Biology subjects

Lissaman, R.

Publications and source records attributed to Lissaman, R..

4 recordsLinked to original sources

bioRxiv2024

Sex differences emerge after the menopause transition:Females show accelerated decline in episodic memory for spatial context at midlife

Background and ObjectivesThe ability to remember past events in rich contextual detail (episodic memory) declines with advancing age, with accelerated decline around midlife. Past research indicates there may be sex differences in cognitive aging trajectories and risk for age-related neurodegenerative diseases, i.e. Alzheimers Disease. Yet, little is known about how biological sex affects episodic memory in the adult lifespan. We examined age differences in episodic memory for spatial context in males and females. Research Design and Methods192 adults aged 21 to 65 (M=44, SD=13, 134 females) completed a face-location task measuring spatial context memory (correct spatial context retrieval rates) and facial item memory (correct recognition rates), and the California Verbal Learning Test version II (CVLT-II) measuring verbal item memory (long free recall, cued recall, and recognition rates). Changepoint regression analysis was used to estimate the slope of memory across age and any significant shifts in the slope (indicating critical transition periods). ResultsRegression analyses revealed that the best-fitting model for females on spatial context memory accuracy was a one-changepoint model, with gradual decline of 2% (SE=1) fewer correct responses per year of age from age 21 until age 50 (95% CI 41, 58), shifting to more rapid decline of 4% (SE=1) fewer correct responses per year of age until age 65. The best fitting model for males on spatial context memory accuracy was linear, with no significant changes across ages. The best fitting models for both sexes were linear for facial item memory accuracy, spatial context memory and facial item memory reaction times, and verbal item memory accuracy. Discussion and ImplicationMales and females show similar decline on spatial context memory from young adulthood until midlife, after which females show greater decline than males. Importantly, disaggregating by sex indicated that past midlife effects on episodic memory for context may be driven by a specific group of females (post-menopausal), as accelerated decline occurred at the same time as menopause in midlife females and did not occur in midlife males. Translational SignificanceO_ST_ABSProblem AddressedC_ST_ABSWe use changepoint regression to examine how biological sex influences age differences in remembering the context of past events (episodic memory). Main outcomeFemales, but not males, showed significantly greater decline on spatial context memory (i.e., correctly recalling the location of previously learned information) after age 50, which aligns with the time of menopause in midlife females. Implications for TranslationEpisodic memory for spatial context shows accelerated decline in females after midlife compared to before midlife, but not in midlife males, indicating the potential influence of menopause on aging of memory.

neuroscience↗

bioRxiv2024

Menopause status and sex affect memory for spatial context information and white matter microstructure at midlife

Decline in spatial context memory emerges in midlife, the time when most females transition from pre-to post-menopause. Recent evidence suggests that, among post-menopausal females, advanced age is associated with functional brain alterations and lower spatial context memory. However, it is unknown whether similar effects are evident for white matter (WM) and, moreover, whether such effects contribute to sex differences at midlife. To address this, we conducted a study on 96 cognitively unimpaired middle-aged adults (30 males, 32 pre-menopausal females, 34 post-menopausal females). Spatial context memory was assessed using a face-location memory paradigm, while WM microstructure was assessed using diffusion tensor imaging. Behaviorally, advanced age was associated with lower spatial context memory in post-menopausal females but not pre-menopausal females or males. Additionally, advanced age was associated with microstructural variability in predominantly frontal WM (e.g., anterior corona radiata, genu of corpus callosum), which was related to lower spatial context memory among post-menopausal females. Our findings suggest that post-menopausal status enhances vulnerability to age effects on the brains WM and episodic memory.

neuroscience↗

bioRxiv2023

The influence of chronological age and menopause status on the functional neural correlates of spatial context memory in middle-aged females.

