1
|
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.
Collapse
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
| |
Collapse
|
2
|
Liao W, Wang Y, Wang L, Li J, Huang D, Cheng W, Luan P. The current status and challenges of olfactory dysfunction study in Alzheimer's Disease. Ageing Res Rev 2024; 100:102453. [PMID: 39127444 DOI: 10.1016/j.arr.2024.102453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2024] [Accepted: 08/07/2024] [Indexed: 08/12/2024]
Abstract
Olfactory functioning involves multiple cognitive processes and the coordinated actions of various neural systems. Any disruption at any stage of this process may result in olfactory dysfunction, which is consequently widely used to predict the onset and progression of diseases, such as Alzheimer's Disease (AD). Although the underlying mechanisms have not yet been fully unraveled, apparent changes were observed in olfactory brain areas form patients who suffer from AD by means of medical imaging and electroencephalography (EEG). Olfactory dysfunction holds significant promise in detecting AD during the preclinical stage preceding mild cognitive impairment (MCI). Owing to the strong specificity, olfactory tests are prevalently applied for screening in community cohorts. And combining olfactory tests with other biomarkers may further establish an optimal model for AD prediction in studies of specific olfactory dysfunctions and improve the sensitivity and specificity of early AD diagnosis.
Collapse
Affiliation(s)
- Wanchen Liao
- Department of Alzheimer's Disease Clinical Research Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
| | - Yulin Wang
- Department of Alzheimer's Disease Clinical Research Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
| | - Lei Wang
- Department of Alzheimer's Disease Clinical Research Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
| | - Jun Li
- Department of Alzheimer's Disease Clinical Research Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
| | - Dongqing Huang
- Department of Alzheimer's Disease Clinical Research Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
| | - Weibin Cheng
- Department of Alzheimer's Disease Clinical Research Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China.
| | - Ping Luan
- Department of Alzheimer's Disease Clinical Research Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China.
| |
Collapse
|
3
|
Yurimoto T, Seki F, Yamada A, Okajima J, Yambe T, Takewa Y, Kamioka M, Inoue T, Inoue Y, Sasaki E. Development of a noninvasive olfactory stimulation fMRI system in marmosets. Sci Rep 2024; 14:17830. [PMID: 39090331 PMCID: PMC11294473 DOI: 10.1038/s41598-024-68508-2] [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: 04/19/2024] [Accepted: 07/24/2024] [Indexed: 08/04/2024] Open
Abstract
Olfactory dysfunction is associated with aging and the earliest stages of neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases; it is thought to be an early biomarker of cognitive decline. In marmosets, a small non-human primate model used in brain research, olfactory pathway activity during olfactory stimulation has not been well studied because of the difficulty in clearly switching olfactory stimuli inside a narrow MRI. Here, we developed an olfactory-stimulated fMRI system using a small-aperture MRI machine. The olfactory presentation system consisted of two tubes, one for supply and one for suction of olfactory stimulants and a balloon valve. A balloon valve installed in the air supply tube controlled the presentation of the olfactory stimulant, which enabled sharp olfactory stimulation within MRI, such as 30 s of stimulation repeated five times at five-minute intervals. The olfactory stimulation system was validated in vivo and in a simulated system. fMRI analysis showed a rapid increase in signal values within 30 s of olfactory stimulation in eight regions related to the sense of smell. As these regions include those associated with Alzheimer's and Parkinson's diseases, olfactory stimulation fMRI may be useful in clarifying the relationship between olfactory dysfunction and dementia in non-human primates.
Collapse
Affiliation(s)
- Terumi Yurimoto
- Department of Marmoset Biology and Medicine, Central Institute for Experimental Medicine and Life Science, Kawasaki, Japan
| | - Fumiko Seki
- Bioimaging Center, Central Institute for Experimental Medicine and Life Science, Kawasaki, Japan
| | - Akihiro Yamada
- Department of Clinical Engineering, Komatsu University, Komatsu, Japan
- Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | | | - Tomoyuki Yambe
- Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Yoshiaki Takewa
- Advanced Medical Engineering Research Center, Asahikawa Medical University, Asahikawa, Japan
| | - Michiko Kamioka
- Department of Marmoset Biology and Medicine, Central Institute for Experimental Medicine and Life Science, Kawasaki, Japan
| | - Takashi Inoue
- Department of Marmoset Biology and Medicine, Central Institute for Experimental Medicine and Life Science, Kawasaki, Japan
- Faculty of Veterinary Medicine, Okayama University of Science, Imabari, Japan
| | - Yusuke Inoue
- Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.
