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1.
Eur Arch Psychiatry Clin Neurosci ; 274(1): 3-18, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36599959

RESUMO

Despite decades of massive neuroimaging research, the comprehensive characterization of short-range functional connectivity in autism spectrum disorder (ASD) remains a major challenge for scientific advances and clinical translation. From the theoretical point of view, it has been suggested a generalized local over-connectivity that would characterize ASD. This stance is known as the general local over-connectivity theory. However, there is little empirical evidence supporting such hypothesis, especially with regard to pediatric individuals with ASD (age [Formula: see text] 18 years old). To explore this issue, we performed a coordinate-based meta-analysis of regional homogeneity studies to identify significant changes of local connectivity. Our analyses revealed local functional under-connectivity patterns in the bilateral posterior cingulate cortex and superior frontal gyrus (key components of the default mode network) and in the bilateral paracentral lobule (a part of the sensorimotor network). We also performed a functional association analysis of the identified areas, whose dysfunction is clinically consistent with the well-known deficits affecting individuals with ASD. Importantly, we did not find relevant clusters of local hyper-connectivity, which is contrary to the hypothesis that ASD may be characterized by generalized local over-connectivity. If confirmed, our result will provide a valuable insight into the understanding of the complex ASD pathophysiology.


Assuntos
Transtorno do Espectro Autista , Humanos , Criança , Adolescente , Transtorno do Espectro Autista/diagnóstico por imagem , Mapeamento Encefálico/métodos , Vias Neurais/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem
2.
Behav Res Methods ; 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37528293

RESUMO

Coordinate-based meta-analysis (CBMA) is a powerful technique in the field of human brain imaging research. Due to its intense usage, several procedures for data preparation and post hoc analyses have been proposed so far. However, these steps are often performed manually by the researcher, and are therefore potentially prone to error and time-consuming. We hence developed the Coordinate-Based Meta-Analyses Toolbox (CBMAT) to provide a suite of user-friendly and automated MATLAB® functions allowing one to perform all these procedures in a fast, reproducible and reliable way. Besides the description of the code, in the present paper we also provide an annotated example of using CBMAT on a dataset including 34 experiments. CBMAT can therefore substantially improve the way data are handled when performing CBMAs. The code can be downloaded from https://github.com/Jordi-Manuello/CBMAT.git .

3.
Nature ; 535(7612): 448-52, 2016 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-27409812

RESUMO

G-protein-coupled receptors (GPCRs) modulate many physiological processes by transducing a variety of extracellular cues into intracellular responses. Ligand binding to an extracellular orthosteric pocket propagates conformational change to the receptor cytosolic region to promote binding and activation of downstream signalling effectors such as G proteins and ß-arrestins. It is well known that different agonists can share the same binding pocket but evoke unique receptor conformations leading to a wide range of downstream responses ('efficacy'). Furthermore, increasing biophysical evidence, primarily using the ß2-adrenergic receptor (ß2AR) as a model system, supports the existence of multiple active and inactive conformational states. However, how agonists with varying efficacy modulate these receptor states to initiate cellular responses is not well understood. Here we report stabilization of two distinct ß2AR conformations using single domain camelid antibodies (nanobodies)­a previously described positive allosteric nanobody (Nb80) and a newly identified negative allosteric nanobody (Nb60). We show that Nb60 stabilizes a previously unappreciated low-affinity receptor state which corresponds to one of two inactive receptor conformations as delineated by X-ray crystallography and NMR spectroscopy. We find that the agonist isoprenaline has a 15,000-fold higher affinity for ß2AR in the presence of Nb80 compared to the affinity of isoprenaline for ß2AR in the presence of Nb60, highlighting the full allosteric range of a GPCR. Assessing the binding of 17 ligands of varying efficacy to the ß2AR in the absence and presence of Nb60 or Nb80 reveals large ligand-specific effects that can only be explained using an allosteric model which assumes equilibrium amongst at least three receptor states. Agonists generally exert efficacy by stabilizing the active Nb80-stabilized receptor state (R80). In contrast, for a number of partial agonists, both stabilization of R80 and destabilization of the inactive, Nb60-bound state (R60) contribute to their ability to modulate receptor activation. These data demonstrate that ligands can initiate a wide range of cellular responses by differentially stabilizing multiple receptor states.


