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Carrero L, Antequera D, Municio C, Carro E. Circadian rhythm disruption and retinal dysfunction: a bidirectional link in Alzheimer's disease? Neural Regen Res 2024; 19:1967-1972. [PMID: 38227523 DOI: 10.4103/1673-5374.390962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 11/07/2023] [Indexed: 01/17/2024] Open
Abstract
Dysfunction in circadian rhythms is a common occurrence in patients with Alzheimer's disease. A predominant function of the retina is circadian synchronization, carrying information to the brain through the retinohypothalamic tract, which projects to the suprachiasmatic nucleus. Notably, Alzheimer's disease hallmarks, including amyloid-β, are present in the retinas of Alzheimer's disease patients, followed/associated by structural and functional disturbances. However, the mechanistic link between circadian dysfunction and the pathological changes affecting the retina in Alzheimer's disease is not fully understood, although some studies point to the possibility that retinal dysfunction could be considered an early pathological process that directly modulates the circadian rhythm.
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Affiliation(s)
- Laura Carrero
- Group of Neurodegenerative Diseases, Hospital Universitario 12 de Octubre Research Institute (imas12), Madrid, Spain; Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, Madrid, Spain
- PhD Program in Neuroscience, Autonoma de Madrid University, Madrid, Spain
| | - Desireé Antequera
- Neurobiology of Alzheimer's Disease Unit, Functional Unit for Research into Chronic Diseases, Instituto de Salud Carlos III, Madrid, Spain; Network Centre for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, Madrid, Spain
| | - Cristina Municio
- Group of Neurodegenerative Diseases, Hospital Universitario 12 de Octubre Research Institute (imas12), Madrid, Spain; Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, Madrid, Spain
| | - Eva Carro
- Neurobiology of Alzheimer's Disease Unit, Functional Unit for Research into Chronic Diseases, Instituto de Salud Carlos III, Madrid, Spain; Network Centre for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, Madrid, Spain
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Gendron WH, Fertan E, Roddick KM, Wong AA, Maliougina M, Hiani YE, Anini Y, Brown RE. Intranasal insulin treatment ameliorates spatial memory, muscular strength, and frailty deficits in 5xFAD mice. Physiol Behav 2024; 281:114583. [PMID: 38750806 DOI: 10.1016/j.physbeh.2024.114583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 05/11/2024] [Accepted: 05/13/2024] [Indexed: 05/19/2024]
Abstract
The 5xFAD mouse model shows age-related weight loss as well as cognitive and motor deficits. Metabolic dysregulation, especially impaired insulin signaling, is also present in AD. This study examined whether intranasal delivery of insulin (INI) at low (0.875 U) or high (1.750 U) doses would ameliorate these deficits compared to saline in 10-month-old female 5xFAD and B6SJL wildtype (WT) mice. INI increased forelimb grip strength in the wire hang test in 5xFAD mice in a dose-dependent manner but did not improve the performance of 5xFAD mice on the balance beam. High INI doses reduced frailty scores in 5xFAD mice and improved spatial memory in both acquisition and reversal probe trials in the Morris water maze. INI increased swim speed in 5xFAD mice but had no effect on object recognition memory or working memory in the spontaneous alternation task, nor did it improve memory in the contextual or cued fear memory tasks. High doses of insulin increased the liver, spleen, and kidney weights and reduced brown adipose tissue weights. P-Akt signaling in the hippocampus was increased by insulin in a dose-dependent manner. Altogether, INI increased strength, reduced frailty scores, and improved visual spatial memory. Hypoglycemia was not present after INI, however alterations in tissue and organ weights were present. These results are novel and important as they indicate that intra-nasal insulin can reverse cognitive, motor and frailty deficits found in this mouse model of AD.
