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Studtmann C, Ladislav M, Safari M, Khondaker R, Chen Y, Vaughan GA, Topolski MA, Tomović E, Balík A, Swanger SA. Ventral posterolateral and ventral posteromedial thalamocortical neurons have distinct physiological properties. J Neurophysiol 2023; 130:1492-1507. [PMID: 37937368 PMCID: PMC11068404 DOI: 10.1152/jn.00525.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 10/09/2023] [Accepted: 11/01/2023] [Indexed: 11/09/2023] Open
Abstract
Somatosensory information is propagated from the periphery to the cerebral cortex by two parallel pathways through the ventral posterolateral (VPL) and ventral posteromedial (VPM) thalamus. VPL and VPM neurons receive somatosensory signals from the body and head, respectively. VPL and VPM neurons may also receive cell type-specific GABAergic input from the reticular nucleus of the thalamus. Although VPL and VPM neurons have distinct connectivity and physiological roles, differences in their functional properties remain unclear as they are often studied as one ventrobasal thalamus neuron population. Here, we directly compared synaptic and intrinsic properties of VPL and VPM neurons in C57Bl/6J mice of both sexes aged P25-P32. VPL neurons showed greater depolarization-induced spike firing and spike frequency adaptation than VPM neurons. VPL and VPM neurons fired similar numbers of spikes during hyperpolarization rebound bursts, but VPM neurons exhibited shorter burst latency compared with VPL neurons, which correlated with larger sag potential. VPM neurons had larger membrane capacitance and more complex dendritic arbors. Recordings of spontaneous and evoked synaptic transmission suggested that VPL neurons receive stronger excitatory synaptic input, whereas inhibitory synapse strength was stronger in VPM neurons. This work indicates that VPL and VPM thalamocortical neurons have distinct intrinsic and synaptic properties. The observed functional differences could have important implications for their specific physiological and pathophysiological roles within the somatosensory thalamocortical network.NEW & NOTEWORTHY This study revealed that somatosensory thalamocortical neurons in the VPL and VPM have substantial differences in excitatory synaptic input and intrinsic firing properties. The distinct properties suggest that VPL and VPM neurons could process somatosensory information differently and have selective vulnerability to disease. This work improves our understanding of nucleus-specific neuron function in the thalamus and demonstrates the critical importance of studying these parallel somatosensory pathways separately.
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Affiliation(s)
- Carleigh Studtmann
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, United States
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, Virginia, United States
| | - Marek Ladislav
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, United States
| | - Mona Safari
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, United States
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, Virginia, United States
| | - Rabeya Khondaker
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, United States
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, Virginia, United States
| | - Yang Chen
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, United States
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, Virginia, United States
| | - Grace A Vaughan
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, United States
- Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, Virginia, United States
| | - Mackenzie A Topolski
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, United States
| | - Eni Tomović
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, United States
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Aleš Balík
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Sharon A Swanger
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, United States
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, United States
- Department of Internal Medicine, Virginia Tech Carilion School of Medicine, Roanoke, Virginia, United States
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2
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van Heusden FC, van Nifterick AM, Souza BC, França ASC, Nauta IM, Stam CJ, Scheltens P, Smit AB, Gouw AA, van Kesteren RE. Neurophysiological alterations in mice and humans carrying mutations in APP and PSEN1 genes. Alzheimers Res Ther 2023; 15:142. [PMID: 37608393 PMCID: PMC10464047 DOI: 10.1186/s13195-023-01287-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 08/11/2023] [Indexed: 08/24/2023]
Abstract
BACKGROUND Studies in animal models of Alzheimer's disease (AD) have provided valuable insights into the molecular and cellular processes underlying neuronal network dysfunction. Whether and how AD-related neurophysiological alterations translate between mice and humans remains however uncertain. METHODS We characterized neurophysiological alterations in mice and humans carrying AD mutations in the APP and/or PSEN1 genes, focusing on early pre-symptomatic changes. Longitudinal local field potential recordings were performed in APP/PS1 mice and cross-sectional magnetoencephalography recordings in human APP and/or PSEN1 mutation carriers. All recordings were acquired in the left frontal cortex, parietal cortex, and hippocampus. Spectral power and functional connectivity were analyzed and compared with wildtype control mice and healthy age-matched human subjects. RESULTS APP/PS1 mice showed increased absolute power, especially at higher frequencies (beta and gamma) and predominantly between 3 and 6 moa. Relative power showed an overall shift from lower to higher frequencies over almost the entire recording period and across all three brain regions. Human mutation carriers, on the other hand, did not show changes in power except for an increase in relative theta power in the hippocampus. Mouse parietal cortex and hippocampal power spectra showed a characteristic peak at around 8 Hz which was not significantly altered in transgenic mice. Human power spectra showed a characteristic peak at around 9 Hz, the frequency of which was significantly reduced in mutation carriers. Significant alterations in functional connectivity were detected in theta, alpha, beta, and gamma frequency bands, but the exact frequency range and direction of change differed for APP/PS1 mice and human mutation carriers. CONCLUSIONS Both mice and humans carrying APP and/or PSEN1 mutations show abnormal neurophysiological activity, but several measures do not translate one-to-one between species. Alterations in absolute and relative power in mice should be interpreted with care and may be due to overexpression of amyloid in combination with the absence of tau pathology and cholinergic degeneration. Future studies should explore whether changes in brain activity in other AD mouse models, for instance, those also including tau pathology, provide better translation to the human AD continuum.
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Affiliation(s)
- Fran C van Heusden
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, Amsterdam, 1081HV, The Netherlands
| | - Anne M van Nifterick
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, 1081HV, The Netherlands
- Clinical Neurophysiology and MEG Center, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, 1081HV, The Netherlands
| | - Bryan C Souza
- Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, 6525AJ, The Netherlands
| | - Arthur S C França
- Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, 6525AJ, The Netherlands
- Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, 1105 BA, The Netherlands
| | - Ilse M Nauta
- MS Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, 1081HV, The Netherlands
| | - Cornelis J Stam
- Clinical Neurophysiology and MEG Center, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, 1081HV, The Netherlands
| | - Philip Scheltens
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, 1081HV, The Netherlands
| | - August B Smit
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, Amsterdam, 1081HV, The Netherlands
| | - Alida A Gouw
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, 1081HV, The Netherlands
- Clinical Neurophysiology and MEG Center, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, 1081HV, The Netherlands
| | - Ronald E van Kesteren
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, Amsterdam, 1081HV, The Netherlands.
