1. |
- Abulafia, C., et al.
(author)
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Relationship between Cognitive and Sleep-wake Variables in Asymptomatic Offspring of Patients with Late-onset Alzheimer's Disease
- 2017
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In: Frontiers in Aging Neuroscience. - : Frontiers Media SA. - 1663-4365. ; 9
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Journal article (peer-reviewed)abstract
- Early neuropathological changes characteristic of late-onset Alzheimer's disease (LOAD) involve brain stem and limbic structures that regulate neurovegetative functions, including sleep-wake rhythm. Indeed, sleep pattern is an emerging biomarker and a potential pathophysiological mechanism in LOAD. We hypothesized that cognitively asymptomatic, middle-aged offspring of patients with LOAD (O-LOAD) would display a series of circadian rhythm abnormalities prior to the onset of objective cognitive alterations. We tested 31 children of patients with LOAD (O-LOAD) and 19 healthy individuals without family history of Alzheimer's disease (control subjects, CS) with basic tests of cognitive function, as well as actigraphy measures of sleep-wake rhythm, cardiac autonomic function, and bodily temperature. Unexpectedly, O-LOAD displayed subtle but significant deficits in verbal episodic memory (Rey Auditory Verbal Learning Test delayed recall 10.6 +/- 0.4 vs. 8.6 +/- 0.6, t = 4.97, df = 49, p < 0.01) and language (Weschler's vocabulary 51.4 +/- 1.3 vs. 44.3 +/- 1.5, t = 2.49, df = 49, p < 0.001) compared to CS, even though all participants had results within the clinically normal range. O-LOAD showed a phase-delayed rhythm of body temperature (2.56 +/- 0.47 h vs. 3.8 +/- 0.26 h, t = 2.48, df = 40, p = 0.031). Cognitive performance in O-LOAD was associated with a series of cardiac autonomic sleep-wake variables; specifically indicators of greater sympathetic activity at night were related to poorer cognition. The present results suggest sleep pattern deserves further study as a potential neurobiological signature in LOAD, even in middle-aged, at risk individuals.
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3. |
- Adelöf, Julia, 1990, et al.
(author)
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Survival-Span Method: How to Qualitatively Estimate Lifespan to Improve the Study of Aging, and not Disease, in Aging Studies
- 2021
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In: Frontiers in Aging. - : Frontiers Media SA. - 1663-4365 .- 2673-6217. ; 2
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Journal article (peer-reviewed)abstract
- Lifespan analyses are important for advancing our understanding of the aging process. There are two major issues in performing lifespan studies: 1) late-stage animal lifespan analysis may include animals with non-terminal, yet advanced illnesses, which can pronounce indirect processes of aging rather than the aging process per se and 2) they often involves challenging welfare considerations. Herein, we present an option to the traditional way of performing lifespan studies by using a novel method that generates high-quality data and allows for the inclusion of excluded animals, even animals removed at early signs of disease. This Survival-span method is designed to be feasibly done with simple means by any researcher and strives to improve the quality of aging studies and increase animal welfare.
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4. |
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5. |
- Aksnes, M, et al.
(author)
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Comparison of Cerebrospinal Fluid Amyloidogenic Nanoplaques With Core Biomarkers of Alzheimer's Disease
- 2021
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In: Frontiers in aging neuroscience. - : Frontiers Media SA. - 1663-4365. ; 12, s. 608628-
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Journal article (peer-reviewed)abstract
- Accurate biomarkers of Alzheimer’s disease (AD) are essential for early diagnosis and intervention. Available biomarkers are not sufficient to permit the monitoring of AD progression over time, and additional biomarkers are required. Measures of aggregated amyloid-β (Aβ) could be useful biomarkers for AD. Here, we investigate whether levels of Thioflavin-T (ThT) positive amyloid aggregates, i.e., nanoplaques, in cerebrospinal fluid (CSF) could serve as useful biomarkers for AD. One-hundred and eighteen memory clinic patients were AT(N) classified, and CSF nanoplaque concentrations were compared between patients on the “Alzheimer’s continuum” (A+ patients) and patients with “Normal AD biomarkers” or “Non-AD pathologic change” (A− patients). CSF nanoplaque concentrations and sizes were quantified using the novel ThT-Fluorescence Correlation Spectroscopy (ThT-FCS) assay, and core biomarkers (Aβ42, total tau and phosphorylated tau) were determined by enzyme-linked immunosorbent assays. We investigated the association between nanoplaque concentrations and core biomarkers, and the diagnostic value of nanoplaque levels. Nanoplaque levels were increased in A+ patients compared to A− patients. Nanoplaque concentrations were negatively associated with Aβ42, but not related to total tau or phosphorylated tau measures. Quantification of nanoplaques did not improve the classification of patients on the Alzheimer’s continuum compared to the core biomarkers alone. Dynamic changes in nanoplaques concentration and size throughout AD stages should be explored in longitudinal studies.
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6. |
- Almkvist, Ove, et al.
(author)
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Practice effects in cognitive assessments three years later in non-carriers but not in symptom-free mutation carriers of autosomal-dominant Alzheimer's disease : Exemplifying procedural learning and memory?
- 2022
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In: Frontiers in Aging Neuroscience. - : Frontiers Media SA. - 1663-4365. ; 14
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Journal article (peer-reviewed)abstract
- Practice effects (PEs) defined as an improvement of performance in cognition due to repeated assessments between sessions are well known in unimpaired individuals, while less is known about impaired cognition and particularly in latent brain disease as autosomal-dominant Alzheimer's disease. The purpose was to evaluate the general (across tests/domains) and domain-specific PE calculated as the annual rate of change (ARC) in relation to years to the estimated disease onset (YECO) and in four groups of AD: asymptomatic mutation carriers (aAD, n = 19), prodromal, i.e., symptomatic mutation carriers, criteria for AD diagnosis not fulfilled (pAD, n = 4) and mutation carriers diagnosed with AD (dAD, n = 6) as well as mutation non-carriers from the AD families serving as a healthy comparison group (HC, n = 35). Cognition was assessed at baseline and follow-up about 3 years later by 12 tests covering six domains. The aAD and HC groups were comparable at baseline in demographic characteristics (age, gender, and education), when they were in their early forties, while the pAD and dAD groups were older and cognitively impaired. The results on mean ARC for the four groups were significantly different, small, positive, and age-insensitive in the HC group, while ARC was negative and declined with time/disease advancement in AD. The differences between HC and aAD groups in mean ARC and domain-specific ARC were not significant, indicating a subtle PE in aAD in the early preclinical stage of AD. In the symptomatic stages of AD, there was no PE probably due to cognitive disease-related progression. PEs were the largest in the verbal domain in both the HC and aAD groups, indicating a relationship with cognitive vulnerability. The group-related difference in mean ARC was predominant in timekeeping tests. To conclude, the practice effect in over 3 years was suggested to be linked to procedural learning and memory.
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7. |
- Alonso-Bellido, Isabel M., et al.
(author)
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The Other Side of SARS-CoV-2 Infection : Neurological Sequelae in Patients
- 2021
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In: Frontiers in Aging Neuroscience. - : Frontiers Media SA. - 1663-4365. ; 13
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Research review (peer-reviewed)abstract
- The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread around the globe causing coronavirus disease 2019 (COVID-19). Because it affects the respiratory system, common symptoms are cough and breathing difficulties with fever and fatigue. Also, some cases progress to acute respiratory distress syndrome (ARDS). The acute phase of COVID-19 has been also related to nervous system symptoms, including loss of taste and smell as well as encephalitis and cerebrovascular disorders. However, it remains unclear if neurological complications are due to the direct viral infection of the nervous system, or they appear as a consequence of the immune reaction against the virus in patients who presented pre-existing deficits or had a certain detrimental immune response. Importantly, the medium and long-term consequences of the infection by SARS-CoV-2 in the nervous system remain at present unknown. This review article aims to give an overview of the current neurological symptoms associated with COVID-19, as well as attempting to provide an insight beyond the acute affectation.
