The subcortical default mode network and Alzheimer's disease: a systematic review and meta-analysis.

The default mode network is a central cortical brain network suggested to play a major role in several disorders and to be particularly vulnerable to the neuropathological hallmarks of Alzheimer's disease. Subcortical involvement in the default mode network and its alteration in Alzheimer's disease remains largely unknown. We performed a systematic review, meta-analysis and empirical validation of the subcortical default mode network in healthy adults, combined with a systematic review, meta-analysis and network analysis of the involvement of subcortical default mode areas in Alzheimer's disease. Our results show that, besides the well-known cortical default mode network brain regions, the default mode network consistently includes subcortical regions, namely the thalamus, lobule and vermis IX and right Crus I/II of the cerebellum and the amygdala. Network analysis also suggests the involvement of the caudate nucleus. In Alzheimer's disease, we observed a left-lateralized cluster of decrease in functional connectivity which covered the medial temporal lobe and amygdala and showed overlap with the default mode network in a portion covering parts of the left anterior hippocampus and left amygdala. We also found an increase in functional connectivity in the right anterior insula. These results confirm the consistency of subcortical contributions to the default mode network in healthy adults and highlight the relevance of the subcortical default mode network alteration in Alzheimer's disease.

Contributions of human amygdala nuclei to resting-state networks.

The amygdala is a brain region with a complex internal structure that is associated with psychiatric disease. Methodological limitations have complicated the study of the internal structure of the amygdala in humans. In the current study we examined the functional connectivity between nine amygdaloid nuclei and existing resting-state networks using a high spatial-resolution fMRI dataset. Using data-driven analysis techniques we found that there were three main clusters inside the amygdala that correlated with the somatomotor, ventral attention and default mode networks. In addition, we found that each resting-state networks depended on a specific configuration of amygdaloid nuclei. Finally, we found that co-activity in the cortical-nucleus increased with the severity of self-rated fear in participants. These results highlight the complex nature of amygdaloid connectivity that is not confined to traditional large-scale divisions, implicates specific configurations of nuclei with certain resting-state networks and highlights the potential clinical relevance of the cortical-nucleus in future studies of the human amygdala.

Estudio sobre el uso de tecnologías de la información y comunicación en personas mayores / Study on the use of information and communication technologies in elderly people

Objetivos: las Tecnologías de la Información y la Comunicación tienen un desarrollo exponencial, formando parte de nuestra vida cotidiana; no obstante, esta incorporación de las tecnologías al día a día se está produciendo a tal velocidad que genera desigualdades entre diferentes grupos de edad como las personas mayores. El objetivo fue indagar sobre el uso de las Tecnologías de la Información y Comunicación en personas mayores, en Porto do Son (La Coruña, España). Métodos: La muestra quedó formada por 237 personas, 57,8 % mujeres y 42,2 % hombres, con una edad media de 74,8 años (SD=6,85). Se empleó un cuestionario sociodemográfico y el Cuestionario Sobre el Uso de Tecnologías-Consumidor. Resultados: se encontraron como factores predictores de uso de tecnologías: el acercamiento a estas mediante cursos de alfabetización digital y a través de un amigo; la percepción por parte de las personas mayores de que las actividades que realizan les resultan satisfactorias y de que la tecnología les acerca a la gente, y usar tecnología concreta en la vida diaria. No se obtuvieron datos significativos con respecto a la influencia de las características personales/sociales. Se observó una relación directa entre el uso de tecnologías y el nivel cultural e inversa con la edad. Conclusiones: la mayor diferencia en la percepción del uso de tecnología por parte de la población adulta se produce a favor de los grupos con menor edad y un nivel cultural superior. (AU)

Objective: Information and Communication Technologies have an exponential development, forming part of our daily life; however, this incorporation of technologies into everyday life is taking place at such speed that it generates inequalities between different age groups such as the elderly. The objective was to investigate the use/non-use of Information and Communication Technologies in the elderly, in Porto do Son. Methods: The sample was made up of 237 people, 137 women and 100 men, with a mean age of 74.8 years (SD=6.85). A sociodemographic questionnaire and the Questionnaire on the Use of Technologies-Consumer were used.Results: The predictive results of the use of technologies were found: the approach to these through digital literacy courses and through a friend; the satisfactory perception of all their common activities and that technology brings them closer to people and the concrete use of technology in daily life. No significant data was obtained regarding the influence of personal/social characteristics on the use/non-use of Information and Communication Technologies.Conclusions: The greatest difference in the perception of the use of technology by the adult population occurs in favor of younger groups and a higher cultural level. (AU)

Daily-Life Physical Activity of Healthy Young Adults Associates With Function and Structure of the Hippocampus.

