these changes as well as emerging therapeutic avenues that are beginning to be explored.
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Kempsell AT, Fieber LA. Habituation in the Tail Withdrawal Reflex Circuit is Impaired During Aging in Aplysia californica. Front Aging Neurosci 2016; 8:24. [PMID: 26903863 PMCID: PMC4751345 DOI: 10.3389/fnagi.2016.00024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 02/01/2016] [Indexed: 12/14/2022] Open
Abstract
The relevance of putative contributors to age-related memory loss are poorly understood. The tail withdrawal circuit of the sea hare, a straightforward neural model, was used to investigate the aging characteristics of rudimentary learning. The simplicity of this neuronal circuit permits attribution of declines in the function of specific neurons to aging declines. Memory was impaired in advanced age animals compared to their performance at the peak of sexual maturity, with habituation training failing to attenuate the tail withdrawal response or to reduce tail motoneuron excitability, as occurred in peak maturity siblings. Baseline motoneuron excitability of aged animals was significantly lower, perhaps contributing to a smaller scope for attenuation. Conduction velocity in afferent fibers to tail sensory neurons (SN) decreased during aging. The findings suggest that age-related changes in tail sensory and motor neurons result in deterioration of a simple form of learning in Aplysia.
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Affiliation(s)
- Andrew T Kempsell
- Division of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami Miami, FL, USA
| | - Lynne A Fieber
- Division of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami Miami, FL, USA
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74
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Zhang H, Liu J, Sun S, Pchitskaya E, Popugaeva E, Bezprozvanny I. Calcium signaling, excitability, and synaptic plasticity defects in a mouse model of Alzheimer's disease. J Alzheimers Dis 2016; 45:561-80. [PMID: 25589721 DOI: 10.3233/jad-142427] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Alzheimer's disease (AD) and aging result in impaired ability to store memories, but the cellular mechanisms responsible for these defects are poorly understood. Presenilin 1 (PS1) mutations are responsible for many early-onset familial AD (FAD) cases. The phenomenon of hippocampal long-term potentiation (LTP) is widely used in studies of memory formation and storage. Recent data revealed long-term LTP maintenance (L-LTP) is impaired in PS1-M146V knock-in (KI) FAD mice. To understand the basis for this phenomenon, in the present study we analyzed structural synaptic plasticity in hippocampal cultures from wild type (WT) and KI mice. We discovered that exposure to picrotoxin induces formation of mushroom spines in both WT and KI cultures, but the maintenance of mushroom spines is impaired in KI neurons. This maintenance defect can be explained by an abnormal firing pattern during the consolidation phase of structural plasticity in KI neurons. Reduced frequency of neuronal firing in KI neurons is caused by enhanced calcium-induced calcium release (CICR), enhanced activity of calcium-activated potassium channels, and increased afterhyperpolarization. As a result, "consolidation" pattern of neuronal activity converted to "depotentiation" pattern of neuronal activity in KI neurons. Consistent with this model, we demonstrated that pharmacological inhibitors of CICR (dantrolene), of calcium-activated potassium channels (apamin), and of calcium-dependent phosphatase calcineurin (FK506) are able to rescue structural plasticity defects in KI neurons. Furthermore, we demonstrate that incubation with dantrolene or apamin also rescued L-LTP defects in KI hippocampal slices, suggesting a role for a similar mechanism. This proposed mechanism may be responsible for memory defects in AD but also for age-related memory decline.
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Affiliation(s)
- Hua Zhang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jie Liu
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Suya Sun
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA Department of Neurology and Institute of Neurology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ekaterina Pchitskaya
- Laboratory of Molecular Neurodegeneration, St Petersburg State Polytechnical University, St Petersburg, Russia
| | - Elena Popugaeva
- Laboratory of Molecular Neurodegeneration, St Petersburg State Polytechnical University, St Petersburg, Russia
| | - Ilya Bezprozvanny
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA Laboratory of Molecular Neurodegeneration, St Petersburg State Polytechnical University, St Petersburg, Russia
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75
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Hardingham GE, Do KQ. Linking early-life NMDAR hypofunction and oxidative stress in schizophrenia pathogenesis. Nat Rev Neurosci 2016; 17:125-34. [PMID: 26763624 DOI: 10.1038/nrn.2015.19] [Citation(s) in RCA: 231] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Molecular, genetic and pathological evidence suggests that deficits in GABAergic parvalbumin-positive interneurons contribute to schizophrenia pathophysiology through alterations in the brain's excitation-inhibition balance that result in impaired behaviour and cognition. Although the factors that trigger these deficits are diverse, there is increasing evidence that they converge on a common pathological hub that involves NMDA receptor hypofunction and oxidative stress. These factors have been separately linked to schizophrenia pathogenesis, but evidence now suggests that they are mechanistically interdependent and contribute to a common schizophrenia-associated pathology.
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Affiliation(s)
- Giles E Hardingham
- School of Biomedical Sciences, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK
| | - Kim Q Do
- Department of Psychiatry, Center of Psychiatric Neuroscience, Centre Hospitalier Universitaire Vaudois and University of Lausanne, CH-1008, Prilly-Lausanne, Switzerland
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76
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Spalloni A, Longone P. Cognitive impairment in amyotrophic lateral sclerosis, clues from the SOD1 mouse. Neurosci Biobehav Rev 2016; 60:12-25. [DOI: 10.1016/j.neubiorev.2015.11.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 11/09/2015] [Accepted: 11/16/2015] [Indexed: 12/11/2022]
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77
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Kumar A. NMDA Receptor Function During Senescence: Implication on Cognitive Performance. Front Neurosci 2015; 9:473. [PMID: 26732087 PMCID: PMC4679982 DOI: 10.3389/fnins.2015.00473] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Accepted: 11/25/2015] [Indexed: 12/13/2022] Open
Abstract
N-methyl-D-aspartate (NMDA) receptors, a family of L-glutamate receptors, play an important role in learning and memory, and are critical for spatial memory. These receptors are tetrameric ion channels composed of a family of related subunits. One of the hallmarks of the aging human population is a decline in cognitive function; studies in the past couple of years have demonstrated deterioration in NMDA receptor subunit expression and function with advancing age. However, a direct relationship between impaired memory function and a decline in NMDA receptors is still ambiguous. Recent studies indicate a link between an age-associated NMDA receptor hypofunction and memory impairment and provide evidence that age-associated enhanced oxidative stress might be contributing to the alterations associated with senescence. However, clear evidence is still deficient in demonstrating the underlying mechanisms and a relationship between age-associated impaired cognitive faculties and NMDA receptor hypofunction. The current review intends to present an overview of the research findings regarding changes in expression of various NMDA receptor subunits and deficits in NMDA receptor function during senescence and its implication in age-associated impaired hippocampal-dependent memory function.
