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Brice Azangue A, Megam Ngouonkadi EB, Kabong Nono M, Fotsin HB, Sone Ekonde M, Yemele D. Stability and synchronization in neural network with delayed synaptic connections. CHAOS (WOODBURY, N.Y.) 2024; 34:013117. [PMID: 38215223 DOI: 10.1063/5.0175408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 12/04/2023] [Indexed: 01/14/2024]
Abstract
In this paper, we investigate the stability of the synchronous state in a complex network using the master stability function technique. We use the extended Hindmarsh-Rose neuronal model including time delayed electrical, chemical, and hybrid couplings. We find the corresponding master stability equation that describes the whole dynamics for each coupling mode. From the maximum Lyapunov exponent, we deduce the stability state for each coupling mode. We observe that for electrical coupling, there exists a mixing between stable and unstable states. For a good setting of some system parameters, the position and the size of unstable areas can be modified. For chemical coupling, we observe difficulties in having a stable area in the complex plane. For hybrid coupling, we observe a stable behavior in the whole system compared to the case where these couplings are considered separately. The obtained results for each coupling mode help to analyze the stability state of some network topologies by using the corresponding eigenvalues. We observe that using electrical coupling can involve a full or partial stability of the system. In the case of chemical coupling, unstable states are observed whereas in the case of hybrid interactions a full stability of the network is obtained. Temporal analysis of the global synchronization is also done for each coupling mode, and the results show that when the network is stable, the synchronization is globally observed, while in the case when it is unstable, its nodes are not globally synchronized.
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Affiliation(s)
- A Brice Azangue
- Research Unit of Condensed Matter, Electronics and Signal Processing, Department of Physics, Faculty of Science, University of Dschang, P.O. Box 067 Dschang, Cameroon
| | - E B Megam Ngouonkadi
- Research Unit of Condensed Matter, Electronics and Signal Processing, Department of Physics, Faculty of Science, University of Dschang, P.O. Box 067 Dschang, Cameroon
- Department of Electrical and Electronic Engineering, College of Technology (COT), University of Buea, P.O. Box 63 Buea, Cameroon
| | - M Kabong Nono
- Research Unit of Condensed Matter, Electronics and Signal Processing, Department of Physics, Faculty of Science, University of Dschang, P.O. Box 067 Dschang, Cameroon
| | - H B Fotsin
- Research Unit of Condensed Matter, Electronics and Signal Processing, Department of Physics, Faculty of Science, University of Dschang, P.O. Box 067 Dschang, Cameroon
| | - M Sone Ekonde
- Department of Electrical and Electronic Engineering, College of Technology (COT), University of Buea, P.O. Box 63 Buea, Cameroon
| | - D Yemele
- Research Unit of Mechanics and Modeling of Physical Systems, Department of Physics, Faculty of Sciences, University of Dschang, P.O. Box 067 Dschang, Cameroon
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Preferential Involvement of BRCA1/BARD1, Not Tip60/Fe65, in DNA Double-Strand Break Repair in Presenilin-1 P117L Alzheimer Models. Neural Plast 2022; 2022:3172861. [PMID: 35237315 PMCID: PMC8885292 DOI: 10.1155/2022/3172861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 01/11/2022] [Accepted: 01/28/2022] [Indexed: 11/20/2022] Open
Abstract
Recently, we showed that DNA double-strand breaks (DSBs) are increased by the Aβ42-amyloid peptide and decreased by all-trans retinoic acid (RA) in SH-SY5Y cells and C57BL/6J mice. The present work was aimed at investigating DSBs in cells and murine models of Alzheimer's disease carrying the preseniline-1 (PS1) P117L mutation. We observed that DSBs could hardly decrease following RA treatment in the mutated cells compared to the wild-type cells. The activation of the amyloidogenic pathway is proposed in the former case as Aβ42- and RA-dependent DSBs changes were reproduced by an α-secretase and a γ-secretase inhibitions, respectively. Unexpectedly, the PS1 P117L cells showed lower DSB levels than the controls. As the DSB repair proteins Tip60 and Fe65 were less expressed in the mutated cell nuclei, they do not appear to contribute to this difference. On the contrary, full-length BRCA1 and BARD1 proteins were significantly increased in the chromatin compartment of the mutated cells, suggesting that they decrease DSBs in the pathological situation. These Western blot data were corroborated by in situ proximity ligation assays: the numbers of BRCA1-BARD1, not of Fe65-Tip60 heterodimers, were increased only in the mutated cell nuclei. RA also enhanced the expression of BARD1 and of the 90 kDa BRCA1 isoform. The increased BRCA1 expression in the mutated cells can be related to the enhanced difficulty to inhibit this pathway by BRCA1 siRNA in these cells. Overall, our study suggests that at earlier stages of the disease, similarly to PS1 P117L cells, a compensatory mechanism exists that decreases DSB levels via an activation of the BRCA1/BARD1 pathway. This supports the importance of this pathway in neuroprotection against Alzheimer's disease.
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Hojjati SH, Babajani-Feremi A. Prediction and Modeling of Neuropsychological Scores in Alzheimer's Disease Using Multimodal Neuroimaging Data and Artificial Neural Networks. Front Comput Neurosci 2022; 15:769982. [PMID: 35069161 PMCID: PMC8770936 DOI: 10.3389/fncom.2021.769982] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 11/16/2021] [Indexed: 11/13/2022] Open
Abstract
Background: In recent years, predicting and modeling the progression of Alzheimer's disease (AD) based on neuropsychological tests has become increasingly appealing in AD research. Objective: In this study, we aimed to predict the neuropsychological scores and investigate the non-linear progression trend of the cognitive declines based on multimodal neuroimaging data. Methods: We utilized unimodal/bimodal neuroimaging measures and a non-linear regression method (based on artificial neural networks) to predict the neuropsychological scores in a large number of subjects (n = 1143), including healthy controls (HC) and patients with mild cognitive impairment non-converter (MCI-NC), mild cognitive impairment converter (MCI-C), and AD. We predicted two neuropsychological scores, i.e., the clinical dementia rating sum of boxes (CDRSB) and Alzheimer's disease assessment scale cognitive 13 (ADAS13), based on structural magnetic resonance imaging (sMRI) and positron emission tomography (PET) biomarkers. Results: Our results revealed that volumes of the entorhinal cortex and hippocampus and the average fluorodeoxyglucose (FDG)-PET of the angular gyrus, temporal gyrus, and posterior cingulate outperform other neuroimaging features in predicting ADAS13 and CDRSB scores. Compared to a unimodal approach, our results showed that a bimodal approach of integrating the top two neuroimaging features (i.e., the entorhinal volume and the average FDG of the angular gyrus, temporal gyrus, and posterior cingulate) increased the prediction performance of ADAS13 and CDRSB scores in the converting and stable stages of MCI and AD. Finally, a non-linear AD progression trend was modeled to describe the cognitive decline based on neuroimaging biomarkers in different stages of AD. Conclusion: Findings in this study show an association between neuropsychological scores and sMRI and FDG-PET biomarkers from normal aging to severe AD.
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Affiliation(s)
- Seyed Hani Hojjati
- Quantitative Neuroimaging Laboratory, Brain Health Imaging Institute, Department of Radiology, Weill Cornell Medicine, New York, NY, United States
| | - Abbas Babajani-Feremi
- Department of Neurology, Dell Medical School, The University of Texas at Austin, Austin, TX, United States
- Department of Neurosurgery, Dell Medical School, The University of Texas at Austin, Austin, TX, United States
- Magnetoencephalography Laboratory, Dell Children’s Medical Center, Austin, TX, United States
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He Y, Xu W, Qin Y. Structural characterization and neuroprotective effect of a polysaccharide from Corydalis yanhusuo. Int J Biol Macromol 2020; 157:759-768. [DOI: 10.1016/j.ijbiomac.2020.01.180] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 01/08/2020] [Accepted: 01/19/2020] [Indexed: 02/07/2023]
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Gao L, Zhou F, Wang KX, Zhou YZ, Du GH, Qin XM. Baicalein protects PC12 cells from Aβ 25-35-induced cytotoxicity via inhibition of apoptosis and metabolic disorders. Life Sci 2020; 248:117471. [PMID: 32112868 DOI: 10.1016/j.lfs.2020.117471] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 02/16/2020] [Accepted: 02/24/2020] [Indexed: 12/18/2022]
Abstract
AIMS This study aimed to explore the protective effects and possible mechanisms of baicalein on Aβ25-35-induced toxicity. MAIN METHODS Thioflavin-T (Th-T) dye was used to determine the effects of baicalein on Aβ25-35 aggregation in vitro. PC12 cells were stimulated with Aβ25-35, then the effects of baicalein on apoptosis, mitochondrial membrane potential (MMP), adenosine triphosphate (ATP), mitochondrial respiratory complex I, reactive oxygen species (ROS) and nitric oxide (NO) levels were determined. Moreover, LC-MS metabolomics approach was used to detect metabolic changes induced by baicalein in Aβ25-35-injured PC12 cells. KEY FINDINGS The results showed that baicalein could inhibit the aggregation of Aβ25-35 in vitro. Furthermore, pretreatment with baicalein significantly prevented Aβ25-35-induced cell apoptosis, as manifested by increasing the levels of MMP, ATP and mitochondrial respiratory complex I, decreasing the contents of ROS and NO. LC-MS metabolomics revealed that baicalein can regulate 5 metabolites, mainly involving two metabolic pathways, arginine and proline metabolism, nicotinate and nicotinamide metabolism. SIGNIFICANCE Our study revealed that baicalein has a protective effect on Aβ25-35-induced neurotoxicity in PC12 cells, which may be related to inhibition of apoptosis and metabolic disorders.
