Effects of prior knowledge on brain activation and functional connectivity during memory retrieval DOI Creative Commons
Dingrong Guo, Haoyu Chen, Lingwei Wang

et al.

Scientific Reports, Journal Year: 2023, Volume and Issue: 13(1)

Published: Aug. 22, 2023

Previous studies have shown that the ventral medial prefrontal cortex (vmPFC) plays an important role in schema-related memory. However, there is intensive debate to what extent activation of subregions hippocampus involved retrieving In addition, it unclear how functional connectivity (FC) between vmPFC and hippocampus, as well with other regions, are modulated by prior knowledge (PK) during memory retrieval over time. To address these issues, participants learned paragraphs described features each unfamiliar word from familiar categories (i.e., high low PK conditions) 20 min, 1 day, week before test. They then performed a recognition task judge whether sentences were old scanner. The results showed anterior-medial (amHPC) cluster was stronger when (vs. low) correctly retrieved. posterior (pHPC) cluster, vmPFC, new rejected CR trials), whereas anterior-lateral (alHPC) opposite. FC amHPC perirhinal cortex/inferior temporal gyrus condition, alHPC, thalamus frontal regions opposite for trials. This study highlighted different brain networks, which associated cognitive control responsible information PK.

Language: Английский

Medial temporal lobe connectivity and its associations with cognition in early Alzheimer’s disease DOI Creative Commons
David Berron, Danielle van Westen, Rik Ossenkoppele

et al.

Brain, Journal Year: 2020, Volume and Issue: 143(4), P. 1233 - 1248

Published: Feb. 25, 2020

Abstract Human episodic memory critically depends on subregions of the medial temporal lobe, which are part functional brain systems such as anterior-temporal and posterior-medial system. Here we analysed how Alzheimer’s pathology affects connectivity within these systems. Data from 256 amyloid-β-negative cognitively unimpaired, 103 amyloid-β-positive 83 individuals with mild cognitive impairment were analysed. Amyloid-β tau measured using CSF amyloid-β42/40 ratio phosphorylated tau, respectively. We found that unimpaired mainly characterized by decreased between lobe regions in system, most prominently left perirhinal/entorhinal cortices prefrontal cortex. Furthermore, correlation analysis this group revealed decreasing bilateral cortices, anterior hippocampus increasing levels tau. The mostly exhibited reduced regions, predominantly posterior cingulate In addition, they showed hyperconnectivity its immediate proximity. Lower temporal-cortical networks resulting comparisons associated performance more rapid longitudinal decline shown linear mixed-effects regression analysis. Finally, mildly impaired was related to entorhinal thickness white matter integrity parahippocampal cingulum fornix. No relationships individuals. conclusion, our findings show earliest changes preclinical disease might involve early be impairment, but not structural changes. With progression increased pathology, seems increasingly impaired. is well emergence locally patterns. Thus, system could serve stage-specific markers disease.

Language: Английский

Citations

238
Anterior-temporal network hyperconnectivity is key to Alzheimer's disease: from ageing to dementia DOI Creative Commons
Léa Chauveau,

Brigitte Landeau,

Sophie Dautricourt

et al.

Brain, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 15, 2025

Abstract Curing Alzheimer’s disease remains hampered by an incomplete understanding of its pathophysiology and progression. Exploring dysfunction in medial temporal lobe networks, particularly the anterior-temporal (AT) posterior-medial (PM) systems, may provide key insights, as these networks exhibit functional connectivity alterations along entire continuum, potentially influencing propagation. However, specific changes each network their clinical relevance across stages are not yet fully understood. This requires considering commonly used biomarkers, progression, individual variability, age confounds. Here, we leveraged monocentric longitudinal data from 261 participants spanning adult lifespan continuum. The sample included cognitively unimpaired adults aged 19 to 85 years (n = 209; eight out 64 older over 60 were Aβ-positive) Aβ-positive patients fulfilling diagnostic criteria for mild cognitive impairment (MCI, n 26; 18 progressed Alzheimer-dementia within seven years) or type dementia 26). Participants underwent structural resting-state (f) MRI, florbetapir FDG-PET, global assessments, with up three visits a maximum period 47 months. Network was assessed using seed-based analyses perirhinal parahippocampal cortices seeds, data-driven masks reflecting AT PM networks. Generalized additive linear mixed models run assess age-specific effects Alzheimer’s-related alterations. In this context, explored various markers pathological severity, including cerebral amyloid uptake, glucose metabolism, hippocampal volume, cognition, staging, time onset. Our findings revealed distinct patterns linked normal aging disease. Advancing throughout adulthood associated lower more subtle connectivity, while characterised hyperconnectivity without connectivity. Specifically, higher MCI compared controls positively burden, hypometabolism, atrophy, deficits adults, ranging demented. Additionally, correlated faster progression patients. comprehensive approach allowed reveal that excessive is intrinsically These insights guide future research better understand cascading events leading hold promise developing prognostic tools therapeutic interventions targeting