Assuntos
Agonistas de Receptores Adrenérgicos beta 2/farmacologia , Receptores Adrenérgicos beta 2/química , Receptores Adrenérgicos beta 2/metabolismo , Anticorpos de Domínio Único/farmacologia , Regulação Alostérica/efeitos dos fármacos , Sítio Alostérico/efeitos dos fármacos , Cristalografia por Raios X , Agonismo Parcial de Drogas , Humanos , Isoproterenol/farmacologia , Ligantes , Modelos Moleculares , Ressonância Magnética Nuclear Biomolecular , Conformação Proteica/efeitos dos fármacos , Estabilidade Proteica/efeitos dos fármacos
4.
Mol Pharmacol ; 100(5): 513-525, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34580163

RESUMO

Among ß-blockers that are clinically prescribed for heart failure, carvedilol is a first-choice agent with unique pharmacological properties. Carvedilol is distinct from other ß-blockers in its ability to elicit ß-arrestin-biased agonism, which has been suggested to underlie its cardioprotective effects. Augmenting the pharmacologic properties of carvedilol thus holds the promise of developing more efficacious and/or biased ß-blockers. We recently identified compound-6 (cmpd-6), the first small molecule positive allosteric modulator of the ß2-adrenergic receptor (ß2AR). Cmpd-6 is positively cooperative with orthosteric agonists at the ß2AR and enhances agonist-mediated transducer (G-protein and ß-arrestin) signaling in an unbiased manner. Here, we report that cmpd-6, quite unexpectedly, displays strong positive cooperativity only with carvedilol among a panel of structurally diverse ß-blockers. Cmpd-6 enhances the binding affinity of carvedilol for the ß2AR and augments its ability to competitively antagonize agonist-induced cAMP generation. Cmpd-6 potentiates ß-arrestin1- but not Gs-protein-mediated high-affinity binding of carvedilol at the ß2AR and ß-arrestin-mediated cellular functions in response to carvedilol including extracellular signal-regulated kinase phosphorylation, receptor endocytosis, and trafficking into lysosomes. Importantly, an analog of cmpd-6 that selectively retains positive cooperativity with carvedilol acts as a negative modulator of agonist-stimulated ß2AR signaling. These unprecedented cooperative properties of carvedilol and cmpd-6 have implications for fundamental understanding of G-protein-coupled receptor (GPCR) allosteric modulation, as well as for the development of more effective biased beta blockers and other GPCR therapeutics. SIGNIFICANCE STATEMENT: This study reports on the small molecule-mediated allosteric modulation of the ß-arrestin-biased ß-blocker, carvedilol. The small molecule, compound-6 (cmpd-6), displays an exclusive positive cooperativity with carvedilol among other ß-blockers and enhances the binding affinity of carvedilol for the ß2-adrenergic receptor. Cooperative effects of cmpd-6 augment the ß-blockade property of carvedilol while potentiating its ß-arrestin-mediated signaling functions. These findings have potential implications in advancing G-protein-coupled receptor allostery, developing biased therapeutics and remedying cardiovascular ailments.


Assuntos
Antagonistas Adrenérgicos beta/farmacologia , Carvedilol/farmacologia , Receptores Adrenérgicos beta 2 , beta-Arrestinas/farmacologia , Antagonistas Adrenérgicos beta/química , Antagonistas Adrenérgicos beta/metabolismo , Regulação Alostérica/efeitos dos fármacos , Regulação Alostérica/fisiologia , Animais , Carvedilol/química , Carvedilol/metabolismo , Relação Dose-Resposta a Droga , Células HEK293 , Humanos , Receptores Adrenérgicos beta 2/metabolismo , Células Sf9 , beta-Arrestinas/química , beta-Arrestinas/metabolismo
5.
Neuroimage ; 225: 117481, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33122115