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8. |
- Altorfer, P, et al.
(author)
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Feasibility of Cognitive-Motor Exergames in Geriatric Inpatient Rehabilitation: A Pilot Randomized Controlled Study
- 2021
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In: Frontiers in aging neuroscience. - : Frontiers Media SA. - 1663-4365. ; 13, s. 739948-
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Journal article (peer-reviewed)abstract
- Objective: The aim of this pilot randomized clinical trial was to test the feasibility and efficacy of an exergame-based cognitive-motor training program in geriatric inpatients.Methods: The study participants were randomly allocated to either the exergame intervention group or the control group. The control group received the standard rehabilitation treatment offered in the clinic. In addition to the standard rehabilitation program, the intervention group conducted supervised exergame training on 5 days per week using the Dividat Senso, an exergame system specifically designed for older adults. The primary outcome was feasibility, as measured by e.g., adherence rate, attrition rate, occurrence of adverse events, System Usability Scale (SUS) and NASA-TLX score. Secondary outcomes included measures of physical and cognitive functioning such as comfortable walking speed, maximal walking speed, dual task walking speed, Short Physical Performance Battery (SPPB), Timed Up and Go test (TUG), Color-Word Interference test (D-KEFS), Trail Making test A and B (TMT), Go/No-Go test and Step Reaction Time test (SRTT). All secondary outcome measures were assessed pre- and post-intervention.Results: Thirty-nine persons were included in the study. Average adherence rate was 99%, there were no intervention-related dropouts and no adverse events. The mean System Usability Scale (SUS) score was 83.6 and the mean NASA-TLX score 45.5. Significant time-group interaction effects were found for the dual task walking speed, the Go/No-Go test and Step Reaction Time test (SRTT).Conclusion: Exergaming is a feasible, safe and effective cognitive-motor training approach in inpatient rehabilitation of geriatric patients. Incorporating exergaming in the rehabilitation program of geriatric patients offers potential to reduce fall risk factors and to increase patients’ exercise motivation and rehabilitation success.
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9. |
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10. |
- Antonsson, Malin, 1986, et al.
(author)
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Using a Discourse Task to Explore Semantic Ability in Persons With Cognitive Impairment.
- 2021
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In: Frontiers in aging neuroscience. - : Frontiers Media SA. - 1663-4365. ; 12
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Journal article (peer-reviewed)abstract
- This paper uses a discourse task to explore aspects of semantic production in persons with various degree of cognitive impairment and healthy controls. The purpose of the study was to test if an in-depth semantic analysis of a cognitive-linguistic challenging discourse task could differentiate persons with a cognitive decline from those with a stable cognitive impairment. Both quantitative measures of semantic ability, using tests of oral lexical retrieval, and qualitative analysis of a narrative were used to detect semantic difficulties. Besides group comparisons a classification experiment was performed to investigate if the discourse features could be used to improve classification of the participants who had a stable cognitive impairment from those who had cognitively declined. In sum, both types of assessment methods captured difficulties between the groups, but tests of oral lexical retrieval most successfully differentiated between the cognitively stable and the cognitively declined group. Discourse features improved classification accuracy and the best combination of features discriminated between participants with a stable cognitive impairment and those who had cognitively declined with an area under the curve (AUC) of 0.93.
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11. |
- Avelar-Pereira, Bárbara, et al.
(author)
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Age-Related Differences in Dynamic Interactions Among Default Mode, Frontoparietal Control, and Dorsal Attention Networks during Resting-State and Interference Resolution
- 2017
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In: Frontiers in Aging Neuroscience. - : Frontiers Media S.A.. - 1663-4365. ; 9
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Journal article (peer-reviewed)abstract
- Resting-state fMRI (rs-fMRI) can identify large-scale brain networks, including the default mode (DMN), frontoparietal control (FPN) and dorsal attention (DAN) networks. Interactions among these networks are critical for supporting complex cognitive functions, yet the way in which they are modulated across states is not well understood. Moreover, it remains unclear whether these interactions are similarly affected in aging regardless of cognitive state. In this study, we investigated age-related differences in functional interactions among the DMN, FPN and DAN during rest and the Multi-Source Interference task (MSIT). Networks were identified using independent component analysis (ICA), and functional connectivity was measured during rest and task. We found that the FPN was more coupled with the DMN during rest and with the DAN during the MSIT. The degree of FPN-DMN connectivity was lower in older compared to younger adults, whereas no age-related differences were observed in FPN-DAN connectivity in either state. This suggests that dynamic interactions of the FPN are stable across cognitive states. The DMN and DAN were anti correlated and age-sensitive during the MSIT only, indicating variation in a task-dependent manner. Increased levels of anticorrelation from rest to task also predicted successful interference resolution. Additional analyses revealed that the degree of DMN-DAN anticorrelation during the MSIT was associated to resting cerebral blood flow (CBF) within the DMN. This suggests that reduced DMN neural activity during rest underlies an impaired ability to achieve higher levels of anticorrelation during a task. Taken together, our results suggest that only parts of age-related differences in connectivity are uncovered at rest and thus, should be studied in the functional connectome across multiple states for a more comprehensive picture.
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13. |
- Badji, A., et al.
(author)
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Cerebrospinal Fluid Biomarkers, Brain Structural and Cognitive Performances Between Normotensive and Hypertensive Controlled, Uncontrolled and Untreated 70-Year-Old Adults
- 2022
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In: Frontiers in Aging Neuroscience. - : Frontiers Media SA. - 1663-4365. ; 13
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Journal article (peer-reviewed)abstract
- Background: Hypertension is an important risk factor for Alzheimer's disease (AD). The pathophysiological mechanisms underlying the relationship between AD and hypertension are not fully understood, but they most likely involve microvascular dysfunction and cerebrovascular pathology. Although previous studies have assessed the impact of hypertension on different markers of brain integrity, no study has yet provided a comprehensive comparison of cerebrospinal fluid (CSF) biomarkers and structural brain differences between normotensive and hypertensive groups in a single and large cohort of older adults in relationship to cognitive performances.Objective: The aim of the present work was to investigate the differences in cognitive performances, CSF biomarkers and magnetic resonance imaging (MRI) of brain structure between normotensive, controlled hypertensive, uncontrolled hypertensive, and untreated hypertensive older adults from the Gothenburg H70 Birth Cohort Studies.Methods: As an indicator of vascular brain pathology, we measured white matter hyperintensities (WMHs), lacunes, cerebral microbleeds, enlarged perivascular space (epvs), and fractional anisotropy (FA). To assess markers of AD pathology/neurodegeneration, we measured hippocampal volume, temporal cortical thickness on MRI, and amyloid-beta(42), phosphorylated tau, and neurofilament light protein (NfL) in cerebrospinal fluid. Various neuropsychological tests were used to assess performances in memory, attention/processing speed, executive function, verbal fluency, and visuospatial abilities.Results: We found more white matter pathology in hypertensive compared to normotensive participants, with the highest vascular burden in uncontrolled participants (e.g., lower FA, more WMHs, and epvs). No significant difference was found in any MRI or CSF markers of AD pathology/neurodegeneration when comparing normotensive and hypertensive participants, nor among hypertensive groups. No significant difference was found in most cognitive functions between groups.Conclusion: Our results suggest that good blood pressure control may help prevent cerebrovascular pathology. In addition, hypertension may contribute to cognitive decline through its effect on cerebrovascular pathology rather than AD-related pathology. These findings suggest that hypertension is associated with MRI markers of vascular pathology in the absence of a significant decline in cognitive functions.
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14. |
- Ballesteros, Soledad, et al.