Language: Английский

Citations

1
The Journey of the Default Mode Network: Development, Function, and Impact on Mental Health DOI Creative Commons

Felipe Rici Azarias,

Gustavo Henrique Doná Rodrigues Almeida, Luana Félix de Melo

et al.

Biology, Journal Year: 2025, Volume and Issue: 14(4), P. 395 - 395

Published: April 10, 2025

The Default Mode Network has been extensively studied in recent decades due to its central role higher cognitive processes and relevance for understanding mental disorders. This neural network, characterized by synchronized coherent activity at rest, is intrinsically linked self-reflection, exploration, social interaction, emotional processing. Our of the DMN extends beyond humans non-human animals, where it observed various species, highlighting evolutionary basis adaptive significance throughout phylogenetic history. Additionally, plays a crucial brain development during childhood adolescence, influencing fundamental processes. literature review aims provide comprehensive overview DMN, addressing structural, functional, aspects, as well impact from infancy adulthood. By gaining deeper organization function we can advance our knowledge mechanisms that underlie cognition, behavior, health. This, turn, lead more effective therapeutic strategies range neuropsychiatric conditions.

Language: Английский

Citations

1
Hippocampus and temporal pole functional connectivity is associated with age and individual differences in autobiographical memory DOI Creative Commons
Roni Setton, Laetitia Mwilambwe-Tshilobo, Signy Sheldon

et al.

Proceedings of the National Academy of Sciences, Journal Year: 2022, Volume and Issue: 119(41)

Published: Oct. 3, 2022

Recollection of one’s personal past, or autobiographical memory (AM), varies across individuals and the life span. This manifests in amount episodic content recalled during AM, which may reflect differences associated functional brain networks. We take an individual approach to examine resting-state connectivity temporal lobe regions known coordinate AM retrieval with default network (anterior posterior hippocampus, pole) test for associations AM. Multiecho magnetic resonance imaging (fMRI) interviews were collected 158 younger 105 older healthy adults. Interviews scored internal (episodic) external (semantic) details. Age group profiles revealed that adults had lower within anterior pole but greater compared pattern was positively related hippocampal volumes adults, smaller than adult volumes. Connectivity showed two significant patterns. The first dissociated vs. participants. Internal hippocampus orbitofrontal cortex hippocampus. External lateral cortex. In second pattern, displayed throughout more detailed AMs overall. Our findings provide evidence discrete ensembles scale systematic variation recollective styles

Language: Английский

Citations

31
Aging and Alzheimer’s disease have dissociable effects on local and regional medial temporal lobe connectivity DOI Creative Commons

Stanislau Hrybouski,

Sandhitsu R. Das, Long Xie

et al.

Brain Communications, Journal Year: 2023, Volume and Issue: 5(5)

Published: Jan. 1, 2023

Abstract Functional disruption of the medial temporal lobe-dependent networks is thought to underlie episodic memory deficits in aging and Alzheimer’s disease. Previous studies revealed that anterior lobe more vulnerable pathological neurodegenerative processes In contrast, cognitive structural imaging literature indicates posterior, as opposed anterior, vulnerability normal aging. However, extent which aging-related relate functional brain poorly understood. To address this knowledge gap, we examined connectivity alterations its immediate neighbourhood—the Anterior-Temporal Posterior-Medial networks—in agers, individuals with preclinical disease patients Mild Cognitive Impairment or mild dementia due network perirhinal cortex, particular, observed an inverted ‘U-shaped’ relationship between stage. According our results, phase characterized by increased cortex other regions lobe, well one-hop neighbours system. This effect no longer present symptomatic Instead, displayed reduced hippocampal within hypoconnectivity For aging, results led three main conclusions: (i) intra-network both declines age; (ii) posterior segments become increasingly decoupled from each advancing (iii) subregions especially parahippocampal are age-associated loss function than their counterparts. Together, current highlight evolving dysfunction indicate different neurobiological mechanisms versus

Language: Английский

Citations

14
Temporal pole volume is associated with episodic autobiographical memory in healthy older adults DOI
Roni Setton, Signy Sheldon, Gary R. Turner

et al.

Hippocampus, Journal Year: 2022, Volume and Issue: 32(5), P. 373 - 385

Published: March 5, 2022

Abstract Recollection of personal past events differs across the lifespan. Older individuals recall fewer episodic details and convey more semantic information than young. Here we examine how gray matter volumes in temporal lobe regions integral to memory (hippocampus poles, respectively) are related age differences autobiographical recollection. Gray were obtained healthy young ( n = 158) old 105) adults. The pole was demarcated hippocampus segmented into anterior posterior test for volume between groups. Autobiographical Interview administered measure memory. Volume associations with then assessed. Brain smaller older adults hippocampus. less semanticized versus younger also showed positive recall; young, positively associated performance on standard laboratory measures Exploratory analyses revealed that age‐related hippocampal depended sex. These findings suggest brain structures implicated may portend reorganization neural circuits support later life.

Language: Английский

Citations

20
The Effects of Transcutaneous Vagus Nerve Stimulation on Functional Connectivity Within Semantic and Hippocampal Networks in Mild Cognitive Impairment DOI Creative Commons

Aidan J. Murphy,

Alexandria O’Neal,

Ronald A. Cohen

et al.

Neurotherapeutics, Journal Year: 2022, Volume and Issue: 20(2), P. 419 - 430

Published: Dec. 7, 2022

Language: Английский

Citations

19
Inhibitory temporo-parietal effective connectivity is associated with explicit memory performance in older adults DOI Creative Commons
Björn H. Schott, Joram Soch, Jasmin M. Kizilirmak

et al.

iScience, Journal Year: 2023, Volume and Issue: 26(10), P. 107765 - 107765

Published: Aug. 29, 2023

Successful explicit memory encoding is associated with inferior temporal activations and medial parietal deactivations, which are attenuated in aging. Here we used dynamic causal modeling (DCM) of functional magnetic resonance imaging data to elucidate effective connectivity patterns between hippocampus, parahippocampal place area (PPA), precuneus during novel visual scenes. In 117 young adults, DCM revealed pronounced activating input from the PPA hippocampus inhibitory novelty processing, both being enhanced successful encoding. This pattern could be replicated two cohorts (N = 141 148) older adults. cohorts, adults selectively exhibited PPA-precuneus connectivity, correlated negatively performance. Our results provide insight into network dynamics underlying suggest that age-related differences memory-related activity are, at least partly, attributable altered temporo-parietal neocortical connectivity.

Language: Английский

Citations

13
Hippocampal network connectivity and episodic memory in individuals aging with traumatic brain injury DOI
Catherine M Carpenter, Hollie A. Mullin, Andrew Cwiek

et al.

Brain Imaging and Behavior, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 21, 2025

Language: Английский

Citations

0
Aging and Alzheimer’s Disease Have Dissociable Effects on Medial Temporal Lobe Connectivity DOI Open Access

Stanislau Hrybouski,

Sandhitsu R. Das, Long Xie

et al.

medRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: Jan. 19, 2023

ABSTRACT Functional disruption of the medial temporal lobe-dependent networks is thought to underlie episodic memory deficits in aging and Alzheimer’s disease. Previous studies revealed that anterior lobe more vulnerable pathological neurodegenerative processes In contrast, cognitive structural imaging literature indicates posterior, as opposed anterior, vulnerability normal aging. However, extent which aging-related relate functional brain poorly understood. To address this knowledge gap, we examined connectivity alterations its immediate neighborhood – Anterior-Temporal Posterior-Medial agers, individuals with preclinical disease, patients Mild Cognitive Impairment or mild dementia due network perirhinal cortex, particular, observed an inverted ‘U-shaped’ relationship between stage. According our results, phase disease characterized by increased cortex other regions lobe, well one-hop neighbors system. This effect no longer present symptomatic Instead, displayed reduced hippocampal within hypoconnectivity For aging, results led three main conclusions: (1) intra-network both declines age; (2) posterior segments become increasingly decoupled from each advancing and, (3) subregions especially parahippocampal are age-associated loss function than their counterparts. Together, current highlight evolving dysfunction indicate different neurobiological mechanisms vs.

Language: Английский

Citations

10