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De Waegenaere S, van den Berg M, Keliris GA, Adhikari MH, Verhoye M. Early altered directionality of resting brain network state transitions in the TgF344-AD rat model of Alzheimer's disease. Front Hum Neurosci 2024; 18:1379923. [PMID: 38646161 PMCID: PMC11026683 DOI: 10.3389/fnhum.2024.1379923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 03/18/2024] [Indexed: 04/23/2024] Open
Abstract
Introduction Alzheimer's disease (AD) is a progressive neurodegenerative disease resulting in memory loss and cognitive decline. Synaptic dysfunction is an early hallmark of the disease whose effects on whole-brain functional architecture can be identified using resting-state functional MRI (rsfMRI). Insights into mechanisms of early, whole-brain network alterations can help our understanding of the functional impact of AD's pathophysiology. Methods Here, we obtained rsfMRI data in the TgF344-AD rat model at the pre- and early-plaque stages. This model recapitulates the major pathological and behavioral hallmarks of AD. We used co-activation pattern (CAP) analysis to investigate if and how the dynamic organization of intrinsic brain functional networks states, undetectable by earlier methods, is altered at these early stages. Results We identified and characterized six intrinsic brain states as CAPs, their spatial and temporal features, and the transitions between the different states. At the pre-plaque stage, the TgF344-AD rats showed reduced co-activation of hub regions in the CAPs corresponding to the default mode-like and lateral cortical network. Default mode-like network activity segregated into two distinct brain states, with one state characterized by high co-activation of the basal forebrain. This basal forebrain co-activation was reduced in TgF344-AD animals mainly at the pre-plaque stage. Brain state transition probabilities were altered at the pre-plaque stage between states involving the default mode-like network, lateral cortical network, and basal forebrain regions. Additionally, while the directionality preference in the network-state transitions observed in the wild-type animals at the pre-plaque stage had diminished at the early-plaque stage, TgF344-AD animals continued to show directionality preference at both stages. Discussion Our study enhances the understanding of intrinsic brain state dynamics and how they are impacted at the early stages of AD, providing a nuanced characterization of the early, functional impact of the disease's neurodegenerative process.
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Affiliation(s)
- Sam De Waegenaere
- Department of Biomedical Sciences, Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Monica van den Berg
- Department of Biomedical Sciences, Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Georgios A. Keliris
- Institute of Computer Science, Foundation for Research and Technology – Hellas, Heraklion, Greece
| | - Mohit H. Adhikari
- Department of Biomedical Sciences, Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Marleen Verhoye
- Department of Biomedical Sciences, Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
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2
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Ceyzériat K, Jaques E, Gloria Y, Badina A, Millet P, Koutsouvelis N, Dipasquale G, Frisoni GB, Zilli T, Garibotto V, Tournier BB. Low-Dose Radiation Therapy Impacts Microglial Inflammatory Response without Modulating Amyloid Load in Female TgF344-AD Rats. J Alzheimers Dis 2024; 98:1001-1016. [PMID: 38489181 DOI: 10.3233/jad-231153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2024]
Abstract
Background Low-dose radiation therapy (LD-RT) has demonstrated in preclinical and clinical studies interesting properties in the perspective of targeting Alzheimer's disease (AD), including anti-amyloid and anti-inflammatory effects. Nevertheless, studies were highly heterogenous with respect to total doses, fractionation protocols, sex, age at the time of treatment and delay post treatment. Recently, we demonstrated that LD-RT reduced amyloid peptides and inflammatory markers in 9-month-old TgF344-AD (TgAD) males. Objective As multiple studies demonstrated a sex effect in AD, we wanted to validate that LD-RT benefits are also observed in TgAD females analyzed at the same age. Methods Females were bilaterally treated with 2 Gy×5 daily fractions, 2 Gy×5 weekly fractions, or 10 fractions of 1 Gy delivered twice a week. The effect of each treatment on amyloid load and inflammation was evaluated using immunohistology and biochemistry. Results A daily treatment did not affect amyloid and reduced only microglial-mediated inflammation markers, the opposite of the results obtained in our previous male study. Moreover, altered fractionations (2 Gy×5 weekly fractions or 10 fractions of 1 Gy delivered twice a week) did not influence the amyloid load or neuroinflammatory response in females. Conclusions A daily treatment consequently appears to be the most efficient for AD. This study also shows that the anti-amyloid and anti-inflammatory response to LD-RT are, at least partly, two distinct mechanisms. It also emphasizes the necessity to assess the sex impact when evaluating responses in ongoing pilot clinical trials testing LD-RT against AD.