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Affiliation(s)
- Ashok Kumar
- Department of Neuroscience, Evelyn F. and William L. McKnight Brain Institute, University of Florida Gainesville, FL, USA
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78
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Chen H, Wang X, Wang M, Yang L, Yan Z, Zhang Y, Liu Z. Behavioral and Neurochemical Deficits in Aging Rats with Increased Neonatal Iron Intake: Silibinin's Neuroprotection by Maintaining Redox Balance. Front Aging Neurosci 2015; 7:206. [PMID: 26578951 PMCID: PMC4623400 DOI: 10.3389/fnagi.2015.00206] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Accepted: 10/12/2015] [Indexed: 02/04/2023] Open
Abstract
Aging is a critical risk factor for Parkinson's disease. Silibinin, a major flavonoid in Silybum marianum, has been suggested to display neuroprotective properties against various neurodegenerative diseases. In the present study, we observed that neonatal iron (120 μg/g body weight) supplementation resulted in significant abnormality of behavior and depletion of striatal dopamine (DA) in the aging male and female rats while it did not do so in the young male and female rats. No significant change in striatal serotonin content was observed in the aging male and female rats with neonatal supplementation of the same dose of iron. Furthermore, we found that the neonatal iron supplementation resulted in significant increase in malondialdehyde (MDA) and decrease in glutathione (GSH) in the substantia nigra (SN) of the aging male and female rats. No significant change in content of MDA and GSH was observed in the cerebellum of the aging male and female rats with the neonatal iron supplementation. Interestingly, silibinin (25 and 50 mg/kg body weight) treatment significantly and dose-dependently attenuated depletion of striatal DA and improved abnormality of behavior in the aging male and female rats with the neonatal iron supplementation. Moreover, silibinin significantly reduced MDA content and increased GSH content in the SN of the aging male and female rats. Taken together, our results indicate that elevated neonatal iron supplementation may result in neurochemical and behavioral deficits in the male and female rats with aging and silibinin may exert dopaminergic neuroprotection by maintaining redox balance.
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Affiliation(s)
- Hanqing Chen
- Department of Neurology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine , Shanghai , China ; School of Biotechnology and Food Engineering, Hefei University of Technology , Hefei , China
| | - Xijin Wang
- Department of Neurology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine , Shanghai , China
| | - Meihua Wang
- Department of Neurology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine , Shanghai , China
| | - Liu Yang
- Department of Neurology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine , Shanghai , China
| | - Zhiqiang Yan
- Shanghai Laboratory Animal Center, Chinese Academy of Sciences , Shanghai , China
| | - Yuhong Zhang
- Department of Neurology, Shanghai Tenth People's Hospital, Tongji University , Shanghai , China
| | - Zhenguo Liu
- Department of Neurology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine , Shanghai , China
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79
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Stein LR, Zorumski CF, Imai SI, Izumi Y. Nampt is required for long-term depression and the function of GluN2B subunit-containing NMDA receptors. Brain Res Bull 2015; 119:41-51. [PMID: 26481044 DOI: 10.1016/j.brainresbull.2015.10.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Revised: 09/13/2015] [Accepted: 10/12/2015] [Indexed: 01/01/2023]
Abstract
Nicotinamide adenine dinucleotide (NAD(+)) is an essential coenzyme/cosubstrate for many biological processes in cellular metabolism. The rate-limiting step in the major pathway of mammalian NAD(+) biosynthesis is mediated by nicotinamide phosphoribosyltransferase (Nampt). Previously, we showed that mice lacking Nampt in forebrain excitatory neurons (CamKIIαNampt(-/-) mice) exhibited hyperactivity, impaired learning and memory, and reduced anxiety-like behaviors. However, it remained unclear if these functional effects were accompanied by synaptic changes. Here, we show that CamKIIαNampt(-/-) mice have impaired induction of long-term depression (LTD) in the Schaffer collateral pathway, but normal induction of long-term potentiation (LTP), at postnatal day 30. Pharmacological assessments demonstrated that CamKIIαNampt(-/-) mice also display dysfunction of synaptic GluN2B (NR2B)-containing N-methyl-d-aspartate receptors (NMDARs) prior to changes in NMDAR subunit expression. These results support a novel, important role for Nampt-mediated NAD(+) biosynthesis in LTD and in the function of GluN2B-containing NMDARs.
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Affiliation(s)
- Liana Roberts Stein
- Department of Developmental Biology, Washington University School of Medicine, Campus Box 8103, 660 South Euclid Avenue, St. Louis, MO 63110, USA; Department of Psychiatry, The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, Campus Box 8134, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
| | - Charles F Zorumski
- Department of Psychiatry, The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, Campus Box 8134, 660 South Euclid Avenue, St. Louis, MO 63110, USA; Department of Anatomy and Neurobiology, Washington University School of Medicine, Campus Box 8134, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
| | - Shin-Ichiro Imai
- Department of Developmental Biology, Washington University School of Medicine, Campus Box 8103, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
| | - Yukitoshi Izumi
- Department of Psychiatry, The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, Campus Box 8134, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
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80
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Kempsell AT, Fieber LA. Age-related deficits in synaptic plasticity rescued by activating PKA or PKC in sensory neurons of Aplysia californica. Front Aging Neurosci 2015; 7:173. [PMID: 26388769 PMCID: PMC4558425 DOI: 10.3389/fnagi.2015.00173] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 08/19/2015] [Indexed: 01/31/2023] Open
Abstract
Brain aging is associated with declines in synaptic function that contribute to memory loss, including reduced postsynaptic response to neurotransmitters and decreased neuronal excitability. To understand how aging affects memory in a simple neural circuit, we studied neuronal proxies of memory for sensitization in mature vs. advanced age Aplysia californica (Aplysia). L-Glutamate- (L-Glu-) evoked excitatory currents were facilitated by the neuromodulator serotonin (5-HT) in sensory neurons (SN) isolated from mature but not aged animals. Activation of protein kinase A (PKA) and protein kinase C (PKC) signaling rescued facilitation of L-Glu currents in aged SN. Similarly, PKA and PKC activators restored increased excitability in aged tail SN. These results suggest that altered synaptic plasticity during aging involves defects in second messenger systems.
