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- Cabeza, Roberto, et al.
(författare)
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Maintenance, reserve and compensation : the cognitive neuroscience of healthy ageing
- 2018
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Ingår i: Nature Reviews Neuroscience. - : Nature Publishing Group. - 1471-003X .- 1471-0048. ; 19:11, s. 701-710
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Forskningsöversikt (refereegranskat)abstract
- Cognitive ageing research examines the cognitive abilities that are preserved and/or those that decline with advanced age. There is great individual variability in cognitive ageing trajectories. Some older adults show little decline in cognitive ability compared with young adults and are thus termed ‘optimally ageing’. By contrast, others exhibit substantial cognitive decline and may develop dementia. Human neuroimaging research has led to a number of important advances in our understanding of the neural mechanisms underlying these two outcomes. However, interpreting the age-related changes and differences in brain structure, activation and functional connectivity that this research reveals is an ongoing challenge. Ambiguous terminology is a major source of difficulty in this venture. Three terms in particular — compensation, maintenance and reserve — have been used in a number of different ways, and researchers continue to disagree about the kinds of evidence or patterns of results that are required to interpret findings related to these concepts. As such inconsistencies can impede progress in both theoretical and empirical research, here, we aim to clarify and propose consensual definitions of these terms.
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| 2. |
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| 3. |
- Brown, Alana, et al.
(författare)
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Womens Brain Health: Midlife Ovarian Removal Affects Associative Memory
- 2023
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Ingår i: Molecular Neurobiology. - : SPRINGER. - 0893-7648 .- 1559-1182. ; 60:11, s. 6145-6159
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Tidskriftsartikel (refereegranskat)abstract
- Women with early bilateral salpingo-oophorectomy (BSO; removal of ovaries and fallopian tubes) have greater Alzheimers disease (AD) risk than women in spontaneous/natural menopause (SM), but early biomarkers of this risk are not well-characterized. Considering associative memory deficits may presage preclinical AD, we wondered if one of the earliest changes might be in associative memory and whether younger women with BSO had changes similar to those observed in SM. Women with BSO (with and without 17 & beta;-estradiol replacement therapy (ERT)), their age-matched premenopausal controls (AMC), and older women in SM completed a functional magnetic resonance imaging face-name associative memory task shown to predict early AD. Brain activation during encoding was compared between groups: AMC (n=25), BSO no ERT (BSO; n=15), BSO+ERT (n=16), and SM without hormone therapy (n=16). Region-of-interest analyses revealed AMC did not contribute to functional group differences. BSO+ERT had higher hippocampal activation than BSO and SM. This hippocampal activation correlated positively with urinary metabolite levels of 17 & beta;-estradiol. Multivariate partial least squares analyses showed BSO+ERT had a different network-level activation pattern than BSO and SM. Thus, despite being approximately 10 years younger, women with BSO without ERT had similar brain function to those with SM, suggesting early 17 & beta;-estradiol loss may lead to an altered functional brain phenotype which could influence late-life AD risk, making face-name encoding a potential biomarker for midlife women with increased AD risk. Despite similarities in activation, BSO and SM groups showed opposite within-hippocampus connectivity, suggesting menopause type is an important consideration when assessing brain function.
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| 4. |
- Gervais, Nicole J., et al.
