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1.
Brain ; 146(3): 1200-1211, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36256589

RESUMEN

Unravelling the complex events driving grade-specific spatial distribution of brain tumour occurrence requires rich datasets from both healthy individuals and patients. Here, we combined open-access data from The Cancer Genome Atlas, the UK Biobank and the Allen Brain Human Atlas to disentangle how the different spatial occurrences of glioblastoma multiforme and low-grade gliomas are linked to brain network features and the normative transcriptional profiles of brain regions. From MRI of brain tumour patients, we first constructed a grade-related frequency map of the regional occurrence of low-grade gliomas and the more aggressive glioblastoma multiforme. Using associated mRNA transcription data, we derived a set of differential gene expressions from glioblastoma multiforme and low-grade gliomas tissues of the same patients. By combining the resulting values with normative gene expressions from post-mortem brain tissue, we constructed a grade-related expression map indicating which brain regions express genes dysregulated in aggressive gliomas. Additionally, we derived an expression map of genes previously associated with tumour subtypes in a genome-wide association study (tumour-related genes). There were significant associations between grade-related frequency, grade-related expression and tumour-related expression maps, as well as functional brain network features (specifically, nodal strength and participation coefficient) that are implicated in neurological and psychiatric disorders. These findings identify brain network dynamics and transcriptomic signatures as key factors in regional vulnerability for glioblastoma multiforme and low-grade glioma occurrence, placing primary brain tumours within a well established framework of neurological and psychiatric cortical alterations.


Asunto(s)
Neoplasias Encefálicas , Conectoma , Glioblastoma , Glioma , Humanos , Glioblastoma/genética , Transcriptoma , Estudio de Asociación del Genoma Completo , Glioma/genética , Neoplasias Encefálicas/metabolismo
2.
Br J Psychiatry ; 223(1): 309-318, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-36805840

RESUMEN

BACKGROUND: Understanding the evolution of negative symptoms in first-episode psychosis (FEP) requires long-term longitudinal study designs that capture the progression of this condition and the associated brain changes. AIMS: To explore the factors underlying negative symptoms and their association with long-term abnormal brain trajectories. METHOD: We followed up 357 people with FEP over a 10-year period. Factor analyses were conducted to explore negative symptom dimensionality. Latent growth mixture modelling (LGMM) was used to identify the latent classes. Analysis of variance (ANOVA) was conducted to investigate developmental trajectories of cortical thickness. Finally, the resulting ANOVA maps were correlated with a wide set of regional molecular profiles derived from public databases. RESULTS: Three trajectories (stable, decreasing and increasing) were found in each of the three factors (expressivity, experiential and attention) identified by the factor analyses. Patients with an increasing trajectory in the expressivity factor showed cortical thinning in caudal middle frontal, pars triangularis, rostral middle frontal and superior frontal regions from the third to the tenth year after the onset of the psychotic disorder. The F-statistic map of cortical thickness expressivity differences was associated with a receptor density map derived from positron emission tomography data. CONCLUSIONS: Stable and decreasing were the most common trajectories. Additionally, cortical thickness abnormalities found at relatively late stages of FEP onset could be exploited as a biomarker of poor symptom outcome in the expressivity dimension. Finally, the brain areas with less density of receptors spatially overlap areas that discriminate the trajectories of the expressivity dimension.


Asunto(s)
Grosor de la Corteza Cerebral , Trastornos Psicóticos , Humanos , Estudios de Seguimiento , Estudios Longitudinales , Trastornos Psicóticos/diagnóstico por imagen , Trastornos Psicóticos/complicaciones , Lóbulo Frontal , Imagen por Resonancia Magnética
3.
Dev Psychopathol ; 35(5): 2253-2263, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37493043

RESUMEN

Childhood adversity is one of the strongest predictors of adolescent mental illness. Therefore, it is critical that the mechanisms that aid resilient functioning in individuals exposed to childhood adversity are better understood. Here, we examined whether resilient functioning was related to structural brain network topology. We quantified resilient functioning at the individual level as psychosocial functioning adjusted for the severity of childhood adversity in a large sample of adolescents (N = 2406, aged 14-24). Next, we examined nodal degree (the number of connections that brain regions have in a network) using brain-wide cortical thickness measures in a representative subset (N = 275) using a sliding window approach. We found that higher resilient functioning was associated with lower nodal degree of multiple regions including the dorsolateral prefrontal cortex, the medial prefrontal cortex, and the posterior superior temporal sulcus (z > 1.645). During adolescence, decreases in nodal degree are thought to reflect a normative developmental process that is part of the extensive remodeling of structural brain network topology. Prior findings in this sample showed that decreased nodal degree was associated with age, as such our findings of negative associations between nodal degree and resilient functioning may therefore potentially resemble a more mature structural network configuration in individuals with higher resilient functioning.