RESUMO

Brain disorders tend to impact on many different regions in a typical way: alterations do not spread randomly; rather, they seem to follow specific patterns of propagation that show a strong overlap between different pathologies. The insular cortex is one of the brain areas more involved in this phenomenon, as it seems to be altered by a wide range of brain diseases. On these grounds we thoroughly investigated the impact of brain disorders on the insular cortices analyzing the patterns of their structural co-alteration. We therefore investigated, applying a network analysis approach to meta-analytic data, 1) what pattern of gray matter alteration is associated with each of the insular cortex parcels; 2) whether or not this pattern correlates and overlaps with its functional meta-analytic connectivity; and, 3) the behavioral profile related to each insular co-alteration pattern. All the analyses were repeated considering two solutions: one with two clusters and another with three. Our study confirmed that the insular cortex is one of the most altered cerebral regions among the cortical areas, and exhibits a dense network of co-alteration including a prevalence of cortical rather than sub-cortical brain regions. Regions of the frontal lobe are the most involved, while occipital lobe is the less affected. Furthermore, the co-alteration and co-activation patterns greatly overlap each other. These findings provide significant evidence that alterations caused by brain disorders are likely to be distributed according to the logic of network architecture, in which brain hubs lie at the center of networks composed of co-altered areas. For the first time, we shed light on existing differences between insula sub-regions even in the pathoconnectivity domain.


Assuntos
Encefalopatias/fisiopatologia , Córtex Cerebral/fisiopatologia , Rede Nervosa/fisiopatologia , Encéfalo/fisiopatologia , Mapeamento Encefálico , Conectoma , Substância Cinzenta/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Rede Nervosa/fisiologia , Lobo Occipital/fisiopatologia
6.
Hum Brain Mapp ; 42(11): 3343-3351, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-33991154

RESUMO

Over the past decades, powerful MRI-based methods have been developed, which yield both voxel-based maps of the brain activity and anatomical variation related to different conditions. With regard to functional or structural MRI data, forward inferences try to determine which areas are involved given a mental function or a brain disorder. A major drawback of forward inference is its lack of specificity, as it suggests the involvement of brain areas that are not specific for the process/condition under investigation. Therefore, a different approach is needed to determine to what extent a given pattern of cerebral activation or alteration is specifically associated with a mental function or brain pathology. In this study, we present a new tool called BACON (Bayes fACtor mOdeliNg) for performing reverse inference both with functional and structural neuroimaging data. BACON implements the Bayes' factor and uses the activation likelihood estimation derived-maps to obtain posterior probability distributions on the evidence of specificity with regard to a particular mental function or brain pathology.


Assuntos
Mapeamento Encefálico/métodos , Encéfalo , Imageamento por Ressonância Magnética/métodos , Modelos Estatísticos , Teorema de Bayes , Encéfalo/anatomia & histologia , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Humanos , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/fisiopatologia , Software
7.
Bioorg Med Chem ; 51: 116498, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34794000

RESUMO

Heptapeptide SFLLRNP is a receptor-tethered ligand of protease-activated receptor 1 (PAR-1), and its Phe at position 2 is essential for the aggregation of human platelets. To validate the structural elements of the Phe-phenyl group in receptor activation, we have synthesized a complete set of S/Phe/LLRNP peptides comprising different series of fluorophenylalanine isomers (Fn)Phe, where n = 1, 2, 3, and 5. Phe-2-phenyl was strongly suggested to be involved in the edge-to-face CH/π interaction with the receptor aromatic group. In the present study, to prove this receptor interaction definitively, we synthesized another series of peptide analogs containing (F4)Phe-isomers, with the phenyl group of each isomer possessing only one hydrogen atom at the ortho, meta, or para position. When the peptides were assayed for their platelet aggregation activity, S/(2,3,4,6-F4)Phe/LLRNP and S/(2,3,4,5-F4)Phe/LLRNP exhibited noticeable activity (34% and 6% intensities of the native peptide, respectively), whereas S/(2,3,5,6-F4)Phe/LLRNP was completely inactive. The results indicated that, at the ortho and meta positions but not at the para position, benzene-hydrogen atoms are required for the CH/π interaction to activate the receptor. The results provided a decisive evidence of the molecular recognition property of Phe, the phenyl benzene-hydrogen atom of which participates directly in the interaction with the receptