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Kim CY, Kim J, Yoon S, Yi IJ, Lee H, Seo S, Kim DW, Ko S, Kim SA, Kwon C, Yi SS. Advancing the early detection of canine cognitive dysfunction syndrome with machine learning-enhanced blood-based biomarkers. Front Vet Sci 2024; 11:1390296. [PMID: 39170638 PMCID: PMC11335684 DOI: 10.3389/fvets.2024.1390296] [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: 02/23/2024] [Accepted: 07/30/2024] [Indexed: 08/23/2024] Open
Abstract
Up to half of the senior dogs suffer from canine cognitive dysfunction syndrome (CCDS), the diagnosis method relies on subjective questionnaires such as canine cognitive dysfunction rating (CCDR) scores. Therefore, the necessity of objective diagnosis is emerging. Here, we developed blood-based biomarkers for CCDS early detection. Blood samples from dogs with CCDR scores above 25 were analyzed, and the biomarkers retinol-binding protein 4 (RBP4), C-X-C-motif chemokine ligand 10 (CXCL10), and NADPH oxidase 4 (NOX4) were validated against neurodegenerative models. Lower biomarker levels were correlated with higher CCDR scores, indicating cognitive decline. Machine-learning analysis revealed the highest predictive accuracy when analyzing the combination of RBP4 and NOX4 using the support vector machine algorithm and confirmed potential diagnostic biomarkers. These results suggest that blood-based biomarkers can notably improve CCDS early detection and treatment, with implications for neurodegenerative disease management in both animals and humans.
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Affiliation(s)
- Chae Young Kim
- BK21 Four program, Department of Medical Sciences, Soonchunhyang University, Asan, Republic of Korea
| | - Jinhye Kim
- iCONNECTOME, Co., Ltd., Cheonan, Republic of Korea
| | - Sunmi Yoon
- iCONNECTOME, Co., Ltd., Cheonan, Republic of Korea
| | - Isaac Jinwon Yi
- Department of Cognitive Science, University of California, San Diego, La Jolla, CA, United States
| | - Hyuna Lee
- iamdt, Co., Ltd., Seoul, Republic of Korea
| | - Sanghyuk Seo
- VIP Animal Medical Center, Seoul, Republic of Korea
| | - Dae Won Kim
- Department of Biochemistry and Molecular Biology, Research Institute of Oral Sciences, College of Dentistry, Gangneung-Wonju National University, Gangneung, Republic of Korea
| | - Soohyun Ko
- GenesisEgo, Co., Ltd., Seoul, Republic of Korea
| | - Sun-A Kim
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
| | | | - Sun Shin Yi
- BK21 Four program, Department of Medical Sciences, Soonchunhyang University, Asan, Republic of Korea
- iCONNECTOME, Co., Ltd., Cheonan, Republic of Korea
- Department of Biomedical Laboratory Science, Soonchunhyang University, Asan, Republic of Korea
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Haake J, Meller S, Meyerhoff N, Twele F, Charalambous M, Talbot SR, Volk HA. Comparing standard screening questionnaires of canine behavior for assessment of cognitive dysfunction. Front Vet Sci 2024; 11:1374511. [PMID: 38835892 PMCID: PMC11149356 DOI: 10.3389/fvets.2024.1374511] [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: 01/22/2024] [Accepted: 04/29/2024] [Indexed: 06/06/2024] Open
Abstract
Background Canine cognitive dysfunction (CCD) is a common, yet underdiagnosed neurodegenerative disease affecting older dogs. Treatment is most effective when started early, so identifying mild cognitive decline in the earlier stages of the disease is considered important. Hypothesis/objective To compare the results of three different standard screening questionnaires [Canine Dementia Scale (CADES), Canine Cognitive Assessment Scale (CCAS), and Canine Cognitive Dysfunction Rating Scale (CCDR)] for CCD diagnosis. Trainability, pain sensitivity, and fear were additionally assessed with the Canine Behavioral Assessment and Research Questionnaire (C-BARQ) in order to evaluate associations between the three dementia scales and behavior. Methods An online survey containing all the mentioned questionnaires was designed for and distributed among owners of elderly dogs. Results Data from 597 dogs were analyzed. Overall, the scores of the three CCD questionnaires correlated well with each other, especially those of the CADES and CCAS. The CADES was more sensitive in identifying dogs with already mild to moderate cognitive impairment, while the others classified them as still undergoing normal aging. CCD scores increased for all questionnaires with age with spatial orientation being a key feature in CCD development. Trainability assessed with the C-BARQ decreased significantly with severity of CCD signs, while pain sensitivity increased. Fear and anxiety was pronounced in animals with mild but not with severe CCD. These associations based on the C-BARQ were more clearly observable in relation to CADES and CCDR than CCAS. Conclusion/clinical relevance The choice of screening questionnaire impacts the evaluation of cognitive status and severity of CCD. Thresholds for severity classification differ significantly and may have an impact on reliable assessment. Further longitudinal studies are required to determine which of the questionnaires investigated in this study is best suited for early detection of CCD.
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Affiliation(s)
- Julia Haake
- Department of Small Animal Medicine & Surgery, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Sebastian Meller
- Department of Small Animal Medicine & Surgery, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Nina Meyerhoff
- Department of Small Animal Medicine & Surgery, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Friederike Twele
- Department of Small Animal Medicine & Surgery, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Marios Charalambous
- Department of Small Animal Medicine & Surgery, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Steven R Talbot
- Institute for Laboratory Animal Science and Central Animal Laboratory, Hannover Medical School, Hannover, Germany
| | - Holger A Volk
- Department of Small Animal Medicine & Surgery, University of Veterinary Medicine Hannover, Hannover, Germany
- Center for Systems Neuroscience Hannover, Hannover, Germany
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Noche JA, Radhakrishnan H, Ubele MF, Boaz K, Mefford JL, Jones ED, van Rooyen HY, Perpich JA, McCarty K, Meacham B, Smiley J, Bembenek Bailey SA, Puskás LG, Powell DK, Sordo L, Phelan MJ, Norris CM, Head E, Stark CEL. Age-Related Brain Atrophy and the Positive Effects of Behavioral Enrichment in Middle-Aged Beagles. J Neurosci 2024; 44:e2366232024. [PMID: 38561226 PMCID: PMC11097262 DOI: 10.1523/jneurosci.2366-23.2024] [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: 12/15/2023] [Revised: 02/08/2024] [Accepted: 02/28/2024] [Indexed: 04/04/2024] Open
Abstract
Aging dogs serve as a valuable preclinical model for Alzheimer's disease (AD) due to their natural age-related development of β-amyloid (Aβ) plaques, human-like metabolism, and large brains that are ideal for studying structural brain aging trajectories from serial neuroimaging. Here we examined the effects of chronic treatment with the calcineurin inhibitor (CNI) tacrolimus or the nuclear factor of activated T cells (NFAT)-inhibiting compound Q134R on age-related canine brain atrophy from a longitudinal study in middle-aged beagles (36 females, 7 males) undergoing behavioral enrichment. Annual MRI was analyzed using modern, automated techniques for region-of-interest-based and voxel-based volumetric assessments. We found that the frontal lobe showed accelerated atrophy with age, while the caudate nucleus remained relatively stable. Remarkably, the hippocampus increased in volume in all dogs. None of these changes were influenced by tacrolimus or Q134R treatment. Our results suggest that behavioral enrichment can prevent atrophy and increase the volume of the hippocampus but does not prevent aging-associated prefrontal cortex atrophy.
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Affiliation(s)
| | - Hamsanandini Radhakrishnan
- University of California, Irvine, California 92697
- University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | | | - Kathy Boaz
- University of Kentucky, Lexington, Kentucky 40506
| | | | - Erin D Jones
- University of Kentucky, Lexington, Kentucky 40506
| | | | | | | | | | | | | | | | | | - Lorena Sordo
- University of California, Irvine, California 92697
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Belshaw Z. Owners of dogs with canine cognitive dysfunction report higher levels of caregiver burden. Vet Rec 2024; 194:73-75. [PMID: 38240432 DOI: 10.1002/vetr.3880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
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Nystuen KL, McNamee SM, Akula M, Holton KM, DeAngelis MM, Haider NB. Alzheimer's Disease: Models and Molecular Mechanisms Informing Disease and Treatments. Bioengineering (Basel) 2024; 11:45. [PMID: 38247923 PMCID: PMC10813760 DOI: 10.3390/bioengineering11010045] [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: 11/14/2023] [Revised: 12/15/2023] [Accepted: 12/22/2023] [Indexed: 01/23/2024] Open
Abstract
Alzheimer's Disease (AD) is a complex neurodegenerative disease resulting in progressive loss of memory, language and motor abilities caused by cortical and hippocampal degeneration. This review captures the landscape of understanding of AD pathology, diagnostics, and current therapies. Two major mechanisms direct AD pathology: (1) accumulation of amyloid β (Aβ) plaque and (2) tau-derived neurofibrillary tangles (NFT). The most common variants in the Aβ pathway in APP, PSEN1, and PSEN2 are largely responsible for early-onset AD (EOAD), while MAPT, APOE, TREM2 and ABCA7 have a modifying effect on late-onset AD (LOAD). More recent studies implicate chaperone proteins and Aβ degrading proteins in AD. Several tests, such as cognitive function, brain imaging, and cerebral spinal fluid (CSF) and blood tests, are used for AD diagnosis. Additionally, several biomarkers seem to have a unique AD specific combination of expression and could potentially be used in improved, less invasive diagnostics. In addition to genetic perturbations, environmental influences, such as altered gut microbiome signatures, affect AD. Effective AD treatments have been challenging to develop. Currently, there are several FDA approved drugs (cholinesterase inhibitors, Aß-targeting antibodies and an NMDA antagonist) that could mitigate AD rate of decline and symptoms of distress.
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Affiliation(s)
- Kaden L. Nystuen
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA 01003, USA
| | - Shannon M. McNamee
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
| | - Monica Akula
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
| | - Kristina M. Holton
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
- Harvard Stem Cell Institute, Cambridge, MA 02138, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Margaret M. DeAngelis
- Department of Ophthalmology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14203, USA
| | - Neena B. Haider
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
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Haake J, Meyerhoff N, Meller S, Twele F, Charalambous M, Wilke V, Volk H. Investigating Owner Use of Dietary Supplements in Dogs with Canine Cognitive Dysfunction. Animals (Basel) 2023; 13:3056. [PMID: 37835662 PMCID: PMC10571926 DOI: 10.3390/ani13193056] [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: 08/07/2023] [Revised: 09/10/2023] [Accepted: 09/28/2023] [Indexed: 10/15/2023] Open
Abstract
Canine cognitive dysfunction (CCD) is becoming increasingly recognized in veterinary medicine, as dogs live longer and with CCD being highly prevalent among the elderly dog population. Various studies have shown that diet and dietary supplementation can positively influence the clinical signs of CCD, especially if given at an early stage. The aim of this study was to investigate owner use of dietary supplements (DSs) in dogs with age-related behavioral changes. An observational study based on an online questionnaire for owners of dogs with age-related behavioral changes was performed. Out of a total of 394 owners who completed the survey, after noticing age-related behavioral changes, over half of the dogs received DSs (54%), whereas only 8% reported changing their dog's base diet. The most used DS was fish oil (48%). The use of DSs should be discussed with and monitored by veterinary surgeons since many geriatric patients have multi-morbidities, may have specific nutritional requirements and receive multi-faceted medications.
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Affiliation(s)
- Julia Haake
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, 30559 Hannover, Germany; (J.H.); (N.M.); (S.M.); (F.T.); (M.C.)
| | - Nina Meyerhoff
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, 30559 Hannover, Germany; (J.H.); (N.M.); (S.M.); (F.T.); (M.C.)
| | - Sebastian Meller
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, 30559 Hannover, Germany; (J.H.); (N.M.); (S.M.); (F.T.); (M.C.)
| | - Friederike Twele
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, 30559 Hannover, Germany; (J.H.); (N.M.); (S.M.); (F.T.); (M.C.)
| | - Marios Charalambous
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, 30559 Hannover, Germany; (J.H.); (N.M.); (S.M.); (F.T.); (M.C.)
| | - Volker Wilke
- Institute for Animal Nutrition, University of Veterinary Medicine, Foundation, 30173 Hannover, Germany;
| | - Holger Volk
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, 30559 Hannover, Germany; (J.H.); (N.M.); (S.M.); (F.T.); (M.C.)