Asunto(s)
Experiencias Adversas de la Infancia , Trastornos Mentales , Resiliencia Psicológica , Humanos , Adolescente , Encéfalo/diagnóstico por imagen , Lóbulo Temporal , Imagen por Resonancia Magnética
4.
Proc Natl Acad Sci U S A ; 117(41): 25911-25922, 2020 10 13.
Artículo en Inglés | MEDLINE | ID: mdl-32989168

RESUMEN

A characteristic of adaptive behavior is its goal-directed nature. An ability to act in a goal-directed manner is progressively refined during development, but this refinement can be impacted by the emergence of psychiatric disorders. Disorders of compulsivity have been framed computationally as a deficit in model-based control, and have been linked also to abnormal frontostriatal connectivity. However, the developmental trajectory of model-based control, including an interplay between its maturation and an emergence of compulsivity, has not been characterized. Availing of a large sample of healthy adolescents (n = 569) aged 14 to 24 y, we show behaviorally that over the course of adolescence there is a within-person increase in model-based control, and this is more pronounced in younger participants. Using a bivariate latent change score model, we provide evidence that the presence of higher compulsivity traits is associated with an atypical profile of this developmental maturation in model-based control. Resting-state fMRI data from a subset of the behaviorally assessed subjects (n = 230) revealed that compulsivity is associated with a less pronounced change of within-subject developmental remodeling of functional connectivity, specifically between the striatum and a frontoparietal network. Thus, in an otherwise clinically healthy population sample, in early development, individual differences in compulsivity are linked to the developmental trajectory of model-based control and a remodeling of frontostriatal connectivity.


Asunto(s)
Desarrollo del Adolescente , Conducta Compulsiva/psicología , Adolescente , Adulto , Conducta Compulsiva/diagnóstico por imagen , Conducta Compulsiva/fisiopatología , Cuerpo Estriado/diagnóstico por imagen , Femenino , Objetivos , Humanos , Imagen por Resonancia Magnética , Masculino , Adulto Joven
5.
Proc Natl Acad Sci U S A ; 117(6): 3248-3253, 2020 02 11.
Artículo en Inglés | MEDLINE | ID: mdl-31992644

RESUMEN

Adolescent changes in human brain function are not entirely understood. Here, we used multiecho functional MRI (fMRI) to measure developmental change in functional connectivity (FC) of resting-state oscillations between pairs of 330 cortical regions and 16 subcortical regions in 298 healthy adolescents scanned 520 times. Participants were aged 14 to 26 y and were scanned on 1 to 3 occasions at least 6 mo apart. We found 2 distinct modes of age-related change in FC: "conservative" and "disruptive." Conservative development was characteristic of primary cortex, which was strongly connected at 14 y and became even more connected in the period from 14 to 26 y. Disruptive development was characteristic of association cortex and subcortical regions, where connectivity was remodeled: connections that were weak at 14 y became stronger during adolescence, and connections that were strong at 14 y became weaker. These modes of development were quantified using the maturational index (MI), estimated as Spearman's correlation between edgewise baseline FC (at 14 y, [Formula: see text]) and adolescent change in FC ([Formula: see text]), at each region. Disruptive systems (with negative MI) were activated by social cognition and autobiographical memory tasks in prior fMRI data and significantly colocated with prior maps of aerobic glycolysis (AG), AG-related gene expression, postnatal cortical surface expansion, and adolescent shrinkage of cortical thickness. The presence of these 2 modes of development was robust to numerous sensitivity analyses. We conclude that human brain organization is disrupted during adolescence by remodeling of FC between association cortical and subcortical areas.


