Using functional neuroimaging techniques two aspects of functional integration in the human brain have been investigated, functional connectivity and effective connectivity. In this study we examined both connectivity types in parallel within an executive attention network during rest and while performing an attention task. We analyzed the predictive value of resting-state functional connectivity on task-induced effective connectivity in patients with prodromal Alzheimer's disease (AD) and healthy elderly. We found that in healthy elderly, functional connectivity was a significant predictor for effective connectivity, however, it was frequency-specific. Effective top-down connectivity emerging from prefrontal areas was related with higher frequencies of functional connectivity (e.g., 0.08-0.15 Hz), in contrast to effective bottom-up connectivity going to prefrontal areas, which was related to lower frequencies of functional connectivity (e.g., 0.001-0.03 Hz). In patients, the prediction of effective connectivity by functional connectivity was disturbed. We conclude that functional connectivity and effective connectivity are interrelated in healthy brains but this relationship is aberrant in very early AD.
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http://dx.doi.org/10.1002/hbm.22226 | DOI Listing |
Can Med Educ J
December 2024
Department of Medical Education, University of Illinois College of Medicine, Illinois, USA.
Background: Cognitive integration occurs when trainees make conceptual connections between relevant knowledges and is known to improve learning. While several experimental studies have demonstrated how text and audio-visual instruction can be designed to enhance cognitive integration, clinical skills training in real-world contexts may require alternative educational strategies. Introducing three-dimensional (3D) printed models during clinical skills instruction may offer unique learning opportunities to support cognitive integration.
View Article and Find Full Text PDFMicrosc Res Tech
January 2025
Department of Zoology and Entomology, Faculty of Science, Helwan University, Helwan, Egypt.
The current study provides the first ultrastructural observations on the intraerythrocytic stages of so-called Haemogregarina damiettae and their cytopathological effects on the infected erythrocytes (IEs) in addition to the recording of new morphometric data. The intraerythrocytic stages are attributed to the immature forms or trophozoites (Ts), and mature gamonts (Gs). Ts are typically bowling-bottle shaped with nucleus (TN) occupying its globose part, while Gs are typically banana- shaped.
View Article and Find Full Text PDFComb Chem High Throughput Screen
January 2025
Department of Urology, The First Affiliated Hospital of Yangtze University, Jingzhou, 434000, Hubei Province, P.R. China.
Introduction: In recent years, there has been a rise in the incidence of renal cell carcinoma (RCC), with metastatic RCC being a prevalent and significant contributor to mortality. While a regulatory role for microRNAs (miRNAs) in the development and progression of RCC has been recognized, their precise functions, molecular mechanisms, and potential clinical implications remain inadequately elucidated. Hence, this study aimed to explore the role of miR-507 in RCC and identify STEAP3 as a downstream target of miR-507.
View Article and Find Full Text PDFExp Neurobiol
December 2024
Department of Brain and Cognitive Engineering, Korea University, Seoul 02841, Korea.
Research on brain aging using resting-state functional magnetic resonance imaging (rs-fMRI) has typically focused on comparing "older" adults to younger adults. Importantly, these studies have often neglected the middle age group, which is also significantly impacted by brain aging, including by early changes in motor, memory, and cognitive functions. This study aims to address this limitation by examining the resting state networks in middle-aged adults via an exploratory whole-brain ROI-to-ROI analysis.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, H3A 2B4, Canada.
Excitation-inhibition (E/I) imbalance is theorized as a key mechanism in the pathophysiology of epilepsy, with ample research focusing on elucidating its cellular manifestations. However, few studies investigate E/I imbalance at the macroscale, whole-brain level, and its microcircuit-level mechanisms and clinical significance remain incompletely understood. Here, the Hurst exponent, an index of the E/I ratio, is computed from resting-state fMRI time series, and microcircuit parameters are simulated using biophysical models.
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