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Reas ET, Triebswetter C, Banks SJ, McEvoy LK. Effects of APOE2 and APOE4 on brain microstructure in older adults: modification by age, sex, and cognitive status. Alzheimers Res Ther 2024; 16:7. [PMID: 38212861 PMCID: PMC10782616 DOI: 10.1186/s13195-023-01380-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 12/30/2023] [Indexed: 01/13/2024]
Abstract
BACKGROUND APOE4 is the strongest genetic risk factor for sporadic Alzheimer's disease (AD), whereas APOE2 confers protection. However, effects of APOE on neurodegeneration in cognitively intact individuals, and how these associations evolve with cognitive decline, are unclear. Furthermore, few studies have evaluated whether effects of APOE on neurodegenerative changes are modified by other AD key risk factors including age and sex. METHODS Participants included older adults (57% women; 77 ± 7 years) from the Rancho Bernardo Study of Health Aging and the University of California San Diego Alzheimer's Disease Research Center, including 192 cognitively normal (CN) individuals and 33 with mild cognitive impairment. Participants underwent diffusion MRI, and multicompartment restriction spectrum imaging (RSI) metrics were computed in white matter, gray matter, and subcortical regions of interest. Participants were classified as APOE4 carriers, APOE2 carriers, and APOE3 homozygotes. Analysis of covariance among CN (adjusting for age, sex, and scanner) assessed differences in brain microstructure by APOE, as well as interactions between APOE and sex. Analyses across all participants examined interactions between APOE4 and cognitive status. Linear regressions assessed APOE by age interactions. RESULTS Among CN, APOE4 carriers showed lower entorhinal cortex neurite density than non-carriers, whereas APOE2 carriers showed lower cingulum neurite density than non-carriers. Differences in entorhinal microstructure by APOE4 and in entorhinal and cingulum microstructure by APOE2 were present for women only. Age correlated with lower entorhinal restricted isotropic diffusion among APOE4 non-carriers, whereas age correlated with lower putamen restricted isotropic diffusion among APOE4 carriers. Differences in microstructure between cognitively normal and impaired participants were stronger for APOE4-carriers in medial temporal regions, thalamus, and global gray matter, but stronger for non-carriers in caudate. CONCLUSIONS The entorhinal cortex may be an early target of neurodegenerative changes associated with APOE4 in presymptomatic individuals, whereas APOE2 may support beneficial white matter and entorhinal microstructure, with potential sex differences that warrant further investigation. APOE modifies microstructural patterns associated with aging and cognitive impairment, which may advance the development of biomarkers to distinguish microstructural changes characteristic of normal brain aging, APOE-dependent pathways, and non-AD etiologies.
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Affiliation(s)
- Emilie T Reas
- Department of Neurosciences, University of California, San Diego, Mail Code 0841, UCSD,9500 Gilman Dr., La Jolla, San Diego, CA, 92093-0841, USA.
| | - Curtis Triebswetter
- Department of Neurosciences, University of California, San Diego, Mail Code 0841, UCSD,9500 Gilman Dr., La Jolla, San Diego, CA, 92093-0841, USA
| | - Sarah J Banks
- Department of Neurosciences, University of California, San Diego, Mail Code 0841, UCSD,9500 Gilman Dr., La Jolla, San Diego, CA, 92093-0841, USA
| | - Linda K McEvoy
- Herbert Wertheim School of Public Health and Human Longevity Science, University of California, San Diego, USA
- Kaiser Permanente Washington Health Research Institute, Seattle, WA, USA
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Reas ET, Shadrin A, Frei O, Motazedi E, McEvoy L, Bahrami S, van der Meer D, Makowski C, Loughnan R, Wang X, Broce I, Banks SJ, Fominykh V, Cheng W, Holland D, Smeland OB, Seibert T, Selbæk G, Brewer JB, Fan CC, Andreassen OA, Dale AM. Improved multimodal prediction of progression from MCI to Alzheimer's disease combining genetics with quantitative brain MRI and cognitive measures. Alzheimers Dement 2023; 19:5151-5158. [PMID: 37132098 PMCID: PMC10620101 DOI: 10.1002/alz.13112] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 03/21/2023] [Accepted: 04/04/2023] [Indexed: 05/04/2023]
Abstract
INTRODUCTION There is a pressing need for non-invasive, cost-effective tools for early detection of Alzheimer's disease (AD). METHODS Using data from the Alzheimer's Disease Neuroimaging Initiative (ADNI), Cox proportional models were conducted to develop a multimodal hazard score (MHS) combining age, a polygenic hazard score (PHS), brain atrophy, and memory to predict conversion from mild cognitive impairment (MCI) to dementia. Power calculations estimated required clinical trial sample sizes after hypothetical enrichment using the MHS. Cox regression determined predicted age of onset for AD pathology from the PHS. RESULTS The MHS predicted conversion from MCI to dementia (hazard ratio for 80th versus 20th percentile: 27.03). Models suggest that application of the MHS could reduce clinical trial sample sizes by 67%. The PHS alone predicted age of onset of amyloid and tau. DISCUSSION The MHS may improve early detection of AD for use in memory clinics or for clinical trial enrichment. HIGHLIGHTS A multimodal hazard score (MHS) combined age, genetics, brain atrophy, and memory. The MHS predicted time to conversion from mild cognitive impairment to dementia. MHS reduced hypothetical Alzheimer's disease (AD) clinical trial sample sizes by 67%. A polygenic hazard score predicted age of onset of AD neuropathology.
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Affiliation(s)
- Emilie T. Reas
- Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Alexey Shadrin
- NORMENT Centre, Institute of Clinical Medicine, University of Oslo and Division of Mental Health and Addiction, Oslo University Hospital, 0407 Oslo, Norway
| | - Oleksandr Frei
- NORMENT Centre, Institute of Clinical Medicine, University of Oslo and Division of Mental Health and Addiction, Oslo University Hospital, 0407 Oslo, Norway
- Center for Bioinformatics, Department of Informatics, University of Oslo, PO box 1080, Blindern, 0316 Oslo, Norway
| | - Ehsan Motazedi
- NORMENT Centre, Institute of Clinical Medicine, University of Oslo and Division of Mental Health and Addiction, Oslo University Hospital, 0407 Oslo, Norway
| | - Linda McEvoy
- Department of Radiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Shahram Bahrami
- NORMENT Centre, Institute of Clinical Medicine, University of Oslo and Division of Mental Health and Addiction, Oslo University Hospital, 0407 Oslo, Norway
| | - Dennis van der Meer
- NORMENT Centre, Institute of Clinical Medicine, University of Oslo and Division of Mental Health and Addiction, Oslo University Hospital, 0407 Oslo, Norway
| | - Carolina Makowski
- Department of Radiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Robert Loughnan
- University of California, San Diego, La Jolla, California, USA
| | - Xin Wang
- Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Iris Broce
- Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Sarah J. Banks
- Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Vera Fominykh
- NORMENT Centre, Institute of Clinical Medicine, University of Oslo and Division of Mental Health and Addiction, Oslo University Hospital, 0407 Oslo, Norway
| | - Weiqiu Cheng
- NORMENT Centre, Institute of Clinical Medicine, University of Oslo and Division of Mental Health and Addiction, Oslo University Hospital, 0407 Oslo, Norway
| | - Dominic Holland
- Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Olav B. Smeland
- NORMENT Centre, Institute of Clinical Medicine, University of Oslo and Division of Mental Health and Addiction, Oslo University Hospital, 0407 Oslo, Norway
| | - Tyler Seibert
- Department of Radiology, University of California, San Diego, La Jolla, CA 92093, USA
| | | | - James B. Brewer
- Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Chun C. Fan
- Population Neuroscience and Genetics Lab, University of California, La Jolla, CA 92093, USA
- Center for Human Development, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Radiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Ole A. Andreassen
- NORMENT Centre, Institute of Clinical Medicine, University of Oslo and Division of Mental Health and Addiction, Oslo University Hospital, 0407 Oslo, Norway
| | - Anders M. Dale
- Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, USA
- Population Neuroscience and Genetics Lab, University of California, La Jolla, CA 92093, USA
- Department of Radiology, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Psychiatry, University of California, San Diego, La Jolla, CA 92093, USA
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Funk-White M, Wing D, Eyler LT, Moore AA, Reas ET, McEvoy L. Neuroimaging-Derived Predicted Brain Age and Alcohol Use Among Community-Dwelling Older Adults. Am J Geriatr Psychiatry 2023; 31:669-678. [PMID: 36925380 DOI: 10.1016/j.jagp.2023.02.043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 02/14/2023] [Accepted: 02/15/2023] [Indexed: 02/22/2023]
Abstract
OBJECTIVES Observational studies have suggested that moderate alcohol use is associated with reduced risk of dementia. However, the nature of this association is not understood. We investigated whether light to moderate alcohol use may be associated with slower brain aging, among a cohort of older community-dwelling adults using a biomarker of brain age based on structural neuroimaging measures. DESIGN Cross-sectional observational study. PARTICIPANTS Well-characterized members of a longitudinal cohort study who underwent neuroimaging. We categorized the 163 participants (mean age 76.7 ± 7.7, 60% women) into current nondrinkers, light drinkers (1-7 drinks/week) moderate drinkers (>7-14 drinks/week), or heavier drinkers (>14 drinks/week). MEASUREMENTS We calculated brain-predicted age using structural MRIs processed with the BrainAgeR program, and calculated the difference between brain-predicted age and chronological age (brain-predicted age difference, or brain-PAD). We used analysis of variance to determine if brain-PAD differed across alcohol groups, controlling for potential confounders. RESULTS Brain-PAD differed across alcohol groups (F[3, 150] = 4.02; p = 0.009) with heavier drinkers showing older brain-PAD than light drinkers (by about 6 years). Brain-PAD did not differ across light, moderate, and nondrinkers. Similar results were obtained after adjusting for potentially mediating health-related measures, and after excluding individuals with a history of heavier drinking. DISCUSSION Among this sample of healthy older adults, consumption of more than 14 drinks/week was associated with a biomarker of advanced brain aging. Light and moderate drinking was not associated with slower brain aging relative to non-drinking.