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Affiliation(s)
- Kelly Ceyzériat
- Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland
- Faculty of Medicine, Geneva University, Geneva, Switzerland
- Diagnostic Department, Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospitals and NIMTLab, Faculty of Medicine, Geneva University, Geneva, Switzerland
- CIBM Center for BioMedical Imaging, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Emma Jaques
- Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland
- Faculty of Medicine, Geneva University, Geneva, Switzerland
| | - Yesica Gloria
- Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland
- Faculty of Medicine, Geneva University, Geneva, Switzerland
- Bertarelli Foundation Gene Therapy Platform, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland
| | - Aurélien Badina
- Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland
- Faculty of Medicine, Geneva University, Geneva, Switzerland
| | - Philippe Millet
- Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland
- Faculty of Medicine, Geneva University, Geneva, Switzerland
| | - Nikolaos Koutsouvelis
- Department of Oncology, Division of Radiation Oncology, Geneva University Hospitals, Geneva, Switzerland
| | - Giovanna Dipasquale
- Department of Oncology, Division of Radiation Oncology, Geneva University Hospitals, Geneva, Switzerland
| | - Giovanni B Frisoni
- Faculty of Medicine, Geneva University, Geneva, Switzerland
- Diagnostic Department, Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospitals and NIMTLab, Faculty of Medicine, Geneva University, Geneva, Switzerland
| | - Thomas Zilli
- Faculty of Medicine, Geneva University, Geneva, Switzerland
- Department of Oncology, Division of Radiation Oncology, Geneva University Hospitals, Geneva, Switzerland
- Department of Radiation Oncology, Oncology Institute of Southern Switzerland, EOC, Bellinzona, Switzerland
- Facoltà di Scienze Biomediche, Università della Svizzera Italiana, Lugano, Switzerland
| | - Valentina Garibotto
- Faculty of Medicine, Geneva University, Geneva, Switzerland
- Diagnostic Department, Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospitals and NIMTLab, Faculty of Medicine, Geneva University, Geneva, Switzerland
- CIBM Center for BioMedical Imaging, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Benjamin B Tournier
- Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland
- Faculty of Medicine, Geneva University, Geneva, Switzerland
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3
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Reyna NC, Clark BJ, Hamilton DA, Pentkowski NS. Anxiety and Alzheimer's disease pathogenesis: focus on 5-HT and CRF systems in 3xTg-AD and TgF344-AD animal models. Front Aging Neurosci 2023; 15:1251075. [PMID: 38076543 PMCID: PMC10699143 DOI: 10.3389/fnagi.2023.1251075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 10/25/2023] [Indexed: 02/12/2024] Open
Abstract
Dementia remains one of the leading causes of morbidity and mortality in older adults. Alzheimer's disease (AD) is the most common type of dementia, affecting over 55 million people worldwide. AD is characterized by distinct neurobiological changes, including amyloid-beta protein deposits and tau neurofibrillary tangles, which cause cognitive decline and subsequent behavioral changes, such as distress, insomnia, depression, and anxiety. Recent literature suggests a strong connection between stress systems and AD progression. This presents a promising direction for future AD research. In this review, two systems involved in regulating stress and AD pathogenesis will be highlighted: serotonin (5-HT) and corticotropin releasing factor (CRF). Throughout the review, we summarize critical findings in the field while discussing common limitations with two animal models (3xTg-AD and TgF344-AD), novel pharmacotherapies, and potential early-intervention treatment options. We conclude by highlighting promising future pharmacotherapies and translational animal models of AD and anxiety.