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3
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Katsuki F, Gerashchenko D, Brown RE. Alterations of sleep oscillations in Alzheimer's disease: A potential role for GABAergic neurons in the cortex, hippocampus, and thalamus. Brain Res Bull 2022; 187:181-198. [PMID: 35850189 DOI: 10.1016/j.brainresbull.2022.07.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 06/01/2022] [Accepted: 07/06/2022] [Indexed: 02/07/2023]
Abstract
Sleep abnormalities are widely reported in patients with Alzheimer's disease (AD) and are linked to cognitive impairments. Sleep abnormalities could be potential biomarkers to detect AD since they are often observed at the preclinical stage. Moreover, sleep could be a target for early intervention to prevent or slow AD progression. Thus, here we review changes in brain oscillations observed during sleep, their connection to AD pathophysiology and the role of specific brain circuits. Slow oscillations (0.1-1 Hz), sleep spindles (8-15 Hz) and their coupling during non-REM sleep are consistently reduced in studies of patients and in AD mouse models although the timing and magnitude of these alterations depends on the pathophysiological changes and the animal model studied. Changes in delta (1-4 Hz) activity are more variable. Animal studies suggest that hippocampal sharp-wave ripples (100-250 Hz) are also affected. Reductions in REM sleep amount and slower oscillations during REM are seen in patients but less consistently in animal models. Thus, changes in a variety of sleep oscillations could impact sleep-dependent memory consolidation or restorative functions of sleep. Recent mechanistic studies suggest that alterations in the activity of GABAergic neurons in the cortex, hippocampus and thalamic reticular nucleus mediate sleep oscillatory changes in AD and represent a potential target for intervention. Longitudinal studies of the timing of AD-related sleep abnormalities with respect to pathology and dysfunction of specific neural networks are needed to identify translationally relevant biomarkers and guide early intervention strategies to prevent or delay AD progression.
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Affiliation(s)
- Fumi Katsuki
- VA Boston Healthcare System and Harvard Medical School, Dept. of Psychiatry, West Roxbury, MA 02132, USA.
| | - Dmitry Gerashchenko
- VA Boston Healthcare System and Harvard Medical School, Dept. of Psychiatry, West Roxbury, MA 02132, USA
| | - Ritchie E Brown
- VA Boston Healthcare System and Harvard Medical School, Dept. of Psychiatry, West Roxbury, MA 02132, USA
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4
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Gourmaud S, Stewart DA, Irwin DJ, Roberts N, Barbour AJ, Eberwine G, O’Brien WT, Vassar R, Talos DM, Jensen FE. The role of mTORC1 activation in seizure-induced exacerbation of Alzheimer's disease. Brain 2022; 145:324-339. [PMID: 34264340 PMCID: PMC9126019 DOI: 10.1093/brain/awab268] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 06/04/2021] [Accepted: 06/21/2021] [Indexed: 11/13/2022] Open
Abstract
The risk of seizures is 10-fold higher in patients with Alzheimer's disease than the general population, yet the mechanisms underlying this susceptibility and the effects of these seizures are poorly understood. To elucidate the proposed bidirectional relationship between Alzheimer's disease and seizures, we studied human brain samples (n = 34) from patients with Alzheimer's disease and found that those with a history of seizures (n = 14) had increased amyloid-β and tau pathology, with upregulation of the mechanistic target of rapamycin (mTOR) pathway, compared with patients without a known history of seizures (n = 20). To establish whether seizures accelerate the progression of Alzheimer's disease, we induced chronic hyperexcitability in the five times familial Alzheimer's disease mouse model by kindling with the chemoconvulsant pentylenetetrazol and observed that the mouse model exhibited more severe seizures than the wild-type. Furthermore, kindled seizures exacerbated later cognitive impairment, Alzheimer's disease neuropathology and mTOR complex 1 activation. Finally, we demonstrated that the administration of the mTOR inhibitor rapamycin following kindled seizures rescued enhanced remote and long-term memory deficits associated with earlier kindling and prevented seizure-induced increases in Alzheimer's disease neuropathology. These data demonstrated an important link between chronic hyperexcitability and progressive Alzheimer's disease pathology and suggest a mechanism whereby rapamycin may serve as an adjunct therapy to attenuate progression of the disease.
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Affiliation(s)
- Sarah Gourmaud
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David A Stewart
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Duke University School of Medicine, Durham, NC 27708, USA
| | - David J Irwin
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Penn Frontotemporal Degeneration Center, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Nicholas Roberts
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Aaron J Barbour
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Grace Eberwine
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - William T O’Brien
- Neurobehavior Testing Core, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Robert Vassar
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Delia M Talos
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Frances E Jensen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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5
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Cope ZA, Murai T, Sukoff Rizzo SJ. Emerging Electroencephalographic Biomarkers to Improve Preclinical to Clinical Translation in Alzheimer’s Disease. Front Aging Neurosci 2022; 14:805063. [PMID: 35250541 PMCID: PMC8891809 DOI: 10.3389/fnagi.2022.805063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 01/26/2022] [Indexed: 11/18/2022] Open
Abstract
Continually emerging data indicate that sub-clinical, non-convulsive epileptiform activity is not only prevalent in Alzheimer’s disease (AD) but is detectable early in the course of the disease and predicts cognitive decline in both humans and animal models. Epileptiform activity and other electroencephalographic (EEG) measures may hold powerful, untapped potential to improve the translational validity of AD-related biomarkers in model animals ranging from mice, to rats, and non-human primates. In this review, we will focus on studies of epileptiform activity, EEG slowing, and theta-gamma coupling in preclinical models, with particular focus on its role in cognitive decline and relevance to AD. Here, each biomarker is described in the context of the contemporary literature and recent findings in AD relevant animal models are discussed.