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Affiliation(s)
- Makaya Funk-White
- Interdisciplinary Research on Substance Use (MFW), University of California San Diego, La Jolla, CA
| | - David Wing
- Herbert Wertheim School of Public Health and Human Longevity Science (DW, LKM), University of California San Diego, La Jolla, CA
| | - Lisa T Eyler
- Department of Psychiatry (LTE), University of California San Diego, La Jolla, CA; Desert-Pacific Mental Illness Research (LTE), Education, and Clinical Center, VA San Diego Healthcare System, San Diego, CA
| | - Alison A Moore
- Division of Geriatrics, Gerontology, and Palliative Care, Department of Medicine (AAM), University of California San Diego, La Jolla, CA
| | - Emilie T Reas
- Department of Neurosciences (ETR), University of California San Diego, La Jolla, CA
| | - Linda McEvoy
- Herbert Wertheim School of Public Health and Human Longevity Science (DW, LKM), University of California San Diego, La Jolla, CA; Department of Radiology (LKM), University of California San Diego, La Jolla, CA
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Tsiknia AA, Parada H, Banks SJ, Reas ET. Sleep quality and sleep duration predict brain microstructure among community-dwelling older adults. Neurobiol Aging 2023; 125:90-97. [PMID: 36871334 PMCID: PMC10115563 DOI: 10.1016/j.neurobiolaging.2023.02.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 01/11/2023] [Accepted: 02/04/2023] [Indexed: 02/12/2023]
Abstract
Although poor sleep quality and extreme sleep durations have been associated with brain atrophy and dementia, it is unclear whether sleep disturbances contribute to neural injury in the absence of neurodegeneration and cognitive impairment. In 146 dementia-free older adults of the Rancho Bernardo Study of Healthy Aging (76.7 ± 7.8 years at MRI), we examined associations of restriction spectrum imaging metrics of brain microstructure with self-reported sleep quality 6.3 ± 0.7 years prior, and with sleep duration reported 25, 15 and 9 years prior. Worse sleep quality predicted lower white matter restricted isotropic diffusion and neurite density and higher amygdala free water, with stronger associations between poor sleep quality and abnormal microstructure for men. Among women only, short or long sleep duration 25 and 15 years before MRI predicted lower white matter restricted isotropic diffusion and increased free water. Associations persisted after accounting for associated health and lifestyle factors. Sleep patterns were not related to brain volume or cortical thickness. Optimizing sleep behaviors throughout the life-course may help to preserve healthy brain aging.
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Affiliation(s)
- Amaryllis A Tsiknia
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Humberto Parada
- Division of Epidemiology and Biostatistics, San Diego State University, San Diego, CA, USA
| | - Sarah J Banks
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Emilie T Reas
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA.
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Parada H, Bergstrom J, Bangen KJ, Reas ET. Pulse pressure trajectories predict brain microstructure in community-dwelling older adults: Associations with executive function and modification by APOE. Alzheimers Dement 2023; 19:1963-1973. [PMID: 36377803 PMCID: PMC10182213 DOI: 10.1002/alz.12844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 08/16/2022] [Accepted: 10/05/2022] [Indexed: 11/16/2022]
Abstract
INTRODUCTION Effects of chronic arterial stiffness on brain aging remain unclear. We, therefore, examined whether long-term trajectories of pulse pressure (PP) predicted brain microstructure, microstructure mediated PP-executive function associations, and APOE genotype modified PP-microstructure associations. METHODS We examined associations of PP trajectories with brain microstructure measured using restriction spectrum imaging in 146 community-dwelling older adults, whether microstructure mediated PP trajectory-executive function associations, and whether PP-restriction spectrum imaging correlations were modified by APOE-ε4 status. RESULTS Participants with trajectories of high PP had lower restricted isotropic diffusion (RI) compared to those with low PP trajectories and PP-executive function associations were mediated by subcortical and white matter RI. High PP more strongly correlated with lower RI and higher hindered diffusion among APOE-ε4 carriers than non-carriers. DISCUSSION Prolonged elevated PP predicts microstructural abnormalities which may contribute to impaired executive function. APOE-ε4 carriers may be most vulnerable to the adverse effects of PP on brain microstructure.
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Affiliation(s)
- Humberto Parada
- Division of Epidemiology and Biostatistics, School of Public Health, San Diego State University, San Diego, CA, USA
- University of California, San Diego Moores Cancer Center, La Jolla, CA, USA
- Department of Radiation Medicine & Applied Science, University of California, San Diego, La Jolla, CA, USA
| | - Jaclyn Bergstrom
- Division of Epidemiology, Department of Family Medicine and Public Health, University of California, San Diego, La Jolla, CA, USA
| | - Katherine J. Bangen
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA
| | - Emilie T. Reas
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
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Tsiknia AA, Bergstrom J, Reas ET. Midlife omega-3 fatty acid intake predicts later life white matter microstructure in an age- and APOE-dependent manner. Cereb Cortex 2023; 33:2143-2151. [PMID: 35584792 PMCID: PMC9977375 DOI: 10.1093/cercor/bhac196] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 04/28/2022] [Accepted: 04/29/2022] [Indexed: 11/13/2022] Open
Abstract
Omega-3 intake has been positively associated with healthy brain aging, yet it remains unclear whether high omega-3 intake beginning early in life may optimize its protective effects against brain aging. We examined whether omega-3 intake is associated with brain microstructure over 2 decades later among dementia-free older adults. The 128 participants (62% women; age at magnetic resonance imaging: 76.6 ± 7.9) from the Rancho Bernardo Study of Healthy Aging completed at least 1 dietary assessment between 1984 and 1996 and underwent restriction spectrum imaging (RSI) 22.8 ± 3.1 years later. We evaluated associations between prior omega-3 intake and RSI metrics of gray and white matter (WM) microstructure. Higher prior omega-3 intake was associated with greater restricted diffusion in the superior cortico-striatal fasciculus. A correlation between higher prior omega-3 intake and greater cingulum restricted diffusion was stronger among participants >80 years old. Higher omega-3 intake correlated with greater restricted diffusion in the inferior longitudinal and inferior fronto-occipital fasciculus more strongly for apolipoprotein E (APOE) ε4 carriers than noncarriers. Associations were not modified by adjustment for dietary pattern, health, or lifestyle. High omega-3 intake in midlife may help to maintain WM integrity into older age, particularly in the latest decades of life and among APOE ε4 carriers.
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Affiliation(s)
- Amaryllis A Tsiknia
- Department of Neurosciences, University of California, San Diego, CA 92093-0841, United States
| | - Jaclyn Bergstrom
- School of Public Health and Human Longevity Science, University of California, San Diego, CA 92093, United States
| | - Emilie T Reas
- Department of Neurosciences, University of California, San Diego, CA 92093-0841, United States
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Wang X, Sundermann EE, Buckley RF, Reas ET, McEvoy LK, Banks SJ. Sex Differences in the Associations of Obesity with Tau, Amyloid PET, and Cognitive Outcomes in Preclinical Alzheimer's Disease: Cross-Sectional A4 Study. J Alzheimers Dis 2023; 95:615-624. [PMID: 37574737 DOI: 10.3233/jad-230466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
BACKGROUND The association between obesity and Alzheimer's disease (AD) is complex. Recent studies indicated the relationships between obesity and AD may differ by sex, and women may benefit from being overweight in terms of AD risk. OBJECTIVE We investigated whether sex modifies the associations of obesity with tau positron emission tomography (PET), amyloid PET, and cognition in preclinical AD. METHODS We included 387 cognitively-unimpaired amyloid-positive participants (221 women, 166 men, 87.6% non-Hispanic White) with available 18F-flortaucipir PET, 18F-florbetapir PET, and completed the Preclinical Alzheimer Cognitive Composite (PACC) tests from the Anti-Amyloid Treatment in Asymptomatic Alzheimer's Disease (A4) study. Participants were categorized based on body mass index (BMI: kg/m2): normal-weight (BMI: 18.5-25), overweight (BMI: 25-30), and obese (BMI≥30). RESULTS Significant sex by BMI category interactions on PACC and its components: Mini-Mental State Examination (MMSE) and Reminding Test-Free+Total Recall (FCSRT96) revealed that overweight and obese women outperformed normal-weight women on FCSRT96, while obese men showed poorer MMSE performance than normal-weight men. These interactions were independent of APOE4. There were no significant interactions of sex by BMI category on tau and amyloid PET. However, sex-stratified analyses observed obesity was associated with less regional tau and mean cortical amyloid in women, not in men. CONCLUSION This study found that in preclinical AD, overweight and obesity were associated with better verbal memory in women, whereas obesity was associated with worse global cognition among men. Future studies focusing on the mechanism for this relationship may inform sex-specific interventions for AD prevention.