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Affiliation(s)
- Li Gao
- Modern Research Center for Traditional Chinese Medicine, Shanxi University, Taiyuan 030006, PR China.
| | - Feng Zhou
- Modern Research Center for Traditional Chinese Medicine, Shanxi University, Taiyuan 030006, PR China; College of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, PR China
| | - Ke-Xin Wang
- Modern Research Center for Traditional Chinese Medicine, Shanxi University, Taiyuan 030006, PR China; College of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, PR China
| | - Yu-Zhi Zhou
- Modern Research Center for Traditional Chinese Medicine, Shanxi University, Taiyuan 030006, PR China
| | - Guan-Hua Du
- Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, PR China
| | - Xue-Mei Qin
- Modern Research Center for Traditional Chinese Medicine, Shanxi University, Taiyuan 030006, PR China.
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Vosoughi A, Sadigh-Eteghad S, Ghorbani M, Shahmorad S, Farhoudi M, Rafi MA, Omidi Y. Mathematical Models to Shed Light on Amyloid-Beta and Tau Protein Dependent Pathologies in Alzheimer's Disease. Neuroscience 2019; 424:45-57. [PMID: 31682825 DOI: 10.1016/j.neuroscience.2019.09.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 09/10/2019] [Accepted: 09/11/2019] [Indexed: 12/11/2022]
Abstract
The number of patients suffering from dementia due to Alzheimer's disease (AD) is constantly rising worldwide. This has accordingly resulted in huge burdens on the health systems and involved families. Lack of profound understanding of neural networking in normal brain and their interruption in AD makes the treatment of this neurodegenerative multifaceted disease a challenging issue. In recent years, mathematical and computational methods have paved the way towards a better understanding of the brain functional connectivity. Thus, much attention has been paid to this matter from both basic science researchers and clinicians with an interdisciplinary approach to determine what is not functioning properly in AD patients and how this malfunctioning can be addressed. In this review, a number of AD-related articles and well-studied pathophysiologic topics (e.g., amyloid-beta, neurofibrillary tangles, Ca2+ dysregulation, and synaptic plasticity alterations) has been literally surveyed from a computational and systems biology point of view. The neural networks were discussed from biological and mathematical point of views and their alterations in recent findings were further highlighted. Application of the graph theoretical analysis in the brain imaging was reviewed, depicting the relations between brain structure and function, without diving into mathematical details. Moreover, differential rate equations were briefly articulated, emphasizing the potential use of these equations in simplifying complex processes in relevance to pathologies of AD. Comprehensive insights were given into the AD progression from neural networks perspective, which may lead us towards potential strategies for early diagnosis and effective treatment of AD.
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Affiliation(s)
- Armin Vosoughi
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Research Center for Pharmaceutical Nanotechnology, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Saeed Sadigh-Eteghad
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | | | - Mehdi Farhoudi
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad A Rafi
- Department of Neurology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Yadollah Omidi
- Research Center for Pharmaceutical Nanotechnology, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Pharmaceutics, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran.
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Inhibiting c-Jun N-terminal kinase (JNK)-mediated apoptotic signaling pathway in PC12 cells by a polysaccharide (CCP) from Coptis chinensis against Amyloid-β (Aβ)-induced neurotoxicity. Int J Biol Macromol 2019; 134:565-574. [PMID: 31071400 DOI: 10.1016/j.ijbiomac.2019.05.041] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 05/06/2019] [Accepted: 05/06/2019] [Indexed: 12/15/2022]
Abstract
In this study, we investigated the protective effect and possible mechanism of a polysaccharide (CCP) from Coptis chinensis against Amyloid-β protein (Aβ)-induced toxicity in PC12 cells. The results showed pretreatment with CCP significantly protected PC12 cells from Aβ25-35 induced cell death, lactate dehydrogenase (LDH) release, nuclear fragmentation, mitochondrial dysfunction and cytochrome c release from mitochondria. Furthermore, CCP (100 μg/ml) significantly inhibited Aβ25-35 induced c-Jun N-terminal kinase (JNK) phosphorylation, but not influence signal-regulated kinase (ERK) and P38 mitogen-activated protein kinase (p38MAPK) pathway, and interestingly, the promoting effect of CCP on PC12 cell survival was only blocked by pre-treatment with a SP600125 (JNK inhibitor). In addition, Aβ25-35-induced increase of Bax and cleaved caspase-3, as well as decrease of Bcl-2 protein expression was markedly reversed by CCP or SP600125. Thus, our results indicate that the neuroprotective effect of CCP is associated with JNK-dependent apoptotic pathway.
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Petel Légaré V, Harji ZA, Rampal CJ, Allard-Chamard X, Rodríguez EC, Armstrong GAB. Augmentation of spinal cord glutamatergic synaptic currents in zebrafish primary motoneurons expressing mutant human TARDBP (TDP-43). Sci Rep 2019; 9:9122. [PMID: 31235725 PMCID: PMC6591224 DOI: 10.1038/s41598-019-45530-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 06/06/2019] [Indexed: 12/12/2022] Open
Abstract
Though there is compelling evidence that de-innervation of neuromuscular junctions (NMJ) occurs early in amyotrophic lateral sclerosis (ALS), defects arising at synapses in the spinal cord remain incompletely understood. To investigate spinal cord synaptic dysfunction, we took advantage of a zebrafish larval model and expressed either wild type human TARDBP (wtTARDBP) or the ALS-causing G348C variant (mutTARDBP). The larval zebrafish is ideally suited to examine synaptic connectivity between descending populations of neurons and spinal cord motoneurons as a fully intact spinal cord is preserved during experimentation. Here we provide evidence that the tail-beat motor pattern is reduced in both frequency and duration in larvae expressing mutTARDBP. In addition, we report that motor-related synaptic depolarizations in primary motoneurons of the spinal cord are shorter in duration and fewer action potentials are evoked in larvae expressing mutTARDBP. To more thoroughly examine spinal cord synaptic dysfunction in our ALS model, we isolated AMPA/kainate-mediated glutamatergic miniature excitatory post-synaptic currents in primary motoneurons and found that in addition to displaying a larger amplitude, the frequency of quantal events was higher in larvae expressing mutTARDBP when compared to larvae expressing wtTARDBP. In a final series of experiments, we optogenetically drove neuronal activity in the hindbrain and spinal cord population of descending ipsilateral glutamatergic interneurons (expressing Chx10) using the Gal4-UAS system and found that larvae expressing mutTARDBP displayed abnormal tail-beat patterns in response to optogenetic stimuli and augmented synaptic connectivity with motoneurons. These findings indicate that expression of mutTARDBP results in functionally altered glutamatergic synapses in the spinal cord.
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Affiliation(s)
- Virginie Petel Légaré
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, Faculty of Medicine, McGill University, Montreal, Canada
| | - Ziyaan A Harji
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, Faculty of Medicine, McGill University, Montreal, Canada
| | - Christian J Rampal
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, Faculty of Medicine, McGill University, Montreal, Canada
| | - Xavier Allard-Chamard
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, Faculty of Medicine, McGill University, Montreal, Canada
| | - Esteban C Rodríguez
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, Faculty of Medicine, McGill University, Montreal, Canada
| | - Gary A B Armstrong
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, Faculty of Medicine, McGill University, Montreal, Canada.
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Paradoxical lucidity: A potential paradigm shift for the neurobiology and treatment of severe dementias. Alzheimers Dement 2019; 15:1107-1114. [DOI: 10.1016/j.jalz.2019.04.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 03/26/2019] [Accepted: 04/03/2019] [Indexed: 01/17/2023]
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10
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Ochoa JF, Alonso JF, Duque JE, Tobón CA, Mañanas MA, Lopera F, Hernández AM. Successful Object Encoding Induces Increased Directed Connectivity in Presymptomatic Early-Onset Alzheimer's Disease. J Alzheimers Dis 2018; 55:1195-1205. [PMID: 27792014 PMCID: PMC5147495 DOI: 10.3233/jad-160803] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Recent studies report increases in neural activity in brain regions critical to episodic memory at preclinical stages of Alzheimer's disease (AD). Although electroencephalography (EEG) is widely used in AD studies, given its non-invasiveness and low cost, there is a need to translate the findings in other neuroimaging methods to EEG. OBJECTIVE To examine how the previous findings using functional magnetic resonance imaging (fMRI) at preclinical stage in presenilin-1 E280A mutation carriers could be assessed and extended, using EEG and a connectivity approach. METHODS EEG signals were acquired during resting and encoding in 30 normal cognitive young subjects, from an autosomal dominant early-onset AD kindred from Antioquia, Colombia. Regions of the brain previously reported as hyperactive were used for connectivity analysis. RESULTS Mutation carriers exhibited increasing connectivity at analyzed regions. Among them, the right precuneus exhibited the highest changes in connectivity. CONCLUSION Increased connectivity in hyperactive cerebral regions is seen in individuals, genetically-determined to develop AD, at preclinical stage. The use of a connectivity approach and a widely available neuroimaging technique opens the possibility to increase the use of EEG in early detection of preclinical AD.
