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Liao W, Wang Y, Wang L, Li J, Huang D, Cheng W, Luan P. The Current Status and Challenges of Olfactory Dysfunction Study in Alzheimer's Disease. Ageing Res Rev 2024:102453. [PMID: 39127444 DOI: 10.1016/j.arr.2024.102453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2024] [Accepted: 08/07/2024] [Indexed: 08/12/2024]
Abstract
Olfactory functioning involves multiple cognitive processes and the coordinated actions of various neural systems. Any disruption at any stage of this process may result in olfactory dysfunction, which is consequently widely used to predict the onset and progression of diseases, such as Alzheimer's Disease (AD). Although the underlying mechanisms have not yet been fully unraveled, apparent changes were observed in olfactory brain areas form patients who suffer from AD by means of medical imaging and electroencephalography (EEG). Olfactory dysfunction holds significant promise in detecting AD during the preclinical stage preceding mild cognitive impairment (MCI). Owing to the strong specificity, olfactory tests are prevalently applied for screening in community cohorts. And combining olfactory tests with other biomarkers may further establish an optimal model for AD prediction in studies of specific olfactory dysfunctions and improve the sensitivity and specificity of early AD diagnosis.
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Affiliation(s)
- Wanchen Liao
- Department of Alzheimer's Disease Clinical Research Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China.
| | - Yulin Wang
- Department of Alzheimer's Disease Clinical Research Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
| | - Lei Wang
- Department of Alzheimer's Disease Clinical Research Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
| | - Jun Li
- Department of Alzheimer's Disease Clinical Research Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
| | - Dongqing Huang
- Department of Alzheimer's Disease Clinical Research Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
| | - Weibin Cheng
- Department of Alzheimer's Disease Clinical Research Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
| | - Ping Luan
- Department of Alzheimer's Disease Clinical Research Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China.
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2
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Chen Y, Al-Nusaif M, Li S, Tan X, Yang H, Cai H, Le W. Progress on early diagnosing Alzheimer's disease. Front Med 2024; 18:446-464. [PMID: 38769282 DOI: 10.1007/s11684-023-1047-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Accepted: 11/15/2023] [Indexed: 05/22/2024]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder that affects both cognition and non-cognition functions. The disease follows a continuum, starting with preclinical stages, progressing to mild cognitive and behavioral impairment, ultimately leading to dementia. Early detection of AD is crucial for better diagnosis and more effective treatment. However, the current AD diagnostic tests of biomarkers using cerebrospinal fluid and/or brain imaging are invasive or expensive, and mostly are still not able to detect early disease state. Consequently, there is an urgent need to develop new diagnostic techniques with higher sensitivity and specificity during the preclinical stages of AD. Various non-cognitive manifestations, including behavioral abnormalities, sleep disturbances, sensory dysfunctions, and physical changes, have been observed in the preclinical AD stage before occurrence of notable cognitive decline. Recent research advances have identified several biofluid biomarkers as early indicators of AD. This review focuses on these non-cognitive changes and newly discovered biomarkers in AD, specifically addressing the preclinical stages of the disease. Furthermore, it is of importance to explore the potential for developing a predictive system or network to forecast disease onset and progression at the early stage of AD.
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Affiliation(s)
- Yixin Chen
- Liaoning Provincial Key Laboratory for Research on the Pathogenic Mechanisms of Neurological Diseases, The First Affiliated Hospital of Dalian Medical University, Dalian, 116021, China
| | - Murad Al-Nusaif
- Liaoning Provincial Key Laboratory for Research on the Pathogenic Mechanisms of Neurological Diseases, The First Affiliated Hospital of Dalian Medical University, Dalian, 116021, China
| | - Song Li
- Liaoning Provincial Key Laboratory for Research on the Pathogenic Mechanisms of Neurological Diseases, The First Affiliated Hospital of Dalian Medical University, Dalian, 116021, China
| | - Xiang Tan
- Liaoning Provincial Key Laboratory for Research on the Pathogenic Mechanisms of Neurological Diseases, The First Affiliated Hospital of Dalian Medical University, Dalian, 116021, China
| | - Huijia Yang
- Liaoning Provincial Key Laboratory for Research on the Pathogenic Mechanisms of Neurological Diseases, The First Affiliated Hospital of Dalian Medical University, Dalian, 116021, China
| | - Huaibin Cai
- Transgenic Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Weidong Le
- Liaoning Provincial Key Laboratory for Research on the Pathogenic Mechanisms of Neurological Diseases, The First Affiliated Hospital of Dalian Medical University, Dalian, 116021, China.
- Institute of Neurology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, 610072, China.
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3
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Salas-Gallardo GA, Lorea-Hernández JJ, Robles-Gómez ÁA, Del Campo CCM, Peña-Ortega F. Morphological differentiation of peritumoral brain zone microglia. PLoS One 2024; 19:e0297576. [PMID: 38451958 PMCID: PMC10919594 DOI: 10.1371/journal.pone.0297576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 01/08/2024] [Indexed: 03/09/2024] Open
Abstract
The Peritumoral Brain Zone (PBZ) contributes to Glioblastoma (GBM) relapse months after the resection of the original tumor, which is influenced by a variety of pathological factors. Among those, microglia are recognized as one of the main regulators of GBM progression and probably relapse. Although microglial morphology has been analyzed inside GBM and its immediate surroundings, it has not been objectively characterized throughout the PBZ. Thus, we aimed to perform a thorough characterization of microglial morphology in the PBZ and its likely differentiation not just from the tumor-associated microglia but from control tissue microglia. For this purpose, Sprague Dawley rats were intrastriatally implanted with C6 cells to induce a GBM formation. Gadolinium-based magnetic resonance imaging (MRI) was performed to locate the tumor and to define the PBZ (2 mm beyond the tumor border), thus delimitating the different regions of interest (ROIs: core tumoral zone and immediate interface; contralateral striatum as control). Brain slices were obtained and immunolabeled with the microglia marker Iba-1. Sixteen morphological parameters were measured for each cell, significative differences were found in all parameters when comparing the four ROIs. To determine if PBZ microglia could be morphologically differentiated from microglia in other ROIs, hierarchical clustering analysis was performed, revealing that microglia can be separated into four morphologically differentiated clusters, each of them mostly integrated by cells sampled in each ROI. Furthermore, a classifier based on linear discriminant analysis, including only three morphological parameters, categorized microglial cells across the studied ROIs and showed a gradual transition between them. The robustness of this classification was assessed through principal component analysis with the remaining 13 morphological parameters, corroborating the obtained results. Thus, in this study we provided objective and quantitative evidence that PBZ microglia represent a differentiable microglial morphotype that could contribute to the recurrence of GBM in this area.
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Affiliation(s)
- G. Anahí Salas-Gallardo
- Laboratorio de Células Neurales Troncales, CIACYT-Facultad de Medicina, Universidad Autónoma de San Luis Potosí, San Luis Potosí, San Luis Potosí, México
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
| | - Jonathan-Julio Lorea-Hernández
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
| | - Ángel Abdiel Robles-Gómez
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
| | - Claudia Castillo-Martin Del Campo
- Laboratorio de Células Neurales Troncales, CIACYT-Facultad de Medicina, Universidad Autónoma de San Luis Potosí, San Luis Potosí, San Luis Potosí, México
| | - Fernando Peña-Ortega
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
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4
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Robles-Gómez ÁA, Ordaz B, Lorea-Hernández JJ, Peña-Ortega F. Deleterious and protective effects of epothilone-D alone and in the context of amyloid β- and tau-induced alterations. Front Mol Neurosci 2023; 16:1198299. [PMID: 37900942 PMCID: PMC10603193 DOI: 10.3389/fnmol.2023.1198299] [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: 04/01/2023] [Accepted: 09/20/2023] [Indexed: 10/31/2023] Open
Abstract
Amyloid-β (Aβ) and hyperphosphorylated tau (P-tau) are Alzheimer's disease (AD) biomarkers that interact in a complex manner to induce most of the cognitive and brain alterations observed in this disease. Since the neuronal cytoskeleton is a common downstream pathological target of tau and Aβ, which mostly lead to augmented microtubule instability, the administration of microtubule stabilizing agents (MSAs) can protect against their pathological actions. However, the effectiveness of MSAs is still uncertain due to their state-dependent negative effects; thus, evaluating their specific actions in different pathological or physiological conditions is required. We evaluated whether epothilone-D (Epo-D), a clinically used MSA, rescues from the functional and behavioral alterations produced by intracerebroventricular injection of Aβ, the presence of P-tau, or their combination in rTg4510 mice. We also explored the side effects of Epo-D. To do so, we evaluated hippocampal-dependent spatial memory with the Hebb-Williams maze, hippocampal CA1 integrity and the intrinsic and synaptic properties of CA1 pyramidal neurons with the patch-clamp technique. Aβ and P-tau mildly impaired memory retrieval, but produced contrasting effects on intrinsic excitability. When Aβ and P-tau were combined, the alterations in excitability and spatial reversal learning (i.e., cognitive flexibility) were exacerbated. Interestingly, Epo-D prevented most of the impairments induced Aβ and P-tau alone and combined. However, Epo-D also exhibited some side effects depending on the prevailing pathological or physiological condition, which should be considered in future preclinical and translational studies. Although we did not perform extensive histopathological evaluations or measured microtubule stability, our findings show that MSAs can rescue the consequences of AD-like conditions but otherwise be harmful if administered at a prodromal stage of the disease.