- Advanced Medical Engineering Research Center, Asahikawa Medical University, Asahikawa, Japan.
| | - Erika Sasaki
- Department of Marmoset Biology and Medicine, Central Institute for Experimental Medicine and Life Science, Kawasaki, Japan.
| |
Collapse
|
4
|
Bouhaben J, Delgado-Lima AH, Delgado-Losada ML. The role of olfactory dysfunction in mild cognitive impairment and Alzheimer's disease: A meta-analysis. Arch Gerontol Geriatr 2024; 123:105425. [PMID: 38615524 DOI: 10.1016/j.archger.2024.105425] [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: 02/27/2024] [Revised: 03/22/2024] [Accepted: 03/27/2024] [Indexed: 04/16/2024]
Abstract
PURPOSE This comprehensive meta-analysis investigates the association between olfactory deficits in mild cognitive impairment (MCI) and Alzheimer's disease (AD). METHODS A thorough search across databases identified articles analyzing olfactory status in MCI or AD patients. Methodological quality assessment followed PRISMA guidelines. Hedges' g effect size statistic computed standard mean differences and 95% confidence intervals. Moderator analysis was conducted. RESULTS Among the included studies (65 for MCI and 61 for AD), odor identification exhibited larger effect sizes compared to odor threshold and discrimination, in both MCI and AD samples. Moderate effect size is found in OI scores in MCI (k = 65, SE = 0.078, CI 95% = [-1.151, -0.844]). Furthermore, compared to MCI, AD had moderate to large heterogeneous effects in olfactory identification (k = 61, g = -2.062, SE = 0.125, CI 95% = [-2.308, -1.816]). Global cognitive status is positively related to olfactory identification impairment in both MCI (k = 57, Z = 2.74, p = 0.006) and AD (k = 53, Z = 5.03, p < 0.0001) samples. CONCLUSION Olfactory impairments exhibit a notable and substantial presence in MCI. Among these impairments, odor identification experiences the greatest decline in MCI, mirroring the primary sensory deficit observed in AD. Consequently, the incorporation of a straightforward odor identification test is advisable in the evaluation of individuals vulnerable to the onset of AD, offering a practical screening tool for early detection.
Collapse
Affiliation(s)
- Jaime Bouhaben
- Experimental Psychology, Cognitive Processes and Speech Therapy Department, Faculty of Psychology, Complutense University of Madrid, 28223 Pozuelo de Alarcon, Spain
| | - Alice Helena Delgado-Lima
- Experimental Psychology, Cognitive Processes and Speech Therapy Department, Faculty of Psychology, Complutense University of Madrid, 28223 Pozuelo de Alarcon, Spain
| | - María Luisa Delgado-Losada
- Experimental Psychology, Cognitive Processes and Speech Therapy Department, Faculty of Psychology, Complutense University of Madrid, 28223 Pozuelo de Alarcon, Spain.
| |
Collapse
|
5
|
Bagheri S, Saboury AA, Saso L. Sequence of Molecular Events in the Development of Alzheimer's Disease: Cascade Interactions from Beta-Amyloid to Other Involved Proteins. Cells 2024; 13:1293. [PMID: 39120323 PMCID: PMC11312137 DOI: 10.3390/cells13151293] [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: 06/11/2024] [Revised: 07/26/2024] [Accepted: 07/30/2024] [Indexed: 08/10/2024] Open
Abstract
Alzheimer's disease is the primary neurodegenerative disease affecting the elderly population. Despite the first description of its pathology over a century ago, its precise cause and molecular mechanism remain unknown. Numerous factors, including beta-amyloid, tau protein, the APOEε4 gene, and different metals, have been extensively investigated in relation to this disease. However, none of them have been proven to have a decisive causal relationship. Furthermore, no single theory has successfully integrated these puzzle pieces thus far. In this review article, we propose the most probable molecular mechanism for AD, which clearly shows the relationship between the main aspects of the disease, and addresses fundamental questions such as: Why is aging the major risk factor for the disease? Are amyloid plaques and tau tangles the causes or consequences of AD? Why are the distributions of senile plaques and tau tangles in the brain different and independent of each other? Why is the APOEε4 gene a risk factor for AD? Finally, why is the disease more prevalent in women?