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Affiliation(s)
- Xin Wang
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Erin E Sundermann
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Rachel F Buckley
- Department of Neurology, Massachusetts General Hospital/Harvard Medical School, Boston, MA, USA
| | - Emilie T Reas
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Linda K McEvoy
- Herbert Wertheim School of Public Health and Human Longevity Science, University of California, San Diego, La Jolla, CA, USA
- Kaiser Permanente Washington Health Research Institute, Seattle, WA, USA
| | - Sarah J Banks
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
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McEvoy LK, Bergstrom J, Hagler DJ, Wing D, Reas ET. Elevated Pure Tone Thresholds Are Associated with Altered Microstructure in Cortical Areas Related to Auditory Processing and Attentional Allocation. J Alzheimers Dis 2023; 96:1163-1172. [PMID: 37955091 PMCID: PMC10793660 DOI: 10.3233/jad-230767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2023]
Abstract
BACKGROUND Hearing loss is associated with cognitive decline and increased risk for Alzheimer's disease, but the basis of this association is not understood. OBJECTIVE To determine whether hearing impairment is associated with advanced brain aging or altered microstructure in areas involved with auditory and cognitive processing. METHODS 130 participants, (mean 76.4±7.3 years; 65% women) of the Rancho Bernardo Study of Healthy Aging had a screening audiogram in 2003-2005 and brain magnetic resonance imaging in 2014-2016. Hearing ability was defined as the average pure tone threshold (PTA) at 500, 1000, 2000, and 4000 Hz in the better-hearing ear. Brain-predicted age difference (Brain-pad) was calculated as the difference between brain-predicted age based on a validated structural imaging biomarker of brain age, and chronological age. Regional diffusion metrics in temporal and frontal cortex regions were obtained from diffusion-weighted MRIs. Linear regression analyses adjusted for age, gender, education, and health-related measures. RESULTS PTAs were not associated with brain-PAD (β= 0.09; 95% CI: -0.084 to 0.243; p = 0.34). PTAs were associated with reduced restricted diffusion and increased free water diffusion primarily in right hemisphere temporal and frontal areas (restricted diffusion: βs = -0.21 to -0.30; 95% CIs from -0.48 to -0.02; ps < 0.03; free water: βs = 0.18 to 0.26; 95% CIs 0.01 to 0.438; ps < 0.04). CONCLUSIONS Hearing impairment is not associated with advanced brain aging but is associated with differences in brain regions involved with auditory processing and attentional control. It is thus possible that increased dementia risk associated with hearing impairment arises, in part, from compensatory brain changes that may decrease resilience.
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Affiliation(s)
- Linda K McEvoy
- Kaiser Permanente Washington Health Research Institute, Seattle, WA, USA
- Herbert Wertheim School of Public Health and Human Longevity Science, University of California San Diego, San Diego, CA, USA
| | - Jaclyn Bergstrom
- Division of Geriatrics, Gerontology, and Palliative Care, Department of Medicine, University of California San Diego, San Diego, CA, USA
| | - Donald J Hagler
- Department of Radiology, University of California San Diego, San Diego, CA, USA
| | - David Wing
- Herbert Wertheim School of Public Health and Human Longevity Science, University of California San Diego, San Diego, CA, USA
| | - Emilie T Reas
- Department of Neurosciences, University of California San Diego, San Diego, CA, USA
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Parada H, Bergstrom J, Reas ET. Pulse pressure trajectories predict brain microstructure in an
APOE
‐dependent manner among cognitively normal older adults. Alzheimers Dement 2022. [DOI: 10.1002/alz.061974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Tsiknia AA, Sundermann EE, Edland SD, Reas ET, Brewer JB, Galasko DR, Banks SJ. The relationship between plasma matrix metalloproteinase‐9 and cerebrospinal fluid biomarkers of tau is sex‐dependent. Alzheimers Dement 2022. [DOI: 10.1002/alz.064323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
| | | | | | | | - James B. Brewer
- University of California San Diego La Jolla CA USA
- Shiley‐Marcos Alzheimer's Disease Research Center La Jolla CA USA
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Funk‐White M, Wing D, Eyler LT, Moore AA, Reas ET, McEvoy LK. The Association between Brain Age and Alcohol Use. Alzheimers Dement 2022. [DOI: 10.1002/alz.069241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
| | - David Wing
- University of California San Diego San Diego CA USA
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Tsiknia AA, Sundermann EE, Reas ET, Edland SD, Brewer JB, Galasko D, Banks SJ. Sex differences in Alzheimer's disease: plasma MMP-9 and markers of disease severity. Alzheimers Res Ther 2022; 14:160. [PMID: 36324151 PMCID: PMC9628176 DOI: 10.1186/s13195-022-01106-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 10/16/2022] [Indexed: 01/24/2023]
Abstract
BACKGROUND Studies have reported higher plasma matrix metalloproteinase-9 (MMP-9) levels in mild cognitive impairment (MCI) and Alzheimer's disease (AD). Despite evidence that MMP-9 activity and its influence on AD pathophysiology may be modulated by sex hormones, sex differences in the association between MMP-9 and AD biomarkers and cognition have not been explored. METHODS Our sample included 238 amyloid-β (Aβ)-positive participants with MCI or AD dementia from the Alzheimer's Disease Neuroimaging Initiative (37.4% women, 74.6 ± 7.3 years). We used linear regression models to examine whether sex modified free and total plasma MMP-9 associations with CSF t-tau, p-tau181, and Aβ42. We used linear mixed effects models to examine whether sex modified total and free plasma MMP-9 associations with cognition, using longitudinal Mini-Mental Status Examination (MMSE) and Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-cog) data. RESULTS Total and free MMP-9 levels did not differ by sex, but AD dementia patients had higher total MMP-9 levels than participants with MCI (β = 0.06 [-0.11 to -0.01], p = 0.031). Sex modified the association of CSF t-tau with total (β = 128.68 [55.37 to 201.99], p < 0.001) and free MMP-9 (β = 98.61 [33.61 to 163.62], p = 0.003), whereby higher total and free MMP-9 correlated with higher CSF t-tau in women and lower CSF t-tau in men. Higher free MMP-9 correlated with lower CSF p-tau181 among men (β = -14.98 [-27.37 to -2.58], p = 0.018), but not women. In participants with MCI, higher free MMP-9 levels were associated with higher CSF Aβ42 among men (β = 26.88 [4.03 to 49.73], p = 0.022) but not women. In the overall sample, higher free and total MMP-9 at baseline predicted worsening MMSE scores in women (β = -2.10 [-3.97 to -0.27], p = 0.027 and β = -2.24 [-4.32 to -0.18], p = 0.035) but not men. Higher free MMP-9 correlated with worse ADAS-cog scores (β = 12.34 [3.02 to 21.65], p = 0.011) in women (β = 12.34 [3.02 to 21.65], p = 0.011) but not men with AD dementia cross-sectionally but correlated with worsening ADAS-cog scores longitudinally only in men (β = 8.98 [0.27 to 17.68], p = 0.042). CONCLUSIONS MMP-9 may have more detrimental effects on AD-related pathological and cognitive changes in women. If replicated, our findings could help uncover potential mechanisms contributing to women's elevated susceptibility to AD.
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Affiliation(s)
- Amaryllis A. Tsiknia
- Department of Neurosciences, School of Medicine, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093 USA
| | - Erin E. Sundermann
- grid.410371.00000 0004 0419 2708Research Service, VA San Diego Healthcare System, San Diego, CA 92161 USA ,grid.266100.30000 0001 2107 4242Department of Psychiatry, University of California, San Diego, La Jolla, CA 92093 USA
| | - Emilie T. Reas
- Department of Neurosciences, School of Medicine, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093 USA
| | - Steven D. Edland
- Department of Neurosciences, School of Medicine, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093 USA ,grid.266100.30000 0001 2107 4242Division of Biostatistics, School of Public Health and Human Longevity Science, University of California, San Diego, La Jolla, CA 92093 USA
| | - James B. Brewer
- Department of Neurosciences, School of Medicine, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093 USA
| | - Douglas Galasko
- Department of Neurosciences, School of Medicine, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093 USA
| | - Sarah J. Banks
- Department of Neurosciences, School of Medicine, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093 USA
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Elman JA, Puckett OK, Hagler DJ, Pearce RC, Fennema-Notestine C, Hatton SN, Lyons MJ, McEvoy LK, Panizzon MS, Reas ET, Dale AM, Franz CE, Kremen WS. Associations between MRI-assessed locus coeruleus integrity and cortical gray matter microstructure. Cereb Cortex 2022; 32:4191-4203. [PMID: 34969072 PMCID: PMC9528780 DOI: 10.1093/cercor/bhab475] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 11/17/2021] [Accepted: 11/22/2021] [Indexed: 01/27/2023] Open
Abstract
The locus coeruleus (LC) is one of the earliest sites of tau pathology, making it a key structure in early Alzheimer's disease (AD) progression. As the primary source of norepinephrine for the brain, reduced LC integrity may have negative consequences for brain health, yet macrostructural brain measures (e.g. cortical thickness) may not be sensitive to early stages of neurodegeneration. We therefore examined whether LC integrity was associated with differences in cortical gray matter microstructure among 435 men (mean age = 67.5; range = 62-71.7). LC structural integrity was indexed by contrast-to-noise ratio (LCCNR) from a neuromelanin-sensitive MRI scan. Restriction spectrum imaging (RSI), an advanced multi-shell diffusion technique, was used to characterize cortical microstructure, modeling total diffusion in restricted, hindered, and free water compartments. Higher LCCNR (greater integrity) was associated with higher hindered and lower free water diffusion in multiple cortical regions. In contrast, no associations between LCCNR and cortical thickness survived correction. Results suggest lower LC integrity is associated with patterns of cortical microstructure that may reflect a reduction in cytoarchitectural barriers due to broader neurodegenerative processes. These findings highlight the potential utility for LC imaging and advanced diffusion measures of cortical microstructure in assessing brain health and early identification of neurodegenerative processes.