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Wu CH, Pan XS, Su LY, Yang SY. Plasma Neurofilament Light Chains as Blood-Based Biomarkers for Early Diagnosis of Canine Cognitive Dysfunction Syndrome. Int J Mol Sci 2023; 24:13771. [PMID: 37762074 PMCID: PMC10531274 DOI: 10.3390/ijms241813771] [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: 07/26/2023] [Revised: 09/02/2023] [Accepted: 09/04/2023] [Indexed: 09/29/2023] Open
Abstract
The number of elderly dogs is increasing significantly worldwide, and many elderly dogs develop canine cognitive dysfunction syndrome (CCDS). CCDS is the canine analog of Alzheimer's disease (AD) in humans. It is very important to develop techniques for detecting CDDS in dogs. Thus, we used the detection of neurofilament light chains (NfL) in plasma as a blood-based biomarker for the early diagnosis of canine Alzheimer's disease using immunomagnetic reduction (IMR) technology by immobilizing NfL antibodies on magnetic nanoparticles. According to the 50-point CCDS rating scale, we divided 36 dogs into 15 with CCDS and 21 without the disease. The results of our IMR assay showed that the plasma NfL levels of dogs with CCDS were significantly increased compared to normal dogs (p < 0.01). By plasma biochemical analysis, we further confirmed that the liver and renal dysfunction biomarkers of dogs with CCDS were significantly elevated compared to normal dogs (p < 0.01-0.05). On the basis of our preliminary study, we propose that IMR technology could be an ideal biosensor for detecting plasma NfL for the early diagnosis of CCDS.
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Affiliation(s)
- Chung-Hsin Wu
- School of Life Science, National Taiwan Normal University, Taipei 106, Taiwan
| | | | - Li-Yu Su
- Department of Physiology, College of Medicine, National Taiwan University, Taipei 106, Taiwan;
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Kutzsche J, Schemmert S, Bujnicki T, Zafiu C, Halbgebauer S, Kraemer-Schulien V, Pils M, Blömeke L, Post J, Kulawik A, Jürgens D, Rossberg WM, Hümpel M, Bannach O, Otto M, Araujo JA, Willuweit A, Willbold D. Oral treatment with the all-d-peptide RD2 enhances cognition in aged beagle dogs - A model of sporadic Alzheimer's disease. Heliyon 2023; 9:e18443. [PMID: 37609390 PMCID: PMC10440458 DOI: 10.1016/j.heliyon.2023.e18443] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 07/14/2023] [Accepted: 07/18/2023] [Indexed: 08/24/2023] Open
Abstract
Disease-modifying therapies to treat Alzheimer's disease (AD) are of fundamental interest for aging humans, societies, and health care systems. Predictable disease progression in transgenic AD models favors preclinical studies employing a preventive study design with an early pre-symptomatic treatment start, instead of assessing a truly curative approach with treatment starting after diagnosed disease onset. The aim of this study was to investigate the pharmacokinetic profile and efficacy of RD2 to enhance short-term memory and cognition in cognitively impaired aged Beagle dogs - a non-transgenic model of truly sporadic AD. RD2 has previously demonstrated pharmacodynamic efficacy in three different transgenic AD mouse models in three different laboratories. Here, we demonstrate that oral treatment with RD2 significantly reduced cognitive deficits in cognitively impaired aged Beagle dogs even beyond the treatment end, which suggests in combination with the treatment dependent CSF tau oligomer decrease a disease-modifying effect of RD2 treatment.
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Affiliation(s)
- Janine Kutzsche
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
| | - Sarah Schemmert
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
| | - Tuyen Bujnicki
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
| | - Christian Zafiu
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
| | | | - Victoria Kraemer-Schulien
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
| | - Marlene Pils
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
- attyloid GmbH, Düsseldorf, Germany
| | - Lara Blömeke
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Julia Post
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Andreas Kulawik
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
| | - Dagmar Jürgens
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
| | | | | | - Oliver Bannach
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
- attyloid GmbH, Düsseldorf, Germany
| | - Markus Otto
- Institute of Experimental Neurology, Ulm University Hospital, Ulm, Germany
| | | | - Antje Willuweit
- Institute of Neuroscience and Medicine, Medical Imaging Physics (INM-4), Forschungszentrum Jülich, Jülich, Germany
| | - Dieter Willbold
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
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Szriber SJ, Novaes LS, Santos NBD, Munhoz CD, Leite-Dellova DCA. Imbalance in the ratio between mineralocorticoid and glucocorticoid receptors and neurodegeneration in the dentate gyrus of aged dogs. Vet World 2022; 15:2543-2550. [PMID: 36590120 PMCID: PMC9798053 DOI: 10.14202/vetworld.2022.2543-2550] [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: 06/20/2022] [Accepted: 09/20/2022] [Indexed: 11/11/2022] Open
Abstract
Background and Aim Cortisol binds to mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) found in the hippocampus. The balanced expression of these receptors is essential to neuronal survival as MR and GR activations have antiapoptotic and proapoptotic effects, respectively. Given the aging changes in dogs' dentate gyrus (DG) and the possible involvement of cortisol receptors in this process, this study aimed to evaluate the expression of MR and GR and neuronal degeneration in this hippocampal region of aged dogs. Materials and Methods This study included cadaveric histologic hippocampus sections from six dogs aged 10 years and older (AG group) and 12 young/adult dogs aged up to 8 years (YAd group). Nissl staining and immunohistochemistry were performed to identify cells and investigate MR and GR expression, respectively. Furthermore, fluorescent labeling (fluoro-Jade B) was used to detect degenerating neurons. Results The AG group's polymorphic layer of the DG had a lower cell count (16%) and more degenerating neurons than the YAd group. In addition to these cellular changes, the AG group had lower MR immunoreactivity and MR-to-GR ratio. Furthermore, the lowest MR expression was associated with neuronal degeneration in the polymorphic layer of the DG of dogs. Conclusion An imbalance in the MR-to-GR ratio was observed in the polymorphic layer of the DG of aged dogs, along with lower MR expression and a greater number of degenerating neurons. These findings have clinical implications for understanding the decline in hippocampal memory formation associated with cognitive changes in aged dogs.
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Affiliation(s)
- Shirley Jaqueline Szriber
- Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering, University of Sao Paulo, Duque de Caxias Norte Avenue, 225, 13635-900, Pirassununga, Brazil,Corresponding author: Shirley Jaqueline Szriber, e-mail: Co-authors: LSN: , NBDS: , CDM: , DCAL:
| | - Leonardo Santana Novaes
- Department of Pharmacology, Institute of Biomedical Science, University of Sao Paulo, Professor Lineu Prestes Avenue, 1524, Room 323, 05508-000, Sao Paulo, Brazil
| | - Nilton Barreto Dos Santos
- Department of Pharmacology, Institute of Biomedical Science, University of Sao Paulo, Professor Lineu Prestes Avenue, 1524, Room 323, 05508-000, Sao Paulo, Brazil
| | - Carolina Demarchi Munhoz
- Department of Pharmacology, Institute of Biomedical Science, University of Sao Paulo, Professor Lineu Prestes Avenue, 1524, Room 323, 05508-000, Sao Paulo, Brazil
| | - Deise Carla Almeida Leite-Dellova
- Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering, University of Sao Paulo, Duque de Caxias Norte Avenue, 225, 13635-900, Pirassununga, Brazil
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Valenzuela M, Duncan T, Abey A, Johnson A, Boulamatsis C, Dalton MA, Jacobson E, Brunel L, Child G, Simpson D, Buckland M, Lowe A, Siette J, Westbrook F, McGreevy P. Autologous skin-derived neural precursor cell therapy reverses canine Alzheimer dementia-like syndrome in a proof of concept veterinary trial. Stem Cell Res Ther 2022; 13:261. [PMID: 35715872 PMCID: PMC9205057 DOI: 10.1186/s13287-022-02933-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 06/01/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Older companion dogs naturally develop a dementia-like syndrome with biological, clinical and therapeutic similarities to Alzheimer disease (AD). Given there has been no new safe, clinically effective and widely accessible treatment for AD for almost 20 years, an all-new cell therapeutic approach was trialled in canine veterinary patients, and further modelled in aged rats for more detailed neurobiological analysis. METHODS A Phase 1/2A veterinary trial was conducted in N = 6 older companion dogs with definitive diagnosis of Canine Cognitive Dysfunction (CCD). Treatment comprised direct microinjection of 250,000 autologous skin-derived neuroprecursors (SKNs) into the bilateral hippocampus using MRI-guided stereotaxis. Safety was assessed clinically and efficacy using the validated Canine Cognitive Dysfunction Rating Scale (CCDR) at baseline and 3-month post treatment. Intention to treat analysis imputed a single patient that had a surgical adverse event requiring euthanasia. Three dog brains were donated following natural death and histology carried out to quantify Alzheimer pathology as well as immature neurons and synapses; these were compared to a brain bank (N = 12) of untreated aged dogs with and without CCD. Further, an age-related memory dysfunction rat model (N = 16) was used to more closely evaluate intrahippocampal engraftment of canine SKN cells, focusing on mnemonic and synaptic effects as well as donor cell survival, neurodifferentation and electrophysiologic circuit integration in a live hippocampal slice preparation. RESULTS Four out-of-five dogs improved on the primary clinical CCDR endpoint, three fell below diagnostic threshold, and remarkably, two underwent full syndromal reversal lasting up to 2 years. At post mortem, synaptic density in the hippocampus specifically was nine standard deviations above non-treated dogs, and intensity of new neurons also several fold higher. There was no impact on AD pathology or long-term safety signals. Modelling in aged rats replicated the main canine trial findings: hippocampally-dependent place memory deficits were reversed and synaptic depletion rescued. In addition, this model confirmed donor cell survival and migration throughout the hippocampus, neuronal differentiation in situ, and physiologically-correct integration into pyramidal layer circuits. CONCLUSIONS With further development, SKN cell therapy may have potential for treating carefully chosen AD patients based on neurosynaptic restoration in the hippocampus.
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Affiliation(s)
- Michael Valenzuela
- Skin2Neuron Pty Ltd, Sydney, Australia.
- University of New South Wales, Sydney, Australia.
| | - T Duncan
- University of New South Wales, Sydney, Australia
| | - A Abey
- University of Sydney, Sydney, Australia
| | - A Johnson
- Skin2Neuron Pty Ltd, Sydney, Australia
| | | | | | - E Jacobson
- Sydney Children's Hospital, Sydney, Australia
| | - L Brunel
- University of Sydney, Sydney, Australia
| | - G Child
- University of Sydney, Sydney, Australia
| | - D Simpson
- Animal Referral Hospital Homebush, Sydney, Australia
| | - M Buckland
- University of Sydney, Sydney, Australia
- Royal Prince Alfred Hospital, Sydney, Australia
| | - A Lowe
- University of New South Wales, Sydney, Australia
| | - J Siette
- Western Sydney University, Sydney, Australia
| | - F Westbrook
- University of New South Wales, Sydney, Australia
| | - P McGreevy
- University of New England, Armidale, Australia
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Nutrients, Cognitive Function, and Brain Aging: What We Have Learned from Dogs. Med Sci (Basel) 2021; 9:medsci9040072. [PMID: 34842769 PMCID: PMC8628994 DOI: 10.3390/medsci9040072] [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: 09/10/2021] [Revised: 10/29/2021] [Accepted: 11/13/2021] [Indexed: 12/29/2022] Open
Abstract
Due to a difference in genetics, environmental factors, and nutrition, just like in people, dogs age at different rates. Brain aging in people and dogs share similar morphological changes including irreversible cortical atrophy, cerebral amyloid angiopathy, and ventricular enlargement. Due to severe and irreversible brain atrophy, some aging dogs develop cognitive dysfunction syndrome (CDS), which is equivalent to dementia or Alzheimer’s disease (AD) in people. The risk factors and causes of CDS in dogs have not been fully investigated, but age, gender, oxidative stress, and deficiency of sex hormones appears to be associated with increased risk of accelerated brain aging and CDS in dogs. Both AD and CDS are incurable diseases at this moment, therefore more efforts should be focused on preventing or reducing brain atrophy and minimizing the risk of AD in people and CDS in dogs. Since brain atrophy leads to irreversible cognitive decline and dementia, an optimal nutritional solution should be able to not only enhance cognitive function during aging but also reduce irreversible brain atrophy. Up to now, only one nutritional intervention has demonstrated both cognition-enhancing benefits and atrophy-reducing benefits.