(author)
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A randomized controlled trial of brain training with non-action video games in older adults : results of the 3-month follow-up
- 2015
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In: Frontiers in Aging Neuroscience. - : Frontiers Media SA. - 1663-4365. ; 7
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Journal article (peer-reviewed)abstract
- This randomized controlled study (ClinicalTrials.gov NCT02007616)investigated the maintenance of training effects of 20 1-hr non-action video gametraining sessions with selected games from a commercial package on several agedecliningcognitive functions and subjective wellbeing after a 3-month no-contactperiod. Two groups of cognitively normal older adults participated in both the posttraining(posttest) and the present follow-up study, the experimental group who receivedtraining and the control group who attended several meetings with the research teamduring the study but did not receive training. Groups were similar at baseline ondemographics, vocabulary, global cognition, and depression status. Significant improvements in the trained group, and no variation in the control group had been previously found at posttest, in processing speed, attention and visual recognition memory, as well as in two dimensions of subjective wellbeing. In the current study, improvement from baseline to 3 months follow-up was found only in wellbeing (Affection and Assertivity dimensions) in the trained group whereas there was no change in the control group. Previous significant improvements in processing speed, attentionand spatial memory become nonsignificant after the 3-month interval. Training olderadults with non-action video games enhanced aspects of cognition just after training butthis effect disappeared after a 3-month no-contact follow-up period. Cognitive plasticitycan be induced in older adults by training, but to maintain the benefits periodic boosting sessions would be necessary.
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15. |
- Ballesteros, Soledad, et al.
(author)
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Brain training with non-action video games enhances aspects of cognition in older adults : a randomized controlled trial
- 2014
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In: Frontiers in Aging Neuroscience. - : Frontiers Media S.A.. - 1663-4365. ; 6
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Journal article (peer-reviewed)abstract
- Age-related cognitive and brain declines can result in functional deterioration in many cognitive domains, dependency, and dementia. A major goal of aging research is to investigate methods that help to maintain brain health, cognition, independent living and wellbeing in older adults. This randomized controlled study investigated the effects of 20 1-hr non-action video game training sessions with games selected from a commercially available package (Lumosity) on a series of age-declined cognitive functions and subjective wellbeing. Two groups of healthy older adults participated in the study, the experimental group who received the training and the control group who attended two meetings with the research team along the study. Groups were similar at baseline on demographics, vocabulary, global cognition, and depression status. All participants were assessed individually before and after the intervention, or a similar period of time, using neuropsychological tests and laboratory tasks to investigate possible transfer effects. The results showed significant improvements in the trained group, and no variation in the control group, in processing speed (choice reaction time), attention (reduction of distraction and increase of alertness), immediate and delayed visual recognition memory, as well as a trend to improve in Affection and Assertivity, two dimensions of the Wellbeing Scale. Visuospatial working memory (WM) and executive control (shifting strategy) did not improve. Overall, the current results support the idea that training healthy older adults with non-action video games will enhance some cognitive abilities but not others.
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16. |
- Barthelemy, JC, et al.
(author)
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Targeting autonomic nervous system as a biomarker of well-ageing in the prevention of stroke
- 2022
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In: Frontiers in aging neuroscience. - : Frontiers Media SA. - 1663-4365. ; 14, s. 969352-
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Journal article (peer-reviewed)abstract
- Stroke prediction is a key health issue for preventive medicine. Atrial fibrillation (AF) detection is well established and the importance of obstructive sleep apneas (OSA) has emerged in recent years. Although autonomic nervous system (ANS) appears strongly implicated in stroke occurrence, this factor is more rarely considered. However, the consequences of decreased parasympathetic activity explored in large cohort studies through measurement of ANS activity indicate that an ability to improve its activity level and equilibrium may prevent stroke. In support of these observations, a compensatory neurostimulation has already proved beneficial on endothelium function. The available data on stroke predictions from ANS is based on many long-term stroke cohorts. These data underline the need of repeated ANS evaluation for the general population, in a medical environment, and remotely by emerging telemedicine digital tools. This would help uncovering the reasons behind the ANS imbalance that would need to be medically adjusted to decrease the risk of stroke. This ANS unbalance help to draw attention on clinical or non-clinical evidence, disclosing the vascular risk, as ANS activity integrates the cumulated risk from many factors of which most are modifiable, such as metabolic inadaptation in diabetes and obesity, sleep ventilatory disorders, hypertension, inflammation, and lack of physical activity. Treating these factors may determine ANS recovery through the appropriate management of these conditions. Natural aging also decreases ANS activity. ANS recovery will decrease global circulating inflammation, which will reinforce endothelial function and thus protect the vessels and the associated organs. ANS is the whistle-blower of vascular risk and the actor of vascular health. Such as, ANS should be regularly checked to help draw attention on vascular risk and help follow the improvements in response to our interventions. While today prediction of stroke relies on classical cardiovascular risk factors, adding autonomic biomarkers as HRV parameters may significantly increase the prediction of stroke.
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17. |
- Behforuzi, Hura, et al.
(author)
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Markers of Novelty Processing in Older Adults Are Stable and Reliable
- 2019
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In: Frontiers in Aging Neuroscience. - : Frontiers Media S.A.. - 1663-4365. ; 11, s. 1-15
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Journal article (peer-reviewed)abstract
- Exploratory behavior and responsiveness to novelty play an important role in maintaining cognitive function in older adults. Inferences about age- or disease-related differences in neural and behavioral responses to novelty are most often based on results from single experimental testing sessions. There has been very limited research on whether such findings represent stable characteristics of populations studied, which is essential if investigators are to determine the result of interventions aimed at promoting exploratory behaviors or draw appropriate conclusions about differences in the processing of novelty across diverse clinical groups. The goal of the current study was to investigate the short-term test-retest reliability of event-related potential (ERP) and behavioral responses to novel stimuli in cognitively normal older adults. ERPs and viewing durations were recorded in 70 healthy older adults participating in a subject-controlled visual novelty oddball task during two sessions occurring 7 weeks apart. Mean midline P3 amplitude and latency, mean midline amplitude during successive 50 ms intervals, temporospatial factors derived from principal component analysis (PCA), and viewing duration in response to novel stimuli were measured during each session. Analysis of variance (ANOVA) revealed no reliable differences in the value of any measurements between Time 1 and 2. Intraclass correlation coefficients (ICCs) between Time 1 and 2 were excellent for mean P3 amplitude (ICC = 0.86), the two temporospatial factors consistent with the P3 components (ICC of 0.88 and 0.76) and viewing duration of novel stimuli (ICC = 0.81). Reliability was only fair for P3 peak latency (ICC = 0.56). Successive 50 ms mean amplitude measures from 100 to 1,000 ms yielded fair to excellent reliabilities, and all but one of the 12 temporospatial factors identified demonstrated ICCs in the good to excellent range. We conclude that older adults demonstrate substantial stability in ERP and behavioral responses to novel visual stimuli over a 7-week period. These results suggest that older adults may have a characteristic way of processing novelty that appears resistant to transient changes in their environment or internal states, which can be indexed during a single testing session. The establishment of reliable measures of novelty processing will allow investigators to determine whether proposed interventions have an impact on this important aspect of behavior.
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18. |
- Belfiori, Lautaro Francisco, et al.
