Structure and Dynamics of Large-Scale Cognitive Networks in Huntington's Disease.

BACKGROUND: Huntington's disease is a neurodegenerative disorder characterized by clinical alterations in the motor, behavioral, and cognitive domains. However, the structure and disruptions to large-scale brain cognitive networks have not yet been established. OBJECTIVE: We aimed to profile changes in large-scale cognitive networks in premanifest and symptomatic patients with Huntington's disease. METHODS: We prospectively recruited premanifest and symptomatic Huntington's disease mutation carriers as well as healthy controls. Clinical and sociodemographic data were obtained from all participants, and resting-state functional connectivity data, using both time-averaged and dynamic functional connectivity, was acquired from whole-brain and cognitively oriented brain parcellations. RESULTS: A total of 64 gene mutation carriers and 23 healthy controls were included; 21 patients with Huntington's disease were classified as premanifest and 43 as symptomatic Huntington's disease. Compared with healthy controls, patients with Huntington's disease showed decreased network connectivity within the posterior hubs of the default-mode network and the medial prefrontal cortex, changes that correlated with cognitive (t = 2.25, P = 0.01) and disease burden scores (t = -2.42, P = 0.009). The salience network showed decreased functional connectivity between insular and supramarginal cortices and also correlated with cognitive (t = 2.11, P = 0.02) and disease burden scores (t = -2.35, P = 0.01). Dynamic analyses showed that network variability was decreased for default-central executive networks, a feature already present in premanifest mutation carriers (dynamic factor 8, P = 0.02). CONCLUSIONS: Huntington's disease shows an early and widespread disruption of large-scale cognitive networks. Importantly, these changes are related to cognitive and disease burden scores, and novel dynamic functional analyses uncovered subtler network changes even in the premanifest stages.

Divergent connectomic organization delineates genetic evolutionary traits in the human brain.

The relationship between human brain connectomics and genetic evolutionary traits remains elusive due to the inherent challenges in combining complex associations within cerebral tissue. In this study, insights are provided about the relationship between connectomics, gene expression and divergent evolutionary pathways from non-human primates to humans. Using in vivo human brain resting-state data, we detected two co-existing idiosyncratic functional systems: the segregation network, in charge of module specialization, and the integration network, responsible for information flow. Their topology was approximated to whole-brain genetic expression (Allen Human Brain Atlas) and the co-localization patterns yielded that neuron communication functionalities-linked to Neuron Projection-were overrepresented cell traits. Homologue-orthologue comparisons using dN/dS-ratios bridged the gap between neurogenetic outcomes and biological data, summarizing the known evolutionary divergent pathways within the Homo Sapiens lineage. Evidence suggests that a crosstalk between functional specialization and information flow reflects putative biological qualities of brain architecture, such as neurite cellular functions like axonal or dendrite processes, hypothesized to have been selectively conserved in the species through positive selection. These findings expand our understanding of human brain function and unveil aspects of our cognitive trajectory in relation to our simian ancestors previously left unexplored.

DHA intake relates to better cerebrovascular and neurodegeneration neuroimaging phenotypes in middle-aged adults at increased genetic risk of Alzheimer disease.

BACKGROUND: The number of APOE-ε4 alleles is a major nonmodifiable risk factor for sporadic Alzheimer disease (AD). There is increasing evidence on the benefits of dietary DHA (22:6n-3) before the onset of AD symptoms, particularly in APOE-ε4 carriers. Brain alterations in the preclinical stage can be detected by structural MRI. OBJECTIVES: We aimed, in middle-aged cognitively unimpaired individuals at increased risk of AD, to cross-sectionally investigate whether dietary DHA intake relates to cognitive performance and to MRI-based markers of cerebral small vessel disease and AD-related neurodegeneration, exploring the effect modification by APOE-ε4 status. METHODS: In 340 participants of the ALFA (ALzheimer and FAmilies) study, which is enriched for APOE-ε4 carriership (n = 122, noncarriers; n = 157, 1 allele; n = 61, 2 alleles), we assessed self-reported DHA intake through an FFQ. We measured cognitive performance by administering episodic memory and executive function tests. We performed high-resolution structural MRI to assess cerebral small vessel disease [white matter hyperintensities (WMHs) and cerebral microbleeds (CMBs)] and AD-related brain atrophy (cortical thickness in an AD signature). We constructed regression models adjusted for potential confounders, exploring the interaction DHA × APOE-ε4. RESULTS: We observed no significant associations between DHA and cognitive performance or WMH burden. We observed a nonsignificant inverse association between DHA and prevalence of lobar CMBs (OR: 0.446; 95% CI: 0.195, 1.018; P = 0.055). DHA was found to be significantly related to greater cortical thickness in the AD signature in homozygotes but not in nonhomozygotes (P-interaction = 0.045). The association strengthened when analyzing homozygotes and nonhomozygotes matched for risk factors. CONCLUSIONS: In cognitively unimpaired APOE-ε4 homozygotes, dietary DHA intake related to structural patterns that may result in greater resilience to AD pathology. This is consistent with the current hypothesis that those subjects at highest risk would obtain the largest benefits from DHA supplementation in the preclinical stage.This trial was registered at clinicaltrials.gov as NCT01835717.