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Affiliation(s)
- John Fredy Ochoa
- Bioinstrumentation and Clinical Engineering Research Group, Bioengineering Program, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia
| | - Joan Francesc Alonso
- Department of Automatic Control (ESAII), Biomedical Engineering Research Center (CREB), Universitat Politènica de Catalunya (UPC), Barcelona, Spain.,Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Spain
| | - Jon Edinson Duque
- Bioinstrumentation and Clinical Engineering Research Group, Bioengineering Program, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia
| | - Carlos Andrés Tobón
- Neuroscience Group of Antioquia, Medical School, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia.,Neuropsychology and Behavior group, Medical School, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia
| | - Miguel Angel Mañanas
- Department of Automatic Control (ESAII), Biomedical Engineering Research Center (CREB), Universitat Politènica de Catalunya (UPC), Barcelona, Spain.,Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Spain
| | - Francisco Lopera
- Neuroscience Group of Antioquia, Medical School, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia
| | - Alher Mauricio Hernández
- Bioinstrumentation and Clinical Engineering Research Group, Bioengineering Program, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia
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Wolff SB, Ölveczky BP. The promise and perils of causal circuit manipulations. Curr Opin Neurobiol 2018; 49:84-94. [PMID: 29414070 DOI: 10.1016/j.conb.2018.01.004] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 11/27/2017] [Accepted: 01/15/2018] [Indexed: 02/07/2023]
Abstract
The development of increasingly sophisticated methods for recording and manipulating neural activity is revolutionizing neuroscience. By probing how activity patterns in different types of neurons and circuits contribute to behavior, these tools can help inform mechanistic models of brain function and explain the roles of distinct circuit elements. However, in systems where functions are distributed over large networks, interpreting causality experiments can be challenging. Here we review common assumptions underlying circuit manipulations in behaving animals and discuss the strengths and limitations of different approaches.
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Affiliation(s)
- Steffen Be Wolff
- Department of Organismic and Evolutionary Biology and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Bence P Ölveczky
- Department of Organismic and Evolutionary Biology and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA.
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Abstract
There is a long history linking traumatic brain injury (TBI) with the development of dementia. Despite significant reservations, such as recall bias or concluding causality for TBI, a summary of recent research points to several conclusions on the TBI-dementia relationship. 1) Increasing severity of a single moderate-to-severe TBI increases the risk of subsequent Alzheimer's disease (AD), the most common type of dementia. 2) Repetitive, often subconcussive, mild TBIs increases the risk for chronic traumatic encephalopathy (CTE), a degenerative neuropathology. 3) TBI may be a risk factor for other neurodegenerative disorders that can be associated with dementia. 4) TBI appears to lower the age of onset of TBI-related neurocognitive syndromes, potentially adding "TBI cognitive-behavioral features". The literature further indicates several specific risk factors for TBI-associated dementia: 5) any blast or blunt physical force to the head as long as there is violent head displacement; 6) decreased cognitive and/or neuronal reserve and the related variable of older age at TBI; and 7) the presence of apolipoprotein E ɛ4 alleles, a genetic risk factor for AD. Finally, there are neuropathological features relating TBI with neurocognitive syndromes: 8) acute TBI results in amyloid pathology and other neurodegenerative proteinopathies; 9) CTE shares features with neurodegenerative dementias; and 10) TBI results in white matter tract and neural network disruptions. Although further research is needed, these ten findings suggest that dose-dependent effects of violent head displacement in vulnerable brains predispose to dementia; among several potential mechanisms is the propagation of abnormal proteins along damaged white matter networks.
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Affiliation(s)
- Mario F Mendez
- Department of Neurology, David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles, CA, USA.,Department of Neurology, Neurobehavior Unit, V.A. Greater Los Angeles Healthcare System, Los Angeles, CA, USA
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13
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Abstract
Early-onset Alzheimer disease (EOAD), with onset in individuals younger than 65 years, although overshadowed by the more common late-onset AD (LOAD), differs significantly from LOAD. EOAD comprises approximately 5% of AD and is associated with delays in diagnosis, aggressive course, and age-related psychosocial needs. One source of confusion is that a substantial percentage of EOAD are phenotypic variants that differ from the usual memory-disordered presentation of typical AD. The management of EOAD is similar to that for LOAD, but special emphasis should be placed on targeting the specific cognitive areas involved and more age-appropriate psychosocial support and education.
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Affiliation(s)
- Mario F Mendez
- Behavioral Neurology Program, David Geffen School of Medicine at UCLA, 300 Westwood Plaza, Suite B-200, Box 956975, Los Angeles, CA 90095, USA; Neurobehavior Unit, VA Greater Los Angeles Healthcare System, 11301 Wilshire Boulevard, Building 206, Los Angeles, CA 90073, USA.
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Falcon MI, Gomez CM, Chen EE, Shereen A, Solodkin A. Early Cerebellar Network Shifting in Spinocerebellar Ataxia Type 6. Cereb Cortex 2016; 26:3205-18. [PMID: 26209844 PMCID: PMC4898673 DOI: 10.1093/cercor/bhv154] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Spinocerebellar ataxia 6 (SCA6), an autosomal dominant degenerative disease, is characterized by diplopia, gait ataxia, and incoordination due to severe progressive degeneration of Purkinje cells in the vestibulo- and spinocerebellum. Ocular motor deficits are common, including difficulty fixating on moving objects, nystagmus and disruption of smooth pursuit movements. In presymptomatic SCA6, there are alterations in saccades and smooth-pursuit movements. We sought to assess functional and structural changes in cerebellar connectivity associated with a visual task, hypothesizing that gradual changes would parallel disease progression. We acquired functional magnetic resonance imaging and diffusion tensor imaging data during a passive smooth-pursuit task in 14 SCA6 patients, representing a range of disease duration and severity, and performed a cross-sectional comparison of cerebellar networks compared with healthy controls. We identified a shift in activation from vermis in presymptomatic individuals to lateral cerebellum in moderate-to-severe cases. Concomitantly, effective connectivity between regions of cerebral cortex and cerebellum was at its highest in moderate cases, and disappeared in severe cases. Finally, we noted structural differences in the cerebral and cerebellar peduncles. These unique results, spanning both functional and structural domains, highlight widespread changes in SCA6 and compensatory mechanisms associated with cerebellar physiology that could be utilized in developing new therapies.
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Affiliation(s)
| | - C M Gomez
- Department of Neurology, University of Chicago, Chicago, IL 60637, USA
| | - E E Chen
- Department of Anatomy and Neurobiology
| | - A Shereen
- Department of Anatomy and Neurobiology
| | - A Solodkin
- Department of Anatomy and Neurobiology Department of Neurology, UC Irvine School of Medicine, Irvine, CA 92697, USA
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The Vitamin A Derivative All-Trans Retinoic Acid Repairs Amyloid-β-Induced Double-Strand Breaks in Neural Cells and in the Murine Neocortex. Neural Plast 2016; 2016:3707406. [PMID: 26881107 PMCID: PMC4735929 DOI: 10.1155/2016/3707406] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 10/13/2015] [Indexed: 12/17/2022] Open
Abstract
The amyloid-β peptide or Aβ is the key player in the amyloid-cascade hypothesis of Alzheimer's disease. Aβ appears to trigger cell death but also production of double-strand breaks (DSBs) in aging and Alzheimer's disease. All-trans retinoic acid (RA), a derivative of vitamin A, was already known for its neuroprotective effects against the amyloid cascade. It diminishes, for instance, the production of Aβ peptides and their oligomerisation. In the present work we investigated the possible implication of RA receptor (RAR) in repair of Aβ-induced DSBs. We demonstrated that RA, as well as RAR agonist Am80, but not AGN 193109 antagonist, repair Aβ-induced DSBs in SH-SY5Y cells and an astrocytic cell line as well as in the murine cortical tissue of young and aged mice. The nonhomologous end joining pathway and the Ataxia Telangiectasia Mutated kinase were shown to be involved in RA-mediated DSBs repair in the SH-SY5Y cells. Our data suggest that RA, besides increasing cell viability in the cortex of young and even of aged mice, might also result in targeted DNA repair of genes important for cell or synaptic maintenance. This phenomenon would remain functional up to a point when Aβ increase and RA decrease probably lead to a pathological state.
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Nyström O, Wallin A, Nordlund A. MCI of different etiologies differ on the Cognitive Assessment Battery. Acta Neurol Scand 2015; 132:31-6. [PMID: 25496135 DOI: 10.1111/ane.12353] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/31/2014] [Indexed: 11/27/2022]
Abstract
OBJECTIVES The study aims to investigate whether patients with mild cognitive impairment (MCI) who have significant vascular disease (MCI-vas) differ from those with no significant vascular disease (MCI-nov) in terms of cognitive profile when assessed with the cognitive assessment battery (CAB). MATERIALS AND METHODS Seventy patients clinically diagnosed with MCI were included in the study, 32 were classified as MCI-vas, and 38 as MCI-nov, together with 40 healthy controls. CAB consists of six short tests measuring speed and attention, memory, visuospatial functions, language, and executive functions. RESULTS The healthy controls performed better than both MCI groups on CAB. MCI-vas patients were significantly older and had fewer years of education than MCI-nov patients. When adjusted for age and education, MCI-vas performed significantly worse than MCI-nov on memory, language, and executive tests. CONCLUSIONS The results suggest that CAB can differentiate between MCI patients with and without vascular disease and that their cognitive profiles differ. Furthermore, CAB classified the patients as vascular and non-vascular MCI with good sensitivity and specificity.