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Affiliation(s)
- Andrew T Kempsell
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami Miami, FL, USA
| | - Lynne A Fieber
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami Miami, FL, USA
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81
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A Special Extract of Bacopa monnieri (CDRI-08)-Restored Memory in CoCl2-Hypoxia Mimetic Mice Is Associated with Upregulation of Fmr-1 Gene Expression in Hippocampus. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 2015:347978. [PMID: 26413121 PMCID: PMC4564622 DOI: 10.1155/2015/347978] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 04/01/2015] [Indexed: 11/18/2022]
Abstract
Fragile X mental retardation protein (FMRP) is a neuronal translational repressor and has been implicated in learning, memory, and cognition. However, the role of Bacopa monnieri extract (CDRI-08) in enhancing cognitive abilities in hypoxia-induced memory impairment via Fmr-1 gene expression is not known. Here, we have studied effects of CDRI-08 on the expression of Fmr-1 gene in the hippocampus of well validated cobalt chloride (CoCl2)-induced hypoxia mimetic mice and analyzed the data with alterations in spatial memory. Results obtained from Morris water maze test suggest that CoCl2 treatment causes severe loss of spatial memory and CDRI-08 is capable of reversing it towards that in the normal control mice. Our semiquantitative RT-PCR, Western blot, and immunofluorescence microscopic data reveal that CoCl2-induced hypoxia significantly upregulates the expression of Hif-1α and downregulates the Fmr-1 expression in the hippocampus, respectively. Further, CDRI-08 administration reverses the memory loss and this is correlated with significant downregulation of Hif-1α and upregulation of Fmr-1 expression. Our data are novel and may provide mechanisms of hypoxia-induced impairments in the spatial memory and action of CDRI-08 in the recovery of hypoxia led memory impairment involving Fmr-1 gene encoded protein called FMRP.
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82
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Berridge MJ. Vitamin D cell signalling in health and disease. Biochem Biophys Res Commun 2015; 460:53-71. [PMID: 25998734 DOI: 10.1016/j.bbrc.2015.01.008] [Citation(s) in RCA: 126] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 01/05/2015] [Indexed: 12/13/2022]
Abstract
Vitamin D deficiency has been linked to many human diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), hypertension and cardiovascular disease. A Vitamin D phenotypic stability hypothesis, which is developed in this review, attempts to describe how this vital hormone acts to maintain healthy cellular functions. This role of Vitamin D as a guardian of phenotypic stability seems to depend on its ability to maintain the redox and Ca(2+) signalling systems. It is argued that its primary action is to maintain the expression of those signalling components responsible for stabilizing the low resting state of these two signalling pathways. This phenotypic stability role is facilitated through the ability of vitamin D to increase the expression of both Nrf2 and the anti-ageing protein Klotho, which are also major regulators of Ca(2+) and redox signalling. A decline in Vitamin D levels will lead to a decline in the stability of this regulatory signalling network and may account for why so many of the major diseases in man, which have been linked to vitamin D deficiency, are associated with a dysregulation in both ROS and Ca(2+) signalling.
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83
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Liu DS, Pan XD, Zhang J, Shen H, Collins NC, Cole AM, Koster KP, Ben Aissa M, Dai XM, Zhou M, Tai LM, Zhu YG, LaDu M, Chen XC. APOE4 enhances age-dependent decline in cognitive function by down-regulating an NMDA receptor pathway in EFAD-Tg mice. Mol Neurodegener 2015; 10:7. [PMID: 25871877 PMCID: PMC4391134 DOI: 10.1186/s13024-015-0002-2] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 01/26/2015] [Indexed: 12/16/2022] Open
Abstract
Background Alzheimer’s disease (AD) causes progressive loss of memory and cognition, exacerbated by APOE4, the greatest genetic risk factor for AD. One proposed mechanism for apolipoprotein E (apoE) effects on cognition is via NMDAR-dependent signaling. APOE genotype-specific effects on this pathway were dissected using EFAD-transgenic (Tg) mice (5xFAD mice, that over-express human amyloid-beta (Aβ) via 5 familial-AD (FAD) mutations, and express human apoE), and 5xFAD/APOE-knockout (KO) mice. Previous data from EFAD-Tg mice demonstrate age-dependent (2-6 months), apoE-specific effects on the development of Aβ pathology. This study tests the hypothesis that apoE4 impairs cognition via modulation of NMDAR-dependent signaling, specifically via a loss of function by comparison of E4FAD mice with 5xFAD/APOE-KO mice, E3FAD and E2FAD mice. Results Using female E2FAD, E3FAD, E4FAD and 5xFAD/APOE-KO mice aged 2-, 4-, and 6-months, the Y-maze and Morris water maze behavioral tests were combined with synaptic protein levels as markers of synaptic viability. The results demonstrate a greater age-induced deficit in cognition and reduction in PSD95, drebrin and NMDAR subunits in the E4FAD and 5xFAD/APOE-KO mice compared with E2FAD and E3FAD mice, consistent with an apoE4 loss of function. Interestingly, for NMDAR-mediated signaling, the levels of p-CaMK-II followed this same apoE-specific pattern as cognition, while the levels of p-CREB and BDNF demonstrate an apoE4 toxic gain of function: E2FAD > E3FAD > 5xFAD/APOE-KO > E4FAD. Conclusion These findings suggest that compared with E2FAD and E3FAD, E4FAD and 5xFAD/APOE-KO mice exhibit enhanced age-induced reductions in cognition and key synaptic proteins via down-regulation of an NMDAR signaling pathway, consistent with an apoE4 loss of function. However, levels of p-CREB and BDNF, signaling factors common to multiple pathways, suggest a gain of toxic function. Publications in this field present contradictory results as to whether APOE4 imparts a loss or gain of function. As with the results reported herein, the overall effect of APOE4 on a given CNS-specific measure will be the product of multiple overlapping mechanisms. Thus, caution remains critical in determining whether APOE gene inactivation or therapies that correct the loss of positive function related to apoE4, are the appropriate therapeutic response. Electronic supplementary material The online version of this article (doi:10.1186/s13024-015-0002-2) contains supplementary material, which is available to authorized users.
