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Stöffel T, Vaqué-Alcázar L, Bartrés-Faz D, Peró-Cebollero M, Cañete-Massé C, Guàrdia-Olmos J. Reduced default mode network effective connectivity in healthy aging is modulated by years of education. Neuroimage 2024; 288:120532. [PMID: 38331332 DOI: 10.1016/j.neuroimage.2024.120532] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 01/20/2024] [Accepted: 02/06/2024] [Indexed: 02/10/2024] Open
Abstract
Aging is a major risk factor for neurodegenerative diseases like dementia and Alzheimer's disease. Even in non-pathological aging, decline in cognitive functioning is observed in the majority of the elderly population, necessitating the importance of studying the processes involved in healthy aging in order to identify brain biomarkers that promote the conservation of functioning. The default mode network (DMN) has been of special interest to aging research due to its vulnerability to atrophy and functional decline over the course of aging. Prior work has focused almost exclusively on functional (i.e. undirected) connectivity, yet converging findings are scarce. Therefore, we set out to use spectral dynamic causal modeling to investigate changes in the effective (i.e. directed) connectivity within the DMN and to discover changes in information flow in a sample of cognitively normal adults spanning from 48 to 89 years (n = 63). Age was associated to reduced verbal memory performance. Modeling of effective connectivity revealed a pattern of age-related downregulation of posterior DMN regions driven by inhibitory connections from the hippocampus and middle temporal gyrus. Additionally, there was an observed decline in the hippocampus' susceptibility to network inputs with age, effectively disconnecting itself from other regions. The estimated effective connectivity parameters were robust and able to predict the age in out of sample estimates in a leave-one-out cross-validation. Attained education moderated the effects of aging, largely reversing the observed pattern of inhibitory connectivity. Thus, medial prefrontal cortex, hippocampus and posterior DMN regions formed an excitatory cycle of extrinsic connections related to the interaction of age and education. This suggests a compensatory role of years of education in effective connectivity, stressing a possible target for interventions. Our findings suggest a connection to the concept of cognitive reserve, which attributes a protective effect of educational level on cognitive decline in aging (Stern, 2009).
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Affiliation(s)
- Tibor Stöffel
- Department of Social Psychology and Quantitative Psychology, Faculty of Psychology, Universitat de Barcelona, Barcelona 08035, Spain; Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, Josef-Holaubek-Platz 2 (UZA II), Vienna 1090, Austria.
| | - Lídia Vaqué-Alcázar
- Department of Medicine, Faculty of Medicine and Health Sciences, Universitat de Barcelona, Barcelona 08036, Spain; Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Barcelona 08036, Spain
| | - David Bartrés-Faz
- Department of Medicine, Faculty of Medicine and Health Sciences, Universitat de Barcelona, Barcelona 08036, Spain; Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Barcelona 08036, Spain
| | - Maribel Peró-Cebollero
- Department of Social Psychology and Quantitative Psychology, Faculty of Psychology, Universitat de Barcelona, Barcelona 08035, Spain; UB Institute of Complex Systems, Universitat de Barcelona, Barcelona 08028, Spain; Institute of Neurosciences, Universitat de Barcelona, Barcelona 08035, Spain
| | - Cristina Cañete-Massé
- Department of Social Psychology and Quantitative Psychology, Faculty of Psychology, Universitat de Barcelona, Barcelona 08035, Spain; Institute of Neurosciences, Universitat de Barcelona, Barcelona 08035, Spain
| | - Joan Guàrdia-Olmos
- Department of Social Psychology and Quantitative Psychology, Faculty of Psychology, Universitat de Barcelona, Barcelona 08035, Spain; UB Institute of Complex Systems, Universitat de Barcelona, Barcelona 08028, Spain; Institute of Neurosciences, Universitat de Barcelona, Barcelona 08035, Spain
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