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Affiliation(s)
- Ángel Abdiel Robles-Gómez
- Instituto de Neurobiología, UNAM Campus Juriquilla, Querétaro, Mexico
- Posgrado en Ciencias Biológicas, UNAM, Ciudad Universitaria, México City, Mexico
| | - Benito Ordaz
- Instituto de Neurobiología, UNAM Campus Juriquilla, Querétaro, Mexico
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Shen J, Li M, Long C, Yang L, Jiang J. Altered Odor-Evoked Electrophysiological Responses in the Anterior Piriform Cortex of Conscious APP/PS1 Mice. J Alzheimers Dis 2022; 90:1277-1289. [DOI: 10.3233/jad-220694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background: Olfactory decline is an indicator of early-stage Alzheimer’s disease (AD). Although the anterior piriform cortex (aPC) is an important brain area involved in processing olfactory input, little is known about how its neuronal activity is affected in early-stage AD. Objective: To elucidate whether odor-induced electrophysiological responses are altered in the aPC of 3-5-month-old APP/PS1 mice. Methods: Using head-fixed multi-channel recording techniques in APP/PS1 AD mouse model to uncover potential aberrance of the aPC neuronal firing and local field potential (LFP) in response to vanillin. Results: We show that the firing rate of aPC neurons evoked by vanillin is significantly reduced in conscious APP/PS1 mice. LFP analysis demonstrates reduced low- and high-gamma (γ low, γ high) oscillations during both the baseline and odor stimulation periods in APP/PS1 mice. Moreover, according to spike-field coherence (SFC) analysis, APP/PS1 mice show decreased coherence between odor-evoked spikes and γ low rhythms, while the coherence with γ high rhythms and the ΔSFC of the oscillations is unaffected. Furthermore, APP/PS1 mice show reduced phase-locking strength in the baseline period, such that there is no difference between baseline and odor-stimulation conditions. This contrasts markedly with wild type mice, where phase-locking strength decreases on stimulation. Conclusion: The abnormalities in both the neuronal and oscillatory activities of the aPC may serve as electrophysiological indicators of underlying olfactory decline in early AD.
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Affiliation(s)
- Jialun Shen
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Meng Li
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Cheng Long
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Li Yang
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Jinxiang Jiang
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou, China
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6
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Wang X, Hu M, Xie Q, Geng C, Jin C, Ren W, Fan J, Ma T, Hu B. Amyloid β oligomers disrupt piriform cortical output via a serotonergic pathway. Neurobiol Aging 2022; 121:64-77. [DOI: 10.1016/j.neurobiolaging.2022.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 09/16/2022] [Accepted: 09/17/2022] [Indexed: 12/01/2022]
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7
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Amyloid Beta Alters Prefrontal-dependent Functions Along with its Excitability and Synaptic Plasticity in Male Rats. Neuroscience 2022; 498:260-279. [PMID: 35839923 DOI: 10.1016/j.neuroscience.2022.07.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 06/20/2022] [Accepted: 07/07/2022] [Indexed: 12/17/2022]
Abstract
Prefrontal cortex (PFC)-related functions, such as working memory (WM) and cognitive flexibility (CF), are among the first to be altered at early stages of Alzheimer's disease (AD). Likewise, transgenic AD models carrying different AD-related mutations, mostly linked to the overproduction of amyloid beta (Aβ) and other peptides, show premature behavioral and functional symptoms associated with PFC alterations. However, little is known about the effects of intracerebral or intra-PFC Aβ infusion on WM and CF, as well as on pyramidal cell excitability and plasticity. Thus, here we evaluated the effects of a single Aβ injection, directly into the PFC, or its intracerebroventricular (icv) application, on PFC-dependent behaviors and on the intrinsic and synaptic properties of layer V pyramidal neurons in PFC slices. We found that a single icv Aβ infusion reduced learning and performance of a delayed non-matching-to-sample WM task and prevented reversal learning in a matching-to-sample version of the task, several weeks after its infusion. The inhibition of WM performance was reproduced more potently by a single PFC Aβ infusion and was associated with Aβ accumulation. This behavioral disruption was related to increased layer V pyramidal cell firing, larger sag membrane potential, increased fast after-hyperpolarization and a failure to sustain synaptic long-term potentiation, even leading to long-term depression, at both the hippocampal-PFC pathway and intracortical synapses. These findings show that Aβ can affect PFC excitability and synaptic plasticity balance, damaging PFC-dependent functions, which could constitute the foundations of the early alterations in executive functions in AD patients.