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6
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Leparulo A, Bisio M, Redolfi N, Pozzan T, Vassanelli S, Fasolato C. Accelerated Aging Characterizes the Early Stage of Alzheimer's Disease. Cells 2022; 11:238. [PMID: 35053352 PMCID: PMC8774248 DOI: 10.3390/cells11020238] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 12/12/2021] [Accepted: 01/08/2022] [Indexed: 02/01/2023] Open
Abstract
For Alzheimer's disease (AD), aging is the main risk factor, but whether cognitive impairments due to aging resemble early AD deficits is not yet defined. When working with mouse models of AD, the situation is just as complicated, because only a few studies track the progression of the disease at different ages, and most ignore how the aging process affects control mice. In this work, we addressed this problem by comparing the aging process of PS2APP (AD) and wild-type (WT) mice at the level of spontaneous brain electrical activity under anesthesia. Using local field potential recordings, obtained with a linear probe that traverses the posterior parietal cortex and the entire hippocampus, we analyzed how multiple electrical parameters are modified by aging in AD and WT mice. With this approach, we highlighted AD specific features that appear in young AD mice prior to plaque deposition or that are delayed at 12 and 16 months of age. Furthermore, we identified aging characteristics present in WT mice but also occurring prematurely in young AD mice. In short, we found that reduction in the relative power of slow oscillations (SO) and Low/High power imbalance are linked to an AD phenotype at its onset. The loss of SO connectivity and cortico-hippocampal coupling between SO and higher frequencies as well as the increase in UP-state and burst durations are found in young AD and old WT mice. We show evidence that the aging process is accelerated by the mutant PS2 itself and discuss such changes in relation to amyloidosis and gliosis.
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Affiliation(s)
- Alessandro Leparulo
- Department of Biomedical Sciences, University of Padua, Via U. Bassi 58/B, 35131 Padua, Italy; (A.L.); (M.B.); (N.R.); (T.P.)
| | - Marta Bisio
- Department of Biomedical Sciences, University of Padua, Via U. Bassi 58/B, 35131 Padua, Italy; (A.L.); (M.B.); (N.R.); (T.P.)
| | - Nelly Redolfi
- Department of Biomedical Sciences, University of Padua, Via U. Bassi 58/B, 35131 Padua, Italy; (A.L.); (M.B.); (N.R.); (T.P.)
| | - Tullio Pozzan
- Department of Biomedical Sciences, University of Padua, Via U. Bassi 58/B, 35131 Padua, Italy; (A.L.); (M.B.); (N.R.); (T.P.)
- Neuroscience Institute-Italian National Research Council (CNR), Via U. Bassi 58/B, 35131 Padua, Italy
- Venetian Institute of Molecular Medicine (VIMM), Via G. Orus 2B, 35129 Padua, Italy
| | - Stefano Vassanelli
- Department of Biomedical Sciences, University of Padua, Via U. Bassi 58/B, 35131 Padua, Italy; (A.L.); (M.B.); (N.R.); (T.P.)
- Padua Neuroscience Center (PNC), University of Padua, Via G. Orus 2B, 35129 Padua, Italy
| | - Cristina Fasolato
- Department of Biomedical Sciences, University of Padua, Via U. Bassi 58/B, 35131 Padua, Italy; (A.L.); (M.B.); (N.R.); (T.P.)
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7
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Huffels CFM, Osborn LM, Hulshof LA, Kooijman L, Henning L, Steinhäuser C, Hol EM. Amyloid-β plaques affect astrocyte Kir4.1 protein expression but not function in the dentate gyrus of APP/PS1 mice. Glia 2022; 70:748-767. [PMID: 34981861 PMCID: PMC9306581 DOI: 10.1002/glia.24137] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 12/16/2021] [Accepted: 12/17/2021] [Indexed: 01/09/2023]
Abstract
Alzheimer pathology is accompanied by astrogliosis. Reactive astrocytes surrounding amyloid plaques may directly affect neuronal communication, and one of the mechanisms by which astrocytes impact neuronal function is by affecting K+ homeostasis. Here we studied, using hippocampal slices from 9‐month‐old Alzheimer mice (APP/PS1) and wild‐type littermates, whether astrocyte function is changed by analyzing Kir4.1 expression and function and astrocyte coupling in astrocytes surrounding amyloid‐β plaques. Immunohistochemical analysis of Kir4.1 protein in the dentate gyrus revealed localized increases in astrocytes surrounding amyloid‐β plaque deposits. We subsequently focused on changes in astrocyte function by using patch‐clamp slice electrophysiology on both plaque‐ and non‐plaque associated astrocytes to characterize general membrane properties. We found that Ba2+‐sensitive Kir4.1 conductance in astrocytes surrounding plaques was not affected by changes in Kir4.1 protein expression. Additional analysis of astrocyte gap junction coupling efficiency in the dentate gyrus revealed no apparent changes. Quantification of basic features of glutamatergic transmission to granule cells did not indicate disturbed neuronal communication in the dentate gyrus of APP/PS1 mice. Together, these results suggest that astrocytes in the dentate gyrus of APP/PS1 mice maintain their ability to buffer extracellular K+ and attempt to rectify imbalances in K+ concentration to maintain normal neuronal and synaptic function, possibly by localized increases in Kir4.1 protein expression. Our earlier transcriptomic data indicated that chronically activated astrocytes lose their neuronal support function. Here we show that, despite localized increased Kir4.1 protein expression, astrocyte Kir4.1 channel dysfunction is likely not involved in the pathogenesis of Alzheimer's disease.
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Affiliation(s)
- Christiaan F. M. Huffels
- Department of Translational Neuroscience, University Medical Center Utrecht Brain CenterUtrecht UniversityUtrechtThe Netherlands
| | - Lana M. Osborn
- Swammerdam Institute for Life Sciences, Center for NeuroscienceUniversity of AmsterdamAmsterdamThe Netherlands
| | - Lianne A. Hulshof
- Department of Translational Neuroscience, University Medical Center Utrecht Brain CenterUtrecht UniversityUtrechtThe Netherlands
| | - Lieneke Kooijman
- Swammerdam Institute for Life Sciences, Center for NeuroscienceUniversity of AmsterdamAmsterdamThe Netherlands
| | - Lukas Henning
- Institute of Cellular Neurosciences, Medical FacultyUniversity of BonnBonnGermany
| | | | - Elly M. Hol
- Department of Translational Neuroscience, University Medical Center Utrecht Brain CenterUtrecht UniversityUtrechtThe Netherlands
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8
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Jagirdar R, Fu CH, Park J, Corbett BF, Seibt FM, Beierlein M, Chin J. Restoring activity in the thalamic reticular nucleus improves sleep architecture and reduces Aβ accumulation in mice. Sci Transl Med 2021; 13:eabh4284. [PMID: 34731016 PMCID: PMC8985235 DOI: 10.1126/scitranslmed.abh4284] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Sleep disruptions promote increases of amyloid β (Aβ) and tau in the brain and increase Alzheimer’s disease (AD) risk, but the precise mechanisms that give rise to sleep disturbances have yet to be defined. The thalamic reticular nucleus (TRN) is essential for sleep maintenance and for the regulation of slow-wave sleep (SWS). We examined the TRN in transgenic mice that express mutant human amyloid precursor protein (APP) and found reduced neuronal activity, increased sleep fragmentation, and decreased SWS time as compared to nontransgenic littermates. Selective activation of the TRN using excitatory DREADDs restored sleep maintenance, increased time in SWS, and reduced amyloid plaque load in both hippocampus and cortex. Our findings suggest that the TRN may play a major role in symptoms associated with AD. Enhancing TRN activity might be a promising therapeutic strategy for AD.
