| 1. |
- Olofsson, Jonas K, 1965-, et al.
(författare)
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Odor identification impairment in carriers of ApoE-ε4 is independent of clinical dementia
- 2010
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Ingår i: Neurobiology of Aging. - : Elsevier. - 0197-4580 .- 1558-1497. ; 31:4, s. 567-577
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Tidskriftsartikel (refereegranskat)abstract
- The ApoE gene is expressed in olfactory brain structures and is believed to play a role in neuronal regenerative processes as well as in development of Alzheimer's disease (AD), the most common form of dementia. The ε4 allele has been reported to be associated with compromised odor identification ability in the elderly, and this deficit has been interpreted as a sign of pre-diagnostic AD. However, because it has not been demonstrated that the relationship between the ε4 allele and odor identification is mediated by dementia, it is possible that the ε4 allele may have an effect on odor identification over and above any effects of dementia. The present study investigated effects of ApoE-status on odor identification in a large, population-based sample (n = 1236) of adults (45–80 years), who were assessed for dementia at time of testing and 5 years later. The results showed that the ε4 allele was associated with an odor identification deficit among elderly participants (75–80). Critically, this effect remained after current and pre-diagnostic dementia, vocabulary, global cognitive status and health variables were partialled out. The present results suggest that the ApoE gene plays a role in olfactory functioning that is independent of dementia conversion within 5 years.
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| 2. |
- Andersson, Pernilla, 1992-, et al.
(författare)
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The association between control of interference and white-matter integrity : A cross-sectional and longitudinal investigation
- 2022
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Ingår i: Neurobiology of Aging. - : Elsevier. - 0197-4580 .- 1558-1497. ; 114, s. 49-60
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Tidskriftsartikel (refereegranskat)abstract
- Proactive interference (PI) occurs when old information interferes with newly acquired information and has been suggested as a major cause of forgetting in working memory. In this study, we investigate cross-sectional (N = 267) and longitudinal (N = 148) associations between PI and white-matter integrity (WMI) using diffusion-weighted imaging in an adult life-span sample (25-80 years; Mage = 60.15; 138 female). Older age was related to higher PI and lower WMI. Cross-sectional analyses showed associations between PI and WMI spanning several white-matter tracts as well as globally, suggesting that the age-related decline in PI may be driven primarily by global changes in WMI. Furthermore, longitudinal changes in PI were shown to be negatively correlated with concurrent changes in WMI in the fornix. Mediation analyses showed that WMI mediated the relationship between age and PI only in older adults, indicating that WMI becomes increasingly connected to cognitive functioning with increasing age. This is the first demonstration of WMI decline contributing to the age-related decline in PI.
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| 3. |
- Avelar-Pereira, Barbara, et al.
(författare)
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Increased functional homotopy of the prefrontal cortex is associated with corpus callosum degeneration and working memory decline
- 2020
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Ingår i: Neurobiology of Aging. - : Elsevier. - 0197-4580 .- 1558-1497. ; 96, s. 68-78
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Tidskriftsartikel (refereegranskat)abstract
- Functional homotopy reflects the link between spontaneous activity in a voxel and its counterpart in the opposite hemisphere. Alterations in homotopic functional connectivity (FC) are seen in normal aging, with highest and lowest homotopy being present in sensory-motor and higher-order regions, respectively. Homotopic FC relates to underlying structural connections, but its neurobiological underpinnings remain unclear. The genu of the corpus callosum joins symmetrical parts of the prefrontal cortex (PFC) and is susceptible to age-related degeneration, suggesting that PFC homotopic connectivity is linked to changes in white-matter integrity. We investigated homotopic connectivity changes and whether these were associated with white-matter integrity in 338 individuals. In addition, we examined whether PFC homotopic FC was related to changes in the genu over 10 years and working memory over 5 years. There were increases and decreases in functional homotopy, with the former being prevalent in subcortical and frontal regions. Increased PFC homotopic FC was partially driven by structural degeneration and negatively associated with working memory, suggesting that it reflects detrimental age-related changes. (C) 2020 The Author(s). Published by Elsevier Inc.