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84
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Guidi M, Kumar A, Foster TC. Impaired attention and synaptic senescence of the prefrontal cortex involves redox regulation of NMDA receptors. J Neurosci 2015; 35:3966-77. [PMID: 25740525 PMCID: PMC4348191 DOI: 10.1523/jneurosci.3523-14.2015] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 12/23/2014] [Accepted: 01/21/2015] [Indexed: 01/05/2023] Open
Abstract
Young (3-6 months) and middle-age (10-14 months) rats were trained on the five-choice serial reaction time task. Attention and executive function deficits were apparent in middle-age animals observed as a decrease in choice accuracy, increase in omissions, and increased response latency. The behavioral differences were not due to alterations in sensorimotor function or a diminished motivational state. Electrophysiological characterization of synaptic transmission in slices from the mPFC indicated an age-related decrease in glutamatergic transmission. In particular, a robust decrease in N-methyl-D-aspartate receptor (NMDAR)-mediated synaptic responses in the mPFC was correlated with several measures of attention. The decrease in NMDAR function was due in part to an altered redox state as bath application of the reducing agent, dithiothreitol, increased the NMDAR component of the synaptic response to a greater extent in middle-age animals. Together with previous work indicating that redox state mediates senescent physiology in the hippocampus, the results indicate that redox changes contribute to senescent synaptic function in vulnerable brain regions involved in age-related cognitive decline.
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Affiliation(s)
- Michael Guidi
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida 32610
| | - Ashok Kumar
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida 32610
| | - Thomas C Foster
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida 32610
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85
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The excitatory amino acid carrier 1 (EAAC1) in the rat nucleus of the solitary tract: subcellular localization suggests no major role in glutamate clearance. Brain Struct Funct 2014; 221:1113-24. [DOI: 10.1007/s00429-014-0958-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 12/03/2014] [Indexed: 11/26/2022]
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86
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Paula-Lima AC, Adasme T, Hidalgo C. Contribution of Ca2+ release channels to hippocampal synaptic plasticity and spatial memory: potential redox modulation. Antioxid Redox Signal 2014; 21:892-914. [PMID: 24410659 DOI: 10.1089/ars.2013.5796] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
SIGNIFICANCE Memory is an essential human cognitive function. Consequently, to unravel the cellular and molecular mechanisms responsible for the synaptic plasticity events underlying memory formation, storage and loss represents a major challenge of present-day neuroscience. RECENT ADVANCES This review article first describes the wide-ranging functions played by intracellular Ca2+ signals in the activity-dependent synaptic plasticity processes underlying hippocampal spatial memory, and next, it focuses on how the endoplasmic reticulum Ca2+ release channels, the ryanodine receptors, and the inositol 1,4,5-trisphosphate receptors contribute to these processes. We present a detailed examination of recent evidence supporting the key role played by Ca2+ release channels in synaptic plasticity, including structural plasticity, and the formation/consolidation of spatial memory in the hippocampus. CRITICAL ISSUES Changes in cellular oxidative state particularly affect the function of Ca2+ release channels and alter hippocampal synaptic plasticity and the associated memory processes. Emphasis is placed in this review on how defective Ca2+ release, presumably due to increased levels of reactive oxygen species, may cause the hippocampal functional defects that are associated to aging and Alzheimer's disease (AD). FUTURE DIRECTIONS Additional studies should examine the precise molecular mechanisms by which Ca2+ release channels contribute to hippocampal synaptic plasticity and spatial memory formation/consolidation. Future studies should test whether redox-modified Ca2+ release channels contribute toward generating the intracellular Ca2+ signals required for sustained synaptic plasticity and hippocampal spatial memory, and whether loss of redox balance and oxidative stress, by altering Ca2+ release channel function, presumably contribute to the abnormal memory processes that occur during aging and AD.
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Affiliation(s)
- Andrea C Paula-Lima
- 1 Faculty of Dentistry, Institute for Research in Dental Sciences, Universidad de Chile , Santiago, Chile
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87
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Dukoff DJ, Hogg DW, Hawrysh PJ, Buck LT. Scavenging ROS dramatically increase NMDA receptor whole-cell currents in painted turtle cortical neurons. ACTA ACUST UNITED AC 2014; 217:3346-55. [PMID: 25063855 DOI: 10.1242/jeb.105825] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Oxygen deprivation triggers excitotoxic cell death in mammal neurons through excessive calcium loading via over-activation of N-methyl-d-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors. This does not occur in the western painted turtle, which overwinters for months without oxygen. Neurological damage is avoided through anoxia-mediated decreases in NMDA and AMPA receptor currents that are dependent upon a modest rise in intracellular Ca(2+) concentrations ([Ca(2+)]i) originating from mitochondria. Anoxia also blocks mitochondrial reactive oxygen species (ROS) generation, which is another potential signaling mechanism to regulate glutamate receptors. To assess the effects of decreased intracellular [ROS] on NMDA and AMPA receptor currents, we scavenged ROS with N-2-mercaptopropionylglycine (MPG) or N-acetylcysteine (NAC). Unlike anoxia, ROS scavengers increased NMDA receptor whole-cell currents by 100%, while hydrogen peroxide decreased currents. AMPA receptor currents and [Ca(2+)]i concentrations were unaffected by ROS manipulation. Because decreases in [ROS] increased NMDA receptor currents, we next asked whether mitochondrial Ca(2+) release prevents receptor potentiation during anoxia. Normoxic activation of mitochondrial ATP-sensitive potassium (mKATP) channels with diazoxide decreased NMDA receptor currents and was unaffected by subsequent ROS scavenging. Diazoxide application following ROS scavenging did not rescue scavenger-mediated increases in NMDA receptor currents. Fluorescent measurement of [Ca(2+)]i and ROS levels demonstrated that [Ca(2+)]i increases before ROS decreases. We conclude that decreases in ROS concentration are not linked to anoxia-mediated decreases in NMDA/AMPA receptor currents but are rather associated with an increase in NMDA receptor currents that is prevented during anoxia by mitochondrial Ca(2+) release.