Collapse
Affiliation(s)
- Soghra Bagheri
- Medical Biology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah 6714415185, Iran
| | - Ali Akbar Saboury
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran 1417614335, Iran;
| | - Luciano Saso
- Department of Physiology and Pharmacology “Vittorio Erspamer”, Sapienza University, 00185 Rome, Italy;
| |
Collapse
|
6
|
Georgiopoulos C, Buechner MA, Falkenburger B, Engström M, Hummel T, Haehner A. Differential connectivity of the posterior piriform cortex in Parkinson's disease and postviral olfactory dysfunction: an fMRI study. Sci Rep 2024; 14:6256. [PMID: 38491209 PMCID: PMC10943068 DOI: 10.1038/s41598-024-56996-1] [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: 11/24/2023] [Accepted: 03/13/2024] [Indexed: 03/18/2024] Open
Abstract
Olfactory dysfunction is a common feature of both postviral upper respiratory tract infections (PV) and idiopathic Parkinson's disease (PD). Our aim was to investigate potential differences in the connectivity of the posterior piriform cortex, a major component of the olfactory cortex, between PV and PD patients. Fifteen healthy controls (median age 66 years, 9 men), 15 PV (median age 63 years, 7 men) and 14 PD patients (median age 70 years, 9 men) were examined with task-based olfactory fMRI, including two odors: peach and fish. fMRI data were analyzed with the co-activation pattern (CAP) toolbox, which allows a dynamic temporal assessment of posterior piriform cortex (PPC) connectivity. CAP analysis revealed 2 distinct brain networks interacting with the PPC. The first network included regions related to emotion recognition and attention, such as the anterior cingulate and the middle frontal gyri. The occurrences of this network were significantly fewer in PD patients compared to healthy controls (p = 0.023), with no significant differences among PV patients and the other groups. The second network revealed a dissociation between the olfactory cortex (piriform and entorhinal cortices), the anterior cingulate gyrus and the middle frontal gyri. This second network was significantly more active during the latter part of the stimulation, across all groups, possibly due to habituation. Our study shows how the PPC interacts with areas that regulate higher order processing and how this network is substantially affected in PD. Our findings also suggest that olfactory habituation is independent of disease.
Collapse
Affiliation(s)
- Charalampos Georgiopoulos
- Diagnostic Radiology, Department of Clinical Sciences, Medical Faculty, Lund University, Lund, Sweden.
- Department of Radiology, Section of Neuroradiology and Odontology, Skånes Universitetssjukhus, Entrégatan 7, 221 85, Lund, Sweden.
| | | | | | - Maria Engström
- Department of Health, Medicine, and Caring Sciences, Linköping University, Linköping, Sweden
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
| | - Thomas Hummel
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | - Antje Haehner
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| |
Collapse
|
7
|
Saraswathula A, Schlosser RJ, Rowan NR. Reimbursement for Olfactory Testing: A Growing Need at a Unique Time in History. JAMA Otolaryngol Head Neck Surg 2023; 149:567-568. [PMID: 37166819 PMCID: PMC11311117 DOI: 10.1001/jamaoto.2023.0837] [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] [Indexed: 05/12/2023]
Abstract
This Viewpoint addresses the lack of reimbursement for olfactory testing, which is especially important in a time when the populations of older adults and patients with COVID-19–associated olfactory dysfunction have grown.
Collapse
Affiliation(s)
- Anirudh Saraswathula
- Department of Otolaryngology–Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Rodney J. Schlosser
- Department of Otolaryngology–Head and Neck Surgery, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Nicholas R. Rowan
- Department of Otolaryngology–Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
8
|
Golub EM, Conner B, Edwards M, Gilllis L, Lacreuse A. Potential trade-off between olfactory and visual discrimination learning in common marmosets (Callithrix jacchus): Implications for the assessment of age-related cognitive decline. Am J Primatol 2022; 84:e23427. [PMID: 35942572 PMCID: PMC9444974 DOI: 10.1002/ajp.23427] [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: 02/07/2022] [Revised: 06/17/2022] [Accepted: 07/23/2022] [Indexed: 11/09/2022]
Abstract
Olfactory dysfunction has been identified as an early biomarker for dementia risk but has rarely been assessed in nonhuman primate models of human aging. To better characterize common marmosets as such models, we assessed olfactory discrimination performance in a sample of 10 animals (5 females), aged 2.5-8.9 years old. The monkeys were proficient in the discrimination and reversal of visual stimuli but naïve to odor stimuli. For olfactory discrimination, the monkeys performed a series of six discriminations of increasing difficulty between two odor stimuli. We found no evidence for an age-related decline as both young and older individuals were able to perform the discriminations in roughly the same number of trials. In addition, the older monkeys had faster responses than the younger animals. However, we noted that when adjusted for age, the speed of acquisition of the first discrimination in the olfactory modality was inversely correlated to the speed of acquisition of their first discrimination of two visual stimuli months earlier. These results suggest that marmosets may compensate for sensory deficits in one modality with higher sensory performance in another. These data have broad implications for the assessment of age-related cognitive decline and the categorization of animals as impaired or nonimpaired.