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8
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Rebeca H, Karen PA, Elva A, Carmen C, Fernando P. Main Olfactory Bulb Reconfiguration by Prolonged Passive Olfactory Experience Correlates with Increased Brain‐Derived Neurotrophic Factor and Improved Innate Olfaction. Eur J Neurosci 2022; 55:1141-1161. [DOI: 10.1111/ejn.15610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 01/19/2022] [Accepted: 01/21/2022] [Indexed: 11/29/2022]
Affiliation(s)
- Hernández‐Soto Rebeca
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, UNAM‐Campus Juriquilla México
| | - Pimentel‐Farfan Ana Karen
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, UNAM‐Campus Juriquilla México
| | - Adan‐Castro Elva
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, UNAM‐Campus Juriquilla México
| | - Clapp Carmen
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, UNAM‐Campus Juriquilla México
| | - Peña‐Ortega Fernando
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, UNAM‐Campus Juriquilla México
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9
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Yan Y, Aierken A, Wang C, Song D, Ni J, Wang Z, Quan Z, Qing H. A potential biomarker of preclinical Alzheimer's disease: The olfactory dysfunction and its pathogenesis-based neural circuitry impairments. Neurosci Biobehav Rev 2021; 132:857-869. [PMID: 34810025 DOI: 10.1016/j.neubiorev.2021.11.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 10/26/2021] [Accepted: 11/07/2021] [Indexed: 01/24/2023]
Abstract
The olfactory dysfunction can signal and act as a potential biomarker of preclinical AD. However, the precise regulatory mechanism of olfactory function on the neural pathogenesis of AD is still unclear. The impairment of neural networks in olfaction system has been shown to be tightly associated with AD. As key brain regions of the olfactory system, the olfactory bulb (OB) and the piriform cortex (PCx) have a profound influence on the olfactory function. Therefore, this review will explore the mechanism of olfactory dysfunction in preclinical AD in the perspective of abnormal neural networks in the OB and PCx and their associated brain regions, especially from two aspects of aberrant oscillations and synaptic plasticity damages, which help better understand the underlying mechanism of olfactory neural network damages related to AD.
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Affiliation(s)
- Yan Yan
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Ailikemu Aierken
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Chunjian Wang
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Da Song
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Junjun Ni
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Zhe Wang
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, The National Clinical Research Center for Geriatric Disease, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Zhenzhen Quan
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China.
| | - Hong Qing
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China.
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10
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Friesen M, Ziegler-Waldkirch S, Egenolf M, d'Errico P, Helm C, Mezö C, Dokalis N, Erny D, Katzmarski N, Coelho R, Loreth D, Prinz M, Meyer-Luehmann M. Distinct Aβ pathology in the olfactory bulb and olfactory deficits in a mouse model of Aβ and α-syn co-pathology. Brain Pathol 2021; 32:e13032. [PMID: 34713522 PMCID: PMC9048518 DOI: 10.1111/bpa.13032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 09/27/2021] [Accepted: 09/29/2021] [Indexed: 01/05/2023] Open
Abstract
Several degenerative brain disorders such as Alzheimer's disease (AD), Parkinson's disease (PD) and Dementia with Lewy bodies (DLB) are characterized by the simultaneous appearance of amyloid‐β (Aβ) and α‐synuclein (α‐syn) pathologies and symptoms that are similar, making it difficult to differentiate between these diseases. Until now, an accurate diagnosis can only be made by postmortem analysis. Furthermore, the role of α‐syn in Aβ aggregation and the arising characteristic olfactory impairments observed during the progression of these diseases is still not well understood. Therefore, we assessed Aβ load in olfactory bulbs of APP‐transgenic mice expressing APP695KM670/671NL and PSEN1L166P under the control of the neuron‐specific Thy‐1 promoter (referred to here as APPPS1) and APPPS1 mice co‐expressing SNCAA30P (referred to here as APPPS1 × [A30P]aSYN). Furthermore, the olfactory capacity of these mice was evaluated in the buried food and olfactory avoidance test. Our results demonstrate an age‐dependent increase in Aβ load in the olfactory bulb of APP‐transgenic mice that go along with exacerbated olfactory performance. Our study provides clear evidence that the presence of α‐syn significantly diminished the endogenous and seed‐induced Aβ deposits and significantly ameliorated olfactory dysfunction in APPPS1 × [A30P]aSYN mice.