(author)
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Nigral transcriptomic profiles in Engrailed-1 hemizygous mouse models of Parkinson's disease reveal upregulation of oxidative phosphorylation-related genes associated with delayed dopaminergic neurodegeneration
- 2024
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In: Frontiers in Aging Neuroscience. - 1663-4365. ; 16
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Journal article (peer-reviewed)abstract
- INTRODUCTION: Parkinson's disease (PD) is the second most common neurodegenerative disorder, increasing both in terms of prevalence and incidence. To date, only symptomatic treatment is available, highlighting the need to increase knowledge on disease etiology in order to develop new therapeutic strategies. Hemizygosity for the gene Engrailed-1 ( En1), encoding a conserved transcription factor essential for the programming, survival, and maintenance of midbrain dopaminergic neurons, leads to progressive nigrostriatal degeneration, motor impairment and depressive-like behavior in SwissOF1 (OF1 -En1 +/-). The neurodegenerative phenotype is, however, absent in C57Bl/6j (C57 -En1 +/-) mice. En1 +/- mice are thus highly relevant tools to identify genetic factors underlying PD susceptibility. METHODS: Transcriptome profiles were defined by RNAseq in microdissected substantia nigra from 1-week old OF1, OF1- En1 +/-, C57 and C57- En1 +/- male mice. Differentially expressed genes (DEGs) were analyzed for functional enrichment. Neurodegeneration was assessed in 4- and 16-week old mice by histology. RESULTS: Nigrostriatal neurodegeneration was manifested in OF1- En1 +/- mice by increased dopaminergic striatal axonal swellings from 4 to 16 weeks and decreased number of dopaminergic neurons in the SNpc at 16 weeks compared to OF1. In contrast, C57- En1 +/- mice had no significant increase in axonal swellings or cell loss in SNpc at 16 weeks. Transcriptomic analyses identified 198 DEGs between OF1- En1 +/- and OF1 mice but only 52 DEGs between C57- En1 +/- and C57 mice. Enrichment analysis of DEGs revealed that the neuroprotective phenotype of C57- En1 +/- mice was associated with a higher expression of oxidative phosphorylation-related genes compared to both C57 and OF1- En1 +/- mice. DISCUSSION: Our results suggest that increased expression of genes encoding mitochondrial proteins before the onset of neurodegeneration is associated with increased resistance to PD-like nigrostriatal neurodegeneration. This highlights the importance of genetic background in PD models, how different strains can be used to model clinical and sub-clinical pathologies and provides insights to gene expression mechanisms associated with PD susceptibility and progression.
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19. |
- Bellander, Martin, et al.
(author)
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No Evidence for Improved Associative Memory Performance Following Process-Based Associative Memory Training in Older Adults
- 2017
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In: Frontiers in Aging Neuroscience. - : Frontiers Media SA. - 1663-4365. ; 8
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Journal article (peer-reviewed)abstract
- Studies attempting to improve episodic memory performance with strategy instructions and training have had limited success in older adults: their training gains are limited in comparison to those of younger adults and do not generalize to untrained tasks and contexts. This limited success has been partly attributed to age-related impairments in associative binding of information into coherent episodes. We therefore investigated potential training and transfer effects of process-based associative memory training (i.e., repeated practice). Thirty-nine older adults (M-age = 68.8) underwent 6 weeks of either adaptive associative memory training or item recognition training. Both groups improved performance in item memory, spatial memory (object-context binding) and reasoning. A disproportionate effect of associative memory training was only observed for item memory, whereas no training-related performance changes were observed for associative memory. Self-reported strategies showed no signs of spontaneous development of memory-enhancing associative memory strategies. Hence, the results do not support the hypothesis that process-based associative memory training leads to higher associative memory performance in older adults.
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20. |
- Bjorkli, Christiana, et al.
(författare)
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Bridging the Gap Between Fluid Biomarkers for Alzheimer's Disease, Model Systems, and Patients
- 2020
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Ingår i: Frontiers in Aging Neuroscience. - : Frontiers Media S.A.. - 1663-4365. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Alzheimer's disease (AD) is a debilitating neurodegenerative disease characterized by the accumulation of two proteins in fibrillar form: amyloid-β (Aβ) and tau. Despite decades of intensive research, we cannot yet pinpoint the exact cause of the disease or unequivocally determine the exact mechanism(s) underlying its progression. This confounds early diagnosis and treatment of the disease. Cerebrospinal fluid (CSF) biomarkers, which can reveal ongoing biochemical changes in the brain, can help monitor developing AD pathology prior to clinical diagnosis. Here we review preclinical and clinical investigations of commonly used biomarkers in animals and patients with AD, which can bridge translation from model systems into the clinic. The core AD biomarkers have been found to translate well across species, whereas biomarkers of neuroinflammation translate to a lesser extent. Nevertheless, there is no absolute equivalence between biomarkers in human AD patients and those examined in preclinical models in terms of revealing key pathological hallmarks of the disease. In this review, we provide an overview of current but also novel AD biomarkers and how they relate to key constituents of the pathological cascade, highlighting confounding factors and pitfalls in interpretation, and also provide recommendations for standardized procedures during sample collection to enhance the translational validity of preclinical AD models.
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21. |
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22. |
- Boltze, Johannes, et al.
(författare)
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New Mechanistic Insights, Novel Treatment Paradigms, and Clinical Progress in Cerebrovascular Diseases
- 2021
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Ingår i: Frontiers in Aging Neuroscience. - : Frontiers Media SA. - 1663-4365. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- The past decade has brought tremendous progress in diagnostic and therapeutic options for cerebrovascular diseases as exemplified by the advent of thrombectomy in ischemic stroke, benefitting a steeply increasing number of stroke patients and potentially paving the way for a renaissance of neuroprotectants. Progress in basic science has been equally impressive. Based on a deeper understanding of pathomechanisms underlying cerebrovascular diseases, new therapeutic targets have been identified and novel treatment strategies such as pre- and post-conditioning methods were developed. Moreover, translationally relevant aspects are increasingly recognized in basic science studies, which is believed to increase their predictive value and the relevance of obtained findings for clinical application.This review reports key results from some of the most remarkable and encouraging achievements in neurovascular research that have been reported at the 10th International Symposium on Neuroprotection and Neurorepair. Basic science topics discussed herein focus on aspects such as neuroinflammation, extracellular vesicles, and the role of sex and age on stroke recovery. Translational reports highlighted endovascular techniques and targeted delivery methods, neurorehabilitation, advanced functional testing approaches for experimental studies, pre-and post-conditioning approaches as well as novel imaging and treatment strategies. Beyond ischemic stroke, particular emphasis was given on activities in the fields of traumatic brain injury and cerebral hemorrhage in which promising preclinical and clinical results have been reported. Although the number of neutral outcomes in clinical trials is still remarkably high when targeting cerebrovascular diseases, we begin to evidence stepwise but continuous progress towards novel treatment options. Advances in preclinical and translational research as reported herein are believed to have formed a solid foundation for this progress. © Copyright © 2021 Boltze, Aronowski, Badaut, Buckwalter, Caleo, Chopp, Dave, Didwischus, Dijkhuizen, Doeppner, Dreier, Fouad, Gelderblom, Gertz, Golubczyk, Gregson, Hamel, Hanley, Härtig, Hummel, Ikhsan, Janowski, Jolkkonen, Karuppagounder, Keep, Koerte, Kokaia, Li, Liu, Lizasoain, Ludewig, Metz, Montagne, Obenaus, Palumbo, Pearl, Perez-Pinzon, Planas, Plesnila, Raval, Rueger, Sansing, Sohrabji, Stagg, Stetler, Stowe, Sun, Taguchi, Tanter, Vay, Vemuganti, Vivien, Walczak, Wang, Xiong and Zille.
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23. |
- Bos, I., et al.
(författare)
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Amyloid-beta, Tau, and Cognition in Cognitively Normal Older Individuals: Examining the Necessity to Adjust for Biomarker Status in Normative Data
- 2018
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Ingår i: Frontiers in Aging Neuroscience. - : Frontiers Media SA. - 1663-4365. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- We investigated whether amyloid-beta (A beta) and tau affected cognition in cognitively normal (CN) individuals, and whether norms for neuropsychological tests based on biomarker-negative individuals would improve early detection of dementia. We included 907 CN individuals from 8 European cohorts and from the Alzheimer's disease Neuroimaging Initiative. All individuals were aged above 40, had A beta status and neuropsychological data available. Linear mixed models were used to assess the associations of Ali and tau with five neuropsychological tests assessing memory (immediate and delayed recall of Auditory Verbal Learning Test, AVLT), verbal fluency (Verbal Fluency Test, VFT), attention and executive functioning (Trail Making Test, TMT, part A and B). All test except the VFT were associated with status and this influence was augmented by age. We found no influence of tau on any of the cognitive tests. For the AVLT Immediate and Delayed recall and the TMT part A and B, we calculated norms in individuals without A beta pathology (A beta- norms), which we validated in an independent memory-clinic cohort by comparing their predictive accuracy to published norms. For memory tests, the A beta- norms rightfully identified an additional group of individuals at risk of dementia. For non-memory test we found no difference. We confirmed the relationship between Ao and cognition in cognitively normal individuals. The Af3- norms for memory tests in combination with published norms improve prognostic accuracy of dementia.