Asunto(s)
Desarrollo del Adolescente/fisiología , Encéfalo/crecimiento & desarrollo , Red Nerviosa/crecimiento & desarrollo , Adolescente , Adulto , Encéfalo/diagnóstico por imagen , Conectoma , Femenino , Movimientos de la Cabeza/fisiología , Humanos , Imagen por Resonancia Magnética , Masculino , Red Nerviosa/diagnóstico por imagen , Adulto Joven
6.
Mol Psychiatry ; 26(12): 7709-7718, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34462574

RESUMEN

Recent discovery of approximately 270 common genetic variants associated with schizophrenia has enabled polygenic risk scores (PRS) to be measured in the population. We hypothesized that normal variation in PRS would be associated with magnetic resonance imaging (MRI) phenotypes of brain morphometry and tissue composition. We used the largest extant genome-wide association dataset (N = 69,369 cases and N = 236,642 healthy controls) to measure PRS for schizophrenia in a large sample of adults from the UK Biobank (Nmax = 29,878) who had multiple micro- and macrostructural MRI metrics measured at each of 180 cortical areas, seven subcortical structures, and 15 major white matter tracts. Linear mixed-effect models were used to investigate associations between PRS and brain structure at global and regional scales, controlled for multiple comparisons. Polygenic risk was significantly associated with reduced neurite density index (NDI) at global brain scale, at 149 cortical regions, five subcortical structures, and 14 white matter tracts. Other microstructural parameters, e.g., fractional anisotropy, that were correlated with NDI were also significantly associated with PRS. Genetic effects on multiple MRI phenotypes were co-located in temporal, cingulate, and prefrontal cortical areas, insula, and hippocampus. Post-hoc bidirectional Mendelian randomization analyses provided preliminary evidence in support of a causal relationship between (reduced) thalamic NDI and (increased) risk of schizophrenia. Risk-related reduction in NDI is plausibly indicative of reduced density of myelinated axons and dendritic arborization in large-scale cortico-subcortical networks. Cortical, subcortical, and white matter microstructure may be linked to the genetic mechanisms of schizophrenia.


Asunto(s)
Esquizofrenia , Sustancia Blanca , Encéfalo/patología , Estudio de Asociación del Genoma Completo , Humanos , Herencia Multifactorial/genética , Esquizofrenia/patología , Sustancia Blanca/patología
7.
Proc Natl Acad Sci U S A ; 116(19): 9604-9609, 2019 05 07.
Artículo en Inglés | MEDLINE | ID: mdl-31004051

RESUMEN

Schizophrenia has been conceived as a disorder of brain connectivity, but it is unclear how this network phenotype is related to the underlying genetics. We used morphometric similarity analysis of MRI data as a marker of interareal cortical connectivity in three prior case-control studies of psychosis: in total, n = 185 cases and n = 227 controls. Psychosis was associated with globally reduced morphometric similarity in all three studies. There was also a replicable pattern of case-control differences in regional morphometric similarity, which was significantly reduced in patients in frontal and temporal cortical areas but increased in parietal cortex. Using prior brain-wide gene expression data, we found that the cortical map of case-control differences in morphometric similarity was spatially correlated with cortical expression of a weighted combination of genes enriched for neurobiologically relevant ontology terms and pathways. In addition, genes that were normally overexpressed in cortical areas with reduced morphometric similarity were significantly up-regulated in three prior post mortem studies of schizophrenia. We propose that this combined analysis of neuroimaging and transcriptional data provides insight into how previously implicated genes and proteins as well as a number of unreported genes in their topological vicinity on the protein interaction network may drive structural brain network changes mediating the genetic risk of schizophrenia.


Asunto(s)
Encéfalo , Regulación de la Expresión Génica , Red Nerviosa , Vías Nerviosas , Neuroimagen , Trastornos Psicóticos , Esquizofrenia , Adulto , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Encéfalo/patología , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Red Nerviosa/diagnóstico por imagen , Red Nerviosa/metabolismo , Red Nerviosa/patología , Vías Nerviosas/metabolismo , Vías Nerviosas/patología , Trastornos Psicóticos/diagnóstico por imagen , Trastornos Psicóticos/metabolismo , Trastornos Psicóticos/patología , Esquizofrenia/diagnóstico por imagen , Esquizofrenia/metabolismo
8.
Acta Neurochir (Wien) ; 164(8): 2021-2034, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35230551