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Affiliation(s)
- Marina Friesen
- Department of Neurology, Medical Center, University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Stephanie Ziegler-Waldkirch
- Department of Neurology, Medical Center, University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Milena Egenolf
- Department of Neurology, Medical Center, University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Paolo d'Errico
- Department of Neurology, Medical Center, University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Christina Helm
- Department of Neurology, Medical Center, University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Charlotte Mezö
- Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany.,Institute of Neuropathology, University of Freiburg, Freiburg, Germany
| | - Nikolaos Dokalis
- Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany.,Institute of Neuropathology, University of Freiburg, Freiburg, Germany
| | - Daniel Erny
- Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Institute of Neuropathology, University of Freiburg, Freiburg, Germany.,Berta-Ottenstein-Programme, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Natalie Katzmarski
- Department of Neurology, Medical Center, University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Romina Coelho
- Department of Neurology, Medical Center, University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Biosystems and Integrative Sciences Institute, Faculdade de Ciências, Departamento de Química e Bioquímica, Universidade de Lisboa, Lisbon, Portugal
| | - Desirée Loreth
- Department of Neurology, Medical Center, University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Marco Prinz
- Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Institute of Neuropathology, University of Freiburg, Freiburg, Germany.,Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Melanie Meyer-Luehmann
- Department of Neurology, Medical Center, University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
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11
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Berry JK, Cox D. Increased oscillatory power in a computational model of the olfactory bulb due to synaptic degeneration. Phys Rev E 2021; 104:024405. [PMID: 34525666 DOI: 10.1103/physreve.104.024405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 06/30/2021] [Indexed: 11/07/2022]
Abstract
Several neurodegenerative diseases impact the olfactory system, and in particular the olfactory bulb, early in disease progression. One mechanism by which damage occurs is via synaptic dysfunction. Here, we implement a computational model of the olfactory bulb and investigate the effect of weakened connection weights on network oscillatory behavior. Olfactory bulb network activity can be modeled by a system of equations that describes a set of coupled nonlinear oscillators. In this modeling framework, we propagate damage to synaptic weights using several strategies, varying from localized to global. Damage propagated in a dispersed or spreading manner leads to greater oscillatory power at moderate levels of damage. This increase arises from a higher average level of mitral cell activity due to a shift in the balance between excitation and inhibition. That this shift leads to greater oscillations depends critically on the nonlinearity of the activation function. Linearized analysis of the network dynamics predicts when this shift leads to loss of oscillatory activity. We thus demonstrate one potential mechanism involved in the increased gamma oscillations seen in some animal models of Alzheimer's disease, and we highlight the potential that pathological olfactory bulb behavior presents as an early biomarker of disease.
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Affiliation(s)
- J Kendall Berry
- University of California, Davis, Davis, California 95616, USA
| | - Daniel Cox
- University of California, Davis, Davis, California 95616, USA
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12
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Hu B, Geng C, Guo F, Liu Y, Zong YC, Hou XY. GABA A receptor agonist muscimol rescues inhibitory microcircuit defects in the olfactory bulb and improves olfactory function in APP/PS1 transgenic mice. Neurobiol Aging 2021; 108:47-57. [PMID: 34507271 DOI: 10.1016/j.neurobiolaging.2021.08.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 05/28/2021] [Accepted: 08/02/2021] [Indexed: 02/09/2023]
Abstract
Olfactory damage develops at the early stages of Alzheimer's disease (AD). While amyloid-β (Aβ) oligomers are shown to impair inhibitory circuits in the olfactory bulb (OB), its underlying mechanisms remain unclear. Here, we investigated the olfactory dysfunction due to impaired inhibitory transmission to mitral cells (MCs) of the OB in APP/PS1 mice. Using electrophysiological studies, we found that MCs exhibited increased spontaneous firing rates as early as 3 months, much before development of Aβ deposits in the brain. Furthermore, the frequencies but not amplitudes of MC inhibitory postsynaptic currents decreased markedly, suggesting that presynaptic GABA release is impaired while postsynaptic GABAA receptor responses remain intact. Notably, muscimol, a GABAA receptor agonist, improved odor identification and discrimination behaviors in APP/PS1 mice, reduced MC basal firing activity, and rescued inhibitory circuits along with reducing the Aβ burden in the OB. Our study links the presynaptic deficits of GABAergic transmission to olfactory dysfunction and subsequent AD development and implicates the therapeutic potential of maintaining local inhibitory microcircuits against early AD progression.