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Affiliation(s)
- Nicole C. Reyna
- Department of Psychology, University of New Mexico, Albuquerque, NM, United States
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Srivastava H, Lasher AT, Nagarajan A, Sun LY. Sexual dimorphism in the peripheral metabolic homeostasis and behavior in the TgF344-AD rat model of Alzheimer's disease. Aging Cell 2023; 22:e13854. [PMID: 37095621 PMCID: PMC10352566 DOI: 10.1111/acel.13854] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 04/03/2023] [Accepted: 04/05/2023] [Indexed: 04/26/2023] Open
Abstract
Alzheimer's disease (AD), a prevalent form of dementia, is characterized by the decline of cognitive abilities with age. Available treatment options for AD are limited, making it a significant public health concern. Recent research suggests that metabolic dysfunction plays a role in the development of AD. In addition, insulin therapy has been shown to improve memory in patients with cognitive decline. In this study, we report the first examination of body composition, peripheral insulin sensitivity, and glucose tolerance in relation to behavioral assessments of learning, memory, and anxiety in the TgF344-AD rat model of AD. Results from glucose and insulin tolerance tests show that female TgF344-AD rats exhibit impaired glucose clearance and reduced insulin sensitivity at both 9 and 12 months of age, while males display no differences at 9 months and even improved glucose clearance at 12 months. Results from the Morris Water Maze assessment of learning and memory reveal that male TgF344-AD rats display impairments at both 9 and 12 months of age, while female TgF344-AD rats only show impairments at 12 months. Furthermore, results from open field and elevated plus maze tests suggest that female TgF344-AD rats display increased anxiety at 9 months of age; however, no differences were detected in males or at 12 months of age. Overall, our findings suggest that impairments in metabolism, commonly associated with type 2 diabetes, occur before or simultaneously with cognitive decline and anxiety in a sexually dimorphic manner in the TgF344-AD rat model.
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Affiliation(s)
- Hemant Srivastava
- Department of BiologyUniversity of Alabama at BirminghamBirminghamAlabamaUSA
| | | | - Akash Nagarajan
- Department of BiologyUniversity of Alabama at BirminghamBirminghamAlabamaUSA
| | - Liou Y. Sun
- Department of BiologyUniversity of Alabama at BirminghamBirminghamAlabamaUSA
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5
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van den Berg M, Toen D, Verhoye M, Keliris GA. Alterations in theta-gamma coupling and sharp wave-ripple, signs of prodromal hippocampal network impairment in the TgF344-AD rat model. Front Aging Neurosci 2023; 15:1081058. [PMID: 37032829 PMCID: PMC10075364 DOI: 10.3389/fnagi.2023.1081058] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 02/27/2023] [Indexed: 04/11/2023] Open
Abstract
Alzheimer's disease (AD) is a severe neurodegenerative disorder caused by the accumulation of toxic proteins, amyloid-beta (Aβ) and tau, which eventually leads to dementia. Disease-modifying therapies are still lacking, due to incomplete insights into the neuropathological mechanisms of AD. Synaptic dysfunction is known to occur before cognitive symptoms become apparent and recent studies have demonstrated that imbalanced synaptic signaling drives the progression of AD, suggesting that early synaptic dysfunction could be an interesting therapeutic target. Synaptic dysfunction results in altered oscillatory activity, which can be detected with electroencephalography and electrophysiological recordings. However, the majority of these studies have been performed at advanced stages of AD, when extensive damage and cognitive symptoms are already present. The current study aimed to investigate if the hippocampal oscillatory activity is altered at pre-plaque stages of AD. The rats received stereotactic surgery to implant a laminar electrode in the CA1 layer of the right