RESUMEN

BACKGROUND: Gliomas are typically considered to cause relatively few neurological impairments. However, cognitive difficulties can arise, for example during treatment, with potential detrimental effects on quality of life. Accurate, reproducible, and accessible cognitive assessment is therefore vital in understanding the effects of both tumor and treatments. Our aim is to compare traditional neuropsychological assessment with an app-based cognitive screening tool in patients with glioma before and after surgical resection. Our hypotheses were that cognitive impairments would be apparent, even in a young and high functioning cohort, and that app-based cognitive screening would complement traditional neuropsychological assessment. METHODS: Seventeen patients with diffuse gliomas completed a traditional neuropsychological assessment and an app-based touchscreen tablet assessment pre- and post-operatively. The app assessment was also conducted at 3- and 12-month follow-up. Impairment rates, mean performance, and pre- and post-operative changes were compared using standardized Z-scores. RESULTS: Approximately 2-3 h of traditional assessment indicated an average of 2.88 cognitive impairments per patient, while the 30-min screen indicated 1.18. As might be expected, traditional assessment using multiple items across the difficulty range proved more sensitive than brief screening measures in areas such as memory and attention. However, the capacity of the screening app to capture reaction times enhanced its sensitivity, relative to traditional assessment, in the area of non-verbal function. Where there was overlap between the two assessments, for example digit span tasks, the results were broadly equivalent. CONCLUSIONS: Cognitive impairments were common in this sample and app-based screening complemented traditional neuropsychological assessment. Implications for clinical assessment and follow-up are discussed.


Asunto(s)
Neoplasias Encefálicas , Trastornos del Conocimiento , Glioma , Aplicaciones Móviles , Neoplasias Encefálicas/complicaciones , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/cirugía , Cognición , Trastornos del Conocimiento/etiología , Glioma/complicaciones , Glioma/diagnóstico , Glioma/cirugía , Humanos , Pruebas Neuropsicológicas , Calidad de Vida
9.
Hum Brain Mapp ; 42(2): 467-484, 2021 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-33094897

RESUMEN

Autism spectrum disorder (ASD) is a highly complex neurodevelopmental condition that is accompanied by neuroanatomical differences on the macroscopic and microscopic level. Findings from histological, genetic, and more recently in vivo neuroimaging studies converge in suggesting that neuroanatomical abnormalities, specifically around the gray-white matter (GWM) boundary, represent a crucial feature of ASD. However, no research has yet characterized the GWM boundary in ASD based on measures of diffusion. Here, we registered diffusion tensor imaging data to the structural T1-weighted images of 92 adults with ASD and 92 matched neurotypical controls in order to examine between-group differences and group-by-sex interactions in fractional anisotropy and mean diffusivity sampled at the GWM boundary, and at different sampling depths within the superficial white and into the gray matter. As hypothesized, we observed atypical diffusion at and around the GWM boundary in ASD, with between-group differences and group-by-sex interactions depending on tissue class and sampling depth. Furthermore, we identified that altered diffusion at the GWM boundary partially (i.e., ~50%) overlapped with atypical gray-white matter tissue contrast in ASD. Our study thus replicates and extends previous work highlighting the GWM boundary as a crucial target of neuropathology in ASD, and guides future work elucidating etiological mechanisms.


Asunto(s)
Trastorno del Espectro Autista/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Imagen de Difusión Tensora/métodos , Sustancia Gris/diagnóstico por imagen , Sustancia Blanca/diagnóstico por imagen , Adolescente , Adulto , Trastorno del Espectro Autista/fisiopatología , Encéfalo/fisiopatología , Femenino , Sustancia Gris/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Sustancia Blanca/fisiopatología , Adulto Joven
10.
Br J Psychiatry ; : 1-3, 2021 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-35049467

RESUMEN

Impulsive and compulsive problem behaviours are associated with a variety of mental disorders. Latent phenotyping indicates the expression of impulsive and compulsive problem behaviours is predominantly governed by a transdiagnostic 'disinhibition' phenotype. In a cohort of 117 individuals, recruited as part of the Neuroscience in Psychiatry Network (NSPN), we examined how brain functional connectome and network properties relate to disinhibition. Reduced functional connectivity within a subnetwork of frontal (especially right inferior frontal gyrus), occipital and parietal regions was linked to disinhibition. Findings provide insights into neurobiological pathways underlying the emergence of impulsive and compulsive disorders.