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Affiliation(s)
- Jeremy A Elman
- Department of Psychiatry, University of California San Diego, La Jolla, CA 92093, USA
- Center for Behavior Genetics of Aging, University of California San Diego, La Jolla, CA 92093, USA
| | - Olivia K Puckett
- Department of Psychiatry, University of California San Diego, La Jolla, CA 92093, USA
- Center for Behavior Genetics of Aging, University of California San Diego, La Jolla, CA 92093, USA
| | - Donald J Hagler
- Department of Radiology, University of California San Diego, La Jolla, CA 92093, USA
| | - Rahul C Pearce
- Department of Psychiatry, University of California San Diego, La Jolla, CA 92093, USA
- Center for Behavior Genetics of Aging, University of California San Diego, La Jolla, CA 92093, USA
| | - Christine Fennema-Notestine
- Department of Psychiatry, University of California San Diego, La Jolla, CA 92093, USA
- Department of Radiology, University of California San Diego, La Jolla, CA 92093, USA
| | - Sean N Hatton
- Center for Behavior Genetics of Aging, University of California San Diego, La Jolla, CA 92093, USA
- Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Michael J Lyons
- Department of Psychological and Brain Sciences, Boston University, Boston, MA 02215, USA
| | - Linda K McEvoy
- Department of Radiology, University of California San Diego, La Jolla, CA 92093, USA
- Herbert Wertheim School of Public Health and Human Longevity Science, University of California San Diego, La Jolla, CA 92093, USA
| | - Matthew S Panizzon
- Department of Psychiatry, University of California San Diego, La Jolla, CA 92093, USA
- Center for Behavior Genetics of Aging, University of California San Diego, La Jolla, CA 92093, USA
| | - Emilie T Reas
- Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Anders M Dale
- Department of Radiology, University of California San Diego, La Jolla, CA 92093, USA
- Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Carol E Franz
- Department of Psychiatry, University of California San Diego, La Jolla, CA 92093, USA
- Center for Behavior Genetics of Aging, University of California San Diego, La Jolla, CA 92093, USA
| | - William S Kremen
- Department of Psychiatry, University of California San Diego, La Jolla, CA 92093, USA
- Center for Behavior Genetics of Aging, University of California San Diego, La Jolla, CA 92093, USA
- Center of Excellence for Stress and Mental Health, VA San Diego Health Care System, La Jolla, CA 92161, USA
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14
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Tsiknia AA, Edland SD, Sundermann EE, Reas ET, Brewer JB, Galasko D, Banks SJ. Sex differences in plasma p-tau181 associations with Alzheimer's disease biomarkers, cognitive decline, and clinical progression. Mol Psychiatry 2022; 27:4314-4322. [PMID: 35768637 PMCID: PMC9718670 DOI: 10.1038/s41380-022-01675-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 05/27/2022] [Accepted: 06/10/2022] [Indexed: 02/07/2023]
Abstract
Studies have shown that women on the Alzheimer's disease (AD) continuum have more pathological tau in the brain and cerebrospinal fluid (CSF), than men. Some studies have found that higher levels of tau biomarkers are more strongly associated with clinical AD, cognitive decline and neurodegeneration in women than in men. Despite major developments in the use of plasma tau phosphorylated at threonine 181 (p-tau181) as an AD biomarker, it is unknown whether these sex differences apply to plasma p-tau181. In 1060 Alzheimer's Disease Neuroimaging Initiative (ADNI) participants (47% women, 73.8 ± 7.6 years old), we examined sex differences in plasma p-tau181 levels and their association with other biomarkers, cognitive decline and incident AD. Linear regressions tested for an effect of sex on plasma p-tau181 levels and for plasma p-tau181 × sex interactions on CSF p-tau181, as well as entorhinal cortex tau, cortical amyloid-β (Aβ) deposition, and brain glucose metabolism, quantified using PET imaging. Linear mixed effects models tested for a sex × baseline plasma p-tau181 interaction on change in cognition over time. Finally, Cox models tested for a sex × plasma p-tau181 interaction on the risk of AD dementia in participants who were free of dementia at baseline. Despite similar plasma p-tau181 levels between sexes, women had lower brain glucose metabolism, greater brain Aβ and entorhinal cortex tau deposition, higher CSF p-tau181 and faster cognitive decline in relation to higher baseline plasma p-tau181 levels compared with men. Among Aβ positive, dementia-free participants, women had higher rates of incident AD dementia associated with increasing baseline plasma p-tau181 levels, relative to men. Our results suggest that sex may impact the clinical interpretation of plasma p-tau181 concentrations. If replicated, these findings could have important implications for the use of plasma p-tau181 as an accessible AD biomarker and screening tool for preventive and therapeutic clinical trials.
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Affiliation(s)
- Amaryllis A. Tsiknia
- grid.266100.30000 0001 2107 4242Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093 USA
| | - Steven D. Edland
- grid.266100.30000 0001 2107 4242Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093 USA ,grid.266100.30000 0001 2107 4242Division of Biostatistics, School of Public Health and Human Longevity Science, University of California, San Diego, La Jolla, CA 92093 USA
| | - Erin E. Sundermann
- grid.266100.30000 0001 2107 4242Department of Psychiatry, University of California, San Diego, La Jolla, CA 92093 USA ,grid.410371.00000 0004 0419 2708Research Service, Veterans Affairs San Diego Healthcare System, San Diego, CA 92161 USA
| | - Emilie T. Reas
- grid.266100.30000 0001 2107 4242Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093 USA
| | - James B. Brewer
- grid.266100.30000 0001 2107 4242Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093 USA
| | - Douglas Galasko
- grid.266100.30000 0001 2107 4242Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093 USA
| | - Sarah J. Banks
- grid.266100.30000 0001 2107 4242Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093 USA ,grid.266100.30000 0001 2107 4242Department of Psychiatry, University of California, San Diego, La Jolla, CA 92093 USA
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15
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Reas ET, Smirnov DS, Banks SJ, Galasko DR, Brewer JB. Brain microstructure mediates effects of tau on cognitive decline in early Alzheimer’s disease. Alzheimers Dement 2021. [DOI: 10.1002/alz.055578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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16
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Banks SJ, Andrews MJ, Digma L, Madsen J, Reas ET, Caldwell JZ, McEvoy LK, Fan CC, Dale AM, Brewer JB. Sex differences in Alzheimer's disease: do differences in tau explain the verbal memory gap? Neurobiol Aging 2021; 107:70-77. [PMID: 34399127 PMCID: PMC8963683 DOI: 10.1016/j.neurobiolaging.2021.05.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/28/2021] [Accepted: 05/23/2021] [Indexed: 10/21/2022]
Abstract
To determine if sex differences in verbal memory in AD are related to differences in extent or distribution of pathological tau, we studied 275 participants who were amyloid PET positive and carried clinical classifications of normal cognition, mild cognitive impairment (MCI) or dementia, and had tau (AV1451) PET. We compared tau distribution between men and women, and as a function of genetic risk. In MCI we further explored the relationship between quantity and distribution of tau in relation to verbal memory scores. Women had more tau burden overall, but this was driven by sex differences at the MCI stage. There was no significant difference in tau load by APOE e4 status. Within the MCI group the association between tau and performance in verbal memory tasks was stronger in women than men. The topography of the associations between tau and verbal memory also differed in MCI; women demonstrated stronger relationships between tau distribution and verbal memory performance, especially in the left hemisphere. These findings have implications for understanding tau distribution and spread, and in interpretation of verbal memory performance.
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Affiliation(s)
- Sarah J. Banks
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA,Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, USA,Corresponding author at: Departments of Neurology and Psychiatry, University of California, San Diego, Office Address: ACTRI 4W-501, Mailing Address: 9500 Gilman Dr, La Jolla CA 92093 M/C 0841, USA. Phone: (858) 246-1264. (S.J. Banks)
| | - Murray J. Andrews
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Leonardino Digma
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - John Madsen
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Emilie T. Reas
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | | | - Linda K. McEvoy
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA
| | - Chun Chieh Fan
- Center for Human Development, University of California, San Diego, La Jolla, CA, USA
| | - Anders M. Dale
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA,Department of Radiology, University of California, San Diego, La Jolla, CA, USA,Center for Molecular Imaging and Genetics, University of California, San Diego, La Jolla, CA, USA,Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - James B. Brewer
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA,Department of Radiology, University of California, San Diego, La Jolla, CA, USA
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17
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Reas ET, Hagler DJ, Zhong AJ, Lee RR, Dale AM, McEvoy LK. Brain microstructure mediates sex-specific patterns of cognitive aging. Aging (Albany NY) 2021; 13:3218-3238. [PMID: 33510046 PMCID: PMC7906181 DOI: 10.18632/aging.202561] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 01/14/2021] [Indexed: 11/25/2022]
Abstract
Normal brain aging is characterized by declining neuronal integrity, yet it remains unclear how microstructural injury influences cognitive aging and whether such mechanisms differ between sexes. Using restriction spectrum imaging (RSI), we examined sex differences in associations between brain microstructure and cognitive function in 147 community-dwelling older men and women (56-99 years). Gray and white matter microstructure correlated with global cognition, executive function, visuospatial memory, episodic memory, and logical memory, with the strongest associations for restricted, hindered and free isotropic diffusion. Associations were stronger for women than for men, a difference likely due to greater age-related variability in cognitive scores and microstructure in women. Isotropic diffusion mediated effects of age on cognition for both sexes, though distinct mediation patterns were present for women and men. For women, hippocampal and corpus callosum microstructure mediated age effects on verbal and visuospatial memory, respectively, whereas for men fiber microstructure (mainly fornix and corpus callosum) mediated age effects on executive function and visuospatial memory. These findings implicate sex-specific pathways by which changing brain cytoarchitecture contributes to cognitive aging, and suggest that RSI may be useful for evaluating risk for cognitive decline or monitoring efficacy of interventions to preserve brain health in later life.
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Affiliation(s)
- Emilie T Reas
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Donald J Hagler
- Department of Radiology, University of California, San Diego, La Jolla, CA 92093, USA
| | | | - Roland R Lee
- Department of Radiology, University of California, San Diego, La Jolla, CA 92093, USA.,Radiology Services, VA San Diego Healthcare System, La Jolla, CA 92093, USA
| | - Anders M Dale
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA.,Department of Radiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Linda K McEvoy
- Department of Radiology, University of California, San Diego, La Jolla, CA 92093, USA.,Department of Family Medicine and Public Health, University of California, San Diego, La Jolla, CA 92093, USA
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18
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Reas ET, Laughlin GA, Hagler DJ, Lee RR, Dale AM, McEvoy LK. Age and Sex Differences in the Associations of Pulse Pressure With White Matter and Subcortical Microstructure. Hypertension 2021; 77:938-947. [PMID: 33461315 DOI: 10.1161/hypertensionaha.120.16446] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Midlife vascular disease increases risk for dementia and effects of vascular dysfunction on brain health differ between men and women. Elevated pulse pressure, a surrogate for arterial stiffness, contributes to cerebrovascular pathology and white matter damage that may advance cognitive aging; however, it remains unclear how associations between pulse pressure and neural integrity differ by sex and age. This study used restriction spectrum imaging to examine associations between pulse pressure and brain microstructure in community-dwelling women (N=88) and men (N=55), aged 56 to 97 (mean, 76.3) years. Restricted isotropic (presumed intracellular), hindered isotropic (presumed extracellular), neurite density, and free water diffusion were computed in white matter tracts and subcortical regions. After adjustment for age and sex, higher pulse pressure correlated with lower restricted isotropic diffusion in global white matter, with more pronounced associations in parahippocampal cingulum, as well as in thalamus and hippocampus. Subgroup analyses demonstrated stronger correlations between pulse pressure and restricted isotropic diffusion in association fibers for participants ≤75 years than for older participants, with stronger effects for women than men of this age group. Microstructure in parahippocampal cingulum and thalamus differed by pulse pressure level regardless of antihypertensive treatment. Increased pulse pressure may lead to widespread injury to white matter and subcortical structures, with greatest vulnerability for women in late middle to early older age. Restriction spectrum imaging could be useful for monitoring microstructural changes indicative of neuronal loss or shrinkage, demyelination, or inflammation that accompany age-related cerebrovascular dysfunction.
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Affiliation(s)
- Emilie T Reas
- From the Department of Neurosciences (E.T.R., A.M.D.), University of California, San Diego
| | - Gail A Laughlin
- Department of Family Medicine and Public Health (G.A.L., L.K.M.), University of California, San Diego
| | - Donald J Hagler
- Department of Radiology (D.J.H., R.R.L., A.M.D., L.K.M.), University of California, San Diego
| | - Roland R Lee
- Department of Radiology (D.J.H., R.R.L., A.M.D., L.K.M.), University of California, San Diego.,Radiology Services, VA San Diego Healthcare System (R.R.L.)
| | - Anders M Dale
- From the Department of Neurosciences (E.T.R., A.M.D.), University of California, San Diego.,Department of Radiology (D.J.H., R.R.L., A.M.D., L.K.M.), University of California, San Diego
| | - Linda K McEvoy
- Department of Family Medicine and Public Health (G.A.L., L.K.M.), University of California, San Diego.,Department of Radiology (D.J.H., R.R.L., A.M.D., L.K.M.), University of California, San Diego
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19
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Reas ET, Hagler DJ, Lee RR, Dale AM, McEvoy LK. Sex differences in associations between brain microstructure and cognitive aging. Alzheimers Dement 2020. [DOI: 10.1002/alz.047459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Ronald R Lee
- University of California, San Diego La Jolla CA USA
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20
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Reas ET, Laughlin GA, Bergstrom J, Kritz-Silverstein D, McEvoy LK. Physical Activity and Trajectories of Cognitive Change in Community-Dwelling Older Adults: The Rancho Bernardo Study. J Alzheimers Dis 2020; 71:109-118. [PMID: 31356211 DOI: 10.3233/jad-190491] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Although physical activity has been associated with better cognitive function and reduced dementia risk, its association with cognitive decline in normal aging remains uncertain. OBJECTIVE To determine whether physical activity in youth and older age are associated with age-related cognitive change. METHODS Over a period of 27 years, 2,027 community-dwelling adults (mean age 73.5; 60% women) of the Rancho Bernardo Study of Healthy Aging completed up to seven cognitive assessments, including tests of global cognitive function, executive function, verbal fluency, and episodic memory. At each visit, participants reported concurrent physical activity. At baseline (1988- 1992), participants additionally reported physical activity as a teenager and at age 30. For each age period, participants were classified as regularly active (3+ times/week) or inactive. RESULTS Associations between concurrent physical activity and better cognitive function were stronger with advancing age on all tests, even after accounting for education, health, and lifestyle factors, as well as survival differences (ps < 0.05). Baseline physical activity did not predict rates of cognitive decline (ps > 0.40). Individuals who were physically active at age 30 and older age maintained the highest global cognitive function with advancing age (p = 0.002). CONCLUSION Regular physical activity is associated with better cognitive function with advancing age. Physical activity in young adulthood may contribute to cognitive reserve, which together with physical activity in later years, may act to preserve cognitive function with age.
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Affiliation(s)
- Emilie T Reas
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Gail A Laughlin
- Department of Family Medicine and Public Health, University of California, San Diego, La Jolla, CA, USA
| | - Jaclyn Bergstrom
- Department of Family Medicine and Public Health, University of California, San Diego, La Jolla, CA, USA
| | - Donna Kritz-Silverstein
- Department of Family Medicine and Public Health, University of California, San Diego, La Jolla, CA, USA
| | - Linda K McEvoy
- Department of Family Medicine and Public Health, University of California, San Diego, La Jolla, CA, USA.,Department of Radiology, University of California, San Diego, La Jolla, CA, USA
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21
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Alattar AA, Bergstrom J, Laughlin GA, Kritz-Silverstein D, Richard EL, Reas ET, Harris JP, Barrett-Connor E, McEvoy LK. Hearing Impairment and Cognitive Decline in Older, Community-Dwelling Adults. J Gerontol A Biol Sci Med Sci 2020; 75:567-573. [PMID: 30753308 PMCID: PMC7328194 DOI: 10.1093/gerona/glz035] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Hearing impairment is prevalent among older adults and has been identified as a risk factor for cognitive impairment and dementia. We evaluated the association of hearing impairment with long-term cognitive decline among community-dwelling older adults. METHODS A population-based longitudinal study of adults not using hearing aids who had hearing acuity and cognitive function assessed in 1992-1996, and were followed for a maximum of 24 years with up to five additional cognitive assessments. Hearing acuity was categorized based on pure-tone average (PTA) thresholds: normal (PTA ≤ 25 dB), mild impairment (PTA > 25-40 dB), moderate/severe impairment (PTA > 40 dB). RESULTS Of 1,164 participants (mean age 73.5 years, 64% women), 580 (49.8%) had mild hearing impairment and 196 (16.8%) had moderate/severe hearing impairment. In fully adjusted models, hearing impairment was associated with steeper decline on the Mini-Mental State Examination (MMSE) (mild impairment β = -0.04, p = .01; moderate/severe impairment β = -0.08, p = .002) and Trails B (mild impairment β = 1.21, p = .003; moderate/severe impairment β = 2.16, p = .003). Associations did not differ by sex or apolipoprotein E (APOE) ϵ4 status and were not influenced by social engagement. The MMSE-hearing association was modified by education: mild hearing impairment was associated with steeper decline on the MMSE among participants without college education but not among those with college education. Moderate/severe hearing impairment was associated with steeper MMSE decline regardless of education level. CONCLUSIONS Hearing impairment is associated with accelerated cognitive decline with age, and should be screened for routinely. Higher education may provide sufficient cognitive reserve to counter effects of mild, but not more severe, hearing impairment.
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Affiliation(s)
- Ali A Alattar
- School of Medicine, University of California San Diego, La Jolla
| | - Jaclyn Bergstrom
- Division of Epidemiology, Department of Family Medicine and Public Health, University of California San Diego, La Jolla
| | - Gail A Laughlin
- Division of Epidemiology, Department of Family Medicine and Public Health, University of California San Diego, La Jolla
| | - Donna Kritz-Silverstein
- Division of Epidemiology, Department of Family Medicine and Public Health, University of California San Diego, La Jolla
| | - Erin L Richard
- Division of Epidemiology, Department of Family Medicine and Public Health, University of California San Diego, La Jolla
| | - Emilie T Reas
- Department of Neurosciences, University of California San Diego, La Jolla
| | - Jeffrey P Harris
- Division of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of California San Diego, La Jolla
| | - Elizabeth Barrett-Connor
- Division of Epidemiology, Department of Family Medicine and Public Health, University of California San Diego, La Jolla
| | - Linda K McEvoy
- Division of Epidemiology, Department of Family Medicine and Public Health, University of California San Diego, La Jolla
- Department of Radiology, University of California San Diego, La Jolla
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22
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Reas ET, Hagler DJ, Kuperman JM, Wierenga CE, Galasko D, White NS, Dale AM, Banks SJ, McEvoy LK, Brewer JB. Associations Between Microstructure, Amyloid, and Cognition in Amnestic Mild Cognitive Impairment and Dementia. J Alzheimers Dis 2020; 73:347-357. [PMID: 31796676 PMCID: PMC7266036 DOI: 10.3233/jad-190871] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Although amyloid-β (Aβ) and microstructural brain changes are both effective biomarkers of Alzheimer's disease, their independent or synergistic effects on cognitive decline are unclear. OBJECTIVE To examine associations of Aβ and brain microstructure with cognitive decline in amnestic mild cognitive impairment and dementia. METHODS Restriction spectrum imaging, cerebrospinal fluid Aβ, and longitudinal cognitive data were collected on 23 healthy controls and 13 individuals with mild cognitive impairment or mild to moderate Alzheimer's disease. Neurite density (ND) and isotropic free water diffusion (IF) were computed in fiber tracts and cortical regions of interest. We examined associations of Aβ with regional and whole-brain microstructure, and assessed whether microstructure mediates effects of Aβ on cognitive decline. RESULTS Lower ND in limbic and association fibers and higher medial temporal lobe IF predicted baseline impairment and longitudinal decline across multiple cognitive domains. ND and IF predicted cognitive outcomes after adjustment for Aβ or whole-brain microstructure. Correlations between microstructure and cognition were present for both amyloid-positive and amyloid-negative individuals. Aβ correlated with whole-brain, rather than regional, ND and IF. CONCLUSION Aβ correlates with widespread microstructural brain changes, whereas regional microstructure correlates with cognitive decline. Microstructural abnormalities predict cognitive decline regardless of amyloid, and may inform about neural injury leading to cognitive decline beyond that attributable to amyloid.