(författare)
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Disturbed sleep is associated with reduced verbal episodic memory and entorhinal cortex volume in younger middle-aged women with risk-reducing early ovarian removal
- 2023
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Ingår i: Frontiers in Endocrinology. - : FRONTIERS MEDIA SA. - 1664-2392. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Women with early ovarian removal (<48 years) have an elevated risk for both late-life Alzheimers disease (AD) and insomnia, a modifiable risk factor. In early midlife, they also show reduced verbal episodic memory and hippocampal volume. Whether these reductions correlate with a sleep phenotype consistent with insomnia risk remains unexplored. Methods: We recruited thirty-one younger middleaged women with risk-reducing early bilateral salpingo-oophorectomy (BSO), fifteen of whom were taking estradiol-based hormone replacement therapy (BSO+ERT) and sixteen who were not (BSO). Fourteen age-matched premenopausal (AMC) and seventeen spontaneously peri-postmenopausal (SM) women who were similar to 10y older and not taking ERT were also enrolled. Overnight polysomnography recordings were collected at participants home across multiple nights (M=2.38 SEM=0.19), along with subjective sleep quality and hot flash ratings. In addition to group comparisons on sleep measures, associations with verbal episodic memory and medial temporal lobe volume were assessed. Results: Increased sleep latency and decreased sleep efficiency were observed on polysomnography recordings of those not taking ERT, consistent with insomnia symptoms. This phenotype was also observed in the older women in SM, implicating ovarian hormone loss. Further, sleep latency was associated with more forgetting on the paragraph recall task, previously shown to be altered in women with early BSO. Both increased sleep latency and reduced sleep efficiency were associated with smaller anterolateral entorhinal cortex volume. Discussion: Together, these findings confirm an association between ovarian hormone loss and insomnia symptoms, and importantly, identify an younger onset age in women with early ovarian removal, which may contribute to poorer cognitive and brain outcomes in these women.
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| 5. |
- Gervais, Nicole J., et al.
(författare)
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Scene memory and hippocampal volume in middle-aged women with early hormone loss
- 2022
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Ingår i: Neurobiology of Aging. - : ELSEVIER SCIENCE INC. - 0197-4580 .- 1558-1497. ; 117, s. 97-106
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Tidskriftsartikel (refereegranskat)abstract
- The present study explored whether early midlife bilateral salpingo-oophorectomy (BSO), a female specific risk factor for dementia, is associated with reduced medial temporal lobe structure and function. Younger middle-aged women with the BRCA1/2 mutation and a BSO prior to spontaneous menopause (SM) were recruited. We determined the performance of women with BSO not taking estradiol-based hormone therapy ( n = 18) on a task measuring object and scene recognition and quantified medial temporal lobe subregion volumes using manually segmented high-resolution T2-weighted MRI scans. Comparisons were made to those with BSO taking estradiol-based hormone therapy ( n = 20), age-matched premenopausal controls ( n = 28), and older women in SM not taking hormone therapy matched for duration of hormone deprivation ( n = 17). Reduced hippocampal integrity specific to the BSO group not taking hormone therapy was observed, reflected by significantly smaller dentate gyrus/CA2/CA3 volumes and lower scene recognition memory performance. These findings show that hippocampal subfield volume may be useful for identifying early midlife changes in women at elevated risk for dementia.
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| 6. |
- Subramaniapillai, Sivaniya, et al.
(författare)
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Sex and gender differences in cognitive and brain reserve: Implications for Alzheimers disease in women
- 2021
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Ingår i: Frontiers in neuroendocrinology (Print). - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 0091-3022 .- 1095-6808. ; 60
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Forskningsöversikt (refereegranskat)abstract
- Women represent (2)/(3) of the cases of Alzheimers disease (AD). Current research has focused on differential risks to explain higher rates of AD in women. However, factors that reduce risk for AD, like cognitive/brain reserve, are less well explored. We asked: what is known about sex and gender differences in how reserve mitigates risk for AD? We conducted a narrative review of the literature, with keywords: "sex/gender differences", "cognitive/brain reserve", "Alzheimers Disease", and the following cognitive reserve contributors: "education", "IQ", "occupation", "cognitive stimulation", "bilingualism", "socioeconomic status", "physical activity", "social support". Sixteen papers disaggregated their data by sex. Those papers observed sex and gender differences in reserve contributors. There is also evidence that greater reserve may be more beneficial in lowering AD risk in women, although more research is needed. We discuss how traditional reserve contributors are gendered and may not capture factors that support cognition in aging women.
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