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| 4. |
- Betts, Matthew J., et al.
(författare)
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Learning in anticipation of reward and punishment : perspectives across the human lifespan
- 2020
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Ingår i: Neurobiology of Aging. - : Elsevier BV. - 0197-4580 .- 1558-1497. ; 96, s. 49-57
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Tidskriftsartikel (refereegranskat)abstract
- Learning to act to receive reward and to withhold to avoid punishment has been found to be easier than learning the opposite contingencies in young adults. To what extent this type of behavioral adaptation might develop during childhood and adolescence and differ during aging remains unclear. We therefore tested 247 healthy individuals across the human life span (7–80 years) with an orthogonalized valenced go/no-go learning task. Computational modeling revealed that peak performance in young adults was attributable to greater sensitivity to both reward and punishment. However, in children and adolescents, we observed an increased bias toward action but not reward sensitivity. By contrast, reduced learning in midlife and older adults was accompanied by decreased reward sensitivity and especially punishment sensitivity along with an age-related increase in the Pavlovian bias. These findings reveal distinct motivation-dependent learning capabilities across the human life span, which cannot be probed using conventional go/reward no-go/punishment style paradigms that have important implications in lifelong education.
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| 5. |
- Bäckman, Lars, et al.
(författare)
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Dopamine D(1) receptors and age differences in brain activation during working memory
- 2011
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Ingår i: Neurobiology of Aging. - Fayetteville, N.Y : Elsevier. - 0197-4580 .- 1558-1497. ; 32:10, s. 1849-1856
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Tidskriftsartikel (refereegranskat)abstract
- In an fMRI study, 20 younger and 20 healthy older adults were scanned while performing a spatial working-memory task under two levels of load. On a separate occasion, the same subjects underwent PET measurements using the radioligand [(11)C] SCH23390 to determine dopamine D(1) receptor binding potential (BP) in caudate nucleus and dorsolateral prefrontal cortex (DLPFC). The fMRI study revealed a significant load modulation of brain activity (higher load>lower load) in frontal and parietal regions for younger, but not older, adults. The PET measurements showed marked age-related reductions of D(1) BP in caudate and DLPFC. Statistical control of caudate and DLPFC D(1) binding eliminated the age-related reduction in load-dependent BOLD signal in left frontal cortex, and attenuated greatly the reduction in right frontal and left parietal cortex. These findings suggest that age-related alterations in dopaminergic neurotransmission may contribute to underrecruitment of task-relevant brain regions during working-memory performance in old age.
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| 6. |
- Darreh-Shori, Taher, et al.
(författare)
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Differential levels of apolipoprotein E and butyrylcholinesterase show strong association with pathological signs of Alzheimer's disease in the brain in vivo
- 2011
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Ingår i: Neurobiology of Aging. - : Elsevier. - 0197-4580 .- 1558-1497. ; 32:12, s. 2320.e15-2320.e32
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Tidskriftsartikel (refereegranskat)abstract
- Recently, we reported that 3 of the known risk factors of Alzheimer's disease (AD), i.e., advanced age, apolipoprotein E (ApoE) ε4, and female gender, are associated with differential levels of ApoE proteins and butyrylcholinesterase (BuChE) in the cerebrospinal fluid (CSF) of AD patients. The ApoE ε4 allele and certain BuChE polymorphisms synergistically affect the conversion rate of mild cognitive impairment (MCI) to AD. Here, we investigated interrelationships between ApoE and BuChE levels, and pathological markers of AD in vivo. CSF from patients with probable AD, assessed for cerebral glucose metabolism (CMRglc; n = 50) and Pittsburgh compound B (PIB) retention (β-amyloid [Aβ] load, n = 29) by positron emission tomography (PET), was used for measurement of BuChE, ApoE, Aβ, tau, phosphorylated tau (P-tau) and interleukin-1β (IL-1β) levels. Levels of ApoE and BuChE strongly correlated with CMRglc (fluorodeoxyglucose [FDG]-PET, r = 0.54, p < 0.0001, n = 50), cerebral Aβ load (PIB retention, r = 0.73, p < 0.0001, n = 29), and CSF P-tau (r = 0.73, p < 0.0001, n = 33). High ApoE protein was tied to low CMRglc and high PIB retention and P-tau. BuChE levels had opposite relationships. Other CSF covariates were levels of interleukin-1β and Aβ42peptide. The pattern of the patients' cognitive Z-scores strongly supported these observations. High ApoE protein was also linked to changes in 3 of the biodynamic properties of BuChE. In vitro analysis indicated that high ApoE protein levels were related to an increased pool of dormant BuChE molecules with an abnormally high intrinsic catalytic rate in CSF, which was “turned on” by excess Aβ peptides. The findings suggest that abnormally high levels of ApoE may play a causative role in the pathological events of AD, particularly those involving the early cholinergic deficit in the AD brain, through modulation of cholinesterases activities, hence disturbing the acetylcholine-dependent activity of neurons and nonexcitable cells such as glial cells.