Collapse
Affiliation(s)
| | - Bryce Conner
- Department of Psychological and Brain Sciences, University of Massachusetts Amherst MA
| | - Mélise Edwards
- Neuroscience and Behavior Program, University of Massachusetts Amherst MA
| | - Lacey Gilllis
- Department of Psychological and Brain Sciences, University of Massachusetts Amherst MA
| | - Agnès Lacreuse
- Department of Psychological and Brain Sciences, University of Massachusetts Amherst MA
- Neuroscience and Behavior Program, University of Massachusetts Amherst MA
| |
Collapse
|
9
|
Yap AC, Mahendran R, Kua EH, Zhou W, Wang DY. Olfactory dysfunction is associated with mild cognitive impairment in community-dwelling older adults. Front Aging Neurosci 2022; 14:930686. [PMID: 36004001 PMCID: PMC9393534 DOI: 10.3389/fnagi.2022.930686] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 07/18/2022] [Indexed: 12/02/2022] Open
Abstract
Background Olfactory impairment is aging related and is associated with cognitive decline in older adults. However, it remains unclear if an olfactory impairment is associated with mild cognitive impairment (MCI) and the degree of impairment in the MCI subtypes. Materials and methods In a cohort of community-living older adults aged 60 years and above, 670 participants were recruited from the Community Health and Intergenerational (CHI) Study. Olfactory function was assessed using a locally developed nine-item smell test in association with neurocognitive assessments. Analysis of covariance (ANCOVA) was used to examine the association of smell identification score and clinical cognitive status while considering demographic, clinical, and neuropsychological factors with Bonferroni correction for group comparisons. Results Age-related smell detection between normal aging (NA) and MCI participants had no significant difference. The overall mean smell identification score in older adults was negatively correlated with age. The mean smell identification score of MCI participants was also not significantly different as compared with NA, but an amnestic MCI multiple domain (aMCI_MD) subgroup had significantly lower (impaired) mean smell identification scores compared with the NA and MCI single domain (amnestic and non-amnestic) group. Conclusion This study demonstrated that olfactory identification impairment is a comorbidity in older adults with amnestic MCI (aMCI) and is a potential marker associated with an early stage of a neurocognitive disorder. The smell test could act as a screening tool to help in the early detection of smell impairment for heterogeneous syndromes of MCI among community-dwelling older adults. Clinicians and researchers could benefit from utilizing the locally developed smell test to screen their patients or research participants before the initiation of an appropriate health intervention or in a clinical trial.