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Affiliation(s)
- William H Gendron
- Departments of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Emre Fertan
- Departments of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Kyle M Roddick
- Departments of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Aimée A Wong
- Departments of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Maria Maliougina
- Departments of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Yassine El Hiani
- Departments of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Younes Anini
- Departments of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada; Departments of Obstetrics and Gynecology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Richard E Brown
- Departments of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada; Departments of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
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O'Leary TP, Brown RE. Age-related changes in species-typical behaviours in the 5xFAD mouse model of Alzheimer's disease from 4 to 16 months of age. Behav Brain Res 2024; 465:114970. [PMID: 38531510 DOI: 10.1016/j.bbr.2024.114970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 03/12/2024] [Accepted: 03/23/2024] [Indexed: 03/28/2024]
Abstract
Alzheimer's disease (AD) patients show age-related decreases in the ability to perform activities of daily living and the decline in these activities is related to the severity of neurobiological deterioration underlying the disease. The 5xFAD mouse model of AD shows age-related impairments in sensory- motor and cognitive function, but little is known about changes in species-typical behaviours that may model activities of daily living in AD patients. Therefore, we examined species-typical behaviours used as indices of exploration (rearing) and compulsivity (grooming) across six tests of anxiety-like behaviour or motor function in female 5xFAD mice from 3 to 16 months of age. Robust decreases in rearing were found in 5xFAD mice across all tests after 9 months of age, although few differences were observed in grooming. A fine-scale analysis of grooming, however, revealed a previously unresolved and spatially restricted pattern of grooming in 5xFAD mice at 13-16 months of age. We then examined changes in species-typical behaviours in the home-cage, and show impaired nest building in 5xFAD mice at all ages tested. Lastly, we examined the relationship between reduced species typical behaviours in 5xFAD mice and the presentation of freezing behaviour, a commonly used measure of memory for conditioned fear. These results showed that along with cognitive and sensory-motor behaviour, 5xFAD mice have robust age-related impairments in species-typical behaviours. Therefore, species typical behaviours in 5xFAD mice may help to model the decline in activities of daily living observed in AD patients, and may provide useful behavioural phenotypes for evaluating the pre-clinical efficacy of novel therapeutics for AD.
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Affiliation(s)
- Timothy P O'Leary
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Richard E Brown
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada.
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Ding J, Kim TH, Ma G, Yao X. Intrinsic signal optoretinography of dark adaptation abnormality due to rod photoreceptor degeneration. Exp Biol Med (Maywood) 2024; 249:10024. [PMID: 38463390 PMCID: PMC10911128 DOI: 10.3389/ebm.2024.10024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 01/04/2024] [Indexed: 03/12/2024] Open
Abstract
This research aims to investigate the potential of using intrinsic optical signal (IOS) optoretinography (ORG) to objectively detect dark adaptation (DA) abnormalities related to rod photoreceptor degeneration. Functional optical coherence tomography (OCT) was employed in both wild-type (WT) and retinal degeneration 10 (rd10) mice to conduct this assessment. Dynamic OCT measurements captured the changes in retinal thickness and reflectance from light-to-dark transition. Comparative analysis revealed significant IOS alterations within the outer retina. Specifically, a reduction in thickness from external limiting membrane (ELM) peak to retinal pigment epithelium (RPE) peak was observed (WT: 1.13 ± 0.69 µm, 30 min DA; rd10: 2.64 ± 0.86 µm, 30 min DA), as well as a decrease in the intensity of the inner segment ellipsoid zone (EZ) in 30 min DA compared to light adaptation (LA). The reduction of relative EZ intensity was notable in rd10 after 5 min DA and in WT after 15 min DA, with a distinguishable difference between rd10 and WT after 10 min DA. Furthermore, our findings indicated a significant decrease in the relative intensity of the hypo-reflective band between EZ and RPE in rd10 retinas during DA, which primarily corresponds to the outer segment (OS) region. In conclusion, the observed DA-IOS abnormalities, including changes in ELM-RPE thickness, EZ, and OS intensity, hold promise as differentiators between WT and rd10 mice before noticeable morphological abnormalities occur. These findings suggest the potential of this non-invasive imaging technique for the early detection of dysfunction in retinal photoreceptors.