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Affiliation(s)
- Rohan Jagirdar
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX 77030
| | - Chia-Hsuan Fu
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX 77030
| | - Jin Park
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX 77030
| | - Brian F. Corbett
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX 77030
| | - Frederik M. Seibt
- Department of Neurobiology and Anatomy, McGovern Medical School at UTHealth, Houston, TX 77030
| | - Michael Beierlein
- Department of Neurobiology and Anatomy, McGovern Medical School at UTHealth, Houston, TX 77030
| | - Jeannie Chin
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX 77030
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9
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Necula D, Cho FS, He A, Paz JT. Secondary thalamic neuroinflammation after focal cortical stroke and traumatic injury mirrors corticothalamic functional connectivity. J Comp Neurol 2021; 530:998-1019. [PMID: 34633669 PMCID: PMC8957545 DOI: 10.1002/cne.25259] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 10/03/2021] [Accepted: 10/04/2021] [Indexed: 12/29/2022]
Abstract
While cortical injuries, such as traumatic brain injury (TBI) and neocortical stroke, acutely disrupt the neocortex, most of their consequent disabilities reflect secondary injuries that develop over time. Thalamic neuroinflammation has been proposed to be a biomarker of cortical injury and of the long-term cognitive and neurological deficits that follow. However, the extent to which thalamic neuroinflammation depends on the type of cortical injury or its location remains unknown. Using two mouse models of focal neocortical injury that do not directly damage subcortical structures-controlled cortical impact and photothrombotic ischemic stroke-we found that chronic neuroinflammation in the thalamic region mirrors the functional connections with the injured cortex, and that sensory corticothalamic regions may be more likely to sustain long-term damage than nonsensory circuits. Currently, heterogeneous clinical outcomes complicate treatment. Understanding how thalamic inflammation depends on the injury site can aid in predicting features of subsequent deficits and lead to more effective, customized therapies.
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Affiliation(s)
- Deanna Necula
- Gladstone Institute of Neurological Disease, San Francisco, California, USA.,Neuroscience Graduate Program, University of California, San Francisco, California, USA.,Department of Neurology and the Kavli Institute for Fundamental Neuroscience, University of California San Francisco, San Francisco, California, USA
| | - Frances S Cho
- Gladstone Institute of Neurological Disease, San Francisco, California, USA.,Neuroscience Graduate Program, University of California, San Francisco, California, USA.,Department of Neurology and the Kavli Institute for Fundamental Neuroscience, University of California San Francisco, San Francisco, California, USA
| | - Andrea He
- Gladstone Institute of Neurological Disease, San Francisco, California, USA
| | - Jeanne T Paz
- Gladstone Institute of Neurological Disease, San Francisco, California, USA.,Neuroscience Graduate Program, University of California, San Francisco, California, USA.,Department of Neurology and the Kavli Institute for Fundamental Neuroscience, University of California San Francisco, San Francisco, California, USA
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10
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Jin N, Babiloni C, Drinkenburg WH, Hajós M, Nygaard HB, Tanila H. Recommendations for Preclinical Testing of Treatments Against Alzheimer's Disease-Related Epileptiform Spikes in Transgenic Rodent Models. J Alzheimers Dis 2021; 88:849-865. [PMID: 34092642 DOI: 10.3233/jad-210209] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Recent evidence suggests that about 30%of patients with mild to moderate Alzheimer's disease (AD) without a known diagnosis of epilepsy may display epileptiform spikes during electroencephalographic (EEG) recordings. These abnormal discharges occur predominantly during sleep and may be associated with accelerated disease progression. Subclinical spikes may represent a relevant target for clinical drug interventions, and there is a clear unmet need for preclinical testing of novel disease modifying agents in suitable animal models. Transgenic rodent models of AD pathology exhibit various forms of epileptiform EEG activity related to the abnormal levels of amyloid species in the brain. Among them, large-amplitude cortical and hippocampal EEG spikes in mouse and rat AD models may be reminiscent of the subclinical epileptiform EEG spikes recorded in some AD patients. This article reports the recommendations of a multidisciplinary panel of experts on optimal EEG markers and experimental designs to measure and report epileptiform activities and their response to symptomatic and disease-modifying drugs in transgenic AD model rodents. These recommendations may harmonize future preclinical EEG studies in the drug discovery research and may increase the comparability of experimental outcomes and their translational clinical value.
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Affiliation(s)
- Nanxiang Jin
- A. I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland
| | - Claudio Babiloni
- Department of Physiology and Pharmacology "Vittorio Erspamer", Sapienza University of Rome, Rome, Italy.,Hospital San Raffaele Cassino, Cassino (FR), Italy
| | - Wilhelmus H Drinkenburg
- Janssen Research & Development, Janssen Pharmaceutica NV, Beerse, Belgium.,Groningen Institute for Evolutionary Life Sciences, University of Groningen, The Netherlands
| | - Mihály Hajós
- Cognito Therapeutics, Cambridge, MA, USA.,Yale University School of Medicine, New Haven, CT, USA
| | - Haakon B Nygaard
- Division of Neurology and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Heikki Tanila
- A. I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland
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11
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Sleep disorders and late-onset epilepsy of unknown origin: Understanding new trajectories to brain amyloidopathy. Mech Ageing Dev 2021; 194:111434. [PMID: 33444630 DOI: 10.1016/j.mad.2021.111434] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/31/2020] [Accepted: 01/07/2021] [Indexed: 12/16/2022]
Abstract
The intertwining between epilepsy, sleep disorders and beta amyloid pathology has been progressively highlighted, as early identification and stratification of patients at high risk of cognitive decline is the need of the hour. Modification of the sleep-wake activity, such as sleep impairment or excessive daytime sleepiness, can critically affect cerebral beta amyloid levels. Both mice models and human studies have demonstrated a substantial increase in the burden of beta amyloid pathology after sleep-deprivation, with potential negative effects partially restored by sleep recovery. The accumulation of beta amyloid has been shown to be an early event in the course of Alzheimer's disease dementia. Beta amyloid accumulation has been linked to epileptic seizures epileptic seizures, with beta amyloid being itself pro-epileptogenic in mice models already at oligomeric stage, well before plaque deposition. Further supporting a potential relationship between beta amyloid and epilepsy: i) seizures happen in 1 out of oofut 10 patients with Alzheimer's disease in the prodromal stage, ii) epileptic activity accelerates cognitive decline in Alzheimer's disease, iii) people with late-onset epilepsy present a critically high risk of developing dementia. In this Review we highlight the role of beta amyloid as a potential shared mechanisms between sleep disorders, late-onset epilepsy, and cognitive decline.