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Affiliation(s)
- O. Nyström
- Institute of Neuroscience and Physiology; Sahlgrenska Academy at University of Gothenburg; Mölndal Sweden
| | - A. Wallin
- Institute of Neuroscience and Physiology; Sahlgrenska Academy at University of Gothenburg; Mölndal Sweden
| | - A. Nordlund
- Institute of Neuroscience and Physiology; Sahlgrenska Academy at University of Gothenburg; Mölndal Sweden
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17
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Buscema M, Vernieri F, Massini G, Scrascia F, Breda M, Rossini PM, Grossi E. An improved I-FAST system for the diagnosis of Alzheimer's disease from unprocessed electroencephalograms by using robust invariant features. Artif Intell Med 2015; 64:59-74. [PMID: 25997573 DOI: 10.1016/j.artmed.2015.03.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Revised: 03/22/2015] [Accepted: 03/25/2015] [Indexed: 02/08/2023]
Abstract
OBJECTIVE This paper proposes a new, complex algorithm for the blind classification of the original electroencephalogram (EEG) tracing of each subject, without any preliminary pre-processing. The medical need in this field is to reach an early differential diagnosis between subjects affected by mild cognitive impairment (MCI), early Alzheimer's disease (AD) and the healthy elderly (CTR) using only the recording and the analysis of few minutes of their EEG. METHODS AND MATERIAL This study analyzed the EEGs of 272 subjects, recorded at Rome's Neurology Unit of the Policlinico Campus Bio-Medico. The EEG recordings were performed using 19 electrodes, in a 0.3-70Hz bandpass, positioned according to the International 10-20 System. Many powerful learning machines and algorithms have been proposed during the last 20 years to effectively resolve this complex problem, resulting in different and interesting outcomes. Among these algorithms, a new artificial adaptive system, named implicit function as squashing time (I-FAST), is able to diagnose, with high accuracy, a few minutes of the subject's EEG track; whether it manifests an AD, MCI or CTR condition. An updating of this system, carried out by adding a new algorithm, named multi scale ranked organizing maps (MS-ROM), to the I-FAST system, is presented, in order to classify with greater accuracy the unprocessed EEG's of AD, MCI and control subjects. RESULTS The proposed system has been measured on three independent pattern recognition tasks from unprocessed EEG tracks of a sample of AD subjects, MCI subjects and CTR: (a) AD compared with CTR; (b) AD compared with MCI; (c) CTR compared with MCI. While the values of accuracy of the previous system in distinguishing between AD and MCI were around 92%, the new proposed system reaches values between 94% and 98%. Similarly, the overall accuracy with best artificial neural networks (ANNs) is 98.25% for the distinguishing between CTR and MCI. CONCLUSIONS This new version of I-FAST makes different steps forward: (a) avoidance of pre-processing phase and filtering procedure of EEG data, being the algorithm able to directly process an unprocessed EEG; (b) noise elimination, through the use of a training variant with input selection and testing system, based on naïve Bayes classifier; (c) a more robust classification phase, showing the stability of results on nine well known learning machine algorithms; (d) extraction of spatial invariants of an EEG signal using, in addition to the unsupervised ANN, the principal component analysis and the multi scale entropy, together with the MS-ROM; a more accurate performance in this specific task.
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Affiliation(s)
- Massimo Buscema
- Semeion Research Centre of Sciences of Communication, Via Sersale 117, Rome 00128, Italy; Department of Mathematical and Statistical Sciences, University of Colorado at Denver, P.O. Box 173364, Denver, CO, USA.
| | - Fabrizio Vernieri
- Institute of Neurology, Campus Bio-Medico University, Via Álvaro del Portillo 200, 00128 Rome, Italy
| | - Giulia Massini
- Semeion Research Centre of Sciences of Communication, Via Sersale 117, Rome 00128, Italy
| | - Federica Scrascia
- Institute of Neurology, Campus Bio-Medico University, Via Álvaro del Portillo 200, 00128 Rome, Italy
| | - Marco Breda
- Semeion Research Centre of Sciences of Communication, Via Sersale 117, Rome 00128, Italy
| | - Paolo Maria Rossini
- Institute of Neurology, Catholic University of The Sacred Heart, Largo Agostino Gemelli 8, 00168 Rome, Italy
| | - Enzo Grossi
- Semeion Research Centre of Sciences of Communication, Via Sersale 117, Rome 00128, Italy
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18
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Jaeger C, Glaab E, Michelucci A, Binz TM, Koeglsberger S, Garcia P, Trezzi JP, Ghelfi J, Balling R, Buttini M. The mouse brain metabolome: region-specific signatures and response to excitotoxic neuronal injury. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 185:1699-712. [PMID: 25934215 DOI: 10.1016/j.ajpath.2015.02.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 02/04/2015] [Accepted: 02/10/2015] [Indexed: 11/26/2022]
Abstract
Neurodegeneration is a multistep process characterized by a multitude of molecular entities and their interactions. Systems analyses, or omics approaches, have become an important tool in characterizing this process. Although RNA and protein profiling made their entry into this field a couple of decades ago, metabolite profiling is a more recent addition. The metabolome represents a large part or all metabolites in a tissue, and gives a snapshot of its physiology. By using gas chromatography coupled to mass spectrometry, we analyzed the metabolic profile of brain regions of the mouse, and found that each region is characterized by its own metabolic signature. We then analyzed the metabolic profile of the mouse brain after excitotoxic injury, a mechanism of neurodegeneration implicated in numerous neurological diseases. More important, we validated our findings by measuring, histologically and molecularly, actual neurodegeneration and glial response. We found that a specific global metabolic signature, best revealed by machine learning algorithms, rather than individual metabolites, was the most robust correlate of neuronal injury and the accompanying gliosis, and this signature could serve as a global biomarker for neurodegeneration. We also observed that brain lesioning induced several metabolites with neuroprotective properties. Our results deepen the understanding of metabolic changes accompanying neurodegeneration in disease models, and could help rapidly evaluate these changes in preclinical drug studies.
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Affiliation(s)
- Christian Jaeger
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Enrico Glaab
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Alessandro Michelucci
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Tina M Binz
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Sandra Koeglsberger
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Pierre Garcia
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Jean-Pierre Trezzi
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Jenny Ghelfi
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Rudi Balling
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Manuel Buttini
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg.
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19
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Savioz A, Leuba G, Vallet PG. A framework to understand the variations of PSD-95 expression in brain aging and in Alzheimer's disease. Ageing Res Rev 2014; 18:86-94. [PMID: 25264360 DOI: 10.1016/j.arr.2014.09.004] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 09/03/2014] [Accepted: 09/18/2014] [Indexed: 10/24/2022]
Abstract
The postsynaptic density protein PSD-95 is a major element of synapses. PSD-95 is involved in aging, Alzheimer's disease (AD) and numerous psychiatric disorders. However, contradictory data about PSD-95 expression in aging and AD have been reported. Indeed in AD versus control brains PSD-95 varies according to regions, increasing in the frontal cortex, at least in a primary stage, and decreasing in the temporal cortex. In contrast, in transgenic mouse models of aging and AD PSD-95 expression is decreased, in behaviorally aged impaired versus unimpaired rodents it can decrease or increase and finally, it is increased in rodents grown in enriched environments. Different factors explain these contradictory results in both animals and humans, among others concomitant psychiatric endophenotypes, such as depression. The possible involvement of PSD-95 in reactive and/or compensatory mechanisms during AD progression is underscored, at least before the occurrence of important synaptic elimination. Thus, in AD but not in AD transgenic mice, enhanced expression might precede the diminution commonly observed in advanced aging. A two-compartments cell model, separating events taking place in cell bodies and synapses, is presented. Overall these data suggest that AD research will progress by untangling pathological from protective events, a prerequisite for effective therapeutic strategies.