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Affiliation(s)
- Jie Ding
- Department of Biomedical Engineering, University of Illinois Chicago, Chicago, IL, United States
| | - Tae-Hoon Kim
- Department of Biomedical Engineering, University of Illinois Chicago, Chicago, IL, United States
| | - Guangying Ma
- Department of Biomedical Engineering, University of Illinois Chicago, Chicago, IL, United States
| | - Xincheng Yao
- Department of Biomedical Engineering, University of Illinois Chicago, Chicago, IL, United States
- Department of Ophthalmology and Visual Sciences, University of Illinois Chicago, Chicago, IL, United States
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Wang S, Jiang X, Peng W, Yang S, Pi R, Zhou S. Acrolein Induces Retinal Abnormalities of Alzheimer's Disease in Mice. Int J Mol Sci 2023; 24:13576. [PMID: 37686379 PMCID: PMC10487815 DOI: 10.3390/ijms241713576] [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: 07/18/2023] [Revised: 08/12/2023] [Accepted: 08/17/2023] [Indexed: 09/10/2023] Open
Abstract
It is reported that retinal abnormities are related to Alzheimer's disease (AD) in patients and animal models. However, it is unclear whether the retinal abnormities appear in the mouse model of sporadic Alzheimer's disease (sAD) induced by acrolein. We investigated the alterations of retinal function and structure, the levels of β-amyloid (Aβ) and phosphorylated Tau (p-Tau) in the retina, and the changes in the retinal vascular system in this mouse model. We demonstrated that the levels of Aβ and p-Tau were increased in the retinas of mice from the acrolein groups. Subsequently, a decreased amplitudes of b-waves in the scotopic and photopic electroretinogram (ERG), decreased thicknesses of the retinal nerve fiber layer (RNFL) in the retina, and slight retinal venous beading were found in the mice induced by acrolein. We propose that sAD mice induced by acrolein showed abnormalities in the retina, which may provide a valuable reference for the study of the retina in sAD.
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Affiliation(s)
- Shuyi Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Xiuying Jiang
- Department of Ophthalmology, Affiliated Foshan Hospital, Southern Medical University, Foshan 528000, China
| | - Weijia Peng
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Shuangjian Yang
- Guangdong Provincial Institute for Vision and Eye Research, Guangzhou 510060, China
| | - Rongbiao Pi
- School of Medicine, Sun Yat-sen University, Shenzhen 528406, China
| | - Shiyou Zhou
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
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Constable PA, Lim JKH, Thompson DA. Retinal electrophysiology in central nervous system disorders. A review of human and mouse studies. Front Neurosci 2023; 17:1215097. [PMID: 37600004 PMCID: PMC10433210 DOI: 10.3389/fnins.2023.1215097] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 07/17/2023] [Indexed: 08/22/2023] Open
Abstract
The retina and brain share similar neurochemistry and neurodevelopmental origins, with the retina, often viewed as a "window to the brain." With retinal measures of structure and function becoming easier to obtain in clinical populations there is a growing interest in using retinal findings as potential biomarkers for disorders affecting the central nervous system. Functional retinal biomarkers, such as the electroretinogram, show promise in neurological disorders, despite having limitations imposed by the existence of overlapping genetic markers, clinical traits or the effects of medications that may reduce their specificity in some conditions. This narrative review summarizes the principal functional retinal findings in central nervous system disorders and related mouse models and provides a background to the main excitatory and inhibitory retinal neurotransmitters that have been implicated to explain the visual electrophysiological findings. These changes in retinal neurochemistry may contribute to our understanding of these conditions based on the findings of retinal electrophysiological tests such as the flash, pattern, multifocal electroretinograms, and electro-oculogram. It is likely that future applications of signal analysis and machine learning algorithms will offer new insights into the pathophysiology, classification, and progression of these clinical disorders including autism, attention deficit/hyperactivity disorder, bipolar disorder, schizophrenia, depression, Parkinson's, and Alzheimer's disease. New clinical applications of visual electrophysiology to this field may lead to earlier, more accurate diagnoses and better targeted therapeutic interventions benefiting individual patients and clinicians managing these individuals and their families.