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Townsend L, Gee NR. Recognizing and Mitigating Canine Stress during Animal Assisted Interventions. Vet Sci 2021; 8:vetsci8110254. [PMID: 34822627 PMCID: PMC8623698 DOI: 10.3390/vetsci8110254] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/22/2021] [Accepted: 10/26/2021] [Indexed: 11/16/2022] Open
Abstract
Animal-assisted Interventions (AAI) proliferated rapidly since clinicians and researchers first noted the positive effects animals have on people struggling with physical and mental health concerns. The intersection of AAI with the field of animal welfare evolved from considering animals’ basic needs, such as freedom from pain, to recognition that animals experience nuanced emotions. Current conceptualizations of the various roles of companion animals as an adjunct to treatments for humans emphasize not only the animals’ physical comfort and autonomy, but also their mental well-being and enjoyment of AAI activities. However, numerous challenges to effective monitoring of animals involved in AAI exist. This article focuses specifically on dogs, highlighting factors that may lead handlers and therapists to miss or ignore canine stress signals during human-animal interactions and offers strategies to recognize and ameliorate dogs’ distress more consistently. The primary goals of this discussion are to summarize the current thinking on canine well-being and to highlight practical applications of animal welfare principles in real-world AAI settings. The paper highlights contextual factors (e.g., physical setting, patient demand), human influences (e.g., desire to help), and intervention characteristics (e.g., presence or absence of a dog-specific advocate) that may promote or inhibit humans’ ability to advocate for therapy dogs during AAI activities. Deidentified examples of each of these factors are discussed, and recommendations are provided to mitigate factors that interfere with timely recognition and amelioration of canine distress.
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Affiliation(s)
- Lisa Townsend
- Center for Human-Animal Interaction, Department of Pediatrics, Division of Adolescent Medicine, School of Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA
- Correspondence:
| | - Nancy R. Gee
- Center for Human-Animal Interaction, Department of Psychiatry, School of Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA;
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13
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Resistance to developing brain pathology due to vascular risk factors: the role of educational attainment. Neurobiol Aging 2021; 106:197-206. [PMID: 34298318 DOI: 10.1016/j.neurobiolaging.2021.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 04/19/2021] [Accepted: 06/10/2021] [Indexed: 11/22/2022]
Abstract
Brain pathology develops at different rates between individuals with similar burden of risk factors, possibly explained by brain resistance. We examined if education contributes to brain resistance by studying its influence on the association between vascular risk factors and brain pathology. In 4111 stroke-free and dementia-free community-dwelling participants (62.9 ± 10.7 years), we explored the association between vascular risk factors (hypertension and the Framingham Stroke Risk Profile [FRSP]) and imaging markers of brain pathology (markers of cerebral small vessel disease and brain volumetry), stratified by educational attainment level. Associations of hypertension and FSRP with markers of brain pathology were not significantly different between levels of educational attainment. Certain associations appeared weaker in those with higher compared to lower educational attainment, particularly for white matter hyperintensities (WMH). Supplementary residual analyses showed significant associations between higher educational attainment and stronger resistance to WMH among others. Our results suggest a role for educational attainment in resistance to vascular brain pathology. Yet, further research is needed to better characterize determinants of brain resistance.
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14
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Edler MK, Mhatre-Winters I, Richardson JR. Microglia in Aging and Alzheimer's Disease: A Comparative Species Review. Cells 2021; 10:1138. [PMID: 34066847 PMCID: PMC8150617 DOI: 10.3390/cells10051138] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 04/30/2021] [Accepted: 05/05/2021] [Indexed: 12/11/2022] Open
Abstract
Microglia are the primary immune cells of the central nervous system that help nourish and support neurons, clear debris, and respond to foreign stimuli. Greatly impacted by their environment, microglia go through rapid changes in cell shape, gene expression, and functional behavior during states of infection, trauma, and neurodegeneration. Aging also has a profound effect on microglia, leading to chronic inflammation and an increase in the brain's susceptibility to neurodegenerative processes that occur in Alzheimer's disease. Despite the scientific community's growing knowledge in the field of neuroinflammation, the overall success rate of drug treatment for age-related and neurodegenerative diseases remains incredibly low. Potential reasons for the lack of translation from animal models to the clinic include the use of a single species model, an assumption of similarity in humans, and ignoring contradictory data or information from other species. To aid in the selection of validated and predictive animal models and to bridge the translational gap, this review evaluates similarities and differences among species in microglial activation and density, morphology and phenotype, cytokine expression, phagocytosis, and production of oxidative species in aging and Alzheimer's disease.
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Affiliation(s)
- Melissa K. Edler
- Department of Anthropology, School of Biomedical Sciences, Brain Health Research Institute, Kent State University, Kent, OH 44240, USA;
| | - Isha Mhatre-Winters
- School of Biomedical Sciences, College of Arts and Sciences, Kent State University, Kent, OH 44240, USA;
- Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL 33199, USA
| | - Jason R. Richardson
- Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL 33199, USA
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15
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Vikartovska Z, Farbakova J, Smolek T, Hanes J, Zilka N, Hornakova L, Humenik F, Maloveska M, Hudakova N, Cizkova D. Novel Diagnostic Tools for Identifying Cognitive Impairment in Dogs: Behavior, Biomarkers, and Pathology. Front Vet Sci 2021; 7:551895. [PMID: 33521072 PMCID: PMC7843503 DOI: 10.3389/fvets.2020.551895] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 12/07/2020] [Indexed: 12/31/2022] Open
Abstract
Canine cognitive dysfunction syndrome (CCDS) is a progressive neurodegenerative disorder in senior dogs that is mainly associated with decreased ability to learn and respond to stimuli. It is commonly under-diagnosed because behavioral changes are often attributed to the natural process of aging. In the present study, we used for the first time a comprehensive approach enabling early diagnosis of canine patients with mild cognitive disorders (MiCI). We included CAnine DEmentia Scale (CADES) questionnaires, biochemical parameters, and biomarkers in blood serum, and correlated them with post-mortem histopathological changes. The CADES questionnaires enabled us to identify MiCI dogs developing changes mainly in domains corresponding to social interaction and spatial orientation, which seems to be crucial for delineating early cognitive disorders. Biochemical analyses in these dogs showed slightly elevated liver enzyme parameters (AST and ALT) and significantly decreased sodium and chloride levels in blood serum. Furthermore, we describe for the first time a significant increase of neurofilament light chain (NFL) in blood serum of MiCI dogs, compared to normal aging seniors and young controls, but no changes in TAU protein and amyloid-β (Aβ42) peptide levels. In canine brains with cognitive impairment, amyloid plaques of mainly diffuse and dense types were detected. Furthermore, activated microglia with amoeboid body and dystrophic processes occurred, in some cases with spheroidal and bulbous swellings. On the other hand, no TAU pathology or neurofibrillary tangles were detected. These results suggest that a combination of CADES questionnaire mainly with CNS injury biomarker (NFL) and with biochemical parameters (ALT, AST, Na, and Cl) in blood serum may predict CCDS in senior dogs.
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Affiliation(s)
- Zuzana Vikartovska
- Center for Experimental and Clinical Regenerative Medicine, University of Veterinary Medicine and Pharmacy in Košice, Košice, Slovakia
| | - Jana Farbakova
- Center for Experimental and Clinical Regenerative Medicine, University of Veterinary Medicine and Pharmacy in Košice, Košice, Slovakia
| | - Tomas Smolek
- Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovakia.,Neuroimunology Institute, n.p.o., Bratislava, Slovakia
| | - Jozef Hanes
- Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Norbert Zilka
- Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Lubica Hornakova
- Center for Experimental and Clinical Regenerative Medicine, University of Veterinary Medicine and Pharmacy in Košice, Košice, Slovakia
| | - Filip Humenik
- Center for Experimental and Clinical Regenerative Medicine, University of Veterinary Medicine and Pharmacy in Košice, Košice, Slovakia
| | - Marcela Maloveska
- Center for Experimental and Clinical Regenerative Medicine, University of Veterinary Medicine and Pharmacy in Košice, Košice, Slovakia
| | - Nikola Hudakova
- Center for Experimental and Clinical Regenerative Medicine, University of Veterinary Medicine and Pharmacy in Košice, Košice, Slovakia
| | - Dasa Cizkova
- Center for Experimental and Clinical Regenerative Medicine, University of Veterinary Medicine and Pharmacy in Košice, Košice, Slovakia.,Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovakia
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16
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Vitek MP, Araujo JA, Fossel M, Greenberg BD, Howell GR, Rizzo SJS, Seyfried NT, Tenner AJ, Territo PR, Windisch M, Bain LJ, Ross A, Carrillo MC, Lamb BT, Edelmayer RM. Translational animal models for Alzheimer's disease: An Alzheimer's Association Business Consortium Think Tank. ALZHEIMER'S & DEMENTIA (NEW YORK, N. Y.) 2021; 6:e12114. [PMID: 33457489 PMCID: PMC7798310 DOI: 10.1002/trc2.12114] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 07/04/2020] [Accepted: 07/09/2020] [Indexed: 12/12/2022]
Abstract
Over 5 million Americans and 50 million individuals worldwide are living with Alzheimer's disease (AD). The progressive dementia associated with AD currently has no cure. Although clinical trials in patients are ultimately required to find safe and effective drugs, animal models of AD permit the integration of brain pathologies with learning and memory deficits that are the first step in developing these new drugs. The purpose of the Alzheimer's Association Business Consortium Think Tank meeting was to address the unmet need to improve the discovery and successful development of Alzheimer's therapies. We hypothesize that positive responses to new therapies observed in validated models of AD will provide predictive evidence for positive responses to these same therapies in AD patients. To achieve this goal, we convened a meeting of experts to explore the current state of AD animal models, identify knowledge gaps, and recommend actions for development of next-generation models with better predictability. Among our findings, we all recognize that models reflecting only single aspects of AD pathogenesis do not mimic AD. Models or combinations of new models are needed that incorporate genetics with environmental interactions, timing of disease development, heterogeneous mechanisms and pathways, comorbidities, and other pathologies that lead to AD and related dementias. Selection of the best models requires us to address the following: (1) which animal species, strains, and genetic backgrounds are most appropriate; (2) which models permit efficient use throughout the drug development pipeline; (3) the translatability of behavioral-cognitive assays from animals to patients; and (4) how to match potential AD therapeutics with particular models. Best practice guidelines to improve reproducibility also need to be developed for consistent use of these models in different research settings. To enhance translational predictability, we discuss a multi-model evaluation strategy to de-risk the successful transition of pre-clinical drug assets to the clinic.