Collapse
Affiliation(s)
- Ai Che Yap
- Department of Food Science and Technology, National University of Singapore, Singapore, Singapore
| | - Rathi Mahendran
- Department of Psychological Medicine, Mind Science Centre, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Ee Heok Kua
- Department of Psychological Medicine, Mind Science Centre, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Department of Psychological Medicine, National University Hospital, Singapore, Singapore
- *Correspondence: Ee Heok Kua,
| | - Weibiao Zhou
- Department of Food Science and Technology, National University of Singapore, Singapore, Singapore
- Weibiao Zhou,
| | - De Yun Wang
- Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- De Yun Wang,
| |
Collapse
|
10
|
Overall KL. Canine olfaction: from detection to biomarkers. J Vet Behav 2022. [DOI: 10.1016/j.jveb.2022.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
11
|
Marín-Pardo D, Giménez-Llort L. Olfactory Signatures in the Food Finding Test in Mice With Normal and Alzheimer's Disease-Pathological Aging With Special Concerns on the Effects of Social Isolation. Front Neurosci 2021; 15:733984. [PMID: 34675767 PMCID: PMC8523944 DOI: 10.3389/fnins.2021.733984] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 08/31/2021] [Indexed: 12/17/2022] Open
Abstract
The temporal course and the severity of the involution of sensory systems through aging can be critical since they ensure the ability to perceive and recognize the world. In older people, sensory impairments significantly increase their risk of biological, psychological, and social impoverishment. Besides this, olfactory loss is considered an early biomarker in Alzheimer’s disease (AD) neurodegenerative process. Here we studied olfactory ethograms in middle-aged male and female gold-standard C57BL/6 mice and 3xTg-AD mice, a genetic model of AD that presents cognitive dysfunction and a conspicuous neuropsychiatric-like phenotype. A paradigm involving 1-day food deprivation was used to investigate the ethological patterns shown in the olfactory inspection of a new cage and the sniffing, finding, and eating of hidden food pellets. The sniffing–find–eat temporal patterns were independent of the loss of weight and unveiled (fast) olfactory signatures in Alzheimer’s disease, differing from those (slow progressive) in normal aging. Male 3xTg-AD mice exhibited an early signature than female mice, opposite to animals with normal aging. The sequence of actions was correlated in male and female 3xTg-AD mice in contrast to control mice. Social isolation, naturally occurring in male 3xTg-AD due to the death of cage mates, emphasized their olfactory patterns and disrupted the behavioral correlates. The paradigm provided distinct contextual, sex, and genotype olfactory ethogram signatures useful to investigate olfactory function in normal and AD-pathological aging. Isolation had an impact on enhancing the changes in the olfactory signature here described, for the first time, in the 3xTg-AD model of Alzheimer’s disease.
Collapse
Affiliation(s)
- Daniela Marín-Pardo
- Institut de Neurociències, Universitat Autònoma de Barcelona, Barcelona, Spain.,Department of Psychiatry and Forensic Medicine, School of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Lydia Giménez-Llort
- Institut de Neurociències, Universitat Autònoma de Barcelona, Barcelona, Spain.,Department of Psychiatry and Forensic Medicine, School of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
| |
Collapse
|
12
|
Xie Y, Zhi K, Meng X. Effects and Mechanisms of Synaptotagmin-7 in the Hippocampus on Cognitive Impairment in Aging Mice. Mol Neurobiol 2021; 58:5756-5771. [PMID: 34403042 DOI: 10.1007/s12035-021-02528-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 08/08/2021] [Indexed: 01/18/2023]
Abstract
Aging is an irreversible biological process that involves oxidative stress, neuroinflammation, and apoptosis, and eventually leads to cognitive dysfunction. However, the underlying mechanisms are not fully understood. In this study, we investigated the role and potential mechanisms of Synaptotagmin-7, a calcium membrane transporter in cognitive impairment in aging mice. Our results indicated that Synaptotagmin-7 expression significantly decreased in the hippocampus of D-galactose-induced or naturally aging mice when compared with healthy controls, as detected by western blot and quantitative reverse transcriptase-polymerase chain reaction analysis. Synaptotagmin-7 overexpression in the dorsal CA1 of the hippocampus reversed long-term potentiation and improved hippocampus-dependent spatial learning in D-galactose-induced aging mice. Synaptotagmin-7 overexpression also led to fully preserved learning and memory in 6-month-old mice. Mechanistically, we demonstrated that Synaptotagmin-7 improved learning and memory by elevating the level of fEPSP and downregulating the expression of aging-related genes such as p53 and p16. The results of our study provide new insights into the role of Synaptotagmin-7 in improving neuronal function and overcoming memory impairment caused by aging, suggesting that Synaptotagmin-7 overexpression may be an innovative therapeutic strategy for treating cognitive impairment.