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Johnson ECB, Ho K, Yu GQ, Das M, Sanchez PE, Djukic B, Lopez I, Yu X, Gill M, Zhang W, Paz JT, Palop JJ, Mucke L. Behavioral and neural network abnormalities in human APP transgenic mice resemble those of App knock-in mice and are modulated by familial Alzheimer's disease mutations but not by inhibition of BACE1. Mol Neurodegener 2020; 15:53. [PMID: 32921309 PMCID: PMC7489007 DOI: 10.1186/s13024-020-00393-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 07/08/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is the most frequent and costly neurodegenerative disorder. Although diverse lines of evidence suggest that the amyloid precursor protein (APP) is involved in its causation, the precise mechanisms remain unknown and no treatments are available to prevent or halt the disease. A favorite hypothesis has been that APP contributes to AD pathogenesis through the cerebral accumulation of the amyloid-β peptide (Aβ), which is derived from APP through sequential proteolytic cleavage by BACE1 and γ-secretase. However, inhibitors of these enzymes have failed in clinical trials despite clear evidence for target engagement. METHODS To further elucidate the roles of APP and its metabolites in AD pathogenesis, we analyzed transgenic mice overexpressing wildtype human APP (hAPP) or hAPP carrying mutations that cause autosomal dominant familial AD (FAD), as well as App knock-in mice that do not overexpress hAPP but have two mouse App alleles with FAD mutations and a humanized Aβ sequence. RESULTS Although these lines of mice had marked differences in cortical and hippocampal levels of APP, APP C-terminal fragments, soluble Aβ, Aβ oligomers and age-dependent amyloid deposition, they all developed cognitive deficits as well as non-convulsive epileptiform activity, a type of network dysfunction that also occurs in a substantive proportion of humans with AD. Pharmacological inhibition of BACE1 effectively reduced levels of amyloidogenic APP C-terminal fragments (C99), soluble Aβ, Aβ oligomers, and amyloid deposits in transgenic mice expressing FAD-mutant hAPP, but did not improve their network dysfunction and behavioral abnormalities, even when initiated at early stages before amyloid deposits were detectable. CONCLUSIONS hAPP transgenic and App knock-in mice develop similar pathophysiological alterations. APP and its metabolites contribute to AD-related functional alterations through complex combinatorial mechanisms that may be difficult to block with BACE inhibitors and, possibly, also with other anti-Aβ treatments.
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Affiliation(s)
- Erik C. B. Johnson
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
- Department of Neurology and Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158 USA
| | - Kaitlyn Ho
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
| | - Gui-Qiu Yu
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
| | - Melanie Das
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
| | - Pascal E. Sanchez
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
| | - Biljana Djukic
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
| | - Isabel Lopez
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
| | - Xinxing Yu
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
| | - Michael Gill
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
| | - Weiping Zhang
- NHC Key Laboratory of Hormones and Development, Tianjin Institute of Endocrinology, Tianjin Medical University Metabolic Diseases Hospital, Tianjin, China
| | - Jeanne T. Paz
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
- Department of Neurology and Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158 USA
| | - Jorge J. Palop
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
- Department of Neurology and Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158 USA
| | - Lennart Mucke
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
- Department of Neurology and Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158 USA
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13
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Epilepsy and Alzheimer’s Disease: Potential mechanisms for an association. Brain Res Bull 2020; 160:107-120. [DOI: 10.1016/j.brainresbull.2020.04.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 04/05/2020] [Accepted: 04/10/2020] [Indexed: 12/16/2022]
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Walsh DA, Brown JT, Randall AD. Neurophysiological alterations in the nucleus reuniens of a mouse model of Alzheimer's disease. Neurobiol Aging 2019; 88:1-10. [PMID: 32065917 DOI: 10.1016/j.neurobiolaging.2019.12.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 11/30/2019] [Accepted: 12/06/2019] [Indexed: 02/06/2023]
Abstract
Recently, increased neuronal activity in nucleus reuniens (Re) has been linked to hyperexcitability within hippocampal-thalamo-cortical networks in the J20 mouse model of amyloidopathy. Here in vitro whole-cell patch clamp recordings were used to compare old pathology-bearing J20 mice and wild-type controls to examine whether altered intrinsic electrophysiological properties could contribute to the amyloidopathy-associated Re hyperactivity. A greater proportion of Re neurons display hyperpolarized membrane potentials in J20 mice without changes to the incidence or frequency of spontaneous action potentials. Re neurons recorded from J20 mice did not exhibit increased action potential generation in response to depolarizing current stimuli but an increased propensity to rebound burst following hyperpolarizing current stimuli. Increased rebound firing did not appear to result from alterations to T-type Ca2+ channels. Finally, in J20 mice, there was an ~8% reduction in spike width, similar to what has been reported in CA1 pyramidal neurons from multiple amyloidopathy mice. We conclude that alterations to the intrinsic properties of Re neurons may contribute to hippocampal-thalmo-cortical hyperexcitability observed under pathological beta-amyloid load.
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Affiliation(s)
- Darren A Walsh
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratory, Exeter, UK
| | - Jon T Brown
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratory, Exeter, UK
| | - Andrew D Randall
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratory, Exeter, UK.