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20
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Abuhassan K, Coyle D, Maguire L. Compensating for thalamocortical synaptic loss in Alzheimer's disease. Front Comput Neurosci 2014; 8:65. [PMID: 24987349 PMCID: PMC4060454 DOI: 10.3389/fncom.2014.00065] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 05/26/2014] [Indexed: 11/13/2022] Open
Abstract
The study presents a thalamocortical network model which oscillates within the alpha frequency band (8-13 Hz) as recorded in the wakeful relaxed state with closed eyes to study the neural causes of abnormal oscillatory activity in Alzheimer's disease (AD). Incorporated within the model are various types of cortical excitatory and inhibitory neurons, recurrently connected to thalamic and reticular thalamic regions with the ratios and distances derived from the mammalian thalamocortical system. The model is utilized to study the impacts of four types of connectivity loss on the model's spectral dynamics. The study focuses on investigating degeneration of corticocortical, thalamocortical, corticothalamic, and corticoreticular couplings, with an emphasis on the influence of each modeled case on the spectral output of the model. Synaptic compensation has been included in each model to examine the interplay between synaptic deletion and compensation mechanisms, and the oscillatory activity of the network. The results of power spectra and event related desynchronization/synchronization (ERD/S) analyses show that the dynamics of the thalamic and cortical oscillations are significantly influenced by corticocortical synaptic loss. Interestingly, the patterns of changes in thalamic spectral activity are correlated with those in the cortical model. Similarly, the thalamic oscillatory activity is diminished after partial corticothalamic denervation. The results suggest that thalamic atrophy is a secondary pathology to cortical shrinkage in Alzheimer's disease. In addition, this study finds that the inhibition from neurons in the thalamic reticular nucleus (RTN) to thalamic relay (TCR) neurons plays a key role in regulating thalamic oscillations; disinhibition disrupts thalamic oscillatory activity even though TCR neurons are more depolarized after being released from RTN inhibition. This study provides information that can be explored experimentally to further our understanding on the neurodegeneration associated with AD pathology.
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Affiliation(s)
- Kamal Abuhassan
- Department of Biology, University of Leicester Leicester, UK
| | - Damien Coyle
- Intelligent Systems Research Centre, School of Computing and Intelligent Systems, University of Ulster Derry, UK
| | - Liam Maguire
- Intelligent Systems Research Centre, School of Computing and Intelligent Systems, University of Ulster Derry, UK
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21
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Rowan MS, Neymotin SA, Lytton WW. Electrostimulation to reduce synaptic scaling driven progression of Alzheimer's disease. Front Comput Neurosci 2014; 8:39. [PMID: 24765074 PMCID: PMC3982056 DOI: 10.3389/fncom.2014.00039] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Accepted: 03/18/2014] [Indexed: 01/23/2023] Open
Abstract
Cell death and synapse dysfunction are two likely causes of cognitive decline in AD. As cells die and synapses lose their drive, remaining cells suffer an initial decrease in activity. Neuronal homeostatic synaptic scaling then provides a feedback mechanism to restore activity. This homeostatic mechanism is believed to sense levels of activity-dependent cytosolic calcium within the cell and to adjust neuronal firing activity by increasing the density of AMPA synapses at remaining synapses to achieve balance. The scaling mechanism increases the firing rates of remaining cells in the network to compensate for decreases in network activity. However, this effect can itself become a pathology, as it produces increased imbalance between excitatory and inhibitory circuits, leading to greater susceptibility to further cell loss via calcium-mediated excitotoxicity. Here, we present a mechanistic explanation of how directed brain stimulation might be expected to slow AD progression based on computational simulations in a 470-neuron biomimetic model of a neocortical column. The simulations demonstrate that the addition of low-intensity electrostimulation (neuroprosthesis) to a network undergoing AD-like cell death can raise global activity and break this homeostatic-excitotoxic cascade. The increase in activity within the remaining cells in the column results in lower scaling-driven AMPAR upregulation, reduced imbalances in excitatory and inhibitory circuits, and lower susceptibility to ongoing damage.
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Affiliation(s)
- Mark S Rowan
- School of Computer Science, University of Birmingham Birmingham, UK
| | - Samuel A Neymotin
- Department Physiology and Pharmacology, State University of New York Downstate Medical Center Brooklyn, NY, USA ; Department Neurobiology, Yale University School of Medicine New Haven, CT, USA
| | - William W Lytton
- Department Physiology and Pharmacology, State University of New York Downstate Medical Center Brooklyn, NY, USA ; Department Neurology, State University of New York Downstate Medical Center Brooklyn, NY, USA ; Department Neurology, Kings County Hospital Center Brooklyn, NY, USA
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22
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Hou J, Lin Y, Zhang W, Song L, Wu W, Wang J, Zhou D, Zou Q, Fang Y, He M, Li H. Abnormalities of frontal-parietal resting-state functional connectivity are related to disease activity in patients with systemic lupus erythematosus. PLoS One 2013; 8:e74530. [PMID: 24069318 PMCID: PMC3771919 DOI: 10.1371/journal.pone.0074530] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 08/02/2013] [Indexed: 12/14/2022] Open
Abstract
Cerebral involvement is common in patients with systemic Lupus erythematosus (SLE) and is characterized by multiple clinical presentations, including cognitive disorders, headaches, and syncope. Several neuroimaging studies have demonstrated cerebral dysfunction during different tasks among SLE patients; however, there have been few studies designed to characterize network alterations or to identify clinical markers capable of reflecting the cerebral involvement in SLE patients. This study was designed to characterize the profile of the cerebral activation area and the functional connectivity of cognitive function in SLE patients by using a task-based and a resting state functional magnetic resonance imaging (fMRI) technique, and to determine whether or not any clinical biomarkers could serve as an indicator of cerebral involvement in this disease. The well-established cognitive function test (Paced Visual Serial Adding Test [PVSAT]) was used. Thirty SLE patients without neuropsychiatric symptoms and 25 age- and gender-matched healthy controls were examined using PVSAT task-based and resting state fMRI. Outside the scanner, the performance of patients and the healthy controls was similar. In the PVSAT task-based fMRI, patients presented significantly expanded areas of activation, and the activated areas exhibited significantly higher functional connectivity strength in patients in the resting state. A positive correlation existed between individual connectivity strength and disease activity scoring. No correlation with cerebral involvement existed for serum markers, such as C3, C4, and anti-dsDNA. Thus, our findings may shed new light on the pathologic mechanism underlying neuropsychiatric SLE, and suggests that disease activity may be a potential effective biomarker reflecting cerebral involvement in SLE.
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Affiliation(s)
- Jingming Hou
- Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Yun Lin
- Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Wei Zhang
- Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Lingheng Song
- Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Wenjing Wu
- Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Jian Wang
- Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Daiquan Zhou
- Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Qinghua Zou
- Department of Rheumatology, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Yongfei Fang
- Department of Rheumatology, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Mei He
- Department of Clinical Psychology, Third Military Medical University, Chongqing, China
- * E-mail: (HL); (MH)
| | - Haitao Li
- Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China
- * E-mail: (HL); (MH)
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Craig TJ, Henley JM. SUMOylation, Arc and the regulation homeostatic synaptic scaling: Implications in health and disease. Commun Integr Biol 2013; 5:634-6. [PMID: 23739045 PMCID: PMC3541335 DOI: 10.4161/cib.21712] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Neurons compensate for changes in network activity by altering the sensitivity of transmission across collections of synapses by up- or downregulating the number of synaptic AMPA receptors. We recently reported that, in parallel to increasing AMPA receptor surface expression, suppression of network activity with TTX increases protein SUMOylation by decreasing levels of the deSUMOylating enzyme SENP1. SUMOylation of the immediate early gene product Arc is required for synaptic scaling. These results reveal a previously unsuspected role for protein SUMOylation in activity-dependent AMPA receptor trafficking and the regulation of neuronal network activity, processes which play important roles in neurodegenerative disease.
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Affiliation(s)
- Tim J Craig
- School of Biochemistry; Medical Research Council Centre for Synaptic Plasticity; Medical Sciences Building; University of Bristol; University Walk; Bristol, UK
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24
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Compensating for synaptic loss in Alzheimer’s disease. J Comput Neurosci 2013; 36:19-37. [DOI: 10.1007/s10827-013-0462-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 05/10/2013] [Accepted: 05/14/2013] [Indexed: 01/08/2023]
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25
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Xian YF, Lin ZX, Ip SP, Su ZR, Chen JN, Lai XP. Comparison the neuropreotective effect of Cortex Phellodendri chinensis and Cortex Phellodendri amurensis against beta-amyloid-induced neurotoxicity in PC12 cells. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2013; 20:187-193. [PMID: 23123224 DOI: 10.1016/j.phymed.2012.09.028] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 08/30/2012] [Accepted: 09/29/2012] [Indexed: 06/01/2023]
Abstract
Cortex Phellodendron chinensis (CPC) and Cortex Phellodendron amurensis (CPA) derived from the dried bark of Phellodendron chinense Schneid. or Phellodendron amurense Rupr., respectively, are used interchangeably in clinical practice under the name "Huang Bai" for centuries in Chinese medicine for the treatment of various inflammatory conditions. Previous study in our laboratory demonstrated that CPC and CPA had different anti-diarrheal, anti-bacterial and anti-inflammatory effects. In this present study, we aimed to compare the protective effect of ethanol extract of Cortex Phellodendri chinensis (ECPC) and Cortex Phellodendri Amurensis (ECPA) against beta-amyloid (Aβ)-induced neurotoxicity in PC12 cells, a typical model of Alzheimer's disease. The results showed that ECPC and ECPA contain four common chemical markers such as berberine, but palmatine and jatrorrhizin were not found in CPC in contrast to the presence in CPA. In addition, both ECPC and ECPA can significantly increase the cell viability in Aβ-treated PC12 cells. Moreover, ECPC and ECPA can markedly elevate the ratio of the protein and mRNA levels of Bcl-2/Bax, while remarkably decrease the release of cytochrome c, and the protein and mRNA expression of caspase-3. Interestingly, ECPA has better protective effect than ECPC against Aβ-induced neurotoxicity in PC12 cells. These results indicate that both ECPC and ECPA have potential protective effect against Aβ-induced neurotoxicity in PC12 cells, and ECPA is more potential of the two species to be used in traditional medicine as a neuroprotective agent for the treatment of AD. The neuroprotective effect of the two species may be mediated, at least in part, via suppressing of the cellular apoptosis.