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24. |
- Boutajangout, Allal, et al.
(författare)
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Affibody-Mediated Sequestration of Amyloid beta Demonstrates Preventive Efficacy in a Transgenic Alzheimer's Disease Mouse Model
- 2019
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Ingår i: Frontiers in Aging Neuroscience. - : Frontiers Media S.A.. - 1663-4365. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Different strategies for treatment and prevention of Alzheimer's disease (AD) are currently under investigation, including passive immunization with anti-amyloid beta (anti-A beta) monoclonal antibodies (mAbs). Here, we investigate the therapeutic potential of a novel type of A beta-targeting agent based on an affibody molecule with fundamentally different properties to mAbs. We generated a therapeutic candidate, denoted Z(SYM73)-albumin-binding domain (ABD; 16.8 kDa), by genetic linkage of the dimeric Z(SYM73) affibody for sequestering of monomeric A beta-peptides and an ABD for extension of its in vivo half-life. Amyloid precursor protein (APP)/PS1 transgenic AD mice were administered with Z(SYM73)-ABD, followed by behavioral examination and immunohistochemistry. Results demonstrated rescued cognitive functions and significantly lower amyloid burden in the treated animals compared to controls. No toxicological symptoms or immunology-related side-effects were observed. To our knowledge, this is the first reported in vivo investigation of a systemically delivered scaffold protein against monomeric A beta, demonstrating a therapeutic potential for prevention of AD.
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25. |
- Brandi, Edoardo, et al.
(författare)
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Brain region-specific microglial and astrocytic activation in response to systemic lipopolysaccharides exposure
- 2022
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Ingår i: Frontiers in Aging Neuroscience. - : Frontiers Media SA. - 1663-4365. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Microglia cells are the macrophage population within the central nervous system, which acts as the first line of the immune defense. These cells present a high level of heterogeneity among different brain regions regarding morphology, cell density, transcriptomes, and expression of different inflammatory mediators. This region-specific heterogeneity may lead to different neuroinflammatory responses, influencing the regional involvement in several neurodegenerative diseases. In this study, we aimed to evaluate microglial response in 16 brain regions. We compared different aspects of the microglial response, such as the extension of their morphological changes, sensitivity, and ability to convert an acute inflammatory response to a chronic one. Then, we investigated the synaptic alterations followed by acute and chronic inflammation in substantia nigra. Moreover, we estimated the effect of partial ablation of fractalkine CX3C receptor 1 (CX3CR1) on microglial response. In the end, we briefly investigated astrocytic heterogeneity and activation. To evaluate microglial response in different brain regions and under the same stimulus, we induced a systemic inflammatory reaction through a single intraperitoneal (i.p.) injection of lipopolysaccharides (LPS). We performed our study using C57BL6 and CX3CR1+/GFP mice to investigate microglial response in different regions and the impact of CX3CR1 partial ablation. We conducted a topographic study quantifying microglia alterations in 16 brain regions through immunohistochemical examination and computational image analysis. Assessing Iba1-immunopositive profiles and the density of the microglia cells, we have observed significant differences in region-specific responses of microglia populations in all parameters considered. Our results underline the peculiar microglial inflammation in the substantia nigra pars reticulata (SNpr). Here and in concomitance with the acute inflammatory response, we observed a transient decrease of dopaminergic dendrites and an alteration of the striato-nigral projections. Additionally, we found a significant decrease in microglia response and the absence of chronic inflammation in CX3CR1+/GFP mice compared to the wild-type ones, suggesting the CX3C axis as a possible pharmacological target against neuroinflammation induced by an increase of systemic tumor necrosis factor-alpha (TNFα) or/and LPS. Finally, we investigated astrocytic heterogeneity in this model. We observed different distribution and morphology of GFAP-positive astrocytes, a heterogeneous response under inflammatory conditions, and a decrease in their activation in CX3CR1 partially ablated mice compared with C57BL6 mice. Altogether, our data confirm that microglia and astrocytes heterogeneity lead to a region-specific inflammatory response in presence of a systemic TNFα or/and LPS treatment.
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26. |
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27. |
- Calvo, Noelia, et al.
(författare)
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Steroid hormones: risk and resilience in womens Alzheimer disease
- 2023
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Ingår i: Frontiers in Aging Neuroscience. - : FRONTIERS MEDIA SA. - 1663-4365. ; 15
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Forskningsöversikt (refereegranskat)abstract
- More women have Alzheimer disease (AD) than men, but the reasons for this phenomenon are still unknown. Including women in clinical research and studying their biology is key to understand not just their increased risk but also their resilience against the disease. In this sense, women are more affected by AD than men, but their reserve or resilience mechanisms might delay symptom onset. The aim of this review was to explore what is known about mechanisms underlying womens risk and resilience in AD and identify emerging themes in this area that merit further research. We conducted a review of studies analyzing molecular mechanisms that may induce neuroplasticity in women, as well as cognitive and brain reserve. We also analyzed how the loss of steroid hormones in aging may be linked to AD. We included empirical studies with human and animal models, literature reviews as well as meta-analyses. Our search identified the importance of 17-b-estradiol (E2) as a mechanism driving cognitive and brain reserve in women. More broadly, our analysis revealed the following emerging perspectives: (1) the importance of steroid hormones and their effects on both neurons and glia for the study of risk and resilience in AD, (2) E2s crucial role in womens brain reserve, (3) womens verbal memory advantage as a cognitive reserve factor, and (4) E2s potential role in linguistic experiences such as multilingualism and hearing loss. Future directions for research include analyzing the reserve mechanisms of steroid hormones on neuronal and glial plasticity, as well as identifying the links between steroid hormone loss in aging and risk for AD.
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28. |
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29. |
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31. |
- Corujo-Bolaños, Graciela, et al.
(författare)
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The block design subtest of the Wechsler adult intelligence scale as a possible non-verbal proxy of cognitive reserve
- 2023
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Ingår i: Frontiers in Aging Neuroscience. - : Frontiers Media SA. - 1663-4365. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To investigate the potential of the Block design subtest of the Wechsler Adults Intelligence Scale as a non-verbal proxy of cognitive reserve.Method: A total of 391 cognitively unimpaired participants were included in this study. The association between the Block design subtest and the Information subtest (an established verbal proxy of cognitive reserve) from the WAIS, as well as the association of the two subtests with a Cognitive Reserve Questionnaire (CRQ) were tested. In addition, multiple linear regression models were conducted to investigate the association of the Block design and Information subtests with cognitive performance. The capacity of the Block design subtest to minimize the negative effect of an older age over cognitive performance was also assessed and this effect was compared with that of the Information subtest. The four cognitive domains included were: verbal memory, visual–visuospatial memory, executive-premotor functions and processing speed.Results: The Block design subtest correlated positively with both the Information subtest and the CRQ. A statistically significant association was observed between the Block design subtest and all four cognitive domains. Higher scores in the Block design subtest minimized the negative effect of aging on the cognitive domains of visual–visuospatial memory and executive-premotor functions, in a similar way to the results obtained for the Information subtest.Conclusion: The Block design subtest is significantly correlated with two established proxies of cognitive reserve: it correlates with cognitive performance and high scores in Block design have the capacity to minimize the negative effect of an older age on cognitive performance. Therefore, the results suggest that the corrected Block design subtest could be considered as a non-verbal proxy of cognitive reserve.
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32. |
- Danics, Lea, et al.