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| 7. |
- Darreh-Shori, Taher, et al.
(författare)
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Functional variability in butyrylcholinesterase activity regulates intrathecal cytokine and astroglial biomarker profiles in patients with Alzheimer's disease
- 2013
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Ingår i: Neurobiology of Aging. - : Elsevier BV. - 0197-4580 .- 1558-1497. ; 34:11, s. 2465-2481
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Tidskriftsartikel (refereegranskat)abstract
- Butyrylcholinesterase (BuChE) activity is associated with activated astrocytes in Alzheimer's disease brain. The BuChE-K variant exhibits 30%-60% reduced acetylcholine (ACh) hydrolyzing capacity. Considering the increasing evidence of an immune-regulatory role of ACh, we investigated if genetic heterogeneity in BuChE affects cerebrospinal fluid (CSF) biomarkers of inflammation and cholinoceptive glial function. Alzheimer's disease patients (n = 179) were BCHE-K-genotyped. Proteomic and enzymatic analyses were performed on CSF and/or plasma. BuChE genotype was linked with differential CSF levels of glial fibrillary acidic protein, S100B, interleukin-1 beta, and tumor necrosis factor (TNF)-alpha. BCHE-K noncarriers displayed 100%-150% higher glial fibrillary acidic protein and 64%-110% higher S100B than BCHE-K carriers, who, in contrast, had 40%-80% higher interleukin-1b and 21%-27% higher TNF-alpha compared with noncarriers. A high level of CSF BuChE enzymatic phenotype also significantly correlated with higher CSF levels of astroglial markers and several factors of the innate complement system, but lower levels of proinflammatory cytokines. These individuals also displayed beneficial paraclinical and clinical findings, such as high cerebral glucose utilization, low beta-amyloid load, and less severe progression of clinical symptoms. In vitro analysis on human astrocytes confirmed the involvement of a regulated BuChE status in the astroglial responses to TNF-alpha and ACh. Histochemical analysis in a rat model of nerve injury-induced neuroinflammation, showed focal assembly of astroglial cells in proximity of BuChE-immunolabeled sites. In conclusion, these results suggest that BuChE enzymatic activity plays an important role in regulating intrinsic inflammation and activity of cholinoceptive glial cells and that this might be of clinical relevance. The dissociation between astroglial markers and inflammatory cytokines indicates that a proper activation and maintenance of astroglial function is a beneficial response, rather than a disease-driving mechanism. Further studies are needed to explore the therapeutic potential of manipulating BuChE activity or astroglial functional status. (C) 2013 Elsevier Inc. All rights reserved.
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| 8. |
- Dintica, Christina S., et al.