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Affiliation(s)
- Yan-Fang Xian
- School of Chinese Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region
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26
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Bories C, Guitton MJ, Julien C, Tremblay C, Vandal M, Msaid M, De Koninck Y, Calon F. Sex-dependent alterations in social behaviour and cortical synaptic activity coincide at different ages in a model of Alzheimer's disease. PLoS One 2012; 7:e46111. [PMID: 23029404 PMCID: PMC3454358 DOI: 10.1371/journal.pone.0046111] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Accepted: 08/28/2012] [Indexed: 01/04/2023] Open
Abstract
Besides memory deficits, Alzheimer's disease (AD) patients suffer from neuropsychiatric symptoms, including alterations in social interactions, which are subject of a growing number of investigations in transgenic models of AD. Yet the biological mechanisms underlying these behavioural alterations are poorly understood. Here, a social interaction paradigm was used to assess social dysfunction in the triple-transgenic mouse model of AD (3xTg-AD). We observed that transgenic mice displayed dimorphic behavioural abnormalities at different ages. Social disinhibition was observed in 18 months old 3xTg-AD males compared to age and sex-matched control mice. In 3xTg-AD females, social disinhibition was present at 12 months followed by reduced social interactions at 18 months. These dimorphic behavioural alterations were not associated with alterations in AD neuropathological markers such as Aβ or tau levels in the frontal cortex. However, patch-clamp recordings revealed that enhanced social interactions coincided temporally with an increase in both excitatory and inhibitory basal synaptic inputs to layer 2-3 pyramidal neurons in the prefrontal cortex. These findings uncover a novel pattern of occurrence of psychiatric-like symptoms between sexes in an AD model. Our results also reveal that functional alterations in synapse activity appear as a potentially significant substrate underlying behavioural correlates of AD.
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Affiliation(s)
- Cyril Bories
- Faculty of Medicine Laval University, Quebec City, Quebec, Canada
- Quebec Mental Health Institute, Quebec City, Quebec, Canada
| | - Matthieu J. Guitton
- Faculty of Medicine Laval University, Quebec City, Quebec, Canada
- Faculty of Pharmacy, Laval University, Quebec City, Quebec, Canada
- Quebec Mental Health Institute, Quebec City, Quebec, Canada
| | - Carl Julien
- Faculty of Pharmacy, Laval University, Quebec City, Quebec, Canada
- Centre Hospitalier de l’Université Laval (CHUL) Research Center, Quebec City, Quebec, Canada
| | - Cyntia Tremblay
- Faculty of Pharmacy, Laval University, Quebec City, Quebec, Canada
- Centre Hospitalier de l’Université Laval (CHUL) Research Center, Quebec City, Quebec, Canada
| | - Milène Vandal
- Faculty of Pharmacy, Laval University, Quebec City, Quebec, Canada
- Centre Hospitalier de l’Université Laval (CHUL) Research Center, Quebec City, Quebec, Canada
| | - Meriem Msaid
- Faculty of Pharmacy, Laval University, Quebec City, Quebec, Canada
- Centre Hospitalier de l’Université Laval (CHUL) Research Center, Quebec City, Quebec, Canada
| | - Yves De Koninck
- Faculty of Medicine Laval University, Quebec City, Quebec, Canada
- Quebec Mental Health Institute, Quebec City, Quebec, Canada
| | - Frédéric Calon
- Faculty of Pharmacy, Laval University, Quebec City, Quebec, Canada
- Centre Hospitalier de l’Université Laval (CHUL) Research Center, Quebec City, Quebec, Canada
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D'Amelio M, Rossini PM. Brain excitability and connectivity of neuronal assemblies in Alzheimer's disease: from animal models to human findings. Prog Neurobiol 2012; 99:42-60. [PMID: 22789698 DOI: 10.1016/j.pneurobio.2012.07.001] [Citation(s) in RCA: 110] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2011] [Revised: 06/08/2012] [Accepted: 07/02/2012] [Indexed: 10/28/2022]
Abstract
The human brain contains about 100 billion neurons forming an intricate network of innumerable connections, which continuously adapt and rewire themselves following inputs from external and internal environments as well as the physiological synaptic, dendritic and axonal sculpture during brain maturation and throughout the life span. Growing evidence supports the idea that Alzheimer's disease (AD) targets selected and functionally connected neuronal networks and, specifically, their synaptic terminals, affecting brain connectivity well before producing neuronal loss and compartmental atrophy. The understanding of the molecular mechanisms underlying the dismantling of neuronal circuits and the implementation of 'clinically oriented' methods to map-out the dynamic interactions amongst neuronal assemblies will enhance early/pre-symptomatic diagnosis and monitoring of disease progression. More important, this will open the avenues to innovative treatments, bridging the gap between molecular mechanisms and the variety of symptoms forming disease phenotype. In the present review a set of evidence supports the idea that altered brain connectivity, exhausted neural plasticity and aberrant neuronal activity are facets of the same coin linked to age-related neurodegenerative dementia of Alzheimer type. Investigating their respective roles in AD pathophysiology will help in translating findings from basic research to clinical applications.
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Affiliation(s)
- Marcello D'Amelio
- IRCCS S. Lucia Foundation, Via del Fosso di Fiorano 65, 00143 Rome, Italy.
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28
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Nahm M, Greyson B, Kelly EW, Haraldsson E. Terminal lucidity: A review and a case collection. Arch Gerontol Geriatr 2012; 55:138-42. [DOI: 10.1016/j.archger.2011.06.031] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Revised: 06/22/2011] [Accepted: 06/25/2011] [Indexed: 11/28/2022]
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Mitra R, Sapolsky RM. Short-term enrichment makes male rats more attractive, more defensive and alters hypothalamic neurons. PLoS One 2012; 7:e36092. [PMID: 22567125 PMCID: PMC3342313 DOI: 10.1371/journal.pone.0036092] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2011] [Accepted: 03/30/2012] [Indexed: 01/10/2023] Open
Abstract
Innate behaviors are shaped by contingencies built during evolutionary history. On the other hand, environmental stimuli play a significant role in shaping behavior. In particular, a short period of environmental enrichment can enhance cognitive behavior, modify effects of stress on learned behaviors and induce brain plasticity. It is unclear if modulation by environment can extend to innate behaviors which are preserved by intense selection pressure. In the present report we investigate this issue by studying effects of relatively short (14-days) environmental enrichment on two prominent innate behaviors in rats, avoidance of predator odors and ability of males to attract mates. We show that enrichment has strong effects on both the innate behaviors: a) enriched males were more avoidant of a predator odor than non-enriched controls, and had a greater rise in corticosterone levels in response to the odor; and b) had higher testosterone levels and were more attractive to females. Additionally, we demonstrate decrease in dendritic length of neurons of ventrolateral nucleus of hypothalamus, important for reproductive mate-choice and increase in the same in dorsomedial nucleus, important for defensive behavior. Thus, behavioral and hormonal observations provide evidence that a short period of environmental manipulation can alter innate behaviors, providing a good example of gene-environment interaction.
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Affiliation(s)
- Rupshi Mitra
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
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Isotalo K, Kok EH, Luoto TM, Haikonen S, Haapasalo H, Lehtimäki T, Karhunen PJ. Upstream transcription factor 1 (USF1) polymorphisms associate with Alzheimer's disease-related neuropathological lesions: Tampere Autopsy Study. Brain Pathol 2012; 22:765-75. [PMID: 22390463 DOI: 10.1111/j.1750-3639.2012.00586.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The apolipoprotein E (APOE) gene associates with Alzheimer's disease (AD) and cholesterol levels. Upstream transcription factor 1 (USF1) regulates lipid metabolism genes, including APOE, and the AD Aβ-precursor protein. We investigated associations between 6 haplotype-tagging USF1 single-nucleotide polymorphisms (and haplotypes) and AD-related neuropathological lesions [senile plaques (SP), neurofibrillary tangles (NFT) ] in an autopsy series comprising 603 cases (ages 0-97, mean 62 years, 215 women) that died out-of-hospital. In age- and APOE-adjusted analyses, the minor G-allele of rs2774276, previously linked to elevated cholesterol, associated with late-stage burnt out SP among women and early non-neuritic SP among men. The G-allele of the previously unreported rs10908821 showed significant risk of having SP, especially neuritic and burnt out SP, among women but not men. USF1 haplotype GCGCAC carriers (risk alleles of rs2774276 and rs10908821) associated with SP risk, especially neuritic and late-stage burnt out SP, among women but not men. Younger CCGCAC carriers (risk allele of rs2774276 and protective of rs10908821) were more likely to have non-neuritic and diffuse SP. Conversely, USF1 CCGCAC haplotype carriers had lower NFT prevalence among 65+ year-olds. These results suggest USF1 has an independent but gender- and age-associated effect on AD-related brain lesion development.