(författare)
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Fountain of youth—Targeting autophagy in aging
- 2023
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Ingår i: Frontiers in Aging Neuroscience. - : Frontiers Media SA. - 1663-4365. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- As our society ages inexorably, geroscience and research focusing on healthy aging is becoming increasingly urgent. Macroautophagy (referred to as autophagy), a highly conserved process of cellular clearance and rejuvenation has attracted much attention due to its universal role in organismal life and death. Growing evidence points to autophagy process as being one of the key players in the determination of lifespan and health. Autophagy inducing interventions show significant improvement in organismal lifespan demonstrated in several experimental models. In line with this, preclinical models of age-related neurodegenerative diseases demonstrate pathology modulating effect of autophagy induction, implicating its potential to treat such disorders. In humans this specific process seems to be more complex. Recent clinical trials of drugs targeting autophagy point out some beneficial effects for clinical use, although with limited effectiveness, while others fail to show any significant improvement. We propose that using more human-relevant preclinical models for testing drug efficacy would significantly improve clinical trial outcomes. Lastly, the review discusses the available cellular reprogramming techniques used to model neuronal autophagy and neurodegeneration while exploring the existing evidence of autophagy’s role in aging and pathogenesis in human-derived in vitro models such as embryonic stem cells (ESCs), induced pluripotent stem cell derived neurons (iPSC-neurons) or induced neurons (iNs).
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33. |
- Dartora, Caroline, et al.
(författare)
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A deep learning model for brain age prediction using minimally preprocessed T1w images as input
- 2023
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Ingår i: Frontiers in Aging Neuroscience. - : Frontiers Media SA. - 1663-4365. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: In the last few years, several models trying to calculate the biological brain age have been proposed based on structural magnetic resonance imaging scans (T1-weighted MRIs, T1w) using multivariate methods and machine learning. We developed and validated a convolutional neural network (CNN)-based biological brain age prediction model that uses one T1w MRI preprocessing step when applying the model to external datasets to simplify implementation and increase accessibility in research settings. Our model only requires rigid image registration to the MNI space, which is an advantage compared to previous methods that require more preprocessing steps, such as feature extraction. Methods: We used a multicohort dataset of cognitively healthy individuals (age range = 32.0–95.7 years) comprising 17,296 MRIs for training and evaluation. We compared our model using hold-out (CNN1) and cross-validation (CNN2–4) approaches. To verify generalisability, we used two external datasets with different populations and MRI scan characteristics to evaluate the model. To demonstrate its usability, we included the external dataset’s images in the cross-validation training (CNN3). To ensure that our model used only the brain signal on the image, we also predicted brain age using skull-stripped images (CNN4). Results: The trained models achieved a mean absolute error of 2.99, 2.67, 2.67, and 3.08 years for CNN1–4, respectively. The model’s performance in the external dataset was in the typical range of mean absolute error (MAE) found in the literature for testing sets. Adding the external dataset to the training set (CNN3), overall, MAE is unaffected, but individual cohort MAE improves (5.63–2.25 years). Salience maps of predictions reveal that periventricular, temporal, and insular regions are the most important for age prediction. Discussion: We provide indicators for using biological (predicted) brain age as a metric for age correction in neuroimaging studies as an alternative to the traditional chronological age. In conclusion, using different approaches, our CNN-based model showed good performance using one T1w brain MRI preprocessing step. The proposed CNN model is made publicly available for the research community to be easily implemented and used to study ageing and age-related disorders.
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34. |
- das Neves, SP, et al.
(författare)
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Association Between Iron-Related Protein Lipocalin 2 and Cognitive Impairment in Cerebrospinal Fluid and Serum
- 2021
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Ingår i: Frontiers in aging neuroscience. - : Frontiers Media SA. - 1663-4365. ; 13, s. 663837-
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Tidskriftsartikel (refereegranskat)abstract
- A worldwide increase in longevity is bringing novel challenges to public health and health care professionals. Cognitive impairment in the elderly may compromise living conditions and precede Alzheimer’s disease (AD), the most prevalent form of dementia. Therefore, finding molecular markers associated with cognitive impairment is of crucial importance. Lipocalin 2 (LCN2), an iron-related protein, has been suggested as a potential marker for mild cognitive impairment (MCI) and AD. This study aimed at investigating the association between LCN2 measured in serum and cerebrospinal fluid (CSF) with cognitive impairment. A cross-sectional design based on two aging cohorts was used: individuals diagnosed with subjective cognitive complaints (SCC), MCI, and AD from a Swedish memory clinic-based cohort, and individuals diagnosed with SCC and AD from a Portuguese cohort. Binary logistic [for the outcome cognitive impairment (MCI + AD) in the Swedish cohort and AD in the Portuguese cohort] and multinomial logistic (for the outcomes MCI and AD) regression analyses were used. No associations were found in both cohorts when controlling for sex, education, and age. This explanatory study suggests that the association between serum and CSF LCN2 concentrations with cognitive impairment reported in the literature must be further analyzed for confounders.
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35. |
- Dauman, Nicolas, et al.
(författare)
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Exploring Tinnitus-Induced Disablement by Persistent Frustration in Aging Individuals : A Grounded Theory Study
- 2017
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Ingår i: Frontiers in Aging Neuroscience. - : Frontiers Media SA. - 1663-4365. ; 9, s. 1-18
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Tidskriftsartikel (refereegranskat)abstract
- Background: Qualitative research can help to improve the management of patients, meet their expectations and assist physicians in alleviating their suffering. The perception of moment-to-moment variability in tinnitus annoyance is an emerging field of exploration. This study sought to enlighten variability in tinnitus-induced disablement using a qualitative approach. Methods: Twelve participants (six females, six males, aged 51-79) were recruited via the French Tinnitus Association Journal for participation in recorded semi-structured interviews. Each participant had three interviews lasting 1 h, the sessions being separated one from the other by 2 weeks. Following recommendations of Charmaz (2014), the second and third interviews were aimed at gathering rich data, by enhancing the participants’ reflexivity in the circumstances of distress caused by tinnitus. After transcription, the data (n = 36 interviews) were analyzed using the approach to Grounded Theory proposed by Strauss and Corbin (1998). Results: Tinnitus as persistent frustration emerged as being the core category uniting all the other categories of the study. Hence, the core category accounted for the broader scope in participants’ experience of chronic tinnitus. It is suggested that tinnitus-induced disablement varied according to the degree of frustration felt by the participants in not being able to achieve their goals. The implications of this were analyzed using the following categories: “Losing body ownership,” “ Lacking perspectives,” and “Persevering through difficulties.” Based on these findings, we draw a substantive theory of tinnitus tolerance that promotes an active, disciplined and individualized approach to tinnitus-induced disablement. The model distinguishes pathways from sustained suffering to reduced annoyance (i.e., emerging tolerance). It accounts for difficulties that the participants experienced with a perceived unchanged annoyance over time. Furthermore, this model identifies a set of new attitudes toward oneself and others that tinnitus tolerance would entail. Conclusion: The subjective experience of frustration enlightens tinnitus-induced disablement, offering new perspectives for long-term self-management. Modulation of frustration, rather than moderation of tinnitus interference, is suggested as a new approach to the clinical management of tinnitus-related distress.
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36. |
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37. |
- Diaz-Galvan, P, et al.
(författare)
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Cerebrovascular Disease and Depressive Symptomatology in Individuals With Subjective Cognitive Decline: A Community-Based Study
- 2021
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Ingår i: Frontiers in aging neuroscience. - : Frontiers Media SA. - 1663-4365. ; 13, s. 656990-
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Tidskriftsartikel (refereegranskat)abstract
- Subjective cognitive decline (SCD) may be the first sign of Alzheimer's disease (AD), but it can also reflect other pathologies such as cerebrovascular disease or conditions like depressive symptomatology. The role of depressive symptomatology in SCD is controversial. We investigated the association between depressive symptomatology, cerebrovascular disease, and SCD. We recruited 225 cognitively unimpaired individuals from a prospective community-based study [mean age (SD) = 54.64 (10.18); age range 35–77 years; 55% women; 123 individuals with one or more subjective cognitive complaints, 102 individuals with zero complaints]. SCD was assessed with a scale of 9 memory and non-memory subjective complaints. Depressive symptomatology was assessed with established questionnaires. Cerebrovascular disease was assessed with magnetic resonance imaging markers of white matter signal abnormalities (WMSA) and mean diffusivity (MD). We combined correlation, multiple regression, and mediation analyses to investigate the association between depressive symptomatology, cerebrovascular disease, and SCD. We found that SCD was associated with more cerebrovascular disease, older age, and increased depressive symptomatology. In turn, depressive symptomatology was not associated with cerebrovascular disease. Variability in MD was mediated by WMSA burden, presumably reflecting cerebrovascular disease. We conclude that, in our community-based cohort, depressive symptomatology is associated with SCD but not with cerebrovascular disease. In addition, depressive symptomatology did not influence the association between cerebrovascular disease and SCD. We suggest that therapeutic interventions for depressive symptomatology could alleviate the psychological burden of negative emotions in people with SCD, and intervening on vascular risk factors to reduce cerebrovascular disease should be tested as an opportunity to minimize neurodegeneration in SCD individuals from the community.