Reductions in the ability to encode and retrieve past experiences in rich spatial contextual detail (episodic memory) are apparent by midlife - a time when most females experience spontaneous menopause. Yet, little is known about how menopause status affects episodic memory-related brain activity at encoding and retrieval in middle-aged pre- and post-menopausal females, and whether any observed group differences in brain activity and memory performance correlate with chronological age within group. We conducted an event-related task fMRI study of episodic memory for spatial context to address this knowledge gap. Multivariate behavioral partial least squares (PLS) was used to investigate how chronological age and retrieval accuracy correlated with brain activity in 31 premenopausal (age range: 39.55 - 53.30 yrs, Mage = 44.28 yrs, SDage = 3.12 yrs) and 41 postmenopausal females (age range: 46.70 to 65.14 yrs, Mage = 57.56 yrs, SDage = 3.93 yrs). We found that postmenopausal status, and advanced age within post-menopause, was associated with lower spatial context memory. The fMRI analysis showed that only in postmenopausal females, advanced age was correlated with decreased activity in occipitotemporal, parahippocampal, and inferior parietal during encoding and retrieval, and poorer spatial context memory performance. In contrast, only premenopausal females exhibited an overlap in encoding and retrieval activity in angular gyrus, midline cortical regions, and prefrontal cortex, which correlated with better spatial context retrieval accuracy. These results highlight how menopause status and chronological age, nested within menopause group, affect episodic memory and its neural correlates at midlife. Significance StatementThis is the first fMRI study to examine how pre- and post-menopause status affects the neural correlates of episodic memory encoding and retrieval, and how chronological age contributes to any observed group similarities and differences. We found that both menopause status (endocrine age) and chronological age affect spatial context memory and its neural correlates. Menopause status directly affected the direction of age- and performance-related correlations with brain activity in inferior parietal, parahippocampal and occipitotemporal cortices across encoding and retrieval. Moreover, we found that only premenopausal females exhibited cortical reinstatement of encoding-related activity in midline cortical, prefrontal, and angular gyrus, at retrieval. This suggests that spatial context memory abilities may rely on distinct brain systems at pre-compared to post-menopause.

neuroscience↗

bioRxiv2022

Tract-specific white matter microstructure alterations among young adult APOE ε4 carriers: A replication and extension study

The parahippocampal cingulum bundle (PHCB) connects regions known to be vulnerable to early Alzheimers disease (AD) pathology, such as posteromedial cortex and medial temporal lobe. While AD-related pathology has been robustly associated with alterations in PHCB microstructure, specifically lower fractional anisotropy (FA) and higher mean diffusivity (MD), emerging evidence indicates that the reverse pattern is evident in younger adults at-risk of AD. In one such study, Hodgetts et al. (2019) reported that healthy young adult carriers of the apolipoprotein-E (APOE) {varepsilon}4 allele - the strongest common genetic risk factor for AD - showed higher FA and lower MD in the PHCB but not the inferior longitudinal fasciculus (ILF). These results are consistent with proposals claiming that heightened neural activity and connectivity have a significant role in posteromedial cortex vulnerability to amyloid-{beta} and tau spread beyond the medial temporal lobe. Given the implications for understanding AD risk, here we sought to replicate Hodgetts et al.s finding in a larger sample (N = 128; 40 APOE {varepsilon}4 carriers, 88 APOE {varepsilon}4 non-carriers) of young adults (age range: 19-33). Extending this work further, we also conducted exploratory analyses using a more advanced measure of microstructure: hindrance modulated orientational anisotropy (HMOA). These analyses included an investigation of hemispheric asymmetry in PHCB and ILF HMOA. Contrary to the original study, we observed no difference in PHCB microstructure between APOE {varepsilon}4 carriers and non-carriers. Bayes factors (BFs) further revealed moderate-to-strong evidence in support of these null findings. APOE {varepsilon}4-related differences in ILF HMOA asymmetry were evident, however, with carriers demonstrating lower leftward asymmetry. Our findings indicate that young adult APOE {varepsilon}4 carriers do not show alterations in PHCB microstructure, as observed by Hodgetts et al., but may show altered asymmetry in ILF microstructure.

neuroscience↗