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Affiliation(s)
| | | | | | | | | | | | - Nicholas T. Seyfried
- Departments of Biochemistry and NeurologyEmory School of MedicineAtlantaGeorgiaUSA
| | - Andrea J. Tenner
- Department of Molecular Biology and BiochemistryUniversity of CaliforniaIrvineCaliforniaUSA
| | | | | | - Lisa J. Bain
- Independent Science and Medical WriterElversonPennsylvaniaUSA
| | - April Ross
- Former Alzheimer's Association EmployeeChicagoIllinoisUSA
| | | | - Bruce T. Lamb
- Indiana University School of MedicineStark Neurosciences Research InstituteIndianapolisIndianaUSA
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17
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Panek WK, Gruen ME, Murdoch DM, Marek RD, Stachel AF, Mowat FM, Saker KE, Olby NJ. Plasma Neurofilament Light Chain as a Translational Biomarker of Aging and Neurodegeneration in Dogs. Mol Neurobiol 2020; 57:3143-3149. [PMID: 32472519 PMCID: PMC7529326 DOI: 10.1007/s12035-020-01951-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 05/22/2020] [Indexed: 02/07/2023]
Abstract
Age is a primary risk factor for multiple comorbidities including neurodegenerative diseases. Pet dogs and humans represent two populations that have experienced a significant increase in average life expectancy over the last century. A higher prevalence of age-related neurodegenerative diseases has been observed across both species, and human diseases, such as Alzheimer's disease (AD) and amyotrophic lateral sclerosis (ALS), have canine analogs, canine cognitive dysfunction (CCD), and degenerative myelopathy (DM) respectively. In humans, protein biomarkers have proved useful in the prediction and diagnosis of neurodegeneration. Molecular signatures of many proteins are highly conserved across species. In this study, we explored the potential of the neuronal cytoskeletal protein neurofilament light chain (NfL) as a biomarker of neuro-aging in dogs using an ultrasensitive single-molecule array assay to measure plasma concentrations. Healthy dogs of different ages and dogs affected with CCD and DM were evaluated. The mean plasma NfL concentrations in the different age groups of the healthy population were as follows: 4.55 ± 1.70 pg/mL in puppy/junior group (0.43-2 years), 13.51 ± 6.8 pg/mL in adult/mature group (2.1-9 years), and 47.1 ± 12.68 pg/mL in geriatric/senior group (9.3-14.5 years). Concentrations in dogs with DM (7.5-12.6 years) and CCD (11.0-15.6 years) were 84.17 ± 53.57 pg/mL and 100.73 ± 83.72 pg/mL, respectively. Plasma NfL increases in an age-dependent manner and is significantly elevated in dogs diagnosed with neurodegenerative disease. This work identified plasma NfL as a key clinical index of neuro-aging and neurodegeneration in pet dogs. Our findings mirror recent reports from human neurodegenerative diseases.
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Affiliation(s)
- Wojciech K Panek
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Dr., Raleigh, NC, 27607, USA
| | - Margaret E Gruen
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Dr., Raleigh, NC, 27607, USA
| | - David M Murdoch
- Department of Medicine, Duke University Medical Center, Durham, NC, 27710, USA
| | - Robert D Marek
- Department of Medicine, Duke University Medical Center, Durham, NC, 27710, USA
| | - Alexandra F Stachel
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Dr., Raleigh, NC, 27607, USA
| | - Freya M Mowat
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Dr., Raleigh, NC, 27607, USA
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Korinn E Saker
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Dr., Raleigh, NC, 27607, USA
| | - Natasha J Olby
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Dr., Raleigh, NC, 27607, USA.
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18
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Zeiss CJ. Utility of spontaneous animal models of Alzheimer’s disease in preclinical efficacy studies. Cell Tissue Res 2020; 380:273-286. [DOI: 10.1007/s00441-020-03198-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 03/03/2020] [Indexed: 12/14/2022]
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19
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von Rüden EL, Gualtieri F, Schönhoff K, Reiber M, Wolf F, Baumgärtner W, Hansmann F, Tipold A, Potschka H. Molecular alterations of the TLR4-signaling cascade in canine epilepsy. BMC Vet Res 2020; 16:18. [PMID: 31959173 PMCID: PMC6971886 DOI: 10.1186/s12917-020-2241-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 01/10/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Cumulating evidence from rodent models points to a pathophysiological role of inflammatory signaling in the epileptic brain with Toll-like receptor-4 signaling acting as one key factor. However, there is an apparent lack of information about expression alterations affecting this pathway in canine patients with epilepsy. Therefore, we have analyzed the expression pattern of Toll-like receptor 4 and its ligands in brain tissue of canine patients with structural or idiopathic epilepsy in comparison with tissue from laboratory dogs or from owner-kept dogs without neurological diseases. RESULTS The analysis revealed an overexpression of Toll-like receptor-4 in the CA3 region of dogs with structural epilepsy. Further analysis provided evidence for an upregulation of Toll-like receptor-4 ligands with high mobility group box-1 exhibiting increased expression levels in the CA1 region of dogs with idiopathic and structural epilepsy, and heat shock protein 70 exhibiting increased expression levels in the piriform lobe of dogs with idiopathic epilepsy. In further brain regions, receptor and ligand expression rates proved to be either in the control range or reduced below control levels. CONCLUSIONS Our study reveals complex molecular alterations affecting the Toll-like receptor signaling cascade, which differ between epilepsy types and between brain regions. Taken together, the data indicate that multi-targeting approaches modulating Toll-like receptor-4 signaling might be of interest for management of canine epilepsy. Further studies are recommended to explore respective molecular alterations in more detail in dogs with different etiologies and to confirm the role of the pro-inflammatory signaling cascade as a putative target.
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Affiliation(s)
- Eva-Lotta von Rüden
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University (LMU), Königinstr. 16, D-80539, Munich, Germany
| | - Fabio Gualtieri
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University (LMU), Königinstr. 16, D-80539, Munich, Germany
| | - Katharina Schönhoff
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University (LMU), Königinstr. 16, D-80539, Munich, Germany
| | - Maria Reiber
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University (LMU), Königinstr. 16, D-80539, Munich, Germany
| | - Fabio Wolf
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University (LMU), Königinstr. 16, D-80539, Munich, Germany
| | - Wolfgang Baumgärtner
- Department of Pathology, University of Veterinary Medicine Hanover, Buenteweg 17, D-30559, Hanover, Germany
| | - Florian Hansmann
- Department of Pathology, University of Veterinary Medicine Hanover, Buenteweg 17, D-30559, Hanover, Germany
| | - Andrea Tipold
- Clinic for small animals, University of Veterinary Medicine Hanover, Buenteweg 9, D-30559, Hanover, Germany
| | - Heidrun Potschka
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University (LMU), Königinstr. 16, D-80539, Munich, Germany.
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20
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Gardini A, Taeymans O, Cherubini GB, de Stefani A, Targett M, Vettorato E. Linear magnetic resonance imaging measurements of the hippocampal formation differ in young versus old dogs. Vet Rec 2019; 185:306. [PMID: 31308154 PMCID: PMC6817983 DOI: 10.1136/vr.105243] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 06/11/2019] [Accepted: 06/23/2019] [Indexed: 12/13/2022]
Abstract
Age-related hippocampal formation (HF) atrophy has been documented on MRI studies using volumetric analysis and visual rating scales. This retrospective cross-sectional study aimed to compare linear MRI measurements of the HF between young (1–3 years) and old (>10 years) non-brachycephalic dogs, with normal brain anatomy and cerebrospinal fluid (CSF) analysis. Right and left hippocampal formation height (HFH), height of the brain (HB) and mean HFH/HB ratio were measured by two observers on a transverse T2 fluid-attenuated inversion recovery sequence containing rostral colliculi and mesencephalic aqueduct.119 MRI studies were enrolled: 75 young and 44 old dogs. Left and right HFH were greater (p<0.0001) in young, while HB was greater in old dogs (p=0.024). Mean HFH/HB ratio was 15.66 per cent and 18.30 per cent in old and young dogs (p<0.0001). No differences were found comparing measurements between epileptic and non-epileptic dogs. Old dogs have a greater HB; this may represent the different study populations or a statistical phenomenon. Ageing affects HF linear measurements. A reduction of mean HFH/HB ratio between 18.30 per cent and 15.66 per cent should be considered a physiological age-related process of the canine lifespan. The use of mean HFH/HB ratio could be considered for quantifying brain atrophy in elderly dogs.
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Affiliation(s)
- Anna Gardini
- Department of Neurology and Neurosurgery, Dick White Referrals, Six Mile Bottom, UK
| | - Olivier Taeymans
- Department of Diagnostic Imaging, Dick White Referrals, Six Mile Bottom, UK
| | | | - Alberta de Stefani
- Department of Neurology and Neurosurgery, Royal Veterinary College, London, UK
| | - Mike Targett
- Department of Neurology and Neurosurgery, University of Nottingham, Loughborough, UK
| | - Enzo Vettorato
- Department of Anaesthesia and Analgesia, Dick White Referrals, Six Mile Bottom, UK
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21
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Pero ME, Cortese L, Mastellone V, Tudisco R, Musco N, Scandurra A, D'Aniello B, Vassalotti G, Bartolini F, Lombardi P. Effects of a Nutritional Supplement on Cognitive Function in Aged Dogs and on Synaptic Function of Primary Cultured Neurons. Animals (Basel) 2019; 9:ani9070393. [PMID: 31252640 PMCID: PMC6680659 DOI: 10.3390/ani9070393] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 06/10/2019] [Accepted: 06/25/2019] [Indexed: 11/16/2022] Open
Abstract
Simple Summary We tested the effects of a nutraceutical product, DiSeniorTM, by spatial navigation test and by in vitro and in vivo experiments. Results showed that DiSeniorTM was safe and able to ameliorate cognitive functions in aged dogs, as demonstrated by the better performances in the treated with respect the untreated groups. The increase of cFOS, a functional marker of activity in cultured neurons, indicated a positive effect of the substance on neuronal functions. The study suggests that DiSeniorTM can improve the quality of life of elderly dogs and may slow the onset of cognitive dysfunction symptoms associated with aging. Abstract The objective of this research was to investigate the efficacy of DìSeniorTM, a nutraceutical formulated to improve cognitive functions in elderly dogs. To this purpose, some clinical and metabolic investigations and a spatial navigation test were performed in treated and untreated dogs. Moreover, the nutraceutical was also tested on primary hippocampal neuron cultures. Results showed no adverse effects on the dogs’ health and a positive effect on learning. In vitro effects on neuron cultures showed an increase in the level of cFOS in treated neurons compared with the vehicle, suggesting that DiSeniorTM has also a positive effect on neuronal functions. Overall, this study suggests that DiSeniorTM can exert a beneficial effect on aged dogs by preventing the negative effects of aging on cognition. Further studies are needed to assess the mechanisms by which it acts on neurons and the specific effect of the different components alone or combined.
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Affiliation(s)
- Maria Elena Pero
- Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, Via Delpino 1, 80137 Naples, Italy
- Department of Pathology, Anatomy and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Laura Cortese
- Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, Via Delpino 1, 80137 Naples, Italy
| | - Vincenzo Mastellone
- Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, Via Delpino 1, 80137 Naples, Italy
| | - Raffaella Tudisco
- Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, Via Delpino 1, 80137 Naples, Italy
| | - Nadia Musco
- Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, Via Delpino 1, 80137 Naples, Italy
| | - Anna Scandurra
- Department of Biology, University of Naples Federico II, Via Cinthia 21, 80126 Naples, Italy.
| | - Biagio D'Aniello
- Department of Biology, University of Naples Federico II, Via Cinthia 21, 80126 Naples, Italy
| | - Giuseppe Vassalotti
- Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, Via Delpino 1, 80137 Naples, Italy
| | - Francesca Bartolini
- Department of Pathology, Anatomy and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Pietro Lombardi
- Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, Via Delpino 1, 80137 Naples, Italy
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22
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Prpar Mihevc S, Majdič G. Canine Cognitive Dysfunction and Alzheimer's Disease - Two Facets of the Same Disease? Front Neurosci 2019; 13:604. [PMID: 31249505 PMCID: PMC6582309 DOI: 10.3389/fnins.2019.00604] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Accepted: 05/27/2019] [Indexed: 12/13/2022] Open
Abstract
Neurodegenerative diseases present a major and increasing burden in the societies worldwide. With aging populations, the prevalence of neurodegenerative diseases is increasing, yet there are no effective cures and very few treatment options are available. Alzheimer's disease is one of the most prevalent neurodegenerative conditions and although the pathology is well studied, the pathogenesis of this debilitating illness is still poorly understood. This is, among other reasons, also due to the lack of good animal models as laboratory rodents do not develop spontaneous neurodegenerative diseases and human Alzheimer's disease is only partially mimicked by transgenic rodent models. On the other hand, older dogs commonly develop canine cognitive dysfunction, a disease that is similar to Alzheimer's disease in many aspects. Dogs show cognitive deficits that could be paralleled to human symptoms such as disorientation, memory loss, changes in behavior, and in their brains, beta amyloid plaques are commonly detected both in extracellular space as senile plaques and around the blood vessels. Dogs could be therefore potentially a very good model for studying pathological process and novel treatment options for Alzheimer's disease. In the present article, we will review the current knowledge about the pathogenesis of canine cognitive dysfunction, its similarities and dissimilarities with Alzheimer's disease, and developments of novel treatments for these two diseases with a focus on canine cognitive dysfunction.