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Affiliation(s)
- Karita Isotalo
- Department of Forensic Medicine, University of Tampere, Tampere, Finland.
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Matsui C, Inoue E, Kakita A, Arita K, Deguchi-Tawarada M, Togawa A, Yamada A, Takai Y, Takahashi H. Involvement of the γ-secretase-mediated EphA4 signaling pathway in synaptic pathogenesis of Alzheimer's disease. Brain Pathol 2012; 22:776-87. [PMID: 22404518 DOI: 10.1111/j.1750-3639.2012.00587.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Loss of synapses is associated with cognitive impairment in Alzheimer's disease (AD). However, the molecular mechanism underlying this synaptic impairment is not well understood. EphA4 is a substrate of γ-secretase, and the γ-secretase-cleaved EphA4 intracellular domain (EICD) is known to enhance the formation of dendritic spines via activation of the Rac signaling pathway. Here, we show that the amount of Rac1 is significantly reduced, and correlated with the level of EICD in the frontal lobes of AD patients. Biochemical analyses revealed that the amount of membrane-associated EICD was decreased and strongly correlated with the level of membrane-associated Rac1, which is considered to be active Rac1. The synaptic scaffolding protein, postsynaptic density (PSD)-95, was specifically decreased in AD, and the amount of PSD-95 correlated with the level of Rac1. Moreover, the amounts of Rac1 and PSD-95 were negatively correlated with the extent of tau phosphorylation, which is crucial for neurofibrillary tangle formation. These results suggest that attenuation of the EICD-mediated Rac signaling pathway is involved in the synaptic pathogenesis of AD.
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Rowan M. Information-selectivity of Beta-amyloid pathology in an associative memory model. Front Comput Neurosci 2012; 6:2. [PMID: 22279434 PMCID: PMC3260488 DOI: 10.3389/fncom.2012.00002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 01/02/2012] [Indexed: 12/28/2022] Open
Abstract
This work models the progression of beta-amyloid pathology according to Small's synaptic scaling theory in an updated version of Ruppin and Reggia's associative neural network model of Alzheimer's disease, leading to a self-reinforcing cascade of damage. Using an information theoretic approach, it is shown that the simulated beta-amyloid pathology initially selectively targets neurons with low informational contribution to the overall performance of the network, but that it targets neurons with increasingly higher significance to the network as the disease progresses. The results additionally provide a possible explanation for the apparent low correlation between amyloid plaque density and cognitive decline in the early stages of Alzheimer's disease.
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Affiliation(s)
- Mark Rowan
- School of Computer Science, University of Birmingham Birmingham, UK
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Dominguez E, Chin TY, Chen CP, Wu TY. Management of moderate to severe Alzheimer’s disease: Focus on memantine. Taiwan J Obstet Gynecol 2011; 50:415-23. [DOI: 10.1016/j.tjog.2011.10.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2011] [Indexed: 12/13/2022] Open
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Jeynes B, Provias J. The case for blood-brain barrier dysfunction in the pathogenesis of Alzheimer's disease. J Neurosci Res 2011; 89:22-8. [PMID: 21046564 DOI: 10.1002/jnr.22527] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease that leads to a progressive loss of integrative and memory capacities of the brain. This is the predominant form of neurodegenerative dementia, with a growing prevalence of between 1 in 50 and 1 in 100 in North America. Numerous hypotheses related to the etiology of AD have developed over the years. However, among the various published hypotheses, the predominant one is related to the progressive and prominent accumulation of central nervous system β-amyloid peptide and the ensuing brain burden created. It is, therefore, important to consider the homeostatic mechanisms underlying β-amyloid transport dynamics between the brain and blood vascular compartments. As well, there is a dynamic interrelationship between soluble and insoluble forms of the peptide. Factors that underlie and regulate these dynamic processes are likely relevant to the end accumulation of β-amyloid peptide in the brain compartment and ultimately in insoluble forms, which is characteristic of, and significant for, the pathophysiology of the Alzheimer's brain. Significantly, and in particular relation to the amyloid burden theory mentioned above, it has been postulated that a dysfunctioning blood-brain barrier (BBB) may play a significant, if not critical, role in the pathogenesis of AD. By allowing the influx of injurious materials or agents into the brain or by impeding or blocking the efflux of those materials and/or agents, BBB-related neuronopathies and their associated sequelae could, and do, ensue.
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Affiliation(s)
- Brian Jeynes
- Faculty of Applied Health Sciences, Brock University, St. Catharine's, Ontario, Canada.
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Traditional chinese medicine for senile dementia. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2011; 2012:692621. [PMID: 21808655 PMCID: PMC3144670 DOI: 10.1155/2012/692621] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Accepted: 05/09/2011] [Indexed: 12/30/2022]
Abstract
Traditional Chinese Medicine (TCM) has a 3000 years' history of human use. A literature survey addressing traditional evidence from human studies was done, with key result that top 10 TCM herb ingredients including Poria cocos, Radix polygalae, Radix glycyrrhizae, Radix angelica sinensis, and Radix rehmanniae were prioritized for highest potential benefit to dementia intervention, related to the highest frequency of use in 236 formulae collected from 29 ancient Pharmacopoeias, ancient formula books, or historical archives on ancient renowned TCM doctors, over the past 10 centuries. Based on the history of use, there was strong clinical support that Radix polygalae is memory improving. Pharmacological investigation also indicated that all the five ingredients mentioned above can elicit memory-improving effects in vivo and in vitro via multiple mechanisms of action, covering estrogen-like, cholinergic, antioxidant, anti-inflammatory, antiapoptotic, neurogenetic, and anti-Aβ activities. Furthermore, 11 active principles were identified, including sinapic acid, tenuifolin, isoliquiritigenin, liquiritigenin, glabridin, ferulic acid, Z-ligustilide, N-methyl-beta-carboline-3-carboxamide, coniferyl ferulate and 11-angeloylsenkyunolide F, and catalpol. It can be concluded that TCM has a potential for complementary and alternative role in treating senile dementia. The scientific evidence is being continuously mined to back up the traditional medical wisdom.
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Borrmann C, Stricker R, Reiser G. Retinoic acid-induced upregulation of the metalloendopeptidase nardilysin is accelerated by co-expression of the brain-specific protein p42(IP4) (centaurin α 1; ADAP1) in neuroblastoma cells. Neurochem Int 2011; 59:936-44. [PMID: 21801775 DOI: 10.1016/j.neuint.2011.07.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Revised: 07/02/2011] [Accepted: 07/05/2011] [Indexed: 11/18/2022]
Abstract
The mainly neuronally expressed protein p42(IP4) (centaurin α1; ADAP1), which interacts with the metalloendopeptidase nardilysin (NRD) was found to be localized in neuritic plaques in Alzheimer disease (AD) brains. NRD was shown to enhance the cleavage of the amyloid precursor protein (APP) by α-secretases, thereby increasing the release of neuroprotective sAPPα. We here investigated in vitro the biochemical interaction of p42(IP4) and NRD and studied the physiological interaction in SH-SY5Y cells. NRD is a member of the M16 family of metalloendopeptidases. Some members of this M16 family act bi-functionally, as protease and as non-enzymatic scaffold protein. Here, we show that p42(IP4) enhances the enzymatic activity of NRD 3-4 times. However, p42(IP4) is not a substrate for NRD. Furthermore, we report that differentiation of SH-SY5Y cells by stimulation with 10μM retinoic acid (RA) results in upregulation of NRD protein levels, with a 6-fold rise after 15 days. NRD is expressed in the neurites of RA-stimulated SH-SY5Y cells, and localized in vesicular structures. Since p42(IP4) is not expressed in untreated SH-SY5Y cells, we could use this cell system as a model to find out, whether there is a functional interaction. Interestingly, SH-SY5Y cells, which we stably transfected with GFP-tagged-p42(IP4) showed an enhanced NRD protein expression already at an earlier time point after RA stimulation.
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Affiliation(s)
- Claudia Borrmann
- Institut für Neurobiochemie, Medizinische Fakultät der Otto-von-Guericke-Universität Magdeburg, Leipziger Str. 44, 39120 Magdeburg, Germany
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Neuroprotective effects of puerarin against beta-amyloid-induced neurotoxicity in PC12 cells via a PI3K-dependent signaling pathway. Brain Res Bull 2011; 85:212-8. [PMID: 21473901 DOI: 10.1016/j.brainresbull.2011.03.024] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Revised: 03/23/2011] [Accepted: 03/28/2011] [Indexed: 11/21/2022]
Abstract
Epidemiological data have indicated that estrogen replacement therapy (ERT) can decrease the risk of developing Alzheimer's disease (AD). Phytoestrogens have been proposed as potential alternatives to ERT. The aim of the present study was to assess the neuroprotective effects of puerarin, a phytoestrogen isolated from Pueraria lobata, against the toxicity of beta-amyloid (Aβ) in relation to the mitochondria-mediated cell death process, and to elucidate the role the activation of Akt and modulation of the pro- and antiapoptotic proteins in puerarin-induced neuroprotection. The present study shows that puerarin afforded protection against Aβ-induced toxicity through inhibiting apoptosis in PC12 cells. This result was also confirmed by the activated caspase-3 assay. P-Akt, Bcl-2 and p-Bad expression increased after pretreatment with puerarin in PC12 cells exposed to Aβ(25-35), whereas Bax expression and cytochrome c release decreased. Interestingly, these effects of puerarin against Aβ(25-35) insult were abolished by wortmannin, an inhibitor of PI3K phosphorylation. These findings suggest that puerarin prevent Aβ-induced neurotoxicity through inhibiting neuronal apoptosis, and might be a potential preventive or therapeutic agent for AD.