11.
Brain ; 143(11): 3294-3307, 2020 12 05.
Artículo en Inglés | MEDLINE | ID: mdl-33278823

RESUMEN

For decades, it has been known that gliomas follow a non-random spatial distribution, appearing more often in some brain regions (e.g. the insula) compared to others (e.g. the occipital lobe). A better understanding of the localization patterns of gliomas could provide clues to the origins of these types of tumours, and consequently inform treatment targets. Following hypotheses derived from prior research into neuropsychiatric disease and cancer, gliomas may be expected to localize to brain regions characterized by functional hubness, stem-like cells, and transcription of genetic drivers of gliomagenesis. We combined neuroimaging data from 335 adult patients with high- and low-grade glioma to form a replicable tumour frequency map. Using this map, we demonstrated that glioma frequency is elevated in association cortex and correlated with multiple graph-theoretical metrics of high functional connectedness. Brain regions populated with putative cells of origin for glioma, neural stem cells and oligodendrocyte precursor cells, exhibited a high glioma frequency. Leveraging a human brain atlas of post-mortem gene expression, we found that gliomas were localized to brain regions enriched with expression of genes associated with chromatin organization and synaptic signalling. A set of glioma proto-oncogenes was enriched among the transcriptomic correlates of glioma distribution. Finally, a regression model incorporating connectomic, cellular, and genetic factors explained 58% of the variance in glioma frequency. These results add to previous literature reporting the vulnerability of hub regions to neurological disease, as well as provide support for cancer stem cell theories of glioma. Our findings illustrate how factors of diverse scale, from genetic to connectomic, can independently influence the anatomic localization of brain dysfunction.


Asunto(s)
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patología , Encéfalo/patología , Conectoma , Glioma/genética , Glioma/patología , Algoritmos , Atlas como Asunto , Mapeo Encefálico , Neoplasias Encefálicas/epidemiología , Corteza Cerebral/patología , Cromatina/genética , Regulación Neoplásica de la Expresión Génica/genética , Glioma/epidemiología , Humanos , Células Madre Neoplásicas/patología , Células-Madre Neurales/patología , Neuroimagen , Células Precursoras de Oligodendrocitos/patología , Cambios Post Mortem , Sinapsis/patología
12.
Acta Neurochir (Wien) ; 163(5): 1299-1309, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33222010

RESUMEN

BACKGROUND: Intraoperative functional mapping with direct electrical stimulation during awake surgery for patients with diffuse low-grade glioma has been used in recent years to optimize the balance between surgical resection and quality of life following surgery. Mapping of executive functions is particularly challenging because of their complex nature, with only a handful of reports published so far. Here, we propose the recording of neural activity directly from the surface of the brain using electrocorticography to map executive functions and demonstrate its feasibility and potential utility. METHODS: To track a neural signature of executive function, we recorded neural activity using electrocorticography during awake surgery from the frontal cortex of three patients judged to have an appearance of diffuse low-grade glioma. Based on existing functional magnetic resonance imaging (fMRI) evidence from healthy participants for the recruitment of areas associated with executive function with increased task demands, we employed a task difficulty manipulation in two counting tasks performed intraoperatively. Following surgery, the data were extracted and analyzed offline to identify increases in broadband high-gamma power with increased task difficulty, equivalent to fMRI findings, as a signature of activity related to executive function. RESULTS: All three patients performed the tasks well. Data were recorded from five electrode strips, resulting in data from 15 channels overall. Eleven out of the 15 channels (73.3%) showed significant increases in high-gamma power with increased task difficulty, 26.6% of the channels (4/15) showed no change in power, and none of the channels showed power decrease. High-gamma power increases with increased task difficulty were more likely in areas that are within the canonical frontoparietal network template. CONCLUSIONS: These results are the first step toward developing electrocorticography as a tool for mapping of executive function complementarily to direct electrical stimulation to guide resection. Further studies are required to establish this approach for clinical use.