Collapse
Affiliation(s)
- Yaru Xie
- Department of Neurobiology, Institute of Brain Research, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Kaining Zhi
- Department of Neurobiology, Institute of Brain Research, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Xianfang Meng
- Department of Neurobiology, Institute of Brain Research, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| |
Collapse
|
13
|
Activation of Endogenous Retrovirus, Brain Infections and Environmental Insults in Neurodegeneration and Alzheimer's Disease. Int J Mol Sci 2021; 22:ijms22147263. [PMID: 34298881 PMCID: PMC8303979 DOI: 10.3390/ijms22147263] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/29/2021] [Accepted: 07/03/2021] [Indexed: 12/18/2022] Open
Abstract
Chronic neurodegenerative diseases are complex, and their pathogenesis is uncertain. Alzheimer’s disease (AD) is a neurodegenerative brain alteration that is responsible for most dementia cases in the elderly. AD etiology is still uncertain; however, chronic neuroinflammation is a constant component of brain pathology. Infections have been associated with several neurological diseases and viruses of the Herpes family appear to be a probable cause of AD neurodegenerative alterations. Several different factors may contribute to the AD clinical progression. Exogeneous viruses or other microbes and environmental pollutants may directly induce neurodegeneration by activating brain inflammation. In this paper, we suggest that exogeneous brain insults may also activate retrotransposons and silent human endogenous retroviruses (HERVs). The initial inflammation of small brain areas induced by virus infections or other brain insults may activate HERV dis-regulation that contributes to neurodegenerative mechanisms. Chronic HERV activation in turn may cause progressive neurodegeneration that thereafter merges in cognitive impairment and dementia in genetically susceptible people. Specific treatment for exogenous end endogenous pathogens and decreasing pollutant exposure may show beneficial effect in early intervention protocol to prevent the progression of cognitive deterioration in the elderly.
Collapse
|
14
|
The Intersection of Parkinson's Disease, Viral Infections, and COVID-19. Mol Neurobiol 2021; 58:4477-4486. [PMID: 34033061 PMCID: PMC8143990 DOI: 10.1007/s12035-021-02408-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 04/27/2021] [Indexed: 02/08/2023]
Abstract
The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the causative agent of human COVID-19, not only causes flu-like symptoms and gut microbiome complications but a large number of infected individuals also experience a host of neurological symptoms including loss of smell and taste, seizures, difficulty concentrating, decreased alertness, and brain inflammation. Although SARS-CoV-2 infections are not more prevalent in Parkinson’s disease patients, a higher mortality rate has been reported not only associated with older age and longer disease duration, but also through several mechanisms, such as interactions with the brain dopaminergic system and through systemic inflammatory responses. Indeed, a number of the neurological symptoms seen in COVID-19 patients, as well as the alterations in the gut microbiome, are also prevalent in patients with Parkinson’s disease. Furthermore, biochemical pathways such as oxidative stress, inflammation, and protein aggregation have shared commonalities between Parkinson’s disease and COVID-19 disease progression. In this review, we describe and compare the numerous similarities and intersections between neurodegeneration in Parkinson’s disease and RNA viral infections, emphasizing the current SARS-CoV-2 global health crisis.
Collapse
|
15
|
Murdaca G, Banchero S, Tonacci A, Nencioni A, Monacelli F, Gangemi S. Vitamin D and Folate as Predictors of MMSE in Alzheimer's Disease: A Machine Learning Analysis. Diagnostics (Basel) 2021; 11:diagnostics11060940. [PMID: 34073931 PMCID: PMC8225187 DOI: 10.3390/diagnostics11060940] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 05/21/2021] [Accepted: 05/23/2021] [Indexed: 12/13/2022] Open
Abstract
Vitamin D (VD) and micronutrients, including folic acid, are able to modulate both the innate and the adaptive immune responses. Low VD and folic acid levels appear to promote cognitive decline as in Alzheimer’s disease (AD). A machine learning approach was applied to analyze the impact of various compounds, drawn from the blood of AD patients, including VD and folic acid levels, on the Mini-Mental State Exam (MMSE) in a cohort of 108 patients with AD. The first analysis was aimed at predicting the MMSE at recruitment, whereas a second investigation sought to predict the MMSE after a 4 year follow-up. The simultaneous presence of low levels of VD and folic acid allow to predict MMSE, suggestive of poorer cognitive function. Such results suggest that the low levels of VD and folic acid could be associated with more severe cases of cognitive impairment in AD. It could be hypothesized that simultaneous supplementation of VD and folic acid could slow down the progression of cerebral degeneration at least in a subset of AD individuals.
Collapse
Affiliation(s)
- Giuseppe Murdaca
- Department of Internal Medicine, University of Genoa, 16132 Genoa, Italy; (G.M.); (S.B.); (A.N.); (F.M.)
- Ospedale Policlinico San Martino IRCCS, 16132 Genoa, Italy
| | - Sara Banchero
- Department of Internal Medicine, University of Genoa, 16132 Genoa, Italy; (G.M.); (S.B.); (A.N.); (F.M.)