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Affiliation(s)
- Emilie T. Reas
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Donald J. Hagler
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA
| | - Joshua M. Kuperman
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA
| | - Christina E. Wierenga
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
- Department of Veterans Affairs, San Diego Healthcare system, La Jolla, CA, USA
| | - Douglas Galasko
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Nathan S. White
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA
| | - Anders M. Dale
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA
| | - Sarah J. Banks
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Linda K. McEvoy
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA
- Department of Family Medicine and Public Health, University of California, San Diego, La Jolla, CA, USA
| | - James B. Brewer
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA
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23
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Abstract
BACKGROUND Late-onset Alzheimer's disease (AD) is characterized by primary memory impairment, which then progresses towards severe deficits across cognitive domains. Here, we report how performance in cognitive domains relates to patterns of tau deposition and cortical thickness. METHODS We analyzed data from 131 amyloid-β positive participants (55 cognitively normal, 46 mild cognitive impairment, 30 AD) of the Alzheimer's Disease Neuroimaging Initiative who underwent magnetic resonance imaging (MRI), flortaucipir (FTP) positron emission tomography, and neuropsychological testing. Surface-based vertex-wise and region-of-interest analyses were conducted between FTP and cognitive test scores, and between cortical thickness and cognitive test scores. RESULTS FTP and thickness were differentially related to cognitive performance in several domains. FTP-cognition associations were more widespread than thickness-cognition associations. Further, FTP-cognition patterns reflected cortical systems that underlie different aspects of cognition. CONCLUSIONS Our findings indicate that AD-related decline in domain-specific cognitive performance reflects underlying progression of tau and atrophy into associated brain circuits. They also suggest that tau-PET may have better sensitivity to this decline than MRI-derived measures of cortical thickness.
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Affiliation(s)
- Leonardino A. Digma
- Department of Neurosciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
| | - John R. Madsen
- Department of Neurosciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
| | - Emilie T. Reas
- Department of Neurosciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
| | - Anders M. Dale
- Department of Neurosciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
- Department of Radiology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
- Center for Molecular Imaging and Genetics, University of California, 9500 Gilman Drive, San Diego, La Jolla, CA 92093 USA
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
| | - James B. Brewer
- Department of Neurosciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
- Department of Radiology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
| | - Sarah J. Banks
- Department of Neurosciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
| | - for the Alzheimer’s Disease Neuroimaging Initiative
- Department of Neurosciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
- Department of Radiology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
- Center for Molecular Imaging and Genetics, University of California, 9500 Gilman Drive, San Diego, La Jolla, CA 92093 USA
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
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24
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Reas ET, Hagler DJ, White N, Kuperman J, Bartsch H, Wierenga C, Galasko DR, Dale AM, Banks SJ, Mcevoy L, Brewer JB. P1-414: ASSOCIATION OF BRAIN MICROSTRUCTURE AND AMYLOID-β WITH COGNITIVE DECLINE IN EARLY ALZHEIMER'S DISEASE. Alzheimers Dement 2019. [DOI: 10.1016/j.jalz.2019.06.1019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
| | | | - Nathan White
- University of California, San Diego; La Jolla CA USA
| | | | - Hauke Bartsch
- University of California, San Diego; La Jolla CA USA
| | | | | | | | | | - Linda Mcevoy
- University of California, San Diego; La Jolla CA USA
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25
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Lo MT, Kauppi K, Fan CC, Sanyal N, Reas ET, Sundar VS, Lee WC, Desikan RS, McEvoy LK, Chen CH. Identification of genetic heterogeneity of Alzheimer's disease across age. Neurobiol Aging 2019; 84:243.e1-243.e9. [PMID: 30979435 DOI: 10.1016/j.neurobiolaging.2019.02.022] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Revised: 12/29/2018] [Accepted: 02/27/2019] [Indexed: 02/07/2023]
Abstract
The risk of APOE for Alzheimer's disease (AD) is modified by age. Beyond APOE, the polygenic architecture may also be heterogeneous across age. We aim to investigate age-related genetic heterogeneity of AD and identify genomic loci with differential effects across age. Stratified gene-based genome-wide association studies and polygenic variation analyses were performed in the younger (60-79 years, N = 14,895) and older (≥80 years, N = 6559) age-at-onset groups using Alzheimer's Disease Genetics Consortium data. We showed a moderate genetic correlation (rg = 0.64) between the two age groups, supporting genetic heterogeneity. Heritability explained by variants on chromosome 19 (harboring APOE) was significantly larger in younger than in older onset group (p < 0.05). APOE region, BIN1, OR2S2, MS4A4E, and PICALM were identified at the gene-based genome-wide significance (p < 2.73 × 10-6) with larger effects at younger age (except MS4A4E). For the novel gene OR2S2, we further performed leave-one-out analyses, which showed consistent effects across subsamples. Our results suggest using genetically more homogeneous individuals may help detect additional susceptible loci.
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Affiliation(s)
- Min-Tzu Lo
- Center for Multimodal Imaging and Genetics, Department of Radiology, University of California, San Diego, CA, USA; Department of Bioinformatics, Ambry Genetics, Aliso Viejo, CA, USA.
| | - Karolina Kauppi
- Center for Multimodal Imaging and Genetics, Department of Radiology, University of California, San Diego, CA, USA; Department of Radiation Sciences, Umea University, Umea, Sweden
| | - Chun-Chieh Fan
- Center for Multimodal Imaging and Genetics, Department of Radiology, University of California, San Diego, CA, USA; Department of Cognitive Science, University of California, San Diego, CA, USA
| | - Nilotpal Sanyal
- Center for Multimodal Imaging and Genetics, Department of Radiology, University of California, San Diego, CA, USA
| | - Emilie T Reas
- Center for Multimodal Imaging and Genetics, Department of Radiology, University of California, San Diego, CA, USA
| | - V S Sundar
- Center for Multimodal Imaging and Genetics, Department of Radiology, University of California, San Diego, CA, USA
| | - Wen-Chung Lee
- Department of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan
| | - Rahul S Desikan
- Neuroradiology Section, Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA
| | - Linda K McEvoy
- Center for Multimodal Imaging and Genetics, Department of Radiology, University of California, San Diego, CA, USA
| | - Chi-Hua Chen
- Center for Multimodal Imaging and Genetics, Department of Radiology, University of California, San Diego, CA, USA.
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26
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Reas ET, Laughlin GA, Bergstrom J, Kritz-Silverstein D, Richard EL, Barrett-Connor E, McEvoy LK. Lifetime physical activity and late-life cognitive function: the Rancho Bernardo study. Age Ageing 2019; 48:241-246. [PMID: 30615048 PMCID: PMC6424376 DOI: 10.1093/ageing/afy188] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 10/16/2018] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND physical activity in older age has been associated with better cognitive function, but the role of earlier life physical activity is less well understood. OBJECTIVE determine associations between physical activity throughout the lifespan and cognitive function in older age. DESIGN cross-sectional study. SETTING the Rancho Bernardo Study of Healthy Aging in southern California. SUBJECTS A total of 1,826 community-dwelling men and women (60-99 years) who attended a research visit in 1988-92. METHODS participants underwent cognitive testing at older age, and reported physical activity as a teenager, at age 30 years, 50 years and currently. For each time-point, participants were classified as regularly active (3+ times/week) or inactive. RESULTS regular physical activity was associated with better cognitive function, with physical activity at older ages showing the strongest associations. Physical activity in older age was associated with better global cognitive function, executive function and episodic memory, regardless of intensity. Intense physical activity in teenage years was associated with better late-life global cognitive function in women. Teenage physical activity interacted with older age physical activity on executive function; those active at both periods performed better than those active at only one period. Similar patterns of associations were observed after excluding individuals with poor health. CONCLUSIONS regular physical activity in older age, regardless of intensity, is associated with better cognitive function. Physical activity in teenage years may enhance cognitive reserve to protect against age-related decline in executive function. Further research is needed to assess the effect of physical activity across the lifespan on healthy brain ageing.