Asunto(s)
Mapeo Encefálico , Neoplasias Encefálicas/fisiopatología , Neoplasias Encefálicas/cirugía , Electrocorticografía , Función Ejecutiva , Glioma/fisiopatología , Glioma/cirugía , Cuidados Intraoperatorios , Adulto , Neoplasias Encefálicas/diagnóstico por imagen , Cognición/fisiología , Estimulación Eléctrica , Femenino , Ritmo Gamma/fisiología , Glioma/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Calidad de Vida
13.
Mol Psychiatry ; 24(7): 1053-1064, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-29483624

RESUMEN

Differences in cortical morphology-in particular, cortical volume, thickness and surface area-have been reported in individuals with autism. However, it is unclear what aspects of genetic and transcriptomic variation are associated with these differences. Here we investigate the genetic correlates of global cortical thickness differences (ΔCT) in children with autism. We used Partial Least Squares Regression (PLSR) on structural MRI data from 548 children (166 with autism, 295 neurotypical children and 87 children with ADHD) and cortical gene expression data from the Allen Institute for Brain Science to identify genetic correlates of ΔCT in autism. We identify that these genes are enriched for synaptic transmission pathways and explain significant variation in ΔCT. These genes are also significantly enriched for genes dysregulated in the autism post-mortem cortex (Odd Ratio (OR) = 1.11, Pcorrected 10-14), driven entirely by downregulated genes (OR = 1.87, Pcorrected 10-15). We validated the enrichment for downregulated genes in two independent data sets: Validation 1 (OR = 1.44, Pcorrected = 0.004) and Validation 2 (OR = 1.30; Pcorrected = 0.001). We conclude that transcriptionally downregulated genes implicated in autism are robustly associated with global changes in cortical thickness variability in children with autism.


Asunto(s)
Trastorno Autístico/genética , Trastorno Autístico/fisiopatología , Corteza Cerebral/fisiopatología , Trastorno del Espectro Autista/genética , Trastorno del Espectro Autista/fisiopatología , Encéfalo/fisiopatología , Mapeo Encefálico/métodos , Niño , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Neuroimagen/métodos , Transmisión Sináptica/genética , Transcriptoma/genética
14.
Cereb Cortex ; 29(3): 1369-1381, 2019 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-30590439

RESUMEN

Seminal human brain histology work has demonstrated developmental waves of myelination. Here, using a micro-structural magnetic resonance imaging (MRI) marker linked to myelin, we studied fine-grained age differences to deduce waves of growth, stability, and decline of cortical myelination over the life-cycle. In 484 participants, aged 8-85 years, we fitted smooth growth curves to T1- to T2-weighted ratio in each of 360 regions from one of seven cytoarchitectonic classes. From the first derivatives of these generally inverted-U trajectories, we defined three milestones: the age at peak growth; the age at onset of a stable plateau; and the age at the onset of decline. Age at peak growth had a bimodal distribution comprising an early (pre-pubertal) wave of primary sensory and motor cortices and a later (post-pubertal) wave of association, insular and limbic cortices. Most regions reached stability in the 30-s but there was a second wave reaching stability in the 50-s. Age at onset of decline was also bimodal: in some right hemisphere regions, the curve declined from the 60-s, but in other left hemisphere regions, there was no significant decline from the stable plateau. These results are consistent with regionally heterogeneous waves of intracortical myelinogenesis and age-related demyelination.


Asunto(s)
Corteza Cerebral/crecimiento & desarrollo , Vaina de Mielina/fisiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Conectoma , Femenino , Humanos , Longevidad , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Adulto Joven
15.
Cereb Cortex ; 28(1): 281-294, 2018 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-29088339

RESUMEN

Motivated by prior data on local cortical shrinkage and intracortical myelination, we predicted age-related changes in topological organization of cortical structural networks during adolescence. We estimated structural correlation from magnetic resonance imaging measures of cortical thickness at 308 regions in a sample of N = 297 healthy participants, aged 14-24 years. We used a novel sliding-window analysis to measure age-related changes in network attributes globally, locally and in the context of several community partitions of the network. We found that the strength of structural correlation generally decreased as a function of age. Association cortical regions demonstrated a sharp decrease in nodal degree (hubness) from 14 years, reaching a minimum at approximately 19 years, and then levelling off or even slightly increasing until 24 years. Greater and more prolonged age-related changes in degree of cortical regions within the brain network were associated with faster rates of adolescent cortical myelination and shrinkage. The brain regions that demonstrated the greatest age-related changes were concentrated within prefrontal modules. We conclude that human adolescence is associated with biologically plausible changes in structural imaging markers of brain network organization, consistent with the concept of tuning or consolidating anatomical connectivity between frontal cortex and the rest of the connectome.