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Affiliation(s)
- Paul A. Constable
- College of Nursing and Health Sciences, Caring Futures Institute, Flinders University, Adelaide, SA, Australia
| | - Jeremiah K. H. Lim
- Discipline of Optometry, School of Allied Health, University of Western Australia, Perth, WA, Australia
| | - Dorothy A. Thompson
- The Tony Kriss Visual Electrophysiology Unit, Clinical and Academic Department of Ophthalmology, Great Ormond Street Hospital for Children NHS Trust, London, United Kingdom
- UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
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Sugasini D, Park JC, McAnany JJ, Kim TH, Ma G, Yao X, Antharavally B, Oroskar A, Oroskar AA, Layden BT, Subbaiah PV. Improvement of retinal function in Alzheimer disease-associated retinopathy by dietary lysophosphatidylcholine-EPA/DHA. Sci Rep 2023; 13:9179. [PMID: 37280266 PMCID: PMC10244360 DOI: 10.1038/s41598-023-36268-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Accepted: 05/31/2023] [Indexed: 06/08/2023] Open
Abstract
Alzheimer disease (AD) is the most prevalent cause of dementia in the elderly. Although impaired cognition and memory are the most prominent features of AD, abnormalities in visual functions often precede them, and are increasingly being used as diagnostic and prognostic markers for the disease. Retina contains the highest concentration of the essential fatty acid docosahexaenoic acid (DHA) in the body, and its deficiency is associated with several retinal diseases including diabetic retinopathy and age related macular degeneration. In this study, we tested the hypothesis that enriching retinal DHA through a novel dietary approach could ameliorate symptoms of retinopathy in 5XFAD mice, a widely employed model of AD. The results show that 5XFAD mice have significantly lower retinal DHA compared to their wild type littermates, and feeding the lysophosphatidylcholine (LPC) form of DHA and eicosapentaenoic acid (EPA) rapidly normalizes the DHA levels, and increases retinal EPA by several-fold. On the other hand, feeding similar amounts of DHA and EPA in the form of triacylglycerol had only modest effects on retinal DHA and EPA. Electroretinography measurements after 2 months of feeding the experimental diets showed a significant improvement in a-wave and b-wave functions by the LPC-diet, whereas the TAG-diet had only a modest benefit. Retinal amyloid β levels were decreased by about 50% by the LPC-DHA/EPA diet, and by about 17% with the TAG-DHA/EPA diet. These results show that enriching retinal DHA and EPA through dietary LPC could potentially improve visual abnormalities associated with AD.
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Affiliation(s)
- Dhavamani Sugasini
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Illinois, Chicago, IL, 60612, USA.
| | - Jason C Park
- Department of Ophthalmology and Visual Sciences, University of Illinois, Chicago, IL, 60612, USA
| | - J Jason McAnany
- Department of Ophthalmology and Visual Sciences, University of Illinois, Chicago, IL, 60612, USA
| | - Tae-Hoon Kim
- Department of Biomedical Engineering, University of Illinois, Chicago, IL, 60607, USA
| | - Guangying Ma
- Department of Biomedical Engineering, University of Illinois, Chicago, IL, 60607, USA
| | - Xincheng Yao
- Department of Ophthalmology and Visual Sciences, University of Illinois, Chicago, IL, 60612, USA
- Department of Biomedical Engineering, University of Illinois, Chicago, IL, 60607, USA
| | | | - Anil Oroskar
- Orochem Technologies, Inc, Naperville, IL, 60563, USA
| | | | - Brian T Layden
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Illinois, Chicago, IL, 60612, USA
- Jesse Brown VA Medical Center, Chicago, IL, 60612, USA
| | - Papasani V Subbaiah
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Illinois, Chicago, IL, 60612, USA.
- Jesse Brown VA Medical Center, Chicago, IL, 60612, USA.