Steady exercise removes VO(2max) difference between mitochondrial genomic variants.

It has been clearly established that mitochondrial variants, among other potential factors, influence on VO(2max). With this study we sought to determine whether this genetic predisposition could be modified by steady exercise. Mitochondrial genetic variants were determined in 70 healthy controls (CON) and in 77 athletes who trained regularly (50 cyclists, aerobic training (AER), and 27 runners of 400m, anaerobic training (NoAER)). All of them were male Spanish Caucasian individuals. A maximum graded exercise test (GXT) in cycle-ergometer was performed to determine VO(2max) (mL kg(-1)min(-1)). Our results confirmed that, in CON, VO(2max) (P=0.007) was higher in Non-J than J individuals. Furthermore, we found that AER and NoAER showed, as it could be expected, higher VO(2max) than CON, but not differences between mitochondrial variants have been found. According with these findings, the influence of mitochondrial DNA (mtDNA) variants on VO(2max) has been confirmed, and a new conclusion has arisen: the steady exercise is able to remove this influence. The interest of these promising findings in muscular performance should be further explored, in particular, the understanding of potential applications in sport training and in muscle pathological syndromes.

Análisis científico de diferentes métodos de entrenamiento en el fútbol sala / Scientific analysis of practice methods used in futsal

El control de la carga de entrenamiento es necesario, siendo la variable del tiempo la más utilizada para su control. Este estudio pretende aportar datos fisiológicos a partir de diferentes sesiones basadas en el empleo de metodologías integrales y determinar si cumplen con los objetivos previstos. El presente estudio se ha realizado durante la temporada 2005-06 y han participado todos los jugadores del DKV fútbol sala, equipo que milita en la División de Honor del fútbol sala español. Se realizaron las siguientes pruebas: Examen médico-deportivo, evaluación antropométrica, prueba de esfuerzo máximo continuo y 4 sesiones de entrenamiento con diferentes objetivos condicionales. Los parámetros analizados han sido frecuencia cardiaca, lactatemia y ergoespirométricos. El análisis estadístico ha sido descriptivo por encontrarnos en una fase piloto de investigación. De los datos obtenidos podemos concluir que: el entrenamiento integrado es válido para conseguir los objetivos marcados. La heterogeneidad de los jugadores hace que la aplicación de un mismo método y carga de entrenamiento provo que diferentes respuestas fisiológicas. El entrenamiento integrado reduce la máxima intensidad de trabajo a la que el jugador debe ser demandado. Para establecer los parámetros de trabajo los métodos clásicos pueden ser tomados como referencia, pero deben ser adaptados a la lógica interna de cada modalidad deportiva. La gran dificultad en la planificación de las cargas de trabajo en los deportes de equipo es saber unir todos los factores influyentes en la mejora del juego, dentro de un proceso lógico y ordenado (AU)

It is necessary to control the total amount of practice sessions. Time control used on each task is actually the method more often used. This study tries to provide physiological facts using different sessions based on different training methods with specific game situations. The main target is to improve on different physiological aspects and to show that they can achieve settled goals. The study took place during the 2005-06 seasons. DKV’s players, which play in the first league in Spain, were involved in the study. They took the following test: medical sport, anthropometric, running or treadmill and 4 practice sessions with different target. Heart rate, lactates and maximum oxygen consumption were analyzed. Considering that we are in the first phase of the investigation the statistical analysis has given us a lot of information. With the data obtained we can conclude that: integrated training will help to achieve the settled goals. We obtained different physiological response on each player applying the same method and using the same amount of practice sessions. Integrated training reduces to the maximum the intensity of work to which the players is exposed to. Classic methods can be used as references in order to establish the work parameters, but these parameters must be adjusted to each sport. The major problem that we found when planning the amount of practice sessions in team sports is to know how to bond all the factors that will help us improve the game, always trying to follow a logical and well organized pattern (AU)