Asunto(s)
Lóbulo Frontal/diagnóstico por imagen , Adolescente , Estudios de Cohortes , Conectoma , Femenino , Lóbulo Frontal/crecimiento & desarrollo , Humanos , Imagen por Resonancia Magnética , Masculino , Vías Nerviosas/diagnóstico por imagen , Vías Nerviosas/crecimiento & desarrollo , Adulto Joven
16.
Proc Natl Acad Sci U S A ; 113(32): 9105-10, 2016 08 09.
Artículo en Inglés | MEDLINE | ID: mdl-27457931

RESUMEN

How does human brain structure mature during adolescence? We used MRI to measure cortical thickness and intracortical myelination in 297 population volunteers aged 14-24 y old. We found and replicated that association cortical areas were thicker and less myelinated than primary cortical areas at 14 y. However, association cortex had faster rates of shrinkage and myelination over the course of adolescence. Age-related increases in cortical myelination were maximized approximately at the internal layer of projection neurons. Adolescent cortical myelination and shrinkage were coupled and specifically associated with a dorsoventrally patterned gene expression profile enriched for synaptic, oligodendroglial- and schizophrenia-related genes. Topologically efficient and biologically expensive hubs of the brain anatomical network had greater rates of shrinkage/myelination and were associated with overexpression of the same transcriptional profile as cortical consolidation. We conclude that normative human brain maturation involves a genetically patterned process of consolidating anatomical network hubs. We argue that developmental variation of this consolidation process may be relevant both to normal cognitive and behavioral changes and the high incidence of schizophrenia during human brain adolescence.


Asunto(s)
Corteza Cerebral/anatomía & histología , Conectoma/métodos , Adolescente , Adulto , Corteza Cerebral/fisiología , Cognición , Femenino , Humanos , Masculino , Vaina de Mielina/fisiología , Red Nerviosa/anatomía & histología , Red Nerviosa/fisiología , Esquizofrenia/fisiopatología , Transcriptoma , Adulto Joven
17.
Neuroimage ; 171: 256-267, 2018 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-29274746

RESUMEN

Complex network topology is characteristic of many biological systems, including anatomical and functional brain networks (connectomes). Here, we first constructed a structural covariance network from MRI measures of cortical thickness on 296 healthy volunteers, aged 14-24 years. Next, we designed a new algorithm for matching sample locations from the Allen Brain Atlas to the nodes of the SCN. Subsequently we used this to define, transcriptomic brain networks by estimating gene co-expression between pairs of cortical regions. Finally, we explored the hypothesis that transcriptional networks and structural MRI connectomes are coupled. A transcriptional brain network (TBN) and a structural covariance network (SCN) were correlated across connection weights and showed qualitatively similar complex topological properties: assortativity, small-worldness, modularity, and a rich-club. In both networks, the weight of an edge was inversely related to the anatomical (Euclidean) distance between regions. There were differences between networks in degree and distance distributions: the transcriptional network had a less fat-tailed degree distribution and a less positively skewed distance distribution than the SCN. However, cortical areas connected to each other within modules of the SCN had significantly higher levels of whole genome co-expression than expected by chance. Nodes connected in the SCN had especially high levels of expression and co-expression of a human supragranular enriched (HSE) gene set that has been specifically located to supragranular layers of human cerebral cortex and is known to be important for large-scale, long-distance cortico-cortical connectivity. This coupling of brain transcriptome and connectome topologies was largely but not entirely accounted for by the common constraint of physical distance on both networks.


Asunto(s)
Algoritmos , Corteza Cerebral/anatomía & histología , Corteza Cerebral/fisiología , Conectoma/métodos , Adolescente , Adulto , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Red Nerviosa , Transcriptoma/fisiología , Adulto Joven
19.
Dis Colon Rectum ; 60(8): 837-844, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28682969