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You JC, Jones E, Cross DE, Lyon AC, Kang H, Newberg AB, Lippa CF. Association of β-Amyloid Burden With Sleep Dysfunction and Cognitive Impairment in Elderly Individuals With Cognitive Disorders. JAMA Netw Open 2019; 2:e1913383. [PMID: 31617927 PMCID: PMC6806437 DOI: 10.1001/jamanetworkopen.2019.13383] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
IMPORTANCE Evidence shows that sleep dysfunction and β-amyloid (Aβ) deposition work synergistically to impair brain function in individuals with normal cognition, increasing the risk of developing dementia later in life. However, whether Aβ continues to play an integral role in sleep dysfunction after the onset of cognitive decline in individuals with dementia is unclear. OBJECTIVE To determine whether Aβ deposition in the brain is associated with subjective measures of sleep quality and cognition in elderly individuals with cognitive disorders. DESIGN, SETTING, AND PARTICIPANTS A nested survey study was conducted at the Cognitive Disorders and Comprehensive Alzheimer Disease Center of Thomas Jefferson University Hospital in Philadelphia, Pennsylvania. Participants included patients aged 65 years and older with cognitive disorders verified by neuropsychological testing. Eligible participants were identified from a referral center-based sample of patients who underwent fluorine 18-labeled florbetaben positron emission tomography imaging at Thomas Jefferson University Hospital as part of the multicenter Imaging Dementia-Evidence for Amyloid Scanning study. Data collection and analysis occurred between November 2018 and March 2019. MAIN OUTCOMES AND MEASURES Sleep quality was measured via responses to sleep questionnaires, Aβ deposition was measured via fluorine 18-labeled florbetaben positron emission tomography, and cognition was measured via Mini-Mental State Examination (MMSE) performance. RESULTS Of the 67 eligible participants, 52 (77.6%) gave informed consent to participate in the study. Of the 52 enrolled participants (mean [SD] age, 76.6 [7.4] years), 27 (51.9%) were women. Daytime sleepiness was associated with Aβ deposition in the brainstem (B = 0.0063; 95% CI, 0.001 to 0.012; P = .02), but not MMSE performance (B = -0.01; 95% CI, -0.39 to 0.37; P = .96). The number of nocturnal awakenings was associated with Aβ deposition in the precuneus (B = 0.11; 95% CI, 0.06 to 0.17; P < .001) and poor MMSE performance (B = -2.13; 95% CI, -3.13 to -1.13; P < .001). Mediation analysis demonstrated an indirect association between Aβ deposition and poor MMSE performance that relied on nocturnal awakenings as an intermediary (B = -3.99; 95% CI, -7.88 to -0.83; P = .01). CONCLUSIONS AND RELEVANCE Nighttime sleep disruption may mediate the association between Aβ and cognitive impairment, suggesting that there is an underlying sleep-dependent mechanism that links Aβ burden in the brain to cognitive decline. Further elucidation of this mechanism may improve understanding of disease processes associated with Aβ accumulation.
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Affiliation(s)
- Jason C. You
- Cognitive Disorders and Comprehensive Alzheimer’s Disease Center, Department of Neurology, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania
- Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
- Department of Internal Medicine, Lankenau Medical Center, Wynnewood, Pennsylvania
| | - Erica Jones
- Cognitive Disorders and Comprehensive Alzheimer’s Disease Center, Department of Neurology, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania
| | - Devon E. Cross
- Cognitive Disorders and Comprehensive Alzheimer’s Disease Center, Department of Neurology, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania
- Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Abigail C. Lyon
- Cognitive Disorders and Comprehensive Alzheimer’s Disease Center, Department of Neurology, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania
| | - Hyunseung Kang
- Department of Statistics, University of Wisconsin-Madison, Madison
| | - Andrew B. Newberg
- Marcus Institute for Integrative Health, Department of Integrative Medicine, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania
- Department of Radiology, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania
| | - Carol F. Lippa
- Cognitive Disorders and Comprehensive Alzheimer’s Disease Center, Department of Neurology, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania
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16
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Fredericks CA, Brown JA, Deng J, Kramer A, Ossenkoppele R, Rankin K, Kramer JH, Miller BL, Rabinovici GD, Seeley WW. Intrinsic connectivity networks in posterior cortical atrophy: A role for the pulvinar? Neuroimage Clin 2018; 21:101628. [PMID: 30528957 PMCID: PMC6411779 DOI: 10.1016/j.nicl.2018.101628] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 11/26/2018] [Accepted: 12/01/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND Posterior cortical atrophy (PCA) is a clinical variant of Alzheimer's disease (AD) that presents with progressive visuospatial symptoms. While amnestic AD is characterized by disrupted default mode network (DMN) connectivity with corresponding increases in salience network (SN) connectivity, a visuospatial network appears to be disrupted early in PCA. Based on PCA patients' clinical features, we hypothesized that, in addition to early decreased integrity within the visuospatial network, patients with PCA would show increases in SN connectivity despite relative preservation of DMN. As the lateral pulvinar nucleus of the thalamus has direct anatomical connections with striate and extrastriate cortex and DMN, and the medial pulvinar is anatomically interconnected with SN, we further hypothesized that lateral and medial pulvinar nuclei might be implicated in intrinsic connectivity changes in PCA. METHODS 26 patients with PCA and 64 matched controls were recruited through UCSF Memory and Aging Center research programs. Each completed a standardized neuropsychological battery, structural MRI, and task-free fMRI. Seed-based functional correlations were used to probe networks of interest, including those seeded by the medial and lateral pulvinar thalamic nuclei, across the whole brain, and functional data analyses were adjusted for brain atrophy. RESULTS Patients with PCA showed disproportionate deficits in the visuospatial domain; they also showed preserved social sensitivity and endorsed more depressive symptoms than HCs. PCA patients had significant parietooccipital atrophy accompanied by widespread connectivity decreases within the visuospatial network, enhanced connectivity between some structures in SN, and enhanced connectivity between key nodes of the DMN compared to controls. Increased SN connectivity correlated with a measure of social sensitivity, and increased DMN connectivity correlated with short-term memory performance. Medial pulvinar connectivity increases in PCA were topographically similar to SN (anterior insula) connectivity increases, while lateral pulvinar connectivity increases were similar to DMN (posterior cingulate) connectivity increases. CONCLUSIONS PCA is characterized by preserved to heightened connectivity in the SN and DMN despite decreased visuospatial network connectivity. The spatial similarity of medial and lateral pulvinar connectivity changes to those seen in the SN and DMN suggests a role for the pulvinar in intrinsic connectivity network changes in PCA.