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Kunze A, Meissner R, Brando S, Renaud P. Co-pathological connected primary neurons in a microfluidic device for alzheimer studies. Biotechnol Bioeng 2011; 108:2241-5. [DOI: 10.1002/bit.23128] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Revised: 02/28/2011] [Accepted: 03/01/2011] [Indexed: 12/19/2022]
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Mouse models of neurological disorders—A comparison of heritable and acquired traits. Biochim Biophys Acta Mol Basis Dis 2010; 1802:785-95. [DOI: 10.1016/j.bbadis.2010.05.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Revised: 05/17/2010] [Accepted: 05/19/2010] [Indexed: 01/17/2023]
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Reynolds S, Lane SJ, Richards L. Using animal models of enriched environments to inform research on sensory integration intervention for the rehabilitation of neurodevelopmental disorders. J Neurodev Disord 2010; 2:120-32. [PMID: 22127899 PMCID: PMC3164047 DOI: 10.1007/s11689-010-9053-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Accepted: 05/28/2010] [Indexed: 01/09/2023] Open
Abstract
The field of behavioral neuroscience has been successful in using an animal model of enriched environments for over five decades to measure the rehabilitative and preventative effects of sensory, cognitive and motor stimulation in animal models. Several key principles of enriched environments match those used in sensory integration therapy, a treatment used for children with neurodevelopmental disorders. This paper reviews the paradigm of environmental enrichment, compares animal models of enriched environments to principles of sensory integration treatment, and discusses applications for the rehabilitation of neurodevelopmental disorders. Based on this review, the essential features in the enriched environment paradigm which should be included in sensory integration treatment are multiple sensory experiences, novelty in the environment, and active engagement in challenging cognitive, sensory, and motor tasks. Use of sensory integration treatment may be most applicable for children with anxiety, hypersensitivity, repetitive behaviors or heightened levels of stress. Additionally, individuals with deficits in social behavior, social participation, or impairments in learning and memory may show gains with this type of treatment.
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Affiliation(s)
- Stacey Reynolds
- Department of Occupational Therapy, School of Allied Health Professions, Virginia Commonwealth University, Box 980008, Richmond, VA, 23298, USA,
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41
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Abstract
Neurons respond homeostatically to chronic changes in network activity with compensatory changes such as a uniform alteration in the size of miniature postsynaptic current (mPSC) amplitudes termed synaptic scaling. However, little is known about the impact of synaptic scaling on the function of neural networks in vivo. We used the embryonic zebrafish to address the effect of synaptic scaling on the neural network underlying locomotion. Activity was decreased during development by TTX injection to block action potentials or CNQX injection to block glutamatergic transmission. Alternatively TNFalpha was chronically applied. Recordings from spinal neurons showed that glutamatergic mPSCs scaled up approximately 25% after activity reduction and fortuitously scaled down approximately 20% after TNFalpha treatment, and were unchanged following blockade of neuromuscular activity alone with alpha-bungarotoxin. Regardless of the direction of scaling, immediately following reversal of treatment no chronic effect was distinguishable in motoneuron activity patterns or in swimming behavior. We also acutely induced a similar increase of glutamatergic mPSC amplitudes using cyclothiazide to reduce AMPA receptor desensitization or decrease of glutamatergic mPSC amplitudes using a low concentration of CNQX to partially block AMPA receptors. Though the strength of the motor output was altered, neither chronic nor acute treatments disrupted the patterning of synaptic activity or swimming. Our results show, for the first time, that scaling of glutamatergic synapses can be induced in vivo in the zebrafish and that synaptic patterning is less plastic than synaptic strength during development.
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Healthy brain aging: role of cognitive reserve, cognitive stimulation, and cognitive exercises. Clin Geriatr Med 2010; 26:99-111. [PMID: 20176296 DOI: 10.1016/j.cger.2009.11.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Current knowledge about the roles of cognitively stimulating lifestyles and cognitive training interventions in preserving cognitive function in later life is reviewed. Potential mechanisms for beneficial effects of cognitive stimulation and training are discussed, and key gaps in research identified. Suggestions are provided for advising patients about brain-healthy lifestyles, acknowledging that much remains to be learned in this area of research. More randomized controlled trials, using challenging regimes of training and stimulation and long-term follow-up, are needed, measuring cognitive trajectories in normal aging and relative risk of Alzheimer disease as outcomes.
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Abstract
Neurodegenerative diseases are characterized by progressive dysfunction of specific populations of neurons, determining clinical presentation. Neuronal loss is associated with extra and intracellular accumulation of misfolded proteins, the hallmarks of many neurodegenerative proteinopathies. Major basic processes include abnormal protein dynamics due to deficiency of the ubiquitin-proteosome-autophagy system, oxidative stress and free radical formation, mitochondrial dysfunction, impaired bioenergetics, dysfunction of neurotrophins, 'neuroinflammatory' processes and (secondary) disruptions of neuronal Golgi apparatus and axonal transport. These interrelated mechanisms lead to programmed cell death is a long run over many years. Neurodegenerative disorders are classified according to known genetic mechanisms or to major components of protein deposits, but recent studies showed both overlap and intraindividual diversities between different phenotypes. Synergistic mechanisms between pathological proteins suggest common pathogenic mechanisms. Animal models and other studies have provided insight into the basic neurodegeneration and cell death programs, offering new ways for future prevention/treatment strategies.
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Affiliation(s)
- Kurt A Jellinger
- Institute of Clinical Neurobiology, Kenyongasse, Vienna, Austria.
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Randall AD, Witton J, Booth C, Hynes-Allen A, Brown JT. The functional neurophysiology of the amyloid precursor protein (APP) processing pathway. Neuropharmacology 2010; 59:243-67. [PMID: 20167227 DOI: 10.1016/j.neuropharm.2010.02.011] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Accepted: 02/11/2010] [Indexed: 01/12/2023]
Abstract
Amyloid beta (Abeta) peptides derived from proteolytic cleavage of amyloid precursor protein (APP) are thought to be a pivotal toxic species in the pathogenesis of Alzheimer's disease (AD). Furthermore, evidence has been accumulating that components of APP processing pathway are involved in non-pathological normal function of the CNS. In this review we aim to cover the extensive body of research aimed at understanding how components of this pathway contribute to neurophysiological function of the CNS in health and disease. We briefly outline changes to clinical neurophysiology seen in AD patients before discussing functional changes in mouse models of AD which range from changes to basal synaptic transmission and synaptic plasticity through to abnormal synchronous network activity. We then describe the various neurophysiological actions that are produced by application of exogenous Abeta in various forms, and finally discuss a number or other neurophysiological aspects of the APP pathway, including functional activities of components of secretase complexes other than Abeta production.
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Affiliation(s)
- A D Randall
- MRC Centre for Synaptic Plasticity, Department of Anatomy, University of Bristol School of Medical Sciences, Bristol, UK.
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Ondrejcak T, Klyubin I, Hu NW, Barry AE, Cullen WK, Rowan MJ. Alzheimer's disease amyloid beta-protein and synaptic function. Neuromolecular Med 2009; 12:13-26. [PMID: 19757208 DOI: 10.1007/s12017-009-8091-0] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Accepted: 08/25/2009] [Indexed: 12/15/2022]
Abstract
Alzheimer's disease (AD) is characterized neuropathologically by the deposition of different forms of amyloid beta-protein (A beta) including variable amounts of soluble species that correlate with severity of dementia. The extent of synaptic loss in the brain provides the best morphological correlate of cognitive impairment in clinical AD. Animal research on the pathophysiology of AD has therefore focussed on how soluble A beta disrupts synaptic mechanisms in vulnerable brain regions such as the hippocampus. Synaptic plasticity in the form of persistent activity-dependent increases or decreases in synaptic strength provide a neurophysiological substrate for hippocampal-dependent learning and memory. Acute treatment with human-derived or chemically prepared soluble A beta that contains certain oligomeric assemblies, potently and selectively disrupts synaptic plasticity causing inhibition of long-term potentiation (LTP) and enhancement of long-term depression (LTD) of glutamatergic transmission. Over time these and related actions of A beta have been implicated in reducing synaptic integrity. This review addresses the involvement of neurotransmitter intercellular signaling in mediating or modulating the synaptic plasticity disrupting actions of soluble A beta, with particular emphasis on the different roles of glutamatergic and cholinergic mechanisms. There is growing evidence to support the view that NMDA and possibly nicotinic receptors are critically involved in mediating the disruptive effect of A beta and that targeting muscarinic receptors can indirectly modulate A beta's actions. Such studies should help inform ongoing and future clinical trials of drugs acting through the glutamatergic and cholinergic systems.
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Affiliation(s)
- Tomas Ondrejcak
- Department of Pharmacology and Therapeutics, Biotechnology Building and Institute of Neuroscience, Trinity College, Dublin 2, Ireland
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