RESUMEN

BACKGROUND: Long waiting times from early symptoms to diagnosis and treatment may influence the staging and prognosis of patients with colorectal cancer. We analyzed the effect of colonoscopy timing on the outcome of these patients. OBJECTIVE: This study aimed to compare the outcome (tumoral staging and long-term survival) of patients with suspected colorectal cancer according to diagnostic colonoscopy timing. DESIGN: This study is an analysis of a prospectively maintained database. SETTINGS: The study was conducted at the Open Access Endoscopy Service of the tertiary public healthcare center Hospital Universitario de Canarias, in the Spanish island of Tenerife. PATIENTS: Consecutive patients diagnosed of colorectal cancer between February 2008 and October 2010, fulfilling 1 or more National Institute for Health and Clinical Excellence criteria, were assigned to early colonoscopy (<30 days from referral) or to standard-schedule colonoscopy at the discretion of the referring physician. Tumor staging (TNM classification) at diagnosis and long-term survival after treatment were compared in both strategies. MAIN OUTCOME MEASURES: The primary outcomes measured were the stage at presentation and overall survival, as determined by prompt or standard referral. RESULTS: Overall, 257 patients with colorectal cancer were diagnosed (101 at early colonoscopy and 156 at standard-schedule colonoscopy). TNM stages I and II were found in 52 (54.2%) and 60 (41.7%) patients in the early colonoscopy group and standard-schedule colonoscopy group. Stage IV was confirmed in 13 patients (13.5%) diagnosed in the early colonoscopy group and in 40 (28%) detected in the standard-schedule colonoscopy group. Survival rates at 12 and 60 months after treatment were significantly higher in the early colonoscopy group compared with the standard-schedule colonoscopy group (p < 0.001). LIMITATIONS: Controlled randomization of early versus standard-referral colonoscopy, size and scope of analysis, the time interval from symptom onset to first physician assessment, and the different locations of colorectal cancer between groups were limitations of the study. CONCLUSIONS: Colonoscopy within 30 days from referral improves outcome in patients with symptomatic colorectal cancer. See Video Abstract at http://journals.lww.com/dcrjournal/Pages/videogallery.aspx.


Asunto(s)
Colonoscopía , Neoplasias Colorrectales/diagnóstico , Detección Precoz del Cáncer , Derivación y Consulta , Anciano , Anciano de 80 o más Años , Anemia Ferropénica/etiología , Neoplasias Colorrectales/complicaciones , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/terapia , Bases de Datos Factuales , Femenino , Hemorragia Gastrointestinal/etiología , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Estudios Prospectivos , España , Tasa de Supervivencia , Factores de Tiempo
20.
Hum Brain Mapp ; 35(6): 2724-40, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24027166

RESUMEN

Understanding how the mammalian neocortex creates cognition largely depends on knowledge about large-scale cortical organization. Accumulated evidence has illuminated cortical substrates of cognition across the lifespan, but how topological properties of cortical networks support structure-function relationships in normal aging remains an open question. Here we investigate the role of connections (i.e., short/long and direct/indirect) and node properties (i.e., centrality and modularity) in predicting functional-structural connectivity coupling in healthy elderly subjects. Connectivity networks were derived from correlations of cortical thickness and cortical glucose consumption in resting state. Local-direct connections (i.e., nodes separated by less than 30 mm) and node modularity (i.e., a set of nodes highly interconnected within a topological community and sparsely interconnected with nodes from other modules) in the functional network were identified as the main determinants of coupling between cortical networks, suggesting that the structural network in aging is mainly constrained by functional topological properties involved in the segregation of information, likely due to aging-related deficits in functional integration. This hypothesis is supported by an enhanced connectivity between cortical regions of different resting-state networks involved in sensorimotor and memory functions in detrimental to associations between fronto-parietal regions supporting executive processes. Taken collectively, these findings open new avenues to identify aging-related failures in the anatomo-functional organization of the neocortical mantle, and might contribute to early detection of prevalent neurodegenerative conditions occurring in the late life.


Asunto(s)
Envejecimiento/patología , Envejecimiento/fisiología , Corteza Cerebral/patología , Corteza Cerebral/fisiología , Descanso/fisiología , Anciano , Mapeo Encefálico/métodos , Corteza Cerebral/diagnóstico por imagen , Femenino , Fluorodesoxiglucosa F18 , Glucosa/metabolismo , Humanos , Imagen por Resonancia Magnética , Masculino , Vías Nerviosas/diagnóstico por imagen , Vías Nerviosas/patología , Vías Nerviosas/fisiología , Tamaño de los Órganos , Tomografía de Emisión de Positrones , Procesamiento de Señales Asistido por Computador
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