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Affiliation(s)
- Carolyn A Fredericks
- Memory and Aging Center, University of California, 675 Nelson Rising Lane, San Francisco, CA 94143, USA.
| | - Jesse A Brown
- Memory and Aging Center, University of California, 675 Nelson Rising Lane, San Francisco, CA 94143, USA.
| | - Jersey Deng
- Memory and Aging Center, University of California, 675 Nelson Rising Lane, San Francisco, CA 94143, USA
| | - Abigail Kramer
- Memory and Aging Center, University of California, 675 Nelson Rising Lane, San Francisco, CA 94143, USA.
| | - Rik Ossenkoppele
- Memory and Aging Center, University of California, 675 Nelson Rising Lane, San Francisco, CA 94143, USA.
| | - Katherine Rankin
- Memory and Aging Center, University of California, 675 Nelson Rising Lane, San Francisco, CA 94143, USA.
| | - Joel H Kramer
- Memory and Aging Center, University of California, 675 Nelson Rising Lane, San Francisco, CA 94143, USA.
| | - Bruce L Miller
- Memory and Aging Center, University of California, 675 Nelson Rising Lane, San Francisco, CA 94143, USA.
| | - Gil D Rabinovici
- Memory and Aging Center, University of California, 675 Nelson Rising Lane, San Francisco, CA 94143, USA.
| | - William W Seeley
- Memory and Aging Center, University of California, 675 Nelson Rising Lane, San Francisco, CA 94143, USA.
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Jin N, Lipponen A, Koivisto H, Gurevicius K, Tanila H. Increased cortical beta power and spike-wave discharges in middle-aged APP/PS1 mice. Neurobiol Aging 2018; 71:127-141. [PMID: 30138766 DOI: 10.1016/j.neurobiolaging.2018.07.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 06/12/2018] [Accepted: 07/14/2018] [Indexed: 12/11/2022]
Abstract
Amyloid plaque-forming transgenic mice display neuronal hyperexcitability, epilepsy, and sudden deaths in early adulthood. However, it is unknown whether hyperexcitability persists until middle ages when memory impairment manifests. We recorded multichannel video electroencephalography (EEG), local field potentials, and auditory evoked potentials in transgenic mice carrying mutated human amyloid precursor protein (APP) and presenilin-1 (PS1) genes and wild-type littermates at 14-16 months and compared the results with data we have earlier collected from 4-month-old mice. Furthermore, we monitored acoustic startle responses in other APP/PS1 and wild-type mice from 3 to 11 months of age. Independent of the age APP/PS1 mice demonstrated increased cortical power at 8-60 Hz. They also displayed over 5-fold increase in the occurrence of spike-wave discharges and augmented auditory evoked potentials compared with nontransgenic littermates. In contrast to evoked potentials, APP/PS1 mice showed normalization of acoustic startle responses with aging. Increased cortical power and spike-wave discharges provide powerful new biomarkers to monitor progression of amyloid pathology in preclinical intervention studies.
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Affiliation(s)
- Nanxiang Jin
- A. I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland
| | - Arto Lipponen
- A. I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland
| | | | | | - Heikki Tanila
- A. I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland.
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18
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Peineau S, Rabiant K, Pierrefiche O, Potier B. Synaptic plasticity modulation by circulating peptides and metaplasticity: Involvement in Alzheimer's disease. Pharmacol Res 2018; 130:385-401. [PMID: 29425728 DOI: 10.1016/j.phrs.2018.01.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 01/23/2018] [Accepted: 01/26/2018] [Indexed: 10/18/2022]
Abstract
Synaptic plasticity is a cellular process involved in learning and memory whose alteration in its two main forms (Long Term Depression (LTD) and Long Term Potentiation (LTP)), is observed in most brain pathologies, including neurodegenerative disorders such as Alzheimer's disease (AD). In humans, AD is associated at the cellular level with neuropathological lesions composed of extracellular deposits of β-amyloid (Aβ) protein aggregates and intracellular neurofibrillary tangles, cellular loss, neuroinflammation and a general brain homeostasis dysregulation. Thus, a dramatic synaptic environment perturbation is observed in AD patients, involving changes in brain neuropeptides, cytokines, growth factors or chemokines concentration and diffusion. Studies performed in animal models demonstrate that these circulating peptides strongly affect synaptic functions and in particular synaptic plasticity. Besides this neuromodulatory action of circulating peptides, other synaptic plasticity regulation mechanisms such as metaplasticity are altered in AD animal models. Here, we will review new insights into the study of synaptic plasticity regulatory/modulatory mechanisms which could influence the process of synaptic plasticity in the context of AD with a particular attention to the role of metaplasticity and peptide dependent neuromodulation.
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Affiliation(s)
- Stéphane Peineau
- GRAP UMR1247, INSERM, Centre Universitaire de Recherche en Santé, Université de Picardie Jules Verne, Amiens, France; Centre for Synaptic Plasticity, School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, UK.
| | - Kevin Rabiant
- GRAP UMR1247, INSERM, Centre Universitaire de Recherche en Santé, Université de Picardie Jules Verne, Amiens, France
| | - Olivier Pierrefiche
- GRAP UMR1247, INSERM, Centre Universitaire de Recherche en Santé, Université de Picardie Jules Verne, Amiens, France.
| | - Brigitte Potier
- Laboratoire Aimé Cotton, CNRS-ENS UMR9188, Université Paris-Sud, Orsay, France.
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19
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Corticothalamic network dysfunction and Alzheimer's disease. Brain Res 2017; 1702:38-45. [PMID: 28919464 DOI: 10.1016/j.brainres.2017.09.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 09/11/2017] [Indexed: 12/11/2022]
Abstract
Alzheimer's disease (AD) is a devastating neurodegenerative disease that is characterized by progressive cognitive decline and a prominent loss of hippocampal-dependent memory. Therefore, much focus has been placed on understanding the function and dysfunction of the hippocampus in AD. However, AD is also accompanied by a number of other debilitating cognitive and behavioral alterations including deficits in attention, cognitive processing, and sleep maintenance. The underlying mechanisms that give rise to impairments in such diverse behavioral domains are unknown, and identifying them would shed insight into the multifactorial nature of AD as well as reveal potential new therapeutic targets to improve overall function in AD. We present here several lines of evidence that suggest that dysregulation of the corticothalamic network may be a common denominator that contributes to the diverse cognitive and behavioral alterations in AD. First, we will review the mechanisms by which this network regulates processes that include attention, cognitive processing, learning and memory, and sleep maintenance. Then we will review how these behavioral and cognitive domains are altered in AD. We will also discuss how dysregulation of tightly regulated activity in the corticothalamic network can give rise to non-convulsive seizures and other forms of epileptiform activity that have also been documented in both AD patients and transgenic mouse models of AD. In summary, the corticothalamic network has the potential to be a master regulator of diverse cognitive and behavioral domains that are affected in AD.