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Affiliation(s)
- Bin Hu
- Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, China
| | - Chi Geng
- Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, China
| | - Feng Guo
- Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, China
| | - Ying Liu
- Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, China; State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, China
| | - Yu-Chen Zong
- Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, China
| | - Xiao-Yu Hou
- Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, China; State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, China.
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Guzmán-Ruiz MA, Herrera-González A, Jiménez A, Candelas-Juárez A, Quiroga-Lozano C, Castillo-Díaz C, Orta-Salazar E, Organista-Juárez D, Díaz-Cintra S, Guevara-Guzmán R. Protective effects of intracerebroventricular adiponectin against olfactory impairments in an amyloid β 1-42 rat model. BMC Neurosci 2021; 22:14. [PMID: 33653273 PMCID: PMC7927416 DOI: 10.1186/s12868-021-00620-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 02/23/2021] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is characterized by cognitive impairment that eventually develops into dementia. Amyloid-beta (Aβ) accumulation is a widely described hallmark in AD, and has been reported to cause olfactory dysfunction, a condition considered an early marker of the disease associated with injuries in the olfactory bulb (OB), the hippocampus (HIPP) and other odor-related cortexes. Adiponectin (APN) is an adipokine with neuroprotective effects. Studies have demonstrated that APN administration decreases Aβ neurotoxicity and Tau hyperphosphorylation in the HIPP, reducing cognitive impairment. However, there are no studies regarding the neuroprotective effects of APN in the olfactory dysfunction observed in the Aβ rat model. The aim of the present study is to determine whether the intracerebroventricular (i.c.v) administration of APN prevents the early olfactory dysfunction in an i.c.v Amyloid-beta1-42 (Aβ1-42) rat model. Hence, we evaluated olfactory function by using a battery of olfactory tests aimed to assess olfactory memory, discrimination and detection in the Aβ rat model treated with APN. In addition, we determined the number of cells expressing the neuronal nuclei (NeuN), as well as the number of microglial cells by using the ionized calcium-binding adapter molecule 1 (Iba-1) marker in the OB and, CA1, CA3, hilus and dentate gyrus (DG) in the HIPP. Finally, we determined Arginase-1 expression in both nuclei through Western blot. RESULTS We observed that the i.c.v injection of Aβ decreased olfactory function, which was prevented by the i.c.v administration of APN. In accordance with the olfactory impairment observed in i.c.v Aβ-treated rats, we observed a decrease in NeuN expressing cells in the glomerular layer of the OB, which was also prevented with the i.c.v APN. Furthermore, we observed an increase of Iba-1 cells in CA1, and DG in the HIPP of the Aβ rats, which was prevented by the APN treatment. CONCLUSION The present study describes the olfactory impairment of Aβ treated rats and evidences the protective role that APN plays in the brain, by preventing the olfactory impairment induced by Aβ1-42. These results may lead to APN-based pharmacological therapies aimed to ameliorate AD neurotoxic effects.
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Affiliation(s)
- Mara A Guzmán-Ruiz
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
| | - Amor Herrera-González
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
| | - Adriana Jiménez
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
| | - Alan Candelas-Juárez
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
| | - Crystal Quiroga-Lozano
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
| | - Claudia Castillo-Díaz
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
| | - Erika Orta-Salazar
- Departamento de Neurobiología del desarrollo y neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Querétaro, Mexico
| | - Diana Organista-Juárez
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
| | - Sofía Díaz-Cintra
- Departamento de Neurobiología del desarrollo y neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Querétaro, Mexico
| | - Rosalinda Guevara-Guzmán
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico.