hippocampus. Electrophysiological recordings during two consecutive days in an open field were performed in 4-5-month-old TgF344-AD rats when increased concentrations of soluble Aβ species were observed in the brain, in the absence of Aβ-plaques. We observed a decreased power of high theta oscillations in TgF344-AD rats compared to wild-type littermates. Sharp wave-ripple (SWR) analysis revealed an increased SWR power and a decreased duration of SWR during quiet wake in TgF344-AD rats. The alterations in properties of SWR and the increased power of fast oscillations are suggestive of neuronal hyperexcitability, as has been demonstrated to occur during presymptomatic stages of AD. In addition, decreased strength of theta-gamma coupling, an important neuronal correlate of memory encoding, was observed in the TgF344-AD rats. Theta-gamma phase amplitude coupling has been associated with memory encoding and the execution of cognitive functions. Studies have demonstrated that mild cognitive impairment patients display decreased coupling strength, similar to what is described here. The current study demonstrates altered hippocampal network activity occurring at pre-plaque stages of AD and provides insights into prodromal network dysfunction in AD. The alterations observed could aid in the detection of AD during presymptomatic stages.
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Affiliation(s)
- Monica van den Berg
- Bio-Imaging Lab, University of Antwerp, Wilrijk, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
- *Correspondence: Monica van den Berg, ; Georgios A. Keliris,
| | - Daniëlle Toen
- Bio-Imaging Lab, University of Antwerp, Wilrijk, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Marleen Verhoye
- Bio-Imaging Lab, University of Antwerp, Wilrijk, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Georgios A. Keliris
- Bio-Imaging Lab, University of Antwerp, Wilrijk, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
- Institute of Computer Science, Foundation for Research and Technology – Hellas, Heraklion, Crete, Greece
- *Correspondence: Monica van den Berg, ; Georgios A. Keliris,
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Pentkowski NS, Bouquin SJ, Maestas-Olguin CR, Villasenor ZM, Clark BJ. Differential effects of chronic stress on anxiety-like behavior and contextual fear conditioning in the TgF344-AD rat model of Alzheimer's disease. Behav Brain Res 2022; 418:113661. [PMID: 34780859 DOI: 10.1016/j.bbr.2021.113661] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 11/02/2021] [Accepted: 11/03/2021] [Indexed: 11/26/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative brain disorder that leads to severe cognitive and functional impairments. Many AD patients also exhibit neuropsychiatric symptoms, such as anxiety and depression, prior to the clinical diagnosis of dementia. Chronic stress is associated with numerous adverse health consequences and disease states, and AD patients exhibit altered stress systems. Thus, stress may represent a causal link between neuropsychiatric symptoms and AD. To address this possibility, we examined the effects of chronic stress in the TgF344-AD rat model that co-expresses the mutant human amyloid precursor protein (APPsw) and presenilin 1 (PS1ΔE9) genes. Adult male transgenic (Tg+) and wild-type (WT) rats (6-7.5 months of age), with and without a history of chronic restraint stress, were tested for footshock-induced conditioned fear and for anxiety-like behavior in the elevated plus-maze. We found that non-stressed Tg+ rats showed increased anxiety-like behavior compared to non-stressed WT rats. In contrast, Tg+ and WT rats did not differ in levels of freezing immediately following footshock or during contextual re-exposure. Additionally, stressed Tg+ rats were not significantly different from stressed WT rats on any measures of anxiety or fear. Thus, while stress has been linked as a risk factor for AD-related pathology, it appears from the present findings that two weeks of daily restraint stress did not further enhance anxiety- or fear-like behaviors in TgF344-AD rats.