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20
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Towards a Better Understanding of GABAergic Remodeling in Alzheimer's Disease. Int J Mol Sci 2017; 18:ijms18081813. [PMID: 28825683 PMCID: PMC5578199 DOI: 10.3390/ijms18081813] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 08/16/2017] [Accepted: 08/17/2017] [Indexed: 12/18/2022] Open
Abstract
γ-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the vertebrate brain. In the past, there has been a major research drive focused on the dysfunction of the glutamatergic and cholinergic neurotransmitter systems in Alzheimer’s disease (AD). However, there is now growing evidence in support of a GABAergic contribution to the pathogenesis of this neurodegenerative disease. Previous studies paint a complex, convoluted and often inconsistent picture of AD-associated GABAergic remodeling. Given the importance of the GABAergic system in neuronal function and homeostasis, in the maintenance of the excitatory/inhibitory balance, and in the processes of learning and memory, such changes in GABAergic function could be an important factor in both early and later stages of AD pathogenesis. Given the limited scope of currently available therapies in modifying the course of the disease, a better understanding of GABAergic remodeling in AD could open up innovative and novel therapeutic opportunities.
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21
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Bagshaw AP, Hale JR, Campos BM, Rollings DT, Wilson RS, Alvim MKM, Coan AC, Cendes F. Sleep onset uncovers thalamic abnormalities in patients with idiopathic generalised epilepsy. NEUROIMAGE-CLINICAL 2017; 16:52-57. [PMID: 28752060 PMCID: PMC5519226 DOI: 10.1016/j.nicl.2017.07.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 06/29/2017] [Accepted: 07/12/2017] [Indexed: 11/16/2022]
Abstract
The thalamus is crucial for sleep regulation and the pathophysiology of idiopathic generalised epilepsy (IGE), and may serve as the underlying basis for the links between the two. We investigated this using EEG-fMRI and a specific emphasis on the role and functional connectivity (FC) of the thalamus. We defined three types of thalamic FC: thalamocortical, inter-hemispheric thalamic, and intra-hemispheric thalamic. Patients and controls differed in all three measures, and during wakefulness and sleep, indicating disorder-dependent and state-dependent modification of thalamic FC. Inter-hemispheric thalamic FC differed between patients and controls in somatosensory regions during wakefulness, and occipital regions during sleep. Intra-hemispheric thalamic FC was significantly higher in patients than controls following sleep onset, and disorder-dependent alterations to FC were seen in several thalamic regions always involving somatomotor and occipital regions. As interactions between thalamic sub-regions are indirect and mediated by the inhibitory thalamic reticular nucleus (TRN), the results suggest abnormal TRN function in patients with IGE, with a regional distribution which could suggest a link with the thalamocortical networks involved in the generation of alpha rhythms. Intra-thalamic FC could be a more widely applicable marker beyond patients with IGE. Sleep onset modifies thalamic FC in generalised epilepsy differently to controls. Differences are regionally specific. Regions connected to somatomotor/occipital cortices are consistently affected. Intra-thalamic FC may be a surrogate marker of thalamic reticular nucleus function.
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Affiliation(s)
- Andrew P Bagshaw
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK.,School of Psychology, University of Birmingham, Birmingham, UK
| | - Joanne R Hale
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK.,School of Psychology, University of Birmingham, Birmingham, UK.,Clinical Physics and Bioengineering, University Hospital Coventry and Warwickshire, Coventry, UK
| | - Brunno M Campos
- Neuroimaging Laboratory, Department of Neurology, University of Campinas, Campinas, Brazil
| | - David T Rollings
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK.,School of Psychology, University of Birmingham, Birmingham, UK.,Department of Neuroscience, Queen Elizabeth Hospital Birmingham, UK
| | - Rebecca S Wilson
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK.,School of Psychology, University of Birmingham, Birmingham, UK
| | - Marina K M Alvim
- Neuroimaging Laboratory, Department of Neurology, University of Campinas, Campinas, Brazil
| | - Ana Carolina Coan
- Neuroimaging Laboratory, Department of Neurology, University of Campinas, Campinas, Brazil
| | - Fernando Cendes
- Neuroimaging Laboratory, Department of Neurology, University of Campinas, Campinas, Brazil
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22
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Vossel KA, Tartaglia MC, Nygaard HB, Zeman AZ, Miller BL. Epileptic activity in Alzheimer's disease: causes and clinical relevance. Lancet Neurol 2017; 16:311-322. [PMID: 28327340 DOI: 10.1016/s1474-4422(17)30044-3] [Citation(s) in RCA: 340] [Impact Index Per Article: 48.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 01/10/2017] [Accepted: 01/31/2017] [Indexed: 01/18/2023]
Abstract
Epileptic activity is frequently associated with Alzheimer's disease; this association has therapeutic implications, because epileptic activity can occur at early disease stages and might contribute to pathogenesis. In clinical practice, seizures in patients with Alzheimer's disease can easily go unrecognised because they usually present as non-motor seizures, and can overlap with other symptoms of the disease. In patients with Alzheimer's disease, seizures can hasten cognitive decline, highlighting the clinical relevance of early recognition and treatment. Some evidence indicates that subclinical epileptiform activity in patients with Alzheimer's disease, detected by extended neurophysiological monitoring, can also lead to accelerated cognitive decline. Treatment of clinical seizures in patients with Alzheimer's disease with select antiepileptic drugs (AEDs), in low doses, is usually well tolerated and efficacious. Moreover, studies in mouse models of Alzheimer's disease suggest that certain classes of AEDs that reduce network hyperexcitability have disease-modifying properties. These AEDs target mechanisms of epileptogenesis involving amyloid β and tau. Clinical trials targeting network hyperexcitability in patients with Alzheimer's disease will identify whether AEDs or related strategies could improve their cognitive symptoms or slow decline.
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Affiliation(s)
- Keith A Vossel
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA, USA.
| | | | - Haakon B Nygaard
- Division of Neurology, University of British Columbia, Vancouver, BC, Canada
| | - Adam Z Zeman
- Cognitive Neurology Research Group, University of Exeter Medical School, Exeter, UK
| | - Bruce L Miller
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA, USA
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