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Affiliation(s)
- Emilie T Reas
- Department of Neurosciences, University of California, San Diego, USA
| | - Gail A Laughlin
- Department of Family Medicine and Public Health, University of California, San Diego, USA
| | - Jaclyn Bergstrom
- Department of Family Medicine and Public Health, University of California, San Diego, USA
| | | | - Erin L Richard
- Department of Family Medicine and Public Health, University of California, San Diego, USA
| | | | - Linda K McEvoy
- Department of Family Medicine and Public Health, University of California, San Diego, USA
- Department of Radiology, University of California, San Diego, USA
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27
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Reas ET, Laughlin GA, Bergstrom J, Kritz-Silverstein D, Barrett-Connor E, McEvoy LK. Effects of APOE on cognitive aging in community-dwelling older adults. Neuropsychology 2019; 33:406-416. [PMID: 30730162 DOI: 10.1037/neu0000501] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVE The apolipoprotein E (APOE) gene is an established risk factor for sporadic Alzheimer's disease, with elevated risk for ε4-carriers and reduced risk for ε2-carriers. However, it is unclear whether APOE modifies risk for cognitive decline in normal aging. The objective of this study was to determine whether ε2 and ε4 are associated with rates of normal cognitive aging, and whether associations of ε4 with cognitive decline are modified by sex, education or health behaviors (exercise, alcohol consumption, smoking). METHOD A community-based sample of 1,393 older adults were genotyped for APOE and underwent cognitive assessment up to seven times over a maximum of period of 27 years. RESULTS ε2-carriers showed slower executive function decline with age relative to ε3 homozygotes or ε4-carriers, whereas ε4-carriers demonstrated more rapid executive function and verbal fluency decline. Accelerated executive function decline was particularly pronounced in ε4-carriers with lower education. After excluding individuals with cognitive impairment, faster executive function decline was still apparent in ε4-carriers, and the effect of ε4 on episodic memory interacted with alcohol consumption, such that only ε4-carriers who did not drink showed more rapid memory decline than ε4 noncarriers. The influence of ε4 on cognitive aging did not differ by sex, nor was it modified by smoking or exercise. CONCLUSIONS These findings indicate that the ε2 and ε4 alleles have differential effects on cognitive aging, and that negative effects of ε4 may be partly mitigated by behavioral choices. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
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28
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Laughlin GA, Kritz-Silverstein D, Bergstrom J, Reas ET, Jassal SK, Barrett-Connor E, McEvoy LK. Vitamin D Insufficiency and Cognitive Function Trajectories in Older Adults: The Rancho Bernardo Study. J Alzheimers Dis 2018; 58:871-883. [PMID: 28505973 DOI: 10.3233/jad-161295] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Evidence of a role for vitamin D (VitD) in cognitive aging is mixed and based primarily on extreme VitD deficiency. We evaluated the association of VitD insufficiency with cognitive function in older, community-dwelling adults living in a temperate climate with year-round sunshine. METHODS A population-based longitudinal study of 1,058 adults (median age 75; 62% women) who had cognitive function assessed and serum levels of 25-hydroxyvitaminD (25OHD) measured in 1997-99 and were followed for up to three additional cognitive function assessments over a 12-year period. RESULTS Overall, 14% (n = 145) of participants had VitD insufficiency defined as 25OHD <30 ng/ml. Adjusting for age, sex, education, and season, VitD insufficiency was associated with poorer baseline performance on the Mini-Mental Status Exam (MMSE) (p = 0.013), Trails Making Test B (Trails B) (p = 0.015), Category Fluency (p = 0.006), and Long Term Retrieval (p = 0.019); differences were equivalent to 5 years of age. For those with VitD insufficiency, the odds of mildly impaired performance at baseline were 38% higher for MMSE (p = 0.08), 78% higher for Trails B (p = 0.017), and 2-fold higher for Category Fluency and Long Term Retrieval (both p = 0.001). VitD insufficiency was not related to the rate of cognitive decline on any test or the risk of developing impaired performance during follow-up. CONCLUSION In this population with little VitD deficiency, even moderately low VitD was associated with poorer performance on multiple domains of cognitive function. Low VitD did not predict 12-year cognitive decline. Clinical trials are essential to establish a causal link between VitD and cognitive well-being.
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Affiliation(s)
- Gail A Laughlin
- Division of Epidemiology, Department of Family Medicine and Public Health, University of California San Diego, La Jolla, CA, USA
| | - Donna Kritz-Silverstein
- Division of Epidemiology, Department of Family Medicine and Public Health, University of California San Diego, La Jolla, CA, USA
| | - Jaclyn Bergstrom
- Division of Epidemiology, Department of Family Medicine and Public Health, University of California San Diego, La Jolla, CA, USA
| | - Emilie T Reas
- Department of Radiology, University of California San Diego, La Jolla, CA, USA
| | - Simerjot K Jassal
- Division of General Internal Medicine, Department of Medicine, VA San Diego Healthcare System, University of California San Diego, San Diego, CA, USA
| | - Elizabeth Barrett-Connor
- Division of Epidemiology, Department of Family Medicine and Public Health, University of California San Diego, La Jolla, CA, USA
| | - Linda K McEvoy
- Division of Epidemiology, Department of Family Medicine and Public Health, University of California San Diego, La Jolla, CA, USA.,Department of Radiology, University of California San Diego, La Jolla, CA, USA
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29
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Reas ET, Hagler DJ, White NS, Kuperman JM, Bartsch H, Cross K, Loi RQ, Balachandra AR, Meloy MJ, Wierenga CE, Galasko D, Brewer JB, Dale AM, McEvoy LK. Sensitivity of restriction spectrum imaging to memory and neuropathology in Alzheimer's disease. Alzheimers Res Ther 2017; 9:55. [PMID: 28764771 PMCID: PMC5539622 DOI: 10.1186/s13195-017-0281-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 06/27/2017] [Indexed: 11/24/2022]
Abstract
Background Diffusion imaging has demonstrated sensitivity to structural brain changes in Alzheimer’s disease (AD). However, there remains a need for a more complete characterization of microstructural alterations occurring at the earliest disease stages, and how these changes relate to underlying neuropathology. This study evaluated the sensitivity of restriction spectrum imaging (RSI), an advanced diffusion magnetic resonance imaging (MRI) technique, to microstructural brain changes in mild cognitive impairment (MCI) and AD. Methods MRI and neuropsychological test data were acquired from 31 healthy controls, 12 individuals with MCI, and 13 individuals with mild AD, aged 63–93 years. Cerebrospinal fluid amyloid-β levels were measured in a subset (n = 38) of participants. RSI measures of neurite density (ND) and isotropic free water (IF) were computed in fiber tracts and in hippocampal and entorhinal cortex gray matter, respectively. Analyses evaluated whether these measures predicted memory performance, correlated with amyloid-β levels, and distinguished impaired individuals from controls. For comparison, analyses were repeated with standard diffusion tensor imaging (DTI) metrics of fractional anisotropy (FA) and mean diffusivity. Results Both RSI and DTI measures correlated with episodic memory and disease severity. RSI, but not DTI, measures correlated with amyloid-β42 levels. ND and FA in the arcuate fasciculus and entorhinal cortex IF most strongly predicted recall performance. RSI measures of arcuate fasciculus ND and entorhinal cortex IF best discriminated memory impaired participants from healthy participants. Conclusions RSI is highly sensitive to microstructural changes in the early stages of AD, and is associated with biochemical markers of AD pathology. Reduced ND in cortical association fibers and increased medial temporal lobe free-water diffusion predicted episodic memory, distinguished cognitively impaired from healthy individuals, and correlated with amyloid-β. Although further research is needed to assess the sensitivity of RSI to preclinical AD and disease progression, these results suggest that RSI may be a promising tool to better understand neuroanatomical changes in AD and their association with neuropathology. Electronic supplementary material The online version of this article (doi:10.1186/s13195-017-0281-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Emilie T Reas
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA. .,Center for Multimodal Imaging and Genetics, University of California, San Diego, La Jolla, CA, USA.
| | - Donald J Hagler
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA.,Center for Multimodal Imaging and Genetics, University of California, San Diego, La Jolla, CA, USA
| | - Nathan S White
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA.,Center for Multimodal Imaging and Genetics, University of California, San Diego, La Jolla, CA, USA
| | - Joshua M Kuperman
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA.,Center for Multimodal Imaging and Genetics, University of California, San Diego, La Jolla, CA, USA
| | - Hauke Bartsch
- Center for Multimodal Imaging and Genetics, University of California, San Diego, La Jolla, CA, USA
| | - Karalani Cross
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Richard Q Loi
- Center for Multimodal Imaging and Genetics, University of California, San Diego, La Jolla, CA, USA.,Wayne State University School of Medicine, Detroit, MI, USA
| | - Akshara R Balachandra
- Center for Multimodal Imaging and Genetics, University of California, San Diego, La Jolla, CA, USA
| | - M J Meloy
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Christina E Wierenga
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA.,Department of Veterans Affairs, San Diego Healthcare system, La Jolla, CA, USA
| | - Douglas Galasko
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA
| | - James B Brewer
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA.,Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Anders M Dale
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA.,Center for Multimodal Imaging and Genetics, University of California, San Diego, La Jolla, CA, USA.,Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Linda K McEvoy
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA.,Center for Multimodal Imaging and Genetics, University of California, San Diego, La Jolla, CA, USA.,Department of Family Medicine and Public Health, University of California, San Diego, La Jolla, CA, USA
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30
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Reas ET, Laughlin GA, Bergstrom J, Kritz-Silverstein D, Barrett-Connor E, McEvoy LK. Effects of Sex and Education on Cognitive Change Over a 27-Year Period in Older Adults: The Rancho Bernardo Study. Am J Geriatr Psychiatry 2017; 25:889-899. [PMID: 28433548 PMCID: PMC5522346 DOI: 10.1016/j.jagp.2017.03.008] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 03/10/2017] [Accepted: 03/11/2017] [Indexed: 11/22/2022]
Abstract
OBJECTIVE This study investigated how cognitive function changes with age and whether rates of decline vary by sex or education in a large, homogenous longitudinal cohort characterized by high participation rates, long duration of follow-up, and minimal loss to follow-up. DESIGN/SETTING/PARTICIPANTS Between 1988 and 2016, 2,225 community-dwelling participants of the Rancho Bernardo Study, aged 31 to 99 years at their initial cognitive assessment, completed neuropsychological testing approximately every 4 years, over a maximum 27-year follow-up. MEASUREMENTS Linear mixed effects regression models defined sex-specific cognitive trajectories, adjusting for education and retest effects. RESULTS Significant decline across all cognitive domains began around age 65 years and accelerated after age 80 years. Patterns of decline were generally similar between sexes, although men declined more rapidly than women on the global function test. Higher education was associated with slower decline on the tests of executive and global functions. After excluding 517 participants with evidence of cognitive impairment, accelerating decline with age remained for all tests, and women declined more rapidly than men on the executive function test. CONCLUSIONS Accelerating decline with advancing age occurs across multiple cognitive domains in community-dwelling older adults, with few differences in rates of decline between men and women. Higher education may provide some protection against executive and global function decline with age. These findings better characterize normal cognitive aging, a critical prerequisite for identifying individuals at risk for cognitive impairment, and lay the groundwork for future studies of health and behavioral factors that affect age-related decline in this cohort.