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Affiliation(s)
- Nathan S Pentkowski
- Department of Psychology, University of New Mexico, Albuquerque, NM 87109, USA.
| | - Samuel J Bouquin
- Department of Psychology, University of New Mexico, Albuquerque, NM 87109, USA
| | | | | | - Benjamin J Clark
- Department of Psychology, University of New Mexico, Albuquerque, NM 87109, USA
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7
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Gloria Y, Ceyzériat K, Tsartsalis S, Millet P, Tournier BB. Dopaminergic dysfunction in the 3xTg-AD mice model of Alzheimer's disease. Sci Rep 2021; 11:19412. [PMID: 34593951 PMCID: PMC8484608 DOI: 10.1038/s41598-021-99025-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 09/16/2021] [Indexed: 11/09/2022] Open
Abstract
Alzheimer's disease (AD) is characterized by amyloid (Aβ) protein aggregation and neurofibrillary tangles accumulation, accompanied by neuroinflammation. With all the therapeutic attempts targeting these biomarkers having been unsuccessful, the understanding of early mechanisms involved in the pathology is of paramount importance. Dopaminergic system involvement in AD has been suggested, particularly through the appearance of dopaminergic dysfunction-related neuropsychiatric symptoms and an overall worsening of cognitive and behavioral symptoms. In this study, we reported an early dopaminergic dysfunction in a mouse model presenting both amyloid and Tau pathology. 3xTg-AD mice showed an increase of postsynaptic D2/3R receptors density in the striatum and D2/3-autoreceptors in SN/VTA cell bodies. Functionally, a reduction of anxiety-like behavior, an increase in locomotor activity and D2R hyper-sensitivity to quinpirole stimulation have been observed. In addition, microglial cells in the striatum showed an early inflammatory response, suggesting its participation in dopaminergic alterations. These events are observed at an age when tau accumulation and Aβ deposits in the hippocampus are low. Thus, our results suggest that early dopaminergic dysfunction could have consequences in behavior and cognitive function, and may shed light on future therapeutic pathways of AD.
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Affiliation(s)
- Yesica Gloria
- Department of Psychiatry, University Hospitals of Geneva, Avenue de la Roseraie, 64, 1206, Geneva, Switzerland.,Department of Psychiatry, University of Geneva, Geneva, Switzerland
| | - Kelly Ceyzériat
- Department of Psychiatry, University Hospitals of Geneva, Avenue de la Roseraie, 64, 1206, Geneva, Switzerland.,Department of Psychiatry, University of Geneva, Geneva, Switzerland.,Division of Nuclear Medicine, Diagnostic Department, University Hospitals of Geneva, Geneva, Switzerland.,Division of Radiation Oncology, Department of Oncology, University Hospitals of Geneva, Geneva, Switzerland
| | - Stergios Tsartsalis
- Department of Psychiatry, University Hospitals of Geneva, Avenue de la Roseraie, 64, 1206, Geneva, Switzerland.,Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Philippe Millet
- Department of Psychiatry, University Hospitals of Geneva, Avenue de la Roseraie, 64, 1206, Geneva, Switzerland.,Department of Psychiatry, University of Geneva, Geneva, Switzerland
| | - Benjamin B Tournier
- Department of Psychiatry, University Hospitals of Geneva, Avenue de la Roseraie, 64, 1206, Geneva, Switzerland. .,Department of Psychiatry, University of Geneva, Geneva, Switzerland.