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38. |
- Ding, Ding, et al.
(författare)
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Predictive Value of Odor Identification for Incident Dementia : The Shanghai Aging Study
- 2020
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Ingår i: Frontiers in Aging Neuroscience. - : Frontiers Media S.A.. - 1663-4365. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Objective: This study aimed to evaluate the value of odors in the olfactory identification (OI) test and other known risk factors for predicting incident dementia in the prospective Shanghai Aging Study.Methods: At baseline, OI was assessed using the Sniffin' Sticks Screening Test 12, which contains 12 different odors. Cognition assessment and consensus diagnosis were conducted at both baseline and follow-up to identify incident dementia. Four different multivariable logistic regression (MLR) models were used for predicting incident dementia. In the no-odor model, only demographics, lifestyle, and medical history variables were included. In the single-odor model, we further added one single odor to the first model. In the full model, all 12 odors were included. In the stepwise model, the variables were selected using a bidirectional stepwise selection method. The predictive abilities of these models were evaluated by the area under the receiver operating characteristic curve (AUC). The permutation importance method was used to evaluate the relative importance of different odors and other known risk factors.Results: Seventy-five (8%) incident dementia cases were diagnosed during 4.9 years of follow-up among 947 participants. The full and the stepwise MLR model (AUC = 0.916 and 0.914, respectively) have better predictive abilities compared with those of the no- or single-odor models. The five most important variables are Mini-Mental State Examination (MMSE) score, age, peppermint detection, coronary artery disease, and height in the full model, and MMSE, age, peppermint detection, stroke, and education in the stepwise model. The combination of only the top five variables in the stepwise model (AUC = 0.901 and sensitivity = 0.880) has as a good a predictive ability as other models.Conclusion: The ability to smell peppermint might be one of the useful indicators for predicting dementia. Combining peppermint detection with MMSE, age, education, and history of stroke may have sensitive and robust predictive value for dementia in older adults.
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39. |
- Dong, R. C., et al.
(författare)
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CSF metabolites associated with biomarkers of Alzheimer's disease pathology
- 2023
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Ingår i: Frontiers in Aging Neuroscience. - 1663-4365. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- IntroductionMetabolomics technology facilitates studying associations between small molecules and disease processes. Correlating metabolites in cerebrospinal fluid (CSF) with Alzheimer's disease (AD) CSF biomarkers may elucidate additional changes that are associated with early AD pathology and enhance our knowledge of the disease.MethodsThe relative abundance of untargeted metabolites was assessed in 161 individuals from the Wisconsin Registry for Alzheimer's Prevention. A metabolome-wide association study (MWAS) was conducted between 269 CSF metabolites and protein biomarkers reflecting brain amyloidosis, tau pathology, neuronal and synaptic degeneration, and astrocyte or microglial activation and neuroinflammation. Linear mixed-effects regression analyses were performed with random intercepts for sample relatedness and repeated measurements and fixed effects for age, sex, and years of education. The metabolome-wide significance was determined by a false discovery rate threshold of 0.05. The significant metabolites were replicated in 154 independent individuals from then Wisconsin Alzheimer's Disease Research Center. Mendelian randomization was performed using genome-wide significant single nucleotide polymorphisms from a CSF metabolites genome-wide association study.ResultsMetabolome-wide association study results showed several significantly associated metabolites for all the biomarkers except A & beta;42/40 and IL-6. Genetic variants associated with metabolites and Mendelian randomization analysis provided evidence for a causal association of metabolites for soluble triggering receptor expressed on myeloid cells 2 (sTREM2), amyloid & beta; (A & beta;40), & alpha;-synuclein, total tau, phosphorylated tau, and neurogranin, for example, palmitoyl sphingomyelin (d18:1/16:0) for sTREM2, and erythritol for A & beta;40 and & alpha;-synuclein.DiscussionThis study provides evidence that CSF metabolites are associated with AD-related pathology, and many of these associations may be causal.
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40. |
- Dong, Yi, et al.
(författare)
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Olfactory Impairment Among Rural-Dwelling Chinese Older Adults : Prevalence and Associations With Demographic, Lifestyle, and Clinical Factors
- 2021
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Ingår i: Frontiers in Aging Neuroscience. - : Frontiers Media SA. - 1663-4365. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Olfactory impairment (OI) refers to decreased (hyposmia) or absent (anosmia) ability to smell. We sought to estimate the prevalence and correlates of OI among rural-dwelling Chinese older adults.Methods: This population-based cross-sectional analysis included 4,514 participants (age >= 65 years; 56.7% women) from the Multidomain Interventions to Delay Dementia and Disability in Rural China (MIND-China). The 16-item Sniffin' Sticks identification test (SSIT) was used to assess olfactory function. Olfactory impairment was defined as the SSIT score <= 10, hyposmia as SSIT score of 8-10, and anosmia as SSIT score <8. Multivariable logistic regression models were used to examine factors associated with OI. Results: The overall prevalence was 67.7% for OI, 35.3% for hyposmia, and 32.5% for anosmia. The prevalence increased with age for OI and anosmia, but not for hyposmia. The multivariable-adjusted odds ratio (OR) of OI was 2.10 (95% CI 1.69-2.61) for illiteracy and 1.41 (1.18-1.70) for elementary school (vs. middle school or above), 1.30 (1.01-1.67) for current smoking (vs. never smoking), 0.86 (0.74-0.99) for overweight and 0.73 (0.61-0.87) for obesity (vs. normal weight), 4.21 (2.23-7.94) for dementia, 1.68 (1.23-2.30) for head injury, and 1.44 (1.14-1.83) for sinonasal disease. Illiteracy in combination with either male sex or diabetes was significantly associated with an over two-fold increased OR of OI (p for interactions <0.05).Conclusion: Olfactory impairment is highly prevalent that affects over two-thirds of rural-dwelling older adults in China. OI is correlated with illiteracy, current smoking, dementia, head injury, and sinonasal disease, but negatively associated with overweight or obesity. Olfactory impairment as a potential clinical marker of neurodegenerative disorders among older adults deserves further investigation.
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41. |
- Ebner, Natalie C., et al.
(författare)
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Oxytocin modulates meta-mood as a function of age and sex
- 2015
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Ingår i: Frontiers in Aging Neuroscience. - : Frontiers Media SA. - 1663-4365. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Attending to and understanding one's own feelings are components of meta mood and constitute important socio-affective skills across the entire lifespan. Growing evidence suggests a modulatory role of the neuropeptide oxytocin on various socio-affective processes. Going beyond previous work that almost exclusively examined young men and perceptions of emotions in others, the current study investigated effects of intranasal oxytocin on meta-mood in young and older men and women. In a double-blind between-group design, participants were randomly assigned to self-administer either intranasal oxytocin or a placebo before responding to items from the Trait Meta Mood Scale (TMMS) about attention to feelings and clarity of feelings. In contrast to older women, oxytocin relative to placebo increased attention to feelings in older men. Oxytocin relative to placebo enhanced meta-mood in young female participants but reduced it in older female participants. This pattern of findings supports an age- and sex-differential modulatory function of the neuropeptide oxytocin on meta-mood, possibly associated with neurobiological differences with age and sex.