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Affiliation(s)
- Sonja Prpar Mihevc
- Veterinary Faculty, Institute for Preclinical Sciences, University of Ljubljana, Ljubljana, Slovenia
| | - Gregor Majdič
- Veterinary Faculty, Institute for Preclinical Sciences, University of Ljubljana, Ljubljana, Slovenia
- Medical Faculty, Institute for Physiology, University of Maribor, Maribor, Slovenia
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23
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Effect of age on discrimination learning, reversal learning, and cognitive bias in family dogs. Learn Behav 2019; 46:537-553. [PMID: 30251103 DOI: 10.3758/s13420-018-0357-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Several studies on age-related cognitive decline in dogs involve laboratory dogs and prolonged training. We developed two spatial tasks that required a single 1-h session. We tested 107 medium-large sized dogs: "young" (N=41, aged 2.5-6.5 years) and "old" (N=66, aged 8-14.5 years). Our results indicated that, in a discrimination learning task and in a reversal learning task, young dogs learned significantly faster than the old dogs, indicating that these two tasks could successfully be used to investigate differences in spatial learning between young and old dogs. We also provide two novel findings. First, in the reversal learning, the dogs trained based on the location of stimuli learned faster than the dogs trained based on stimulus characteristics. Most old dogs did not learn the task within our cut-off of 50 trials. Training based on an object's location is therefore more appropriate for reversal learning tasks. Second, the contrast between the response to the positive and negative stimuli was narrower in old dogs, compared to young dogs, during the reversal learning task, as well as the cognitive bias test. This measure favors comparability between tasks and between studies. Following the cognitive bias test, we could not find any indication of differences in the positive and negative expectations between young and old dogs. Taken together, these findings do not support the hypothesis that old dogs have more negative expectations than young dogs and the use of the cognitive bias test in older dogs requires further investigation.
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Biochemical deficits and cognitive decline in brain aging: Intervention by dietary supplements. J Chem Neuroanat 2019; 95:70-80. [DOI: 10.1016/j.jchemneu.2018.04.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 02/28/2018] [Accepted: 04/13/2018] [Indexed: 01/23/2023]
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Hadley KB, Bauer J, Milgram NW. The oil-rich alga Schizochytrium sp. as a dietary source of docosahexaenoic acid improves shape discrimination learning associated with visual processing in a canine model of senescence. Prostaglandins Leukot Essent Fatty Acids 2017; 118:10-18. [PMID: 28288702 DOI: 10.1016/j.plefa.2017.01.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 12/07/2016] [Accepted: 01/24/2017] [Indexed: 12/22/2022]
Abstract
Whole cell Schizochytrium sp. is a rich source of omega-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA) including docosahexaenoic acid (DHA), an important nutrient for brain health. Aged beagle dogs experienced on a visuospatial task of working memory, variable-delay delayed-non-matching-to-position were used to assess efficacy of DHA-rich microalgae based upon DHA wt% of total phospholipids and 8-iso-PGF2α concentrations in plasma, and performance on cognitive assessments of visual object discrimination, learning, and memory consolidation after 25 weeks on fortified diet. Improved DHA status (p<0.001) and initial learning of the protocols for visual and variable contrast discrimination (p<0.05), but not long-term recall of the concurrent discrimination task were observed in animals fed the algal-fortified diet. Overall, results were consistent with dried Schizochytrium sp. as a source of n-3 LCPUFA nutrition to support DHA status in large mammals, and healthy brain function in a canine model of senescence.
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Affiliation(s)
- K B Hadley
- Clinical Research Department, DSM Nutritional Products, Columbia, MD 21045, USA.
| | - J Bauer
- Clinical Research Department, DSM Nutritional Products, Columbia, MD 21045, USA
| | - N W Milgram
- Clinical Research Department, DSM Nutritional Products, Columbia, MD 21045, USA
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Schütt T, Helboe L, Pedersen LØ, Waldemar G, Berendt M, Pedersen JT. Dogs with Cognitive Dysfunction as a Spontaneous Model for Early Alzheimer's Disease: A Translational Study of Neuropathological and Inflammatory Markers. J Alzheimers Dis 2017; 52:433-49. [PMID: 27003213 DOI: 10.3233/jad-151085] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Aged companion dogs with canine cognitive dysfunction (CCD) spontaneously develop varying degrees of progressive cognitive decline and particular neuropathological features correspondent to the changes associated with Alzheimer's disease (AD) in humans. The aim of the present study was to characterize certain aspects of neuropathology and inflammatory markers related to aging and CCD in dogs in comparison with human AD. Fifteen brains from aged dogs with normal cognitive function, mild cognitive impairment, or CCD were investigated and compared with two control brains from young dogs and brain sections from human AD subjects. The neuropathological investigations included evaluation of amyloid-β (Aβ) plaque deposition (N-terminally truncated and pyroglutamyl-modified Aβ included), tau pathology, and inflammatory markers in prefrontal cortex. Cortical Aβ deposition was found to be only of the diffuse subtype as no dense-core or neuritic plaques were found. The Aβ deposition followed a progressive pattern in four maturation stages. Accumulation of the Aβ peptide was also observed in the vessel walls. Both immunohistochemically and biochemically measured levels of Aβ pathology in prefrontal cortex showed a consistent positive correlation to age but not to cognitive deficit severity. No evidence of neurofibrillary tau pathology was found. The level of pro-inflammatory cytokines was generally low and showed no significant association to cognitive status. The findings of the present study support the senescent dog with spontaneous cognitive dysfunction as a valuable non-transgenic model for further investigations of the molecular events involved in the neurodegenerative processes associated with aging and early stage AD, especially the Aβ-related pathology.
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Affiliation(s)
- Trine Schütt
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.,Department of Neurodegeneration, H. Lundbeck A/S, Valby, Denmark
| | - Lone Helboe
- Department of Neurodegeneration, H. Lundbeck A/S, Valby, Denmark
| | | | - Gunhild Waldemar
- Danish Dementia Research Centre, Rigshospitalet, University of Copenhagen, Denmark
| | - Mette Berendt
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
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Davis PR, Giannini G, Rudolph K, Calloway N, Royer CM, Beckett TL, Murphy MP, Bresch F, Pagani D, Platt T, Wang X, Donovan AS, Sudduth TL, Lou W, Abner E, Kryscio R, Wilcock DM, Barrett EG, Head E. Aβ vaccination in combination with behavioral enrichment in aged beagles: effects on cognition, Aβ, and microhemorrhages. Neurobiol Aging 2016; 49:86-99. [PMID: 27776266 DOI: 10.1016/j.neurobiolaging.2016.09.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 09/08/2016] [Accepted: 09/15/2016] [Indexed: 11/30/2022]
Abstract
Beta-amyloid (Aβ) immunotherapy is a promising intervention to slow Alzheimer's disease. Aging dogs naturally accumulate Aβ and show cognitive decline. An active vaccine against fibrillar Aβ 1-42 (VAC) in aged beagles resulted in maintenance but not improvement of cognition along with reduced brain Aβ. Behavioral enrichment (ENR) led to cognitive benefits but no reduction in Aβ. We hypothesized cognitive outcomes could be improved by combining VAC with ENR in aged dogs. Aged dogs (11-12 years) were placed into 4 groups: (1) control/control (C/C); (2) control/VAC (C/V); (3) ENR/control (E/C); and (4) ENR/VAC (E/V) and treated for 20 months. VAC decreased brain Aβ, pyroglutamate Aβ, increased cerebrospinal fluid Aβ 42 and brain-derived neurotrophic factor RNA levels but also increased microhemorrhages. ENR reduced brain Aβ and prevented microhemorrhages. The combination treatment resulted in a significant maintenance of learning over time, reduced Aβ, and increased brain-derived neurotrophic factor mRNA despite increased microhemorrhages; however, there were no benefits to memory. These results suggest that the combination of immunotherapy with behavioral enrichment leads to cognitive maintenance associated with reduced neuropathology that may benefit people with Alzheimer's disease.
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Affiliation(s)
- Paulina R Davis
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA; Department of Pharmacology & Nutritional Sciences, University of Kentucky, Lexington, KY, USA
| | | | - Karin Rudolph
- Lovelace Respiratory Research Institute, Albuquerque, NM, USA
| | - Nathaniel Calloway
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | | | - Tina L Beckett
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - M Paul Murphy
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA; Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | - Frederick Bresch
- Metacog Testing Systems, New Westminster, British Columbia, Canada
| | | | - Thomas Platt
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA; Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | - Xiaohong Wang
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | | | - Tiffany L Sudduth
- Department of Physiology, University of Kentucky, Lexington, KY, USA
| | - Wenjie Lou
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Erin Abner
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Richard Kryscio
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Donna M Wilcock
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA; Department of Physiology, University of Kentucky, Lexington, KY, USA
| | | | - Elizabeth Head
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA; Department of Pharmacology & Nutritional Sciences, University of Kentucky, Lexington, KY, USA.
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van Dijk RM, Huang SH, Slomianka L, Amrein I. Taxonomic Separation of Hippocampal Networks: Principal Cell Populations and Adult Neurogenesis. Front Neuroanat 2016; 10:22. [PMID: 27013984 PMCID: PMC4783399 DOI: 10.3389/fnana.2016.00022] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 02/23/2016] [Indexed: 11/13/2022] Open
Abstract
While many differences in hippocampal anatomy have been described between species, it is typically not clear if they are specific to a particular species and related to functional requirements or if they are shared by species of larger taxonomic units. Without such information, it is difficult to infer how anatomical differences may impact on hippocampal function, because multiple taxonomic levels need to be considered to associate behavioral and anatomical changes. To provide information on anatomical changes within and across taxonomic ranks, we present a quantitative assessment of hippocampal principal cell populations in 20 species or strain groups, with emphasis on rodents, the taxonomic group that provides most animals used in laboratory research. Of special interest is the importance of adult hippocampal neurogenesis (AHN) in species-specific adaptations relative to other cell populations. Correspondence analysis of cell numbers shows that across taxonomic units, phylogenetically related species cluster together, sharing similar proportions of principal cell populations. CA3 and hilus are strong separators that place rodent species into a tight cluster based on their relatively large CA3 and small hilus while non-rodent species (including humans and non-human primates) are placed on the opposite side of the spectrum. Hilus and CA3 are also separators within rodents, with a very large CA3 and rather small hilar cell populations separating mole-rats from other rodents that, in turn, are separated from each other by smaller changes in the proportions of CA1 and granule cells. When adult neurogenesis is included, the relatively small populations of young neurons, proliferating cells and hilar neurons become main drivers of taxonomic separation within rodents. The observations provide challenges to the computational modeling of hippocampal function, suggest differences in the organization of hippocampal information streams in rodent and non-rodent species, and support emerging concepts of functional and structural interactions between CA3 and the dentate gyrus.