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Carrero L, Antequera D, Alcalde I, Megías D, Figueiro-Silva J, Merayo-Lloves J, Municio C, Carro E. Disturbed circadian rhythm and retinal degeneration in a mouse model of Alzheimer's disease. Acta Neuropathol Commun 2023; 11:55. [PMID: 37004084 PMCID: PMC10067208 DOI: 10.1186/s40478-023-01529-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 02/11/2023] [Indexed: 04/03/2023] Open
Abstract
The circadian clock is synchronized to the 24 h day by environmental light which is transmitted from the retina to the suprachiasmatic nucleus (SCN) primarily via the retinohypothalamic tract (RHT). Circadian rhythm abnormalities have been reported in neurodegenerative disorders such as Alzheimer's disease (AD). Whether these AD-related changes are a result of the altered clock gene expression, retina degeneration, including the dysfunction in RHT transmission, loss of retinal ganglion cells and its electrophysiological capabilities, or a combination of all of these pathological mechanisms, is not known. Here, we evaluated transgenic APP/PS1 mouse model of AD and wild-type mice at 6- and 12-month-old, as early and late pathological stage, respectively. We noticed the alteration of circadian clock gene expression not only in the hypothalamus but also in two extra-hypothalamic brain regions, cerebral cortex and hippocampus, in APP/PS1 mice. These alterations were observed in 6-month-old transgenic mice and were exacerbated at 12 months of age. This could be explained by the reduced RHT projections in the SCN of APP/PS1 mice, correlating with downregulation of hypothalamic GABAergic response in APP/PS1 mice in advanced stage of pathology. Importantly, we also report retinal degeneration in APP/PS1 mice, including Aβ deposits and reduced choline acetyltransferase levels, loss of melanopsin retinal ganglion cells and functional integrity mainly of inner retina layers. Our findings support the theory that retinal degeneration constitutes an early pathological event that directly affects the control of circadian rhythm in AD.
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Affiliation(s)
- Laura Carrero
- Group of Neurodegenerative Diseases, Hospital Universitario 12 de Octubre Research Institute (imas12), 28041, Madrid, Spain
- Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, Madrid, Spain
- Autonoma de Madrid University, Madrid, Spain
| | - Desireé Antequera
- Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, Madrid, Spain
- Neurobiology of Alzheimer's Disease Unit, Functional Unit for Research into Chronic Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Ignacio Alcalde
- Instituto Universitario Fernández-Vega, Universidad de Oviedo and Fundación de Investigación Oftalmológica, Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
| | - Diego Megías
- Advanced Optical Microscopy Unit, Unidades Centrales Científico-Técnicas, Instituto de Salud Carlos III, Madrid, Spain
| | - Joana Figueiro-Silva
- Institute of Medical Genetics, University of Zurich, Zurich, Switzerland
- Department of Molecular Life Science, University of Zurich, Zurich, Switzerland
| | - Jesús Merayo-Lloves
- Instituto Universitario Fernández-Vega, Universidad de Oviedo and Fundación de Investigación Oftalmológica, Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
| | - Cristina Municio
- Group of Neurodegenerative Diseases, Hospital Universitario 12 de Octubre Research Institute (imas12), 28041, Madrid, Spain.
- Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, Madrid, Spain.
| | - Eva Carro
- Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), ISCIII, Madrid, Spain.
- Neurobiology of Alzheimer's Disease Unit, Functional Unit for Research into Chronic Diseases, Instituto de Salud Carlos III, Madrid, Spain.
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Lustig-Barzelay Y, Sher I, Sharvit-Ginon I, Feldman Y, Mrejen M, Dallasheh S, Livny A, Schnaider Beeri M, Weller A, Ravona-Springer R, Rotenstreich Y. Machine learning for comprehensive prediction of high risk for Alzheimer's disease based on chromatic pupilloperimetry. Sci Rep 2022; 12:9945. [PMID: 35705601 PMCID: PMC9200977 DOI: 10.1038/s41598-022-13999-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 05/13/2022] [Indexed: 11/30/2022] Open
Abstract
Currently there are no reliable biomarkers for early detection of Alzheimer's disease (AD) at the preclinical stage. This study assessed the pupil light reflex (PLR) for focal red and blue light stimuli in central and peripheral retina in 125 cognitively normal middle age subjects (45-71 years old) at high risk for AD due to a family history of the disease (FH+), and 61 age-similar subjects with no family history of AD (FH-) using Chromatic Pupilloperimetry coupled with Machine Learning (ML). All subjects had normal ophthalmic assessment, and normal retinal and optic nerve thickness by optical coherence tomography. No significant differences were observed between groups in cognitive function and volumetric brain MRI. Chromatic pupilloperimetry-based ML models were highly discriminative in differentiating subjects with and without AD family history, using transient PLR for focal red (primarily cone-mediated), and dim blue (primarily rod-mediated) light stimuli. Features associated with transient pupil response latency (PRL) achieved Area Under the Curve Receiver Operating Characteristic (AUC-ROC) of 0.90 ± 0.051 (left-eye) and 0.87 ± 0.048 (right-eye). Parameters associated with the contraction arm of the rod and cone-mediated PLR were more discriminative compared to parameters associated with the relaxation arm and melanopsin-mediated PLR. Significantly shorter PRL for dim blue light was measured in the FH+ group in two test targets in the temporal visual field in right eye that had highest relative weight in the ML algorithm (mean ± standard error, SE 0.449 s ± 0.007 s vs. 0.478 s ± 0.010 s, p = 0.038). Taken together our study suggests that subtle focal changes in pupil contraction latency may be detected in subjects at high risk to develop AD, decades before the onset of AD clinical symptoms. The dendrites of melanopsin containing retinal ganglion cells may be affected very early at the preclinical stages of AD.