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Affiliation(s)
- David James Dukoff
- Department of Cell and Systems Biology and Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - David William Hogg
- Department of Cell and Systems Biology and Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Peter John Hawrysh
- Department of Cell and Systems Biology and Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Leslie Thomas Buck
- Department of Cell and Systems Biology and Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
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88
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Rani A, Prasad S. CoCl2-induced biochemical hypoxia down regulates activities and expression of super oxide dismutase and catalase in cerebral cortex of mice. Neurochem Res 2014; 39:1787-96. [PMID: 25052430 DOI: 10.1007/s11064-014-1388-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Revised: 07/08/2014] [Accepted: 07/14/2014] [Indexed: 12/11/2022]
Abstract
Hypoxia-induced oxidative stress is one of the major hallmark reasons underlying brain dysfunction. In the present manuscript, we have used CoCl2-induced hypoxic mice to investigate alterations in the activities of chief antioxidative stress enzymes- superoxide dismutase (SOD) and catalase (CAT) and expression of their genes Sod1 and Cat in the cerebral cortex as this model has not been routinely used for carrying out such study. Hypoxia mimetic mice model was accordingly developed by oral CoCl2 administration to mice and validated by analyzing alterations in the expression of the hypoxia inducible factor gene Hif-1α and its immediate responsive genes. Our Western blot data demonstrated that a dose of 40 mg/kg BW of CoCl2 was able to generate hypoxia like condition in mice in which Hif-1α and its immediate responsive genes-glutamate transporter-1 (Slc2a1) and erythropoietin (Epo) expression were up regulated. Our in-gel assay data indicated that SOD and CAT activities significantly declined and it was associated with significant down regulation of Sod1 and Epo expression as evident from our semi quantitative RT-PCR and Western blot data, which might be correlated with up regulation of Hif-1α expression in the cerebral cortex of the CoCl2-treated hypoxic mice. Our findings suggest that CoCl2-induced hypoxic mouse model is useful for studying alterations in the anti oxidative enzymes and biochemical/molecular/neurobiological analysis of hypoxia-induced alterations in brain function.
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Affiliation(s)
- Anupama Rani
- Biochemistry and Molecular Biology Lab, Department of Zoology, Centre of Advanced Study in Zoology, Banaras Hindu University, Varanasi, 221005, Uttar Pradesh, India
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89
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Kumar A, Foster TC. Interaction of DHPG-LTD and synaptic-LTD at senescent CA3-CA1 hippocampal synapses. Hippocampus 2014; 24:466-75. [PMID: 24390964 DOI: 10.1002/hipo.22240] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 12/18/2013] [Accepted: 12/19/2013] [Indexed: 12/12/2022]
Abstract
The susceptibility, but not the magnitude, of long-term depression (LTD) induced by hippocampal CA3-CA1 synaptic activity (synaptic-LTD) increases with advanced age. In contrast, the magnitude of LTD induced by pharmacological activation of CA3-CA1 group I metabotropic glutamate receptors (mGluRs) increases during aging. This study examined the signaling pathways involved in induction of LTD and the interaction between paired-pulse low frequency stimulation-induced synaptic-LTD and group I mGluR selective agonist, (RS)-3,5-dihydroxyphenylglycine (DHPG, 100 µM)-induced DHPG-LTD in hippocampal slices obtained from aged (22-24 months) male Fischer 344 rats. Prior induction of synaptic-LTD did not affect induction of DHPG-LTD; however, prior induction of the DHPG-LTD occluded synaptic-LTD suggesting that expression of DHPG-LTD may incorporate synaptic-LTD mechanisms. Application of individual antagonist for the group I mGluR (AIDA), the N-methyl-d-aspartate receptor (NMDAR) (AP-5), or L-type voltage-dependent Ca(2+) channel (VDCC) (nifedipine) failed to block synaptic-LTD and any two antagonists severely impaired synaptic-LTD induction, indicating that activation of any two mechanisms is sufficient to induce synaptic-LTD in aged animals. For DHPG-LTD, AIDA blocked DHPG-LTD and individually applied NMDAR or VDCC attenuated but did not block DHPG-LTD, indicating that the magnitude of DHPG-LTD depends on all three mechanisms.
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Affiliation(s)
- Ashok Kumar
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida
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90
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Wang Y, Mattson MP. L-type Ca2+ currents at CA1 synapses, but not CA3 or dentate granule neuron synapses, are increased in 3xTgAD mice in an age-dependent manner. Neurobiol Aging 2014; 35:88-95. [PMID: 23932880 PMCID: PMC3864587 DOI: 10.1016/j.neurobiolaging.2013.07.007] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 07/10/2013] [Accepted: 07/14/2013] [Indexed: 02/04/2023]
Abstract
Abnormal neuronal excitability and impaired synaptic plasticity might occur before the degeneration and death of neurons in Alzheimer's disease (AD). To elucidate potential biophysical alterations underlying aberrant neuronal network activity in AD, we performed whole-cell patch clamp analyses of L-type (nifedipine-sensitive) Ca(2+) currents (L-VGCC), 4-aminopyridine-sensitive K(+) currents, and AMPA (2-amino-3-(3-hydroxy-5-methyl-isoxazol-4-yl)propanoic acid) and NMDA (N-methyl-D-aspartate) currents in CA1, CA3, and dentate granule neurons in hippocampal slices from young, middle-age, and old 3xTgAD mice and age-matched wild type mice. 3xTgAD mice develop progressive widespread accumulation of amyloid β-peptide, and selective hyperphosphorylated tau pathology in hippocampal CA1 neurons, which are associated with cognitive deficits, but independent of overt neuronal degeneration. An age-related elevation of L-type Ca(2+) channel current density occurred in CA1 neurons in 3xTgAD mice, but not in wild type mice, with the magnitude being significantly greater in older 3xTgAD mice. The NMDA current was also significantly elevated in CA1 neurons of old 3xTgAD mice compared with in old wild type mice. There were no differences in the amplitude of K(+) or AMPA currents in CA1 neurons of 3xTgAD mice compared with wild type mice at any age. There were no significant differences in Ca(2+), K(+), AMPA, or NMDA currents in CA3 and dentate neurons from 3xTgAD mice compared with wild type mice at any age. Our results reveal an age-related increase of L-VGCC density in CA1 neurons, but not in CA3 or dentate granule neurons, of 3xTgAD mice. These findings suggest a potential contribution of altered L-VGCC to the selective vulnerability of CA1 neurons to tau pathology in the 3xTgAD mice and to their degeneration in AD patients.
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MESH Headings
- Aging/pathology
- Aging/physiology
- Alzheimer Disease/genetics
- Alzheimer Disease/pathology
- Alzheimer Disease/physiopathology
- Amyloid beta-Peptides/metabolism
- Animals
- CA1 Region, Hippocampal/cytology
- CA1 Region, Hippocampal/metabolism
- CA1 Region, Hippocampal/physiology
- CA3 Region, Hippocampal/cytology
- CA3 Region, Hippocampal/physiology
- Calcium Channels, L-Type/metabolism
- Calcium Channels, L-Type/physiology
- Cells, Cultured
- Cognition Disorders/genetics
- Dentate Gyrus/cytology
- Dentate Gyrus/physiology
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- N-Methylaspartate
- Patch-Clamp Techniques/methods
- Phosphorylation
- Potassium Channels, Voltage-Gated/physiology
- Synapses/pathology
- Synapses/physiology
- alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
- tau Proteins/metabolism
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Affiliation(s)
- Yue Wang
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD, USA.