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Affiliation(s)
- R Maarten van Dijk
- Functional Neuroanatomy, Institute of Anatomy, University of ZürichZurich, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH ZurichZürich, Switzerland; Department of Health Sciences and Technology, Institute of Human Movement Sciences and Sport, ETH ZurichZürich, Switzerland
| | - Shih-Hui Huang
- Functional Neuroanatomy, Institute of Anatomy, University of ZürichZurich, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH ZurichZürich, Switzerland; Department of Health Sciences and Technology, Institute of Human Movement Sciences and Sport, ETH ZurichZürich, Switzerland
| | - Lutz Slomianka
- Functional Neuroanatomy, Institute of Anatomy, University of Zürich Zurich, Switzerland
| | - Irmgard Amrein
- Functional Neuroanatomy, Institute of Anatomy, University of ZürichZurich, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH ZurichZürich, Switzerland
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Youssef SA, Capucchio MT, Rofina JE, Chambers JK, Uchida K, Nakayama H, Head E. Pathology of the Aging Brain in Domestic and Laboratory Animals, and Animal Models of Human Neurodegenerative Diseases. Vet Pathol 2016; 53:327-48. [DOI: 10.1177/0300985815623997] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
According to the WHO, the proportion of people over 60 years is increasing and expected to reach 22% of total world’s population in 2050. In parallel, recent animal demographic studies have shown that the life expectancy of pet dogs and cats is increasing. Brain aging is associated not only with molecular and morphological changes but also leads to different degrees of behavioral and cognitive dysfunction. Common age-related brain lesions in humans include brain atrophy, neuronal loss, amyloid plaques, cerebrovascular amyloid angiopathy, vascular mineralization, neurofibrillary tangles, meningeal osseous metaplasia, and accumulation of lipofuscin. In aging humans, the most common neurodegenerative disorder is Alzheimer’s disease (AD), which progressively impairs cognition, behavior, and quality of life. Pathologic changes comparable to the lesions of AD are described in several other animal species, although their clinical significance and effect on cognitive function are poorly documented. This review describes the commonly reported age-associated neurologic lesions in domestic and laboratory animals and the relationship of these lesions to cognitive dysfunction. Also described are the comparative interspecies similarities and differences to AD and other human neurodegenerative diseases including Parkinson’s disease and progressive supranuclear palsy, and the spontaneous and transgenic animal models of these diseases.
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Affiliation(s)
- S. A. Youssef
- Department of Pathobiology, Dutch Molecular Pathology Center, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - M. T. Capucchio
- Department of Veterinary Sciences, Torino University, Torino, Italy
| | - J. E. Rofina
- Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - J. K. Chambers
- Department of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - K. Uchida
- Department of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - H. Nakayama
- Department of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - E. Head
- Sanders Brown Center on Aging, Pharmacology & Nutritional Sciences, University of Kentucky, Lexington, UK, USA
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Chambers JK, Tokuda T, Uchida K, Ishii R, Tatebe H, Takahashi E, Tomiyama T, Une Y, Nakayama H. The domestic cat as a natural animal model of Alzheimer's disease. Acta Neuropathol Commun 2015; 3:78. [PMID: 26651821 PMCID: PMC4674944 DOI: 10.1186/s40478-015-0258-3] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 11/19/2015] [Indexed: 12/27/2022] Open
Abstract
Introduction Alzheimer’s disease (AD) is the most dominant neurodegenerative disorder that causes dementia, and no effective treatments are available. To study its pathogenesis and develop therapeutics, animal models representing its pathologies are needed. Although many animal species develop senile plaques (SP) composed of amyloid-β (Aβ) proteins that are identical to those found in humans, none of them exhibit neurofibrillary tangles (NFT) and subsequent neurodegeneration, which are integral parts of the pathology of AD. Results The present study shows that Aβ accumulation, NFT formation, and significant neuronal loss all emerge naturally in the hippocampi of aged domestic cats. The NFT that form in the cat brain are identical to those seen in human AD in terms of their spatial distribution, the cells they affect, and the tau isoforms that comprise them. Interestingly, aged cats do not develop mature argyrophilic SP, but instead accumulate intraneuronal Aβ oligomers in their hippocampal pyramidal cells, which might be due to the amino acid sequence of felid Aβ. Conclusions These results suggest that Aβ oligomers are more important than SP for NFT formation and the subsequent neurodegeneration. The domestic cat is a unique animal species that naturally replicates various AD pathologies, especially Aβ oligomer accumulation, NFT formation, and neuronal loss. Electronic supplementary material The online version of this article (doi:10.1186/s40478-015-0258-3) contains supplementary material, which is available to authorized users.
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Smolek T, Madari A, Farbakova J, Kandrac O, Jadhav S, Cente M, Brezovakova V, Novak M, Zilka N. Tau hyperphosphorylation in synaptosomes and neuroinflammation are associated with canine cognitive impairment. J Comp Neurol 2015; 524:874-95. [PMID: 26239295 DOI: 10.1002/cne.23877] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 07/28/2015] [Accepted: 07/30/2015] [Indexed: 12/24/2022]
Abstract
Canine cognitive impairment syndrome (CDS) represents a group of symptoms related to the aging of the canine brain. These changes ultimately lead to a decline of memory function and learning abilities, alteration of social interaction, impairment of normal housetraining, and changes in sleep-wake cycle and general activity. We have clinically examined 215 dogs, 28 of which underwent autopsy. With canine brains, we performed extensive analysis of pathological abnormalities characteristic of human Alzheimer's disease and frontotemporal lobar degeneration, including β-amyloid senile plaques, tau neurofibrillary tangles, and fused in sarcoma (FUS) and TAR DNA-binding protein 43 (TDP43) inclusions. Most demented dogs displayed senile plaques, mainly in the frontal and temporal cortex. Tau neurofibrillary inclusions were found in only one dog. They were identified with antibodies used to detect tau neurofibrillary lesions in the human brain. The inclusions were also positive for Gallyas silver staining. As in humans, they were distributed mainly in the entorhinal cortex, hippocampus, and temporal cortex. On the other hand, FUS and TDP43 aggregates were not present in any of the examined brain samples. We also found that CDS was characterized by the presence of reactive and senescent microglial cells in the frontal cortex. Our transcriptomic study revealed a significant dysregulation of genes involved in neuroinflammation. Finally, we analyzed tau phosphoproteome in the synaptosomes. Proteomic studies revealed a significant increase of hyperphosphorylated tau in synaptosomes of demented dogs compared with nondemented dogs. This study suggests that cognitive decline in dogs is related to the tau synaptic impairment and neuroinflammation. J. Comp. Neurol. 524:874-895, 2016. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Tomas Smolek
- Institute of Neuroimmunology, Slovak Academy of Sciences, 845 10, Bratislava, Slovak Republic
| | - Aladar Madari
- University of Veterinary Medicine and Pharmacy, 040 01, Kosice, Slovak Republic
| | - Jana Farbakova
- University of Veterinary Medicine and Pharmacy, 040 01, Kosice, Slovak Republic
| | - Ondrej Kandrac
- University of Veterinary Medicine and Pharmacy, 040 01, Kosice, Slovak Republic
| | - Santosh Jadhav
- Institute of Neuroimmunology, Slovak Academy of Sciences, 845 10, Bratislava, Slovak Republic
| | - Martin Cente
- Institute of Neuroimmunology, Slovak Academy of Sciences, 845 10, Bratislava, Slovak Republic.,Axon Neuroscience SE, 811 02, Bratislava, Slovak Republic
| | - Veronika Brezovakova
- Institute of Neuroimmunology, Slovak Academy of Sciences, 845 10, Bratislava, Slovak Republic
| | - Michal Novak
- Institute of Neuroimmunology, Slovak Academy of Sciences, 845 10, Bratislava, Slovak Republic.,Axon Neuroscience SE, 811 02, Bratislava, Slovak Republic
| | - Norbert Zilka
- Institute of Neuroimmunology, Slovak Academy of Sciences, 845 10, Bratislava, Slovak Republic.,Axon Neuroscience SE, 811 02, Bratislava, Slovak Republic.,Institute of Neuroimmunology, n.o., 811 02, Bratislava, Slovak Republic
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Impact of the Baltimore Experience Corps Trial on cortical and hippocampal volumes. Alzheimers Dement 2015; 11:1340-8. [PMID: 25835516 DOI: 10.1016/j.jalz.2014.12.005] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 12/07/2014] [Accepted: 12/10/2014] [Indexed: 11/24/2022]
Abstract
INTRODUCTION There is a substantial interest in identifying interventions that can protect and buffer older adults from atrophy in the cortex and particularly, the hippocampus, a region important to memory. We report the 2-year effects of a randomized controlled trial of an intergenerational social health promotion program on older men's and women's brain volumes. METHODS The Brain Health Study simultaneously enrolled, evaluated, and randomized 111 men and women (58 interventions; 53 controls) within the Baltimore Experience Corps Trial to evaluate the intervention impact on biomarkers of brain health at baseline and annual follow-ups during the 2-year trial exposure. RESULTS Intention-to-treat analyses on cortical and hippocampal volumes for full and sex-stratified samples revealed program-specific increases in volumes that reached significance in men only (P's ≤ .04). Although men in the control arm exhibited age-related declines for 2 years, men in the Experience Corps arm showed a 0.7% to 1.6% increase in brain volumes. Women also exhibited modest intervention-specific gains of 0.3% to 0.54% by the second year of exposure that contrasted with declines of about 1% among women in the control group. DISCUSSION These findings showed that purposeful activity embedded within a social health promotion program halted and, in men, reversed declines in brain volume in regions vulnerable to dementia. CLINICAL TRIAL REGISTRATION NCT0038.
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Olaleye OO, Ihunwo AO. Adult neurogenesis in the four-striped mice (Rhabdomys pumilio). Neural Regen Res 2015; 9:1907-11. [PMID: 25558241 PMCID: PMC4281430 DOI: 10.4103/1673-5374.143435] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/04/2014] [Indexed: 11/06/2022] Open
Abstract
In this study, we investigated non-captive four-striped mice (Rhabdomys pumilio) for evidence that adult neurogenesis occurs in the adult brain of animal models in natural environment. Ki-67 (a marker for cell proliferation) and doublecortin (a marker for immature neurons) immunostaining confirmed that adult neurogenesis occurs in the active sites of subventricular zone of the lateral ventricle with the migratory stream to the olfactory bulb, and the subgranular zone of the dentate gyrus of the hippocampus. No Ki-67 proliferating cells were observed in the striatum substantia nigra, amygdala, cerebral cortex or dorsal vagal complex. Doublecortin-immunoreactive cells were observed in the striatum, third ventricle, cerebral cortex, amygdala, olfactory bulb and along the rostral migratory stream but absent in the substantia nigra and dorsal vagal complex. The potential neurogenic sites in the four-striped mouse species could invariably lead to increased neural plasticity.
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Affiliation(s)
- Olatunbosun O Olaleye
- Department of Oral Biological Sciences, School of Oral Health Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa ; School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Amadi O Ihunwo
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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Abstract
Aging dogs and cats show neurodegenerative features that are similar to human aging and Alzheimer disease. Neuropathologic changes with age may be linked to signs of cognitive dysfunction both in the laboratory and in a clinic setting. Less is known about cat brain aging and cognition and this represents an area for further study. Neurodegenerative diseases such as lysosomal storage diseases in dogs and cats also show similar features of human aging, suggesting some common underlying pathogenic mechanisms and also suggesting pathways that can be modified to promote healthy brain aging.
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Affiliation(s)
- Charles H Vite
- Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Section of Neurology & Neurosurgery, Department of Clinical Studies - Philadelphia, 3900 Delancey Street, Philadelphia, PA 19104, USA
| | - Elizabeth Head
- Department of Pharmacology & Nutritional Sciences, Sanders-Brown Center on Aging, University of Kentucky, 800 South Limestone Street, 203 Sanders Brown Building, Lexington, KY 40515, USA.
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Finch CE, Austad SN. Commentary: is Alzheimer's disease uniquely human? Neurobiol Aging 2014; 36:553-5. [PMID: 25533426 DOI: 10.1016/j.neurobiolaging.2014.10.025] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 10/16/2014] [Indexed: 11/17/2022]
Abstract
That Alzheimer's disease (AD) might be a human-specific disease was hypothesized by Rapoport in 1989. Apes and humans share an identical amyloid beta (Aβ) peptide amino acid sequence and accumulate considerable Aβ deposits after age 40 years, an age when amyloid plaques are uncommon in humans. Despite their early Aβ buildup, ape brains have not shown evidence dystrophic neurites near plaques. Aging great ape brains also have few neurofibrillary tangles, with one exception of 1 obese chimpanzee euthanized after a stroke who displayed abundant neurofibrillary tangles, but without the typical AD distribution. We discuss the need for more exacting evaluation of neuron density with age, and note husbandry issues that may allow great apes to live to greater ages. We remain reserved about expectations for fully developed AD-like pathology in the great apes of advanced ages and cautiously support Rapoport's hypothesis.