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Affiliation(s)
- Yael Lustig-Barzelay
- Goldschleger Eye Institute, Sheba Medical Center, 52621, Tel-Hashomer, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ifat Sher
- Goldschleger Eye Institute, Sheba Medical Center, 52621, Tel-Hashomer, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Nehemia Rubin Excellence in Biomedical Research, TELEM Program, Sheba Medical Center, Tel Hashomer, Israel
| | - Inbal Sharvit-Ginon
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel Hashomer, Israel
- Department of Psychology, Bar-Ilan University, Ramat Gan, Israel
| | - Yael Feldman
- Goldschleger Eye Institute, Sheba Medical Center, 52621, Tel-Hashomer, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Michael Mrejen
- Condensed Matter Physics Department, School of Physics and Astronomy, Tel-Aviv University, Tel Aviv, Israel
| | - Shada Dallasheh
- Goldschleger Eye Institute, Sheba Medical Center, 52621, Tel-Hashomer, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Abigail Livny
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Nehemia Rubin Excellence in Biomedical Research, TELEM Program, Sheba Medical Center, Tel Hashomer, Israel
- Department of Diagnostic Imaging, Sheba Medical Center, Tel Hashomer, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Michal Schnaider Beeri
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel Hashomer, Israel
- Department of Psychiatry, The Icahn School of Medicine at Mount Sinai, New York, USA
| | - Aron Weller
- Department of Psychology, Bar-Ilan University, Ramat Gan, Israel
- Gonda Brain Research Center, Bar Ilan University, Ramat Gan, Israel
| | - Ramit Ravona-Springer
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel Hashomer, Israel
- Memory Clinic, Sheba Medical Center, Tel Hashomer, Israel
| | - Ygal Rotenstreich
- Goldschleger Eye Institute, Sheba Medical Center, 52621, Tel-Hashomer, Israel.
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
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Concomitant Retinal Alterations in Neuronal Activity and TNFα Pathway Are Detectable during the Pre-Symptomatic Stage in a Mouse Model of Alzheimer's Disease. Cells 2022; 11:cells11101650. [PMID: 35626688 PMCID: PMC9140134 DOI: 10.3390/cells11101650] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 04/21/2022] [Accepted: 05/13/2022] [Indexed: 12/10/2022] Open
Abstract
The pre-symptomatic stage of Alzheimer’s disease (AD) is associated with increased amyloid-β (Aβ) precursor protein (APP) processing and Aβ accumulation in the retina and hippocampus. Because neuronal dysfunctions are among the earliest AD-related alterations, we asked whether they are already detectable in the retina during the pre-symptomatic stage in a APPswePS1dE9 (APP/PS1) mouse model. The age chosen for the study (3–4 months) corresponds to the pre-symptomatic stage because no retinal Aβ was detected, in spite of the presence of βCTF (the first cleavage product of APP). We observed an increase in ERG amplitudes in APP/PS1 mice in comparison to the controls, which indicated an increased retinal neuron activity. These functional changes coincided with an increased expression of retinal TNFα and its receptors type-1 (TNFR1). Consistently, the IkB expression increased in APP/PS1 mice with a greater proportion of the phosphorylated protein (P-IkB) over total IkB, pointing to the putative involvement of the NFkB pathway. Because TNFα plays a crucial role in the control of neuronal excitability, it is likely that, as in the hippocampus, TNFα signaling via the TNFR1/NFkB pathway may be also involved in early, AD-associated, retinal neuron hyperexcitability. These results further demonstrate the interest of the retina for early disease detection with a potential to assess future therapeutic strategies.
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