- Ospedale Policlinico San Martino IRCCS, 16132 Genoa, Italy
| | - Alessandro Tonacci
- Clinical Physiology Institute, National Research Council of Italy (IFC-CNR), 56124 Pisa, Italy
- Correspondence: ; Tel.: +39-050-3152175
| | - Alessio Nencioni
- Department of Internal Medicine, University of Genoa, 16132 Genoa, Italy; (G.M.); (S.B.); (A.N.); (F.M.)
- Ospedale Policlinico San Martino IRCCS, 16132 Genoa, Italy
| | - Fiammetta Monacelli
- Department of Internal Medicine, University of Genoa, 16132 Genoa, Italy; (G.M.); (S.B.); (A.N.); (F.M.)
- Ospedale Policlinico San Martino IRCCS, 16132 Genoa, Italy
| | - Sebastiano Gangemi
- School and Operative Unit of Allergy and Clinical Immunology, Department of Clinical and Experimental Medicine, University of Messina, 98125 Messina, Italy;
| |
Collapse
|
16
|
Erichsen JM, Calva CB, Reagan LP, Fadel JR. Intranasal insulin and orexins to treat age-related cognitive decline. Physiol Behav 2021; 234:113370. [PMID: 33621561 PMCID: PMC8053680 DOI: 10.1016/j.physbeh.2021.113370] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 02/19/2021] [Indexed: 02/06/2023]
Abstract
The intranasal (IN) administration of neuropeptides, such as insulin and orexins, has been suggested as a treatment strategy for age-related cognitive decline (ARCD). Because dysfunctional neuropeptide signaling is an observed characteristic of ARCD, it has been suggested that IN delivery of insulin and/or orexins may restore endogenous peptide signaling and thereby preserve cognition. IN administration is particularly alluring as it is a relatively non-invasive method that directly targets peptides to the brain. Several laboratories have examined the behavioral effects of IN insulin in young, aged, and cognitively impaired rodents and humans. These studies demonstrated improved performance on various cognitive tasks following IN insulin administration. Fewer laboratories have assessed the effects of IN orexins; however, this peptide also holds promise as an effective treatment for ARCD through the activation of the cholinergic system and/or the reduction of neuroinflammation. Here, we provide a brief overview of the advantages of IN administration and the delivery pathway, then summarize the current literature on IN insulin and orexins. Additional preclinical studies will be useful to ultimately uncover the mechanisms underlying the pro-cognitive effects of IN insulin and orexins, whereas future clinical studies will aid in the determination of the most efficacious dose and dosing paradigm. Eventually, IN insulin and/or orexin administration may be a widely used treatment strategy in the clinic for ARCD.
Collapse
Affiliation(s)
- Jennifer M Erichsen
- University of South Carolina School of Medicine, Department of Pharmacology, Physiology, and Neuroscience, Columbia, SC 29208, United States.
| | - Coleman B Calva
- University of South Carolina School of Medicine, Department of Pharmacology, Physiology, and Neuroscience, Columbia, SC 29208, United States
| | - Lawrence P Reagan
- University of South Carolina School of Medicine, Department of Pharmacology, Physiology, and Neuroscience, Columbia, SC 29208, United States; Columbia VA Health Care System, Columbia, SC, 29208, United States
| | - Jim R Fadel
- University of South Carolina School of Medicine, Department of Pharmacology, Physiology, and Neuroscience, Columbia, SC 29208, United States
| |
Collapse
|
17
|
Pontifex MG, Malik MMAH, Connell E, Müller M, Vauzour D. Citrus Polyphenols in Brain Health and Disease: Current Perspectives. Front Neurosci 2021; 15:640648. [PMID: 33679318 PMCID: PMC7933480 DOI: 10.3389/fnins.2021.640648] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 01/25/2021] [Indexed: 12/17/2022] Open
Abstract
In addition to essential micronutrients such as vitamin C, citrus fruits represent a considerably rich source of non-essential bioactive compounds, in particular flavanones which form a sub-set of the flavonoid group. Preclinical studies have demonstrated the neuroprotective potential of citrus flavonoids and have highlighted both the well-established (anti-inflammatory and anti-oxidative properties), and newly emerging (influence upon blood-brain barrier function/integrity) mechanistic actions by which these neurological effects are mediated. Encouragingly, results from human studies, although limited in number, appear to support this preclinical basis, with improvements in cognitive performance and disease risk observed across healthy and disease states. Therefore, citrus fruits - both as whole fruit and 100% juices - should be encouraged within the diet for their potential neurological benefit. In addition, there should be further exploration of citrus polyphenols to establish therapeutic efficacy, particularly in the context of well-designed human interventions.