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Affiliation(s)
- Caleb E Finch
- Davis School of Gerontology and Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA.
| | - Steven N Austad
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL, USA
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Effect of Resveratrol as Caloric Restriction Mimetic and Environmental Enrichment on Neurobehavioural Responses in Young Healthy Mice. ACTA ACUST UNITED AC 2014. [DOI: 10.1155/2014/545170] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Caloric restriction and environmental enrichment have been separately reported to possess health benefits such as improvement in motor and cognitive functions. Resveratrol, a natural polyphenolic compound, has been reported to be caloric restriction mimetic. This study therefore aims to investigate the potential benefit of the combination of resveratrol as CR and EE on learning and memory, motor coordination, and motor endurance in young healthy mice. Fifty mice of both sexes were randomly divided into five groups of 10 animals each: group I animals received carboxymethylcellulose (CMC) orally per kg/day (control), group II animals were maintained on every other day feeding, group III animals received resveratrol 50 mg/kg, suspended in 10 g/L of (CMC) orally per kg/day, group IV animals received CMC and were kept in an enriched environment, and group V animals received resveratrol 50 mg/kg and were kept in EE. The treatment lasted for four weeks. On days 26, 27, and 28 of the study period, the animals were subjected to neurobehavioural evaluation. The results obtained showed that there was no significant change (P>0.05) in neurobehavioural responses in all the groups when compared to the control which indicates that 50 mg/kg of resveratrol administration and EE have no significant effects on neurobehavioural responses in young healthy mice over a period of four weeks.
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Davis PR, Head E. Prevention approaches in a preclinical canine model of Alzheimer's disease: benefits and challenges. Front Pharmacol 2014; 5:47. [PMID: 24711794 PMCID: PMC3968758 DOI: 10.3389/fphar.2014.00047] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 02/28/2014] [Indexed: 12/30/2022] Open
Abstract
Aged dogs spontaneously develop many features of human aging and Alzheimer's disease (AD) including cognitive decline and neuropathology. In this review, we discuss age-dependent learning tasks, memory tasks, and functional measures that can be used in aged dogs for sensitive treatment outcome measures. Neuropathology that is linked to cognitive decline is described along with examples of treatment studies that show reduced neuropathology in aging dogs (dietary manipulations, behavioral enrichment, immunotherapy, and statins). Studies in canine show that multi-targeted approaches may be more beneficial than single pathway manipulations (e.g., antioxidants combined with behavioral enrichment). Aging canine studies show good predictive validity for human clinical trials outcomes (e.g., immunotherapy) and several interventions tested in dogs strongly support a prevention approach (e.g., immunotherapy and statins). Further, dogs are ideally suited for prevention studies as they the age because onset of cognitive decline and neuropathology strongly support longitudinal interventions that can be completed within a 3-5 year period. Disadvantages to using the canine model are that they lengthy, use labor-intensive comprehensive cognitive testing, and involve costly housing (almost as high as that of non-human primates). However, overall, using the dog as a preclinical model for testing preventive approaches for AD may complement work in rodents and non-human primates.
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Affiliation(s)
- Paulina R Davis
- Sanders-Brown Center on Aging, University of Kentucky Lexington, KY, USA ; Department of Molecular and Biomedical Pharmacology, University of Kentucky Lexington, KY, USA
| | - Elizabeth Head
- Sanders-Brown Center on Aging, University of Kentucky Lexington, KY, USA ; Department of Molecular and Biomedical Pharmacology, University of Kentucky Lexington, KY, USA
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Lee GS, Jeong YW, Kim JJ, Park SW, Ko KH, Kang M, Kim YK, Jung EM, Moon C, Hyun SH, Hwang KC, Kim NH, Shin T, Jeung EB, Hwang WS. A canine model of Alzheimer's disease generated by overexpressing a mutated human amyloid precursor protein. Int J Mol Med 2014; 33:1003-12. [PMID: 24481173 DOI: 10.3892/ijmm.2014.1636] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 01/22/2014] [Indexed: 11/06/2022] Open
Abstract
Canines are considered the most authentic model for studying multifactorial human diseases, as these animals typically share a common environment with man. Somatic cell nuclear transfer (SCNT) technology along with genetic engineering of nuclear donor cells provides a unique opportunity for examining human diseases using transgenic canines. In the present study, we generated transgenic canines that overexpressed the human amyloid precursor protein (APP) gene containing well-characterized familial Alzheimer's disease (AD) mutations. We successfully obtained five out of six live puppies by SCNT. This was confirmed by observing the expression of green fluorescence protein in the body as a visual transgenic marker and the overexpression of the mutated APP gene in the brain. The transgenic canines developed AD-like symptoms, such as enlarged ventricles, an atrophied hippocampus, and β-amyloid plaques in the brain. Thus, the transgenic canines we created can serve as a novel animal model for studying human AD.
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Affiliation(s)
- Geun-Shik Lee
- College of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, Chucheon, Gangwon 200‑701, Republic of Korea
| | - Yeon Woo Jeong
- SooAm Biotech Research Foundation, Seoul 152-904, Republic of Korea
| | - Joung Joo Kim
- SooAm Biotech Research Foundation, Seoul 152-904, Republic of Korea
| | - Sun Woo Park
- SooAm Biotech Research Foundation, Seoul 152-904, Republic of Korea
| | - Kyeong Hee Ko
- SooAm Biotech Research Foundation, Seoul 152-904, Republic of Korea
| | - Mina Kang
- SooAm Biotech Research Foundation, Seoul 152-904, Republic of Korea
| | - Yu Kyung Kim
- SooAm Biotech Research Foundation, Seoul 152-904, Republic of Korea
| | - Eui-Man Jung
- Laboratory of Veterinary Biochemistry and Molecular Biology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea
| | - Changjong Moon
- Department of Veterinary Anatomy, College of Veterinary Medical Institute, Chonnam National University, Gwangju, Gyeonggi 500-757, Republic of Korea
| | - Sang Hwan Hyun
- Laboratory of Veterinary Embryology and Biotechnology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea
| | - Kyu-Chan Hwang
- SooAm Biotech Research Foundation, Seoul 152-904, Republic of Korea
| | - Nam-Hyung Kim
- Department of Animal Science, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea
| | - Taeyoung Shin
- SooAm Biotech Research Foundation, Seoul 152-904, Republic of Korea
| | - Eui-Bae Jeung
- Laboratory of Veterinary Biochemistry and Molecular Biology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea
| | - Woo Suk Hwang
- SooAm Biotech Research Foundation, Seoul 152-904, Republic of Korea
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Neprilysin is poorly expressed in the prefrontal cortex of aged dogs with cognitive dysfunction syndrome. Int J Alzheimers Dis 2014; 2014:483281. [PMID: 24511411 PMCID: PMC3912887 DOI: 10.1155/2014/483281] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 12/16/2013] [Accepted: 12/21/2013] [Indexed: 12/16/2022] Open
Abstract
Neprilysin (NEP) is the principal amyloid β (A β ) degrading peptidase; this activity may protect against Alzheimer's disease (AD), the most important age-related neurodegenerative process. The aim of this work was to analyze NEP mRNA expression in the frontal cortex of dogs with and without canine cognitive dysfunction syndrome (CDS), which is considered a natural model for AD. Expression of canine cerebral NEP mRNA was assessed by RT-PCR followed by qPCR in young, aged-cognitively unimpaired (CU), and aged-cognitively impaired (CI) dogs. On average, aged-CI dogs showed 80% (P < 0.01) lower expression levels of NEP mRNA than their aged-CU counterparts. Furthermore, the standard deviation of the qPCR measurements was more than 6 times higher in the cognitively healthy animals (young and aged-CU) than in the aged-CI group. Another interesting find is the determination of a positive correlation between NEP expression and the number of cholinergic neurons in basal telencephalon, indicating a probable connection between both events in these types of neurodegeneration processes. These results suggest that high expression levels of NEP might be a protective factor for canine CDS and, most likely, for other A β -associated neurodegenerative diseases, such as AD.
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Mongillo P, Araujo JA, Pitteri E, Carnier P, Adamelli S, Regolin L, Marinelli L. Spatial reversal learning is impaired by age in pet dogs. AGE (DORDRECHT, NETHERLANDS) 2013; 35:2273-82. [PMID: 23529504 PMCID: PMC3824977 DOI: 10.1007/s11357-013-9524-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 03/08/2013] [Indexed: 05/18/2023]
Abstract
Aged dogs spontaneously develop progressive decline in both cognitive and behavioral function, in addition to neuropathological changes, that collectively parallel several aspects of human aging and Alzheimer's disease progression and likely contribute to the development of canine cognitive dysfunction syndrome. In the current study, ethologically relevant spatial learning, retention, and reversal learning tasks were conducted, with the goal of expanding canine neuropsychological testing to pet dogs. Initially, dogs (N = 44, aged 7.8 ± 2.8 years, mean ± SD) had to learn which of two alternative routes successfully led out of a T-maze. Two weeks later, long-term memory retention was assessed, immediately followed by a reversal learning task in which the previously correct route out of the maze was reversed compared with the initial learning and memory retention tasks. No effects of age were evident on the learning or retention tasks. However, older (≥ 8 years) dogs were significantly impaired on the reversal learning task compared with younger ones (< 8 years). Moreover, trial response latency was significantly increased in aged dogs across both the initial and reversal learning tasks but not on the retention task, which suggests that processing speed was impaired by increasing age during the acquisition of novel spatial information but not during performance of previously learned responses. Overall, the current study provides a framework for assessing cognitive function in pet dogs, which should improve understanding of the effects of aging on cognition in the dog population.
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Affiliation(s)
- Paolo Mongillo
- Dipartimento di Biomedicina Comparata e Alimentazione, Università degli Studi di Padova, Padua, Italy,
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Slomianka L, Drenth T, Cavegn N, Menges D, Lazic SE, Phalanndwa M, Chimimba CT, Amrein I. The hippocampus of the eastern rock sengi: cytoarchitecture, markers of neuronal function, principal cell numbers, and adult neurogenesis. Front Neuroanat 2013; 7:34. [PMID: 24194702 PMCID: PMC3810719 DOI: 10.3389/fnana.2013.00034] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 09/26/2013] [Indexed: 12/04/2022] Open
Abstract
The brains of sengis (elephant shrews, order Macroscelidae) have long been known to contain a hippocampus that in terms of allometric progression indices is larger than that of most primates and equal in size to that of humans. In this report, we provide descriptions of hippocampal cytoarchitecture in the eastern rock sengi (Elephantulus myurus), of the distributions of hippocampal calretinin, calbindin, parvalbumin, and somatostatin, of principal neuron numbers, and of cell numbers related to proliferation and neuronal differentiation in adult hippocampal neurogenesis. Sengi hippocampal cytoarchitecture is an amalgamation of characters that are found in CA1 of, e.g., guinea pig and rabbits and in CA3 and dentate gyrus of primates. Correspondence analysis of total cell numbers and quantitative relations between principal cell populations relate this sengi to macaque monkeys and domestic pigs, and distinguish the sengi from distinct patterns of relations found in humans, dogs, and murine rodents. Calretinin and calbindin are present in some cell populations that also express these proteins in other species, e.g., interneurons at the stratum oriens/alveus border or temporal hilar mossy cells, but neurons expressing these markers are often scarce or absent in other layers. The distributions of parvalbumin and somatostatin resemble those in other species. Normalized numbers of PCNA+ proliferating cells and doublecortin-positive (DCX+) differentiating cells of neuronal lineage fall within the overall ranges of murid rodents, but differed from three murid species captured in the same habitat in that fewer DCX+ cells relative to PCNA+ were observed. The large and well-differentiated sengi hippocampus is not accompanied by correspondingly sized cortical and subcortical limbic areas that are the main hippocampal sources of afferents and targets of efferents. This points to intrinsic hippocampal information processing as the selective advantage of the large sengi hippocampus.