(författare)
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Tooth loss is associated with accelerated cognitive decline and volumetric brain differences : a population-based study
- 2018
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Ingår i: Neurobiology of Aging. - : Elsevier BV. - 0197-4580 .- 1558-1497. ; 67, s. 23-30
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Tidskriftsartikel (refereegranskat)abstract
- Tooth loss has been related to cognitive impairment; however, its relation to structural brain differences in humans is unknown. Dementia-free participants (n = 2715) of age >= 60 years were followed up for up to 9 years. A subsample (n = 394) underwent magnetic resonance imaging at baseline. Information on tooth loss was collected at baseline, and cognitive function was assessed using the Mini-Mental State Examination at baseline and at follow-ups. Data were analyzed using linear mixed effects models and linear regression models. At baseline, 404 (14.9%) participants had partial tooth loss, and 206 (7.6%) had complete tooth loss. Tooth loss was significantly associated with a steeper cognitive decline (beta: -0.18, 95% confidence interval [CI]: -0.24 to -0.11) and remained significant after adjusting for or stratifying by potential confounders. In cross-sectional analyses, persons with complete or partial tooth loss had significantly lower total brain volume (beta: -28.89, 95% CI: -49.33 to -8.45) and gray matter volume (beta: -22.60, 95% CI: -38.26 to -6.94). Thus, tooth loss may be a risk factor for accelerated cognitive aging.
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| 9. |
- Enache, Daniela, et al.
(författare)
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CAIDE Dementia Risk Score and biomarkers of neurodegeneration in memory clinic patients without dementia
- 2016
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Ingår i: Neurobiology of Aging. - : Elsevier BV. - 0197-4580 .- 1558-1497. ; 42, s. 124-131
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to explore cross-sectional associations between Cardiovascular Risk Factors, Aging and Dementia Study (CAIDE) Dementia Risk Score and dementia-related cerebrospinal fluid and neuroimaging biomarkers in 724 patients without dementia from the Memory Clinic at Karolinska University Hospital, Huddinge, Sweden. We additionally evaluated the score's capacity to predict dementia. Two risk score versions were calculated: one including age, gender, obesity, hyperlipidemia, and hypertension; and one additionally including apolipoprotein E (APOE) ε4 carrier status. Cerebrospinal fluid was analyzed for amyloid β (Aβ), total tau, and phosphorylated tau. Visual assessments of medial temporal lobe atrophy (MTA), global cortical atrophy-frontal subscale, and Fazekas scale for white matter changes (WMC) were performed. Higher CAIDE Dementia Risk Score (version without APOE) was significantly associated with higher total tau, more severe MTA, WMC, and global cortical atrophy-frontal subscale. Higher CAIDE Dementia Risk Score (version with APOE) was associated with reduced Aβ, more severe MTA, and WMC. CAIDE Dementia Risk Score version with APOE seemed to predict dementia better in this memory clinic population with short follow-up than the version without APOE.
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| 10. |
- Ferrari, Camilla, et al.
(författare)
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How can elderly apolipoprotein E epsilon 4 carriers remain free from dementia?
- 2013
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Ingår i: Neurobiology of Aging. - : Elsevier BV. - 0197-4580 .- 1558-1497. ; 34:1, s. 13-21
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Tidskriftsartikel (refereegranskat)abstract
- Apolipoprotein E (APOE) epsilon 4 is a major risk factor for Alzheimer's disease (AD) and dementia, but not all epsilon 4 carriers develop dementia. We sought to identify factors that may play a role in modifying the risk of dementia due to epsilon 4. A cognitively intact cohort (n = 932, age >= 75) was followed for 9 years to detect incident dementia cases. At baseline, information on education, leisure activities, and vascular risk factors was collected, and APOE was genotyped. During the follow-up, 324 subjects developed dementia, including 247 AD cases. The hazard ratio (HR, 95% confidence interval [95% CI]) of dementia related to the epsilon 4 was 1.39 (1.11-1.76), while the risk was reduced when epsilon 4 carriers had high education, no vascular risk factors, or high score of leisure activities. Among epsilon 4 carriers, the multiadjusted HRs of dementia that were associated with high education, high level of leisure activities, and absence of vascular risk factors were 0.59 (0.40-0.87), 0.49 (0.29-0.85), and 0.61 (0.41-0.90), respectively. The epsilon 4 carriers with these factors had about 1.2 years delayed time to dementia onset compared with those without these factors. High education, active leisure activities, or maintaining vascular health seems to reduce the risk of dementia related to APOE epsilon 4. The epsilon 4 carriers with these characteristics appear to have similar dementia-free survival time to non-epsilon 4 carriers.
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