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91
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Lee WH, Kumar A, Rani A, Foster TC. Role of antioxidant enzymes in redox regulation of N-methyl-D-aspartate receptor function and memory in middle-aged rats. Neurobiol Aging 2013; 35:1459-68. [PMID: 24388786 DOI: 10.1016/j.neurobiolaging.2013.12.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 11/19/2013] [Accepted: 12/04/2013] [Indexed: 01/21/2023]
Abstract
Overexpression of superoxide dismutase 1 (SOD1) in the hippocampus results in age-dependent impaired cognition and altered synaptic plasticity suggesting a possible model for examining the role of oxidative stress in senescent neurophysiology. However, it is unclear if SOD1 overexpression involves an altered redox environment and a decrease in N-methyl-D-aspartate receptor (NMDAR) synaptic function reported for aging animals. Viral vectors were used to express SOD1 and green fluorescent protein (SOD1 + GFP), SOD1 and catalase (SOD1 + CAT), or GFP alone in the hippocampus of middle-aged (17 months) male Fischer 344 rats. We confirm that SOD1 + GFP and SOD1 + CAT reduced lipid peroxidation indicating superoxide metabolites were primarily responsible for lipid peroxidation. SOD1 + GFP impaired learning, decreased glutathione peroxidase activity, decreased glutathione levels, decreased NMDAR-mediated synaptic responses, and impaired long-term potentiation. Co-expression of SOD1 + CAT rescued the effects of SOD1 expression on learning, redox measures, and synaptic function suggesting the effects were mediated by excess hydrogen peroxide. Application of the reducing agent dithiolthreitol to hippocampal slices increased the NMDAR-mediated component of the synaptic response in SOD1 + GFP animals relative to animals that overexpress SOD1 + CAT indicating that the effect of antioxidant enzyme expression on NMDAR function was because of a shift in the redox environment. The results suggest that overexpression of neuronal SOD1 and CAT in middle age may provide a model for examining the role of oxidative stress in senescent physiology and the progression of age-related neurodegenerative diseases.
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Affiliation(s)
- Wei-Hua Lee
- Department of Medical Genetics, University of Wisconsin, Madison, WI, USA
| | - Ashok Kumar
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Asha Rani
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Thomas C Foster
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA.
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92
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Abstract
NMDA receptors (NMDARs) play a critical role in learning and memory; however, there is a lack of evidence for a direct relationship between a well characterized decline in NMDAR function and impaired cognition during aging. The present study was designed to test the idea that a redox-mediated decrease in the NMDAR component of synaptic transmission during aging is related to a specific cognitive phenotype: impaired memory for rapidly acquired novel spatial information. Young and middle-aged male F344 rats were provided 1 d of training on the spatial version of the water maze, and retention was examined 24 h later. The performance of young rats was used as a criterion for classifying middle-aged rats as impaired and unimpaired on the task. Subsequent construction of CA3-CA1 synaptic input-output curves in hippocampal slices confirmed an age-related decrease in synaptic responses, including the NMDAR component of synaptic transmission. Examination of synaptic transmission according to behavioral classification revealed that animals classified as impaired exhibited a decrease in the total and the NMDAR component of the synaptic response relative to unimpaired animals. Furthermore, bath application of the reducing agent dithiothreitol increased the NMDAR component of the synaptic response to a greater extent in impaired animals relative to unimpaired and young rats. These results provide evidence for a link between the redox-mediated decline in NMDAR function and emergence of an age-related cognitive phenotype, impairment in the rapid acquisition and retention of novel spatial information.
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93
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Patten AR, Brocardo PS, Sakiyama C, Wortman RC, Noonan A, Gil-Mohapel J, Christie BR. Impairments in hippocampal synaptic plasticity following prenatal ethanol exposure are dependent on glutathione levels. Hippocampus 2013; 23:1463-75. [PMID: 23996467 DOI: 10.1002/hipo.22199] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2013] [Indexed: 11/09/2022]
Abstract
Previous studies from our laboratory have shown that prenatal ethanol exposure (PNEE) causes a significant deficit in synaptic plasticity, namely long-term potentiation (LTP), in the dentate gyrus (DG) region of the hippocampus of male rats. PNEE has also been shown to induce an increase in oxidative stress and a reduction in antioxidant capacity in the brains of both male and female animals. In this study the interaction between LTP and the major antioxidant in the brain, glutathione (GSH), is examined. We show that depletion of the intracellular reserves of GSH with diethyl maleate (DEM) reduces LTP in control male, but not female animals, mirroring the effects of PNEE. Furthermore, treatment of PNEE animals with N-acetyl cysteine (NAC), a cysteine donor for the synthesis of GSH, increases GSH levels in the hippocampus and completely restores the deficits in LTP in PNEE males. These results indicate that in males GSH plays a major role in regulating LTP, and that PNEE may cause reductions in LTP by reducing the intracellular pool of this endogenous antioxidant.
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Affiliation(s)
- Anna R Patten
- Division of Medical Sciences, Island Medical Program, University of Victoria, Victoria, British Columbia, Canada; Department of Biology, University of Victoria, Victoria, British Columbia, Canada
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94
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Gutierrez DA, Fernandez-Tenorio M, Ogrodnik J, Niggli E. NO-dependent CaMKII activation during β-adrenergic stimulation of cardiac muscle. Cardiovasc Res 2013; 100:392-401. [PMID: 23963842 DOI: 10.1093/cvr/cvt201] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS During β-adrenergic receptor (β-AR) stimulation, phosphorylation of cardiomyocyte ryanodine receptors by protein kinases may contribute to an increased diastolic Ca(2+) spark frequency. Regardless of prompt activation of protein kinase A during β-AR stimulation, this appears to rely more on activation of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), by a not yet identified signalling pathway. The goal of the present study was to identify and characterize the mechanisms which lead to CaMKII activation and elevated Ca(2+) spark frequencies during β-AR stimulation in single cardiomyocytes in diastolic conditions. METHODS AND RESULTS Confocal imaging revealed that β-AR stimulation increases endogenous NO production in cardiomyocytes, resulting in NO-dependent activation of CaMKII and a subsequent increase in diastolic Ca(2+) spark frequency. These changes of spark frequency could be mimicked by exposure to the NO donor GSNO and were sensitive to the CaMKII inhibitors KN-93 and AIP. In vitro, CaMKII became nitrosated and its activity remained increased independent of Ca(2+) in the presence of GSNO, as assessed with biochemical assays. CONCLUSIONS β-AR stimulation of cardiomyocytes may activate CaMKII by a novel direct pathway involving NO, without requiring Ca(2+) transients. This crosstalk between two established signalling pathways may contribute to arrhythmogenic diastolic Ca(2+) release and Ca(2+) waves during adrenergic stress, particularly in combination with cardiac diseases. In addition, NO-dependent activation of CaMKII is likely to have repercussions in many cellular signalling systems and cell types.