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Affiliation(s)
- Lutz Slomianka
- Institute of Anatomy, University of ZürichZürich, Switzerland
| | - Tanja Drenth
- Institute of Anatomy, University of ZürichZürich, Switzerland
| | - Nicole Cavegn
- Institute of Anatomy, University of ZürichZürich, Switzerland
| | - Dominik Menges
- Institute of Anatomy, University of ZürichZürich, Switzerland
| | - Stanley E. Lazic
- In Silico Lead Discovery, Novartis Institutes for Biomedical ResearchBasel, Switzerland
| | - Mashudu Phalanndwa
- Mammal Research Institute, Department of Zoology and Entomology, University of PretoriaHatfield, South Africa
- Western Cape Nature Conservation Board (CapeNature)Cape Town, South Africa
| | - Christian T. Chimimba
- Mammal Research Institute, Department of Zoology and Entomology, University of PretoriaHatfield, South Africa
- Department of Science and Technology-National Research Foundation Centre of Excellence for Invasion Biology, Department of Zoology and Entomology University of PretoriaHatfield, South Africa
| | - Irmgard Amrein
- Institute of Anatomy, University of ZürichZürich, Switzerland
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Head E. A canine model of human aging and Alzheimer's disease. Biochim Biophys Acta Mol Basis Dis 2013; 1832:1384-9. [PMID: 23528711 DOI: 10.1016/j.bbadis.2013.03.016] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 03/15/2013] [Accepted: 03/17/2013] [Indexed: 12/22/2022]
Abstract
The aged dog naturally develops cognitive decline in many different domains (including learning and memory) but also exhibits human-like individual variability in the aging process. The neurobiological basis for cognitive dysfunction may be related to structural changes that reflect neurodegeneration. Molecular cascades that contribute to degeneration in the aging dog brain include the progressive accumulation of beta-amyloid (Aβ) in diffuse plaques and in the cerebral vasculature. In addition, neuronal dysfunction occurs as a consequence of mitochondrial dysfunction and cumulative oxidative damage. In combination, the aged dog captures key features of human aging, making them particularly useful for the development of preventive or therapeutic interventions to improve aged brain function. These interventions can then be translated into human clinical trials. This article is part of a Special Issue entitled: Animal Models of Disease.
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Affiliation(s)
- Elizabeth Head
- Department of Molecular and Biomedical Pharmacology, University of Kentucky, Lexington, KY 40536, USA.
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Cognitive enhancement in middle-aged and old cats with dietary supplementation with a nutrient blend containing fish oil, B vitamins, antioxidants and arginine. Br J Nutr 2012; 110:40-9. [DOI: 10.1017/s0007114512004771] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Cognitive dysfunction syndrome is a major disease affecting old cats and is the consequence of severe and irreversible loss of brain cells and brain atrophy. The present study focused on the hypothesis that the optimal strategy for promoting successful brain ageing is to target risk factors associated with brain ageing and dementia. We used a nutritional strategy involving supplementation with a blend of nutrients (antioxidants, arginine, B vitamins and fish oil) to test this hypothesis. Middle-aged and old cats between 5·5 and 8·7 years of age were assigned to cognitively equivalent control or treatment groups based on prior cognitive experience and performance on baseline cognitive tests. The cats in the treatment group were maintained on a diet supplemented with the nutrient blend and the cats in the control group were maintained on the identical base diet without the additional supplementation. After an initial wash-in period, all cats were tested on a battery of cognitive test protocols. The cats fed the test diet showed significantly better performance on three of four test protocols: a protocol assessing egocentric learning, a protocol assessing discrimination and reversal learning and a protocol focused on acquisition of a spatial memory task. The results support the hypothesis that brain function of middle-aged and old cats can be improved by the nutrient blend that was selected to minimise or eliminate the risk factors associated with brain ageing and dementia.
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Comparison of α-synuclein immunoreactivity in the hippocampus between the adult and aged beagle dogs. Cell Mol Neurobiol 2012; 33:75-84. [PMID: 22972205 DOI: 10.1007/s10571-012-9873-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 08/02/2012] [Indexed: 10/27/2022]
Abstract
Alpha-synuclein (α-syn), as a neuroprotein, is expressed in neural tissue, and it is related to a synaptic transmission and neuronal plasticity. In this study, we compared the distribution and immunoreactivity of α-syn and related gliosis in hippocampus between young adult (2-3 years) and aged (10-12 years) beagle dogs. In both groups, α-syn immunoreactivity was detected in neuropil of all the hippocampal sub-regions, but not in neuronal somata. In the aged hippocampus, α-syn immunoreactivity was apparently increased in mossy fibers compared to that in the adult dog. In addition, α-syn protein level was markedly increased in the aged hippocampus. On the other hand, GFAP and Iba-1 immunoreactivity in astrocytes and microglia, respectively, were increased in all the hippocampal sub-regions of the aged group compared to that in the adult group: especially, their immunoreactivity was apparently increased around mossy fibers. In addition, in this study, we could not find any expression of α-syn in astrocytes and microglia. These results indicate that α-syn immunoreactivity apparently increases in the aged hippocampus and that GFAP and Iba-1 immunoreactivity are also apparently increased at the regions with increased α-syn immunoreactivity. This increase in α-syn expression might be a feature of normal aging.
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James BD, Glass TA, Caffo B, Bobb JF, Davatzikos C, Yousem D, Schwartz BS. Association of social engagement with brain volumes assessed by structural MRI. J Aging Res 2012; 2012:512714. [PMID: 22997582 PMCID: PMC3446736 DOI: 10.1155/2012/512714] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 08/02/2012] [Indexed: 11/17/2022] Open
Abstract
We tested the hypothesis that social engagement is associated with larger brain volumes in a cohort study of 348 older male former lead manufacturing workers (n = 305) and population-based controls (n = 43), age 48 to 82. Social engagement was measured using a summary scale derived from confirmatory factor analysis. The volumes of 20 regions of interest (ROIs), including total brain, total gray matter (GM), total white matter (WM), each of the four lobar GM and WM, and 9 smaller structures were derived from T1-weighted structural magnetic resonance images. Linear regression models adjusted for age, education, race/ethnicity, intracranial volume, hypertension, diabetes, and control (versus lead worker) status. Higher social engagement was associated with larger total brain and GM volumes, specifically temporal and occipital GM, but was not associated with WM volumes except for corpus callosum. A voxel-wise analysis supported an association in temporal lobe GM. Using longitudinal data to discern temporal relations, change in ROI volumes over five years showed null associations with current social engagement. Findings are consistent with the hypothesis that social engagement preserves brain tissue, and not consistent with the alternate hypothesis that persons with smaller or shrinking volumes become less socially engaged, though this scenario cannot be ruled out.
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Affiliation(s)
- Bryan D. James
- Rush Alzheimer's Disease Center, Department of Internal Medicine, Rush University Medical Center, Chicago, IL 60612, USA
| | - Thomas A. Glass
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Brian Caffo
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Jennifer F. Bobb
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Christos Davatzikos
- Department of Radiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - David Yousem
- Department of Radiology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Brian S. Schwartz
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
- Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
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Unverzagt FW, Guey LT, Jones RN, Marsiske M, King JW, Wadley VG, Crowe M, Rebok GW, Tennstedt SL. ACTIVE cognitive training and rates of incident dementia. J Int Neuropsychol Soc 2012; 18:669-77. [PMID: 22400989 PMCID: PMC3384749 DOI: 10.1017/s1355617711001470] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Systematic cognitive training produces long-term improvement in cognitive function and less difficulty in performing activities of daily living. We examined whether cognitive training was associated with reduced rate of incident dementia. Participants were from the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study (n = 2,802). Incident dementia was defined using a combination of interview- and performance-based methods. Survival analysis was used to determine if ACTIVE treatment affected the rate of incident dementia during 5 years of follow-up. A total of 189 participants met criteria for incident dementia. Baseline factors predictive of incident dementia were older age, male gender, African American race, fewer years of education, relationship other than married, no alcohol use, worse MMSE, worse SF-36 physical functioning, higher depressive symptomatology, diabetes, and stroke (all p < .05). A multivariable model with significant predictors of incident dementia and training group revealed that cognitive training was not associated with a lower rate of incident dementia. Cognitive training did not affect rates of incident dementia after 5 years of follow-up. Longer follow-up or enhanced training may be needed to fully explore the preventive capacity of cognitive training in forestalling onset of dementia.
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Affiliation(s)
- Frederick W Unverzagt
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.
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Dowling ALS, Head E. Antioxidants in the canine model of human aging. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1822:685-9. [PMID: 22005070 PMCID: PMC3291812 DOI: 10.1016/j.bbadis.2011.09.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Revised: 09/29/2011] [Accepted: 09/30/2011] [Indexed: 01/15/2023]
Abstract
Oxidative damage can lead to neuronal dysfunction in the brain due to modifications to proteins, lipids and DNA/RNA. In both human and canine brain, oxidative damage progressively increases with age. In the Alzheimer's disease (AD) brain, oxidative damage is further exacerbated, possibly due to increased deposition of beta-amyloid (Aβ) peptide in senile plaques. These observations have led to the hypothesis that antioxidants may be beneficial for brain aging and AD. Aged dogs naturally develop AD-like neuropathology (Aβ) and cognitive dysfunction and are a useful animal model in which to test antioxidants. In a longitudinal study of aging beagles, a diet rich in antioxidants improved cognition, maintained cognition and reduced oxidative damage and Aβ pathology in treated animals. These data suggest that antioxidants may be beneficial for human brain aging and for AD, particularly as a preventative intervention. This article is part of a Special Issue entitled: Antioxidants and Antioxidant Treatment in Disease.
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Affiliation(s)
- Amy L S Dowling
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536, USA
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Verdaguer E, Junyent F, Folch J, Beas-Zarate C, Auladell C, Pallàs M, Camins A. Aging biology: a new frontier for drug discovery. Expert Opin Drug Discov 2012; 7:217-29. [DOI: 10.1517/17460441.2012.660144] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Araujo JA, Greig NH, Ingram DK, Sandin J, de Rivera C, Milgram NW. Cholinesterase inhibitors improve both memory and complex learning in aged beagle dogs. J Alzheimers Dis 2012; 26:143-55. [PMID: 21593569 DOI: 10.3233/jad-2011-110005] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Similar to patients with Alzheimer's disease (AD), dogs exhibit age-dependent cognitive decline, amyloid-β (Aβ) pathology, and evidence of cholinergic hypofunction. The present study sought to further investigate the role of cholinergic hypofunction in the canine model by examining the effect of the cholinesterase inhibitors phenserine and donepezil on performance of two tasks, a delayed non-matching-to-position task (DNMP) designed to assess working memory, and an oddity discrimination learning task designed to assess complex learning, in aged dogs. Phenserine (0.5 mg/kg; PO) significantly improved performance on the DNMP at the longest delay compared to wash-out and partially attenuated scopolamine-induced deficits (15 μg/kg; SC). Phenserine also improved learning on a difficult version of an oddity discrimination task compared to placebo, but had no effect on an easier version. We also examined the effects of three doses of donepezil (0.75, 1.5, and 6 mg/kg; PO) on performance of the DNMP. Similar to the results with phenserine, 1.5 mg/kg of donepezil improved performance at the longest delay compared to baseline and wash-out, indicative of memory enhancement. These results further extend the findings of cholinergic hypofunction in aged dogs and provide pharmacological validation of the canine model with a cholinesterase inhibitor approved for use in AD. Collectively, these studies support utilizing the aged dog in future screening of therapeutics for AD, as well as for investigating the links among cholinergic function, Aβ pathology, and cognitive decline.
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Affiliation(s)
- Joseph A Araujo
- Department of Pharmacology, University of Toronto, Toronto, ON, Canada.
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50
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Morris CL, Grandin T, Irlbeck NA. COMPANION ANIMALS SYMPOSIUM: Environmental enrichment for companion, exotic, and laboratory animals1. J Anim Sci 2011; 89:4227-38. [DOI: 10.2527/jas.2010-3722] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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