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Hernández-Soto R, Villasana-Salazar B, Pinedo-Vargas L, Peña-Ortega F. Chronic intermittent hypoxia alters main olfactory bulb activity and olfaction. Exp Neurol 2021; 340:113653. [PMID: 33607078 DOI: 10.1016/j.expneurol.2021.113653] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 02/02/2021] [Accepted: 02/14/2021] [Indexed: 02/08/2023]
Abstract
Olfactory dysfunction is commonly observed in patients with obstructive sleep apnea (OSA), which is related to chronic intermittent hypoxia (CIH). OSA patients exhibit alterations in discrimination, identification and odor detection threshold. These olfactory functions strongly rely on neuronal processing within the main olfactory bulb (MOB). However, a direct evaluation of the effects of controlled CIH on olfaction and MOB network activity has not been performed. Here, we used electrophysiological field recordings in vivo to evaluate the effects of 21-day-long CIH on MOB network activity and its response to odors. In addition, we assessed animals´ olfaction with the buried food and habituation/dishabituation tests. We found that mice exposed to CIH show alterations in MOB spontaneous activity in vivo, consisting of a reduction in beta and gamma frequency bands power along with an increase in the theta band power. Likewise, the MOB was less responsive to odor stimulation, since the proportional increase of the power of its population activity in response to four different odorants was smaller than the one observed in control animals. These CIH-induced MOB functional alterations correlate with a reduction in the ability to detect, habituate and discriminate olfactory stimuli. Our findings indicate that CIH generates alterations in the MOB neural network, which could be involved in the olfactory deterioration in patients with OSA.
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Affiliation(s)
- Rebeca Hernández-Soto
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, Querétaro, Mexico
| | - Benjamín Villasana-Salazar
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, Querétaro, Mexico
| | - Laura Pinedo-Vargas
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, Querétaro, Mexico
| | - Fernando Peña-Ortega
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, Querétaro, Mexico.
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Martínez-García I, Hernández-Soto R, Villasana-Salazar B, Ordaz B, Peña-Ortega F. Alterations in Piriform and Bulbar Activity/Excitability/Coupling Upon Amyloid-β Administration in vivo Related to Olfactory Dysfunction. J Alzheimers Dis 2021; 82:S19-S35. [PMID: 33459655 DOI: 10.3233/jad-201392] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Deficits in odor detection and discrimination are premature symptoms of Alzheimer's disease (AD) that correlate with pathological signs in the olfactory bulb (OB) and piriform cortex (PCx). Similar olfactory dysfunction has been characterized in AD transgenic mice that overproduce amyloid-β peptide (Aβ), which can be prevented by reducing Aβ levels by immunological and pharmacological means, suggesting that olfactory dysfunction depends on Aβ accumulation and Aβ-driven alterations in the OB and/or PCx, as well as on their activation. However, this possibility needs further exploration. OBJECTIVE To characterize the effects of Aβ on OB and PCx excitability/coupling and on olfaction. METHODS Aβ oligomerized solution (containing oligomers, monomers, and protofibrils) or its vehicle were intracerebroventricularlly injected two weeks before OB and PCx excitability and synchrony were evaluated through field recordings in vivo and in brain slices. Synaptic transmission from the OB to the PCx was also evaluated in slices. Olfaction was assessed through the habituation/dishabituation test. RESULTS Aβ did not affect lateral olfactory tract transmission into the PCx but reduced odor habituation and cross-habituation. This olfactory dysfunction was related to a reduction of PCx and OB network activity power in vivo. Moreover, the coherence between PCx-OB activities was also reduced by Aβ. Finally, Aβ treatment exacerbated the 4-aminopyridine-induced excitation in the PCx in slices. CONCLUSION Our results show that Aβ-induced olfactory dysfunction involves a complex set of pathological changes at different levels of the olfactory pathway including alterations in PCx excitability and its coupling with the OB. These pathological changes might contribute to hyposmia in AD.
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Affiliation(s)
- Ignacio Martínez-García
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, UNAM-Campus Juriquilla, México
| | - Rebeca Hernández-Soto
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, UNAM-Campus Juriquilla, México
| | - Benjamín Villasana-Salazar
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, UNAM-Campus Juriquilla, México
| | - Benito Ordaz
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, UNAM-Campus Juriquilla, México
| | - Fernando Peña-Ortega
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, UNAM-Campus Juriquilla, México
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