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Affiliation(s)
- Daniel A Gutierrez
- Department of Physiology, University of Bern, Bühlplatz 5, CH-3012 Bern, Switzerland
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95
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Ghosh D, LeVault KR, Brewer GJ. Dual-energy precursor and nuclear erythroid-related factor 2 activator treatment additively improve redox glutathione levels and neuron survival in aging and Alzheimer mouse neurons upstream of reactive oxygen species. Neurobiol Aging 2013; 35:179-90. [PMID: 23954169 DOI: 10.1016/j.neurobiolaging.2013.06.023] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 05/24/2013] [Accepted: 06/30/2013] [Indexed: 01/01/2023]
Abstract
To determine whether glutathione (GSH) loss or increased reactive oxygen species (ROS) are more important to neuron loss, aging, and Alzheimer's disease (AD), we stressed or boosted GSH levels in neurons isolated from aging 3xTg-AD neurons compared with those from age-matched nontransgenic (non-Tg) neurons. Here, using titrating with buthionine sulfoximine, an inhibitor of γ-glutamyl cysteine synthetase (GCL), we observed that GSH depletion increased neuronal death of 3xTg-AD cultured neurons at increasing rates across the age span, whereas non-Tg neurons were resistant to GSH depletion until old age. Remarkably, the rate of neuron loss with ROS did not increase in old age and was the same for both genotypes, which indicates that cognitive deficits in the AD model were not caused by ROS. Therefore, we targeted for neuroprotection activation of the redox sensitive transcription factor, nuclear erythroid-related factor 2 (Nrf2) by 18 alpha glycyrrhetinic acid to stimulate GSH synthesis through GCL. This balanced stimulation of a number of redox enzymes restored the lower levels of Nrf2 and GCL seen in 3xTg-AD neurons compared with those of non-Tg neurons and promoted translocation of Nrf2 to the nucleus. By combining the Nrf2 activator together with the NADH precursor, nicotinamide, we increased neuron survival against amyloid beta stress in an additive manner. These stress tests and neuroprotective treatments suggest that the redox environment is more important for neuron survival than ROS. The dual neuroprotective treatment with nicotinamide and an Nrf2 inducer indicates that these age-related and AD-related changes are reversible.
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Affiliation(s)
- Debolina Ghosh
- Department of Medical Microbiology, Immunology and Cell Biology, Southern Illinois University School of Medicine, Springfield, IL, USA
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96
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Sonntag WE, Deak F, Ashpole N, Toth P, Csiszar A, Freeman W, Ungvari Z. Insulin-like growth factor-1 in CNS and cerebrovascular aging. Front Aging Neurosci 2013; 5:27. [PMID: 23847531 PMCID: PMC3698444 DOI: 10.3389/fnagi.2013.00027] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 06/14/2013] [Indexed: 12/26/2022] Open
Abstract
Insulin-like growth factor-1 (IGF-1) is an important anabolic hormone that decreases with age. In the past two decades, extensive research has determined that the reduction in IGF-1 is an important component of the age-related decline in cognitive function in multiple species including humans. Deficiency in circulating IGF-1 results in impairment in processing speed and deficiencies in both spatial and working memory. Replacement of IGF-1 or factors that increase IGF-1 to old animals and humans reverses many of these cognitive deficits. Despite the overwhelming evidence for IGF-1 as an important neurotrophic agent, the specific mechanisms through which IGF-1 acts have remained elusive. Recent evidence indicates that IGF-1 is both produced by and has important actions on the cerebrovasculature as well as neurons and glia. Nevertheless, the specific regulation and actions of brain- and vascular-derived IGF-1 is poorly understood. The diverse effects of IGF-1 discovered thus far reveal a complex endocrine and paracrine system essential for integrating many of the functions necessary for brain health. Identification of the mechanisms of IGF-1 actions will undoubtedly provide critical insight into regulation of brain function in general and the causes of cognitive decline with age.
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Affiliation(s)
- William E Sonntag
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center Oklahoma City, OK, USA
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97
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Marsden WN. Synaptic plasticity in depression: molecular, cellular and functional correlates. Prog Neuropsychopharmacol Biol Psychiatry 2013; 43:168-84. [PMID: 23268191 DOI: 10.1016/j.pnpbp.2012.12.012] [Citation(s) in RCA: 213] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2012] [Revised: 12/14/2012] [Accepted: 12/15/2012] [Indexed: 12/31/2022]
Abstract
Synaptic plasticity confers environmental adaptability through modification of the connectivity between neurons and neuronal circuits. This is achieved through changes to synapse-associated signaling systems and supported by complementary changes to cellular morphology and metabolism within the tripartite synapse. Mounting evidence suggests region-specific changes to synaptic form and function occur as a result of chronic stress and in depression. Within subregions of the prefrontal cortex (PFC) and hippocampus structural and synapse-related findings seem consistent with a deficit in long-term potentiation (LTP) and facilitation of long-term depression (LTD), particularly at excitatory pyramidal synapses. Other brain regions are less well-studied; however the amygdala may feature a somewhat opposite synaptic pathology including reduced inhibitory tone. Changes to synaptic plasticity in stress and depression may correlate those to several signal transduction pathways (e.g. NOS-NO, cAMP-PKA, Ras-ERK, PI3K-Akt, GSK-3, mTOR and CREB) and upstream receptors (e.g. NMDAR, TrkB and p75NTR). Deficits in synaptic plasticity may further correlate disrupted brain redox and bioenergetics. Finally, at a functional level region-specific changes to synaptic plasticity in depression may relate to maladapted neurocircuitry and parallel reduced cognitive control over negative emotion.
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Affiliation(s)
- W N Marsden
- Highclere Court, Woking, Surrey, GU21 2QP, UK.