Collapse
Affiliation(s)
- Matthew G Pontifex
- Norwich Medical School, Biomedical Research Centre, Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, United Kingdom
| | - Mohammad M A H Malik
- Norwich Medical School, Biomedical Research Centre, Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, United Kingdom
| | - Emily Connell
- Norwich Medical School, Biomedical Research Centre, Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, United Kingdom
| | - Michael Müller
- Norwich Medical School, Biomedical Research Centre, Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, United Kingdom
| | - David Vauzour
- Norwich Medical School, Biomedical Research Centre, Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, United Kingdom
| |
Collapse
|
18
|
Delgado-Losada ML, Bouhaben J, Delgado-Lima AH. Development of the Spanish Version of Sniffin's Sticks Olfactory Identification Test: Normative Data and Validity of Parallel Measures. Brain Sci 2021; 11:216. [PMID: 33578970 PMCID: PMC7916642 DOI: 10.3390/brainsci11020216] [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: 01/15/2021] [Revised: 02/04/2021] [Accepted: 02/06/2021] [Indexed: 12/22/2022] Open
Abstract
The Sniffin' Sticks Olfactory Identification Test is a tool for measurement of olfactory performance developed in Germany and validated in several countries. This research aims to develop the Spanish version of the Sniffin' Sticks Olfactory Identification Test and obtain normative values for the Spanish population. The parameters are free recall and subjective intensity of odorants are included. The influence of possible demographic covariates such as sex, age, smoking, or educational level are analyzed, and the items that best discriminate are studied. In addition, the internal structure validity of the blue and purple versions is studied as a parallel measure, and a cultural adaptation of the purple version is carried out. For this, three independent samples of normosmic healthy volunteers were studied. To obtain normative values, the sample was of 417 participants (18-89 years). For the internal structure validity study of both versions, the sample was 226 (18-70 years), and for familiarity of the purple version, the sample was 75 participants (21-79 years). Results indicated that men and women and smokers and non-smokers perform equally. However, differences were found as age progresses, being more pronounced after 60 years old in all three measurements of the identification test. This research also provides the items that best discriminate in the blue version and a cultural adaptation for the purple version. In conclusion, the Sniffin' Sticks Odor Identification Test is a suitable tool for olfactory assessment in the Spanish population. The instrument has been expanded with two new scores, and normative data as a function of age are provided. Its parallel version also seems appropriate for testing, as items have been culturally adapted and evidence of internal structure validity for both versions is reported.
Collapse
Affiliation(s)
- María Luisa Delgado-Losada
- Experimental Psychology, Cognitive Processes and Speech Therapy Department, Faculty of Psychology, Complutense University of Madrid, Campus de Somosaguas, 28223 Pozuelo de Alarcón, Spain; (J.B.); (A.H.D.-L.)
| | | | | |
Collapse
|
19
|
Spanish Validation for Olfactory Function Testing Using the Sniffin' Sticks Olfactory Test: Threshold, Discrimination, and Identification. Brain Sci 2020; 10:brainsci10120943. [PMID: 33297359 PMCID: PMC7762307 DOI: 10.3390/brainsci10120943] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/04/2020] [Accepted: 12/04/2020] [Indexed: 12/14/2022] Open
Abstract
The assessment of olfactory function is becoming increasingly relevant, especially in cases of cognitive decline (i.e., neurodegenerative diseases), where olfactory alterations may be relevant as potential early biomarkers. The Sniffin' Sticks Olfactory Test, developed in Germany and validated in several countries, is an objective measure of olfactory performance. This study aims to validate this test in a Spanish sample. This study included 209 healthy normosmic volunteers (154 females and 55 males) aged between 20 to 79 years (mean age = 50.11 ± 15.18 years) as the normative sample. From this group, 22 participants were retested in order to obtain test-retest reliability evidence. Odor familiarity for descriptors in the olfactory identification test was also studied on an independent healthy sample (n = 69), and required cultural modifications were applied. Results indicate that men and women, as well as smokers and non-smokers, performed equally in every test. However, significant differences were found between age groups in every score. The general trend is that olfactory function progressively decreases as a function of age, the elderly group (+60 years) being the one with the lowest scores. In conclusion, this normative data, in addition to the test's cultural modifications, allows the Sniffin' Sticks Olfactory Test to be administered on a Spanish population.
Collapse
|