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42. |
- Eek, Tom, et al.
(författare)
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Odor Recognition Memory in Parkinson's Disease : A Systematic Review
- 2021
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Ingår i: Frontiers in Aging Neuroscience. - : Frontiers Media SA. - 1663-4365. ; 13
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Forskningsöversikt (refereegranskat)abstract
- Olfactory impairment is a central non-motor symptom in Parkinson's disease (PD). Previous studies have demonstrated that olfactory dysfunction is associated with mental illness and impaired cognition. The frequently investigated olfactory functions are odor detection, discrimination, and identification. However, few studies have focused on odor recognition memory (ORM). ORM tasks involves episodic memory which therefore can facilitate the detection of dementia among patients with PD and consequently adjust their treatment. Thus, the aim of this systematic review is to summarize the existing research on ORM in PD. Databases and reference lists were used for data collection. Studies were included in the review if they met the eligibility criteria derived from the PICOS-framework. Quality evaluation of the studies was based on the STROBE-statement. Six studies with small samples were included in the analysis which demonstrated the scarce research on the subject. The studies targeting ORM were heterogenous and involved two main tasks: odor recognition and odor matching. The synthesis of the data demonstrated that PD patients performed significantly lower than controls on both tasks, especially on odor matching task. Only the odor recognition task exhibited a difference between patients with PD vs. Alzheimer's disease (AD). PD patients performed significantly better than AD patients. The findings based on the available limited data support the notion that odor recognition task can be of importance in identifying Parkinson's disease dementia (PDD). To investigate this hypothesis, future research needs to include larger samples of PD, PDD and AD patients executing the same odor recognition task.
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45. |
- Eyjolfsdottir, H, et al.
(författare)
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Fast Alpha Activity in EEG of Patients With Alzheimer's Disease Is Paralleled by Changes in Cognition and Cholinergic Markers During Encapsulated Cell Biodelivery of Nerve Growth Factor
- 2022
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Ingår i: Frontiers in aging neuroscience. - : Frontiers Media SA. - 1663-4365. ; 14, s. 756687-
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Tidskriftsartikel (refereegranskat)abstract
- Basal forebrain cholinergic neurons are dependent on nerve growth factor (NGF) for growth and survival and these cells are among the first to degenerate in Alzheimer’s disease (AD). Targeted delivery of NGF has been suggested as a potential therapy for AD. This hypothesis was tested in a clinical trial with encapsulated cell biodelivery of NGF (NGF-ECB) in AD patients. Three of six patients showed improved biomarkers for cognition by the end of the study. Here, we report on the effects of targeted delivery of NGF on human resting EEG.Materials and methodsNGF-ECB implants were implanted bilaterally in the basal forebrain of six AD patients for 12 months. EEG recordings and quantitative analysis were performed at baseline, 3 and 12 months of NGF delivery, and analyzed for correlation with changes in Mini-mental state examination (MMSE) and levels of the cholinergic marker choline acetyltransferase (ChAT) in cerebrospinal fluid (CSF).ResultsWe found significant correlations between the topographic variance of EEG spectral power at the three study points (baseline, 3 and 12 months) and changes in MMSE and CSF ChAT. This possible effect of NGF was identified in a narrow window of alpha frequency 10–11.5 Hz, where a stabilization in MMSE score during treatment was related to an increase in EEG alpha power. A similar relation was observed between the alpha power and ChAT. More theta power at 6.5 Hz was on the contrary associated with a decrease in CSF ChAT during the trial period.ConclusionIn this exploratory study, there was a positive correlative pattern between physiological high-frequency alpha activity and stabilization in MMSE and increase in CSF ChAT in AD patients receiving targeted delivery of NGF to the cholinergic basal forebrain.
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49. |
- Fiuza, Felipe P., et al.
(författare)
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Aging Alters Daily and Regional Calretinin Neuronal Expression in the Rat Non-image Forming Visual Thalamus
- 2021
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Ingår i: Frontiers in Aging Neuroscience. - : Frontiers Media S.A.. - 1663-4365. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Aging affects the overall physiology, including the image-forming and non-image forming visual systems. Among the components of the latter, the thalamic retinorecipient inter-geniculate leaflet (IGL) and ventral lateral geniculate (vLGN) nucleus conveys light information to subcortical regions, adjusting visuomotor, and circadian functions. It is noteworthy that several visual related cells, such as neuronal subpopulations in the IGL and vLGN are neurochemically characterized by the presence of calcium binding proteins. Calretinin (CR), a representative of such proteins, denotes region-specificity in a temporal manner by variable day-night expression. In parallel, age-related brain dysfunction and neurodegeneration are associated with abnormal intracellular concentrations of calcium. Here, we investigated whether daily changes in the number of CR neurons are a feature of the aged IGL and vLGN in rats. To this end, we perfused rats, ranging from 3 to 24 months of age, within distinct phases of the day, namely zeitgeber times (ZTs). Then, we evaluated CR immunolabeling through design-based stereological cell estimation. We observed distinct daily rhythms of CR expression in the IGL and in both the retinorecipient (vLGNe) and non-retinorecipient (vLGNi) portions of the vLGN. In the ZT 6, the middle of the light phase, the CR cells are reduced with aging in the IGL and vLGNe. In the ZT 12, the transition between light to dark, an age-related CR loss was found in all nuclei. While CR expression predominates in specific spatial domains of vLGN, age-related changes appear not to be restricted at particular portions. No alterations were found in the dark/light transition or in the middle of the dark phase, ZTs 0, and 18, respectively. These results are relevant in the understanding of how aging shifts the phenotype of visual related cells at topographically organized channels of visuomotor and circadian processing.
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50. |
- Flodin, Pär, 1982-, et al.
(författare)
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Does Aerobic Exercise Influence Intrinsic Brain Activity? An Aerobic Exercise Intervention among Healthy Old Adults
- 2017
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Ingår i: Frontiers in Aging Neuroscience. - : Frontiers Media SA. - 1663-4365. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies have indicated that aerobic exercise could reduce age related decline in cognition and brain functioning. Here we investigated the effects of aerobic exercise on intrinsic brain activity. Sixty sedentary healthy males and females (64–78 years) were randomized into either an aerobic exercise group or an active control group. Both groups recieved supervised training, 3 days a week for 6 months. Multimodal brain imaging data was acquired before and after the intervention, including 10 min of resting state brain functional magnetic resonance imaging (rs-fMRI) and arterial spin labeling (ASL). Additionally, a comprehensive battery of cognitive tasks assessing, e.g., executive function and episodic memory was administered. Both the aerobic and the control group improved in aerobic capacity (VO2-peak) over 6 months, but a significant group by time interaction confirmed that the aerobic group improved more. Contrary to our hypothesis, we did not observe any significant group by time interactions with regard to any measure of intrinsic activity. To further probe putative relationships between fitness and brain activity, we performed post hoc analyses disregarding group belongings. At baseline, VO2-peak was negativly related to BOLD-signal fluctuations (BOLDSTD) in mid temporal areas. Over 6 months, improvements in aerobic capacity were associated with decreased connectivity between left hippocampus and contralateral precentral gyrus, and positively to connectivity between right mid-temporal areas and frontal and parietal regions. Independent component analysis identified a VO2-related increase in coupling between the default mode network and left orbitofrontal cortex, as well as a decreased connectivity between the sensorimotor network and thalamus. Extensive exploratory data analyses of global efficiency, connectome wide multivariate pattern analysis (connectome-MVPA), as well as ASL, did not reveal any relationships between aerobic fitness and intrinsic brain activity. Moreover, fitness-predicted changes in functional connectivity did not relate to changes in cognition, which is likely due to absent cross- sectional or longitudinal relationships between VO2-peak and cognition. We conclude that the aerobic exercise intervention had limited influence on patterns of intrinsic brain activity, although post hoc analyses indicated that individual changes in aerobic capacity preferentially influenced mid-temporal brain areas.
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