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98
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Huang YJ, Lin CH, Lane HY, Tsai GE. NMDA Neurotransmission Dysfunction in Behavioral and Psychological Symptoms of Alzheimer's Disease. Curr Neuropharmacol 2013; 10:272-85. [PMID: 23450042 PMCID: PMC3468881 DOI: 10.2174/157015912803217288] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Revised: 06/04/2012] [Accepted: 07/09/2012] [Indexed: 01/06/2023] Open
Abstract
Dementia has become an all-important disease because the population is aging rapidly and the cost of health care associated with dementia is ever increasing. In addition to cognitive function impairment, associated behavioral and psychological symptoms of dementia (BPSD) worsen patient’s quality of life and increase caregiver’s burden. Alzheimer’s disease is the most common type of dementia and both behavioral disturbance and cognitive impairment of Alzheimer’s disease are thought to be associated with the N-methyl-D-aspartate (NMDA) dysfunction as increasing evidence of dysfunctional glutamatergic neurotransmission had been reported in behavioral changes and cognitive decline in Alzheimer’s disease. We review the literature regarding dementia (especially Alzheimer’s disease), BPSD and relevant findings on glutamatergic and NMDA neurotransmission, including the effects of memantine, a NMDA receptor antagonist, and NMDA-enhancing agents, such as D-serine and D-cycloserine. Literatures suggest that behavioral disturbance and cognitive impairment of Alzheimer’s disease may be associated with excitatory neurotoxic effects which result in impairment of neuronal plasticity and degenerative processes. Memantine shows benefits in improving cognition, function, agitation/aggression and delusion in Alzheimer’s disease. On the other hand, some NMDA modulators which enhance NMDA function through the co-agonist binding site can also improve cognitive function and psychotic symptoms. We propose that modulating NMDA neurotransmission is effective in treating behavioral and psychological symptoms of Alzheimer’s disease. Prospective study using NMDA enhancers in patients with Alzheimer’s disease and associated behavioral disturbance is needed to verify this hypothesis.
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Affiliation(s)
- Yu-Jhen Huang
- Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan ; Department of Psychiatry, China Medical University Hospital, Taichung, Taiwan
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99
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van Zundert B, Izaurieta P, Fritz E, Alvarez FJ. Early pathogenesis in the adult-onset neurodegenerative disease amyotrophic lateral sclerosis. J Cell Biochem 2013; 113:3301-12. [PMID: 22740507 DOI: 10.1002/jcb.24234] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a devastating paralytic disorder caused by dysfunction and degeneration of motor neurons starting in adulthood. Most of our knowledge about the pathophysiological mechanisms of ALS comes from transgenic mice models that emulate a subgroup of familial ALS cases (FALS), with mutations in the gene encoding superoxide dismutase (SOD1). In the more than 15 years since these mice were generated, a large number of abnormal cellular mechanisms underlying motor neuron degeneration have been identified, but to date this effort has led to few improvements in therapy, and no cure. Here, we consider that this surfeit of mechanisms is best interpreted by current insights that suggest a very early initiation of pathology in motor neurons, followed by a diversity of secondary cascades and compensatory mechanisms that mask symptoms for decades, until trauma and/or aging overloads their protective function. This view thus posits that adult-onset ALS is the consequence of processes initiated during early development. In fact, motor neurons in neonatal mutant SOD mice display important alterations in their intrinsic electrical properties, synaptic inputs and morphology that are accompanied by subtle behavioral abnormalities. We consider evidence that human mutant SOD1 protein in neonatal hSOD1(G93A) mice instigates motor neuron degeneration by increasing persistent sodium currents and excitability, in turn altering synaptic circuits that control excessive motor neuron firing and leads to excitotoxicity. We also discuss how therapies that are aimed at suppressing abnormal neuronal activity might effectively mitigate or prevent the onset of irreversible neuronal damage in adulthood. J. Cell. Biochem. 113: 3301-3312, 2012. © 2012 Wiley Periodicals, Inc.
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Affiliation(s)
- Brigitte van Zundert
- Faculty of Biological Sciences and Faculty of Medicine, Center for Biomedical Research, Universidad Andres Bello, Avenida Republica 217, Santiago, Chile.
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100
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McQuail JA, Davis KN, Miller F, Hampson RE, Deadwyler SA, Howlett AC, Nicolle MM. Hippocampal Gαq/₁₁ but not Gαo-coupled receptors are altered in aging. Neuropharmacology 2013; 70:63-73. [PMID: 23347951 DOI: 10.1016/j.neuropharm.2013.01.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 01/08/2013] [Accepted: 01/10/2013] [Indexed: 10/27/2022]
Abstract
Normal aging may limit the signaling efficacy of certain GPCRs by disturbing the function of specific Gα-subunits and leading to deficient modulation of intracellular functions that subserve synaptic plasticity, learning and memory. Evidence suggests that Gαq/₁₁ is more sensitive to the effects of aging relative to other Gα-subunits, including Gαo. To test this hypothesis, the functionality of Gαq/₁₁ and Gαo were compared in the hippocampus of young (6 months) and aged (24 months) F344 × BNF₁ hybrid rats assessed for spatial learning ability. Basal GTPγS-binding to Gαq/₁₁ was significantly elevated in aged rats relative to young and but not reliably associated with spatial learning. mAChR stimulation of Gαq/₁₁ with oxotremorine-M produced equivocal GTPγS-binding between age groups although values tended to be lower in the aged hippocampus and were inversely related to basal activity. Downstream Gαq/₁₁ function was measured in hippocampal subregion CA₁ by determining changes in [Ca(2+)]i after mAChR and mGluR (DHPG) stimulation. mAChR-stimulated peak change in [Ca(2+)]i was lower in aged CA₁ relative to young while mGluR-mediated integrated [Ca(2+)]i responses tended to be larger in aged. GPCR modulation of [Ca(2+)]i was observed to depend on intracellular stores to a greater degree in aged than young. In contrast, measures of Gαo-mediated GTPγS-binding were stable across age, including basal, mAChR-, GABABR (baclofen)-stimulated levels. Overall, the data indicate that aging selectively modulates the activity of Gαq/₁₁ within the hippocampus leading to deficient modulation of [Ca(2+)]i following stimulation of mAChRs but these changes are not related to spatial learning.
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Affiliation(s)
- Joseph A McQuail
- Neuroscience Program, Wake Forest University Graduate School of Arts & Sciences, Medical Center Boulevard, Winston-Salem, NC 27157, USA.
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