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Affiliation(s)
- Emilie T Reas
- Departments of Radiology, University of California, San Diego, CA.
| | - Gail A Laughlin
- Family Medicine and Public Health, University of California, San Diego, CA
| | - Jaclyn Bergstrom
- Family Medicine and Public Health, University of California, San Diego, CA
| | | | | | - Linda K McEvoy
- Departments of Radiology, University of California, San Diego, CA; Family Medicine and Public Health, University of California, San Diego, CA
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31
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Reas ET, Brewer JB. Mean signal and response time influences on multivoxel signals of contextual retrieval in the medial temporal lobe. Brain Behav 2015; 5:e00302. [PMID: 25646149 PMCID: PMC4312925 DOI: 10.1002/brb3.302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 10/16/2014] [Accepted: 10/22/2014] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION The medial temporal lobe supports integrating the "what," "where," and "when" of an experience into a unified memory. However, it remains unclear how representations of these contextual features are neurally encoded and distributed across medial temporal lobe subregions. METHODS This study conducted functional magnetic resonance imaging of the medial temporal lobe, while participants retrieved pair, spatial, and temporal source memories. Multivoxel classifiers were trained to distinguish between retrieval conditions before and after correction for mean signal and response times, to more thoroughly characterize the multivoxel signal associated with memory context. RESULTS Activity in perirhinal and parahippocampal cortex dissociated between memory for associated items and memory for their spatiotemporal context, and hippocampal activity was linked to memory for spatial context. However, perirhinal and hippocampal classifiers were, respectively, driven by effects of mean signal amplitude and task difficulty, whereas the parahippocampal classifier survived correction for these effects. CONCLUSION These findings demonstrate dissociable coding mechanisms for episodic memory context across the medial temporal lobe, and further highlight a critical distinction between multivoxel representations driven by spatially distributed activity patterns, and those driven by the regional signal.
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Affiliation(s)
- Emilie T Reas
- Department of Neurosciences, University of California, San Diego 9500 Gilman Dr., La Jolla, California, 92093-0949
| | - James B Brewer
- Department of Neurosciences, University of California, San Diego 9500 Gilman Dr., La Jolla, California, 92093-0949 ; Department of Radiology, University of California, San Diego 9500 Gilman Dr., La Jolla, California, 92093-0949
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Abstract
Methylphenidate (MPH), introduced more than 60 years ago, accounts for two-thirds of current prescriptions for attention deficit hyperactivity disorder (ADHD). Although many studies have modeled MPH's effect on executive function, almost none have directly modeled its effect on long-term memory (LTM), even though improvement in LTM is a critical target of therapeutic intervention in ADHD. We examined the effects of a wide range of doses of MPH (0.01–10 mg/kg, i.p.) on Pavlovian fear learning, a leading model of memory. MPH's effects were then compared to those of atomoxetine (0.1–10 mg/kg, i.p.), bupropion (0.5–20 mg/kg, i.p.), and citalopram (0.01–10 mg/kg, i.p.). At low, clinically relevant doses, MPH enhanced fear memory; at high doses it impaired memory. MPH's memory-enhancing effects were not confounded by its effects on locomotion or anxiety. Further, MPH-induced memory enhancement seemed to require both dopamine and norepinephrine transporter inhibition. Finally, the addictive potential of MPH (1 mg/kg and 10 mg/kg) was compared to those of two other psychostimulants, amphetamine (0.005 mg/kg and 1.5 mg/kg) and cocaine (0.15 mg/kg and 15 mg/kg), using a conditioned place preference and behavioral sensitization paradigm. We found that memory-enhancing effects of psychostimulants observed at low doses are readily dissociable from their reinforcing and locomotor activating effects at high doses. Together, our data suggest that fear conditioning will be an especially fruitful platform for modeling the effects of psychostimulants on LTM in drug development.
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Affiliation(s)
- Stephanie A Carmack
- Molecular Cognition Laboratory, Department of Psychology, University of California, San Diego, California 92093-0109, USA
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Reas ET, Brewer JB. Imbalance of incidental encoding across tasks: an explanation for non-memory-related hippocampal activations? J Exp Psychol Gen 2013; 142:1171-9. [PMID: 23773160 DOI: 10.1037/a0033461] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Functional neuroimaging studies have increasingly noted hippocampal activation associated with a variety of cognitive functions--such as decision making, attention, perception, incidental learning, prediction, and working memory--that have little apparent relation to declarative memory. Such findings might be difficult to reconcile with classical hippocampal lesion studies that show remarkable sparing of cognitive functions outside the realm of declarative memory. Even the oft-reported hippocampal activations during confident episodic retrieval are not entirely congruent with evidence that hippocampal lesions reliably impair encoding but inconsistently affect retrieval. Here we explore the conditions under which the hippocampus responds during episodic recall and recognition. Our findings suggest that anterior hippocampal activity may be related to the imbalance of incidental encoding across tasks and conditions rather than due to retrieval per se. Incidental encoding and hippocampal activity may be reduced during conditions where retrieval requires greater attentional engagement. During retrieval, anterior hippocampal activity decreases with increasing search duration and retrieval effort, and this deactivation corresponds with a coincident impaired encoding of the external environment (Israel, Seibert, Black, & Brewer, 2010; Reas & Brewer, 2013; Reas, Gimbel, Hales, & Brewer, 2011). In light of this emerging evidence, we discuss the proposal that some hippocampal activity observed during memory retrieval, or other non-memory conditions, may in fact be attributable to concomitant encoding activity that is regulated by the attentional demands of the principal task.
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Abstract
Functional imaging studies frequently report that the hippocampus is engaged by successful episodic memory retrieval. However, considering that concurrent encoding of the background environment occurs during retrieval and influences medial temporal lobe activity, it is plausible that hippocampal encoding functions are reduced with increased attentional engagement during effortful retrieval. Expanding upon evidence that retrieval efforts suppress activity in hippocampal regions implicated in encoding, this study examines the influence of retrieval effort on encoding performance and the interactive effects of encoding and retrieval on hippocampal and neocortical activity. Functional magnetic resonance imaging was conducted while subjects performed a word recognition task with incidental picture encoding. Both lower memory strength and increased search duration were associated with encoding failure and reduced hippocampal and default network activity. Activity in the anterior hippocampus tracked encoding, which was more strongly deactivated when incidental encoding was unsuccessful. These findings highlight potential contributions from background encoding processes to hippocampal activations during neuroimaging studies of episodic memory retrieval.
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Affiliation(s)
- Emilie T Reas
- Department of Neurosciences, University of California, San Diego, California, USA
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Reas ET, Gimbel SI, Hales JB, Brewer JB. Erratum: search-related suppression of hippocampus and default network activity during associative memory retrieval. Front Hum Neurosci 2013; 7:2. [PMID: 23355818 PMCID: PMC3553375 DOI: 10.3389/fnhum.2013.00002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 01/05/2013] [Indexed: 11/13/2022] Open
Affiliation(s)
- Emilie T. Reas
- Department of Neurosciences, University of CaliforniaSan Diego, La Jolla, CA, USA
| | - Sarah I. Gimbel
- Department of Neurosciences, University of CaliforniaSan Diego, La Jolla, CA, USA
| | - Jena B. Hales
- Department of Neurosciences, University of CaliforniaSan Diego, La Jolla, CA, USA
| | - James B. Brewer
- Department of Neurosciences, University of CaliforniaSan Diego, La Jolla, CA, USA
- Department of Radiology, University of CaliforniaSan Diego, La Jolla, CA, USA
- *Correspondence: e-mail:
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Abstract
Neuroimaging studies of episodic memory retrieval have revealed activations in the human frontal, parietal, and medial-temporal lobes that are associated with memory strength. However, it remains unclear whether these brain responses are veritable signals of memory strength or are instead regulated by concomitant subcomponents of retrieval such as retrieval effort or mental search. This study used event-related fMRI during cued recall of previously memorized word-pair associates to dissociate brain responses modulated by memory search from those modulated by the strength of a recalled memory. Search-related deactivations, dissociated from activity due to memory strength, were observed in regions of the default network, whereas distinctly strength-dependent activations were present in superior and inferior parietal and dorsolateral PFC. Both search and strength regulated activity in dorsal anterior cingulate and anterior insula. These findings suggest that, although highly correlated and partially subserved by overlapping cognitive control mechanisms, search and memory strength engage dissociable regions of frontoparietal attention and default networks.
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Reas ET, Gimbel SI, Hales JB, Brewer JB. Search-Related Suppression of Hippocampus and Default Network Activity during Associative Memory Retrieval. Front Hum Neurosci 2011; 5:112. [PMID: 22046159 PMCID: PMC3202230 DOI: 10.3389/fnhum.2011.00112] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Accepted: 09/15/2011] [Indexed: 11/13/2022] Open
Abstract
Episodic memory retrieval involves the coordinated interaction of several cognitive processing stages such as mental search, access to a memory store, associative re-encoding, and post-retrieval monitoring. The neural response during memory retrieval is an integration of signals from multiple regions that may subserve supportive cognitive control, attention, sensory association, encoding, or working memory functions. It is particularly challenging to dissociate contributions of these distinct components to brain responses in regions such as the hippocampus, which lies at the interface between overlapping memory encoding and retrieval, and “default” networks. In the present study, event-related functional magnetic resonance imaging (fMRI) and measures of memory performance were used to differentiate brain responses to memory search from subcomponents of episodic memory retrieval associated with successful recall. During the attempted retrieval of both poorly and strongly remembered word pair associates, the hemodynamic response was negatively deflected below baseline in anterior hippocampus and regions of the default network. Activations in anterior hippocampus were functionally distinct from those in posterior hippocampus and negatively correlated with response times. Thus, relative to the pre-stimulus period, the hippocampus shows reduced activity during intensive engagement in episodic memory search. Such deactivation was most salient during trials that engaged only pre-retrieval search processes in the absence of successful recollection or post-retrieval processing. Implications for interpretation of hippocampal fMRI responses during retrieval are discussed. A model is presented to interpret such activations as representing modulation of encoding-related activity, rather than retrieval-related activity. Engagement in intensive mental search may reduce neural and attentional resources that are otherwise tonically devoted to encoding an individual’s stream of experience into episodic memory.
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Affiliation(s)
- Emilie T Reas
- Department of Neurosciences, University of California San Diego, CA, USA
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