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8
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Goodman AM, Langner BM, Jackson N, Alex C, McMahon LL. Heightened Hippocampal β-Adrenergic Receptor Function Drives Synaptic Potentiation and Supports Learning and Memory in the TgF344-AD Rat Model during Prodromal Alzheimer's Disease. J Neurosci 2021; 41:5747-5761. [PMID: 33952633 PMCID: PMC8244969 DOI: 10.1523/jneurosci.0119-21.2021] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 02/23/2021] [Accepted: 04/28/2021] [Indexed: 01/27/2023] Open
Abstract
The central noradrenergic (NA) system is critical for the maintenance of attention, behavioral flexibility, spatial navigation, and learning and memory, those cognitive functions lost first in early Alzheimer's disease (AD). In fact, the locus coeruleus (LC), the sole source of norepinephrine (NE) for >90% of the brain, is the first site of pathologic tau accumulation in human AD with axon loss throughout forebrain, including hippocampus. The dentate gyrus is heavily innervated by LC-NA axons, where released NE acts on β-adrenergic receptors (ARs) at excitatory synapses from entorhinal cortex to facilitate long-term synaptic plasticity and memory formation. These synapses experience dysfunction in early AD before cognitive impairment. In the TgF344-AD rat model of AD, degeneration of LC-NA axons in hippocampus recapitulates human AD, providing a preclinical model to investigate synaptic and behavioral consequences. Using immunohistochemistry, Western blot analysis, and brain slice electrophysiology in 6- to 9-month-old wild-type and TgF344-AD rats, we discovered that the loss of LC-NA axons coincides with the heightened β-AR function at medial perforant path-dentate granule cell synapses that is responsible for the increase in LTP magnitude at these synapses. Furthermore, novel object recognition is facilitated in TgF344-AD rats that requires β-ARs, and pharmacological blockade of β-ARs unmasks a deficit in extinction learning only in TgF344-AD rats, indicating a greater reliance on β-ARs in both behaviors. Thus, a compensatory increase in β-AR function during prodromal AD in TgF344-AD rats heightens synaptic plasticity and preserves some forms of learning and memory.SIGNIFICANCE STATEMENT The locus coeruleus (LC), a brain region located in the brainstem which is responsible for attention and arousal, is damaged first by Alzheimer's disease (AD) pathology. The LC sends axons to hippocampus where released norepinephrine (NE) modulates synaptic function required for learning and memory. How degeneration of LC axons and loss of NE in hippocampus in early AD impacts synaptic function and learning and memory is not well understood despite the importance of LC in cognitive function. We used a transgenic AD rat model with LC axon degeneration mimicking human AD and found that heightened function of β-adrenergic receptors in the dentate gyrus increased synaptic plasticity and preserved learning and memory in early stages of the disease.
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Affiliation(s)
- Anthoni M Goodman
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294-0006
| | - Bethany M Langner
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294-0006
| | - Nateka Jackson
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294-0006
| | - Capri Alex
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294-0006
| | - Lori L McMahon
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294-0006
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Pentkowski NS, Rogge-Obando KK, Donaldson TN, Bouquin SJ, Clark BJ. Anxiety and Alzheimer's disease: Behavioral analysis and neural basis in rodent models of Alzheimer's-related neuropathology. Neurosci Biobehav Rev 2021; 127:647-658. [PMID: 33979573 DOI: 10.1016/j.neubiorev.2021.05.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 04/28/2021] [Accepted: 05/05/2021] [Indexed: 11/29/2022]
Abstract
Alzheimer's disease (AD) pathology is commonly associated with cognitive decline but is also composed of neuropsychiatric symptoms including psychological distress and alterations in mood, including anxiety and depression. Emotional dysfunction in AD is frequently modeled using tests of anxiety-like behavior in transgenic rodents. These tests often include the elevated plus-maze, light/dark test and open field test. In this review, we describe prototypical behavioral paradigms used to examine emotional dysfunction in transgenic models of AD, specifically anxiety-like behavior. Next, we summarize the results of studies examining anxiety-like behavior in transgenic rodents, noting that the behavioral outcomes using these paradigms have produced inconsistent results. We suggest that future research will benefit from using a battery of tests to examine emotional behavior in transgenic AD models. We conclude by discussing putative, overlapping neurobiological mechanisms underlying AD-related neuropathology, stress and anxiety-like behavior reported in AD models.
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Affiliation(s)
- Nathan S Pentkowski
- Department of Psychology, University of New Mexico, Albuquerque, NM, 87109, Mexico.
| | | | - Tia N Donaldson
- Department of Psychology, University of New Mexico, Albuquerque, NM, 87109, Mexico
| | - Samuel J Bouquin
- Department of Psychology, University of New Mexico, Albuquerque, NM, 87109, Mexico
| | - Benjamin J Clark
- Department of Psychology, University of New Mexico, Albuquerque, NM, 87109, Mexico.
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10
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Ceyzériat K, Gloria Y, Tsartsalis S, Fossey C, Cailly T, Fabis F, Millet P, Tournier BB. Alterations in dopamine system and in its connectivity with serotonin in a rat model of Alzheimer's disease. Brain Commun 2021; 3:fcab029. [PMID: 34286270 PMCID: PMC8287930 DOI: 10.1093/braincomms/fcab029] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 01/20/2021] [Accepted: 01/22/2021] [Indexed: 12/20/2022] Open
Abstract
Dopamine pathways alterations are reported in Alzheimer’s disease. However, it is
difficult in humans to establish when these deficits appear and their impact in the course
of Alzheimer’s disease. In the TgF344-Alzheimer’s disease rat model at the age of
6 months, we showed a reduction in in vivo release of striatal dopamine
due to serotonin 5HT2A-receptor blockade, in the absence of alterations in
5HT2A-receptor binding, suggesting a reduction in
5HT2A-receptor-dopamine system connectivity. In addition, a functional
hypersensitivity of postsynaptic dopamine D2-receptors and
D2-autoreceptors was also reported without any change in D2-receptor
density and in the absence of amyloid plaques or overexpression of the 18 kDa translocator
protein (an inflammatory marker) in areas of the dopamine system. Citalopram, a selective
serotonin reuptake inhibitor, induced functional
5HT2A-receptor−D2-receptor connectivity changes but had no effect on
D2-autoreceptor hypersensitivity. In older rats, dopamine cell bodies
overexpressed translocator protein and dopamine projection sites accumulated amyloid.
Interestingly, the 5HT2A-receptor density is decreased in the accumbens
subdivisions and the substantia nigra pars compacta. This reduction in the striatum is
related to the astrocytic expression of 5HT2A-receptor. Our results indicate
that both serotonin/dopamine connectivity and dopamine signalling pathways are
dysregulated and potentially represent novel early diagnostic and therapeutic avenues.
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Affiliation(s)
- Kelly Ceyzériat
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, 1206 Geneva, Switzerland.,Division of Nuclear medicine, Diagnostic Department, University Hospitals and Geneva University of Geneva, 1206 Geneva, Switzerland.,Division of Radiation Oncology, Department of Oncology, University Hospitals of Geneva, 1206 Geneva, Switzerland
| | - Yesica Gloria
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, 1206 Geneva, Switzerland
| | - Stergios Tsartsalis
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, 1206 Geneva, Switzerland
| | - Christine Fossey
- Normandie University, UNICAEN, Centre d'Etudes et de Recherche sur le Médicament de Normandie (CERMN), 14000 Caen, France
| | - Thomas Cailly
- Normandie University, UNICAEN, Centre d'Etudes et de Recherche sur le Médicament de Normandie (CERMN), 14000 Caen, France.,Department of Nuclear Medicine, CHU Cote de Nacre, 14000 Caen, France.,Normandie University, UNICAEN, IMOGERE, 14000 Caen, France
| | - Frédéric Fabis
- Normandie University, UNICAEN, Centre d'Etudes et de Recherche sur le Médicament de Normandie (CERMN), 14000 Caen, France
| | - Philippe Millet
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, 1206 Geneva, Switzerland.,Department of Psychiatry, University of Geneva, Geneva, Switzerland
| | - Benjamin B Tournier
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, 1206 Geneva, Switzerland.,Department of Psychiatry, University of Geneva, Geneva, Switzerland
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