Previous research on Physical Activity (PA) has been highly valuable in elucidating how PA affects the structure and function of the hippocampus in elderly populations that take part in structured interventions. However, how PA affects the hippocampus in younger populations that perform PA during daily-life activities remains poorly understood. In addition, this research has not examined the impact of PA on the internal structure of the hippocampus. Here, we performed a cross-sectional exploration of the way structural and functional aspects of the hippocampus are associated with habitual PA performed during work, leisure time, and sports in the daily lives of healthy young adults (n = 30; 14 female; mean age = 23.9 y.o.; SD = 7.8 y.o.). We assessed PA in these three different contexts through a validated questionnaire. The results show that PA performed during work time correlated with higher subicular volumes. In addition, we found that PA changed functional connectivity (FC) between a location in the middle/posterior hippocampus and regions of the default mode network, and between a location in the anterior hippocampus and regions of the somatomotor network. No statistical effects of PA performed during leisure time and sports were found. The results generalize the impact of PA on younger populations and show how PA performed in daily-life situations correlates with the precise internal structure and functional connectivity of the hippocampus.

Medial temporal lobe contributions to resting-state networks.

The medial temporal lobe (MTL) is a set of interconnected brain regions that have been shown to play a central role in behavior as well as in neurological disease. Recent studies using resting-state functional magnetic resonance imaging (rsfMRI) have attempted to understand the MTL in terms of its functional connectivity with the rest of the brain. However, the exact characterization of the whole-brain networks that co-activate with the MTL as well as how the various sub-regions of the MTL are associated with these networks remains poorly understood. Here, we attempted to advance these issues by exploiting the high spatial resolution 7T rsfMRI dataset from the Human Connectome Project with a data-driven analysis approach that relied on independent component analysis (ICA) restricted to the MTL. We found that four different well-known resting-state networks co-activated with a unique configuration of MTL subcomponents. Specifically, we found that different sections of the parahippocampal cortex were involved in the default mode, visual and dorsal attention networks; sections of the hippocampus in the somatomotor and default mode networks; and the lateral entorhinal cortex in the dorsal attention network. We replicated this set of results in a validation sample. These results provide new insight into how the MTL and its subcomponents contribute to known resting-state networks. The participation of the MTL in an expanded range of resting-state networks is in line with recent proposals on MTL function.

Developmental Coordination Disorder, Motor Performance, and Daily Participation in Children with Attention Deficit and Hyperactivity Disorder.

Children with Attention Deficit and Hyperactivity Disorder (ADHD) often present with Developmental Coordination Disorder (DCD) or motor coordination problems that further impact their daily functioning. However, little is known about the prevalence of co-occurring DCD and ADHD in the Spanish context, and research about the impact of ADHD on performance and participation in motor-based activities of daily living (ADL) is scarce. The aims of this study were to explore the prevalence of co-occurring DCD in children with ADHD, and to examine differences in performance and participation in motor-based ADL between children with ADHD and typically developing children. We conducted a case-control study including 20 children with ADHD and 40 typically developing controls randomly matched for exact age and sex (males = 80%; mean age = 8, 9 (2, 3) years). Presence of probable DCD (p-DCD) was confirmed with the Developmental Coordination Disorder Questionnaire (DCDQ). The DCDDaily-Q was administered to assess performance and participation in ADL. A 75% prevalence of p-DCD was found in the ADHD group (OR = 27; p < 0.001). Children with ADHD showed poorer motor performance and less participation in ADL (p < 0.01; d = 0.9-1.4). These findings contribute to understand the functional consequences of ADHD in motor-based ADL and its relationship with DCD.

Functional connectivity of the hippocampus and its subfields in resting-state networks.

Many neuroimaging studies have shown that the hippocampus participates in a resting-state network called the default mode network. However, how the hippocampus connects to the default mode network, whether the hippocampus connects to other resting-state networks and how the different hippocampal subfields take part in resting-state networks remains poorly understood. Here, we examined these issues using the high spatial-resolution 7T resting-state fMRI dataset from the Human Connectome Project. We used data-driven techniques that relied on spatially-restricted Independent Component Analysis, Dual Regression and linear mixed-effect group-analyses based on participant-specific brain morphology. The results revealed two main activity hotspots inside the hippocampus. The first hotspot was located in an anterior location and was correlated with the somatomotor network. This network was subserved by co-activity in the CA1, CA3, CA4 and Dentate Gyrus fields. In addition, there was an activity hotspot that extended from middle to posterior locations along the hippocampal long-axis and correlated with the default mode network. This network reflected activity in the Subiculum, CA4 and Dentate Gyrus fields. These results show how different sections of the hippocampus participate in two known resting-state networks and how these two resting-state networks depend on different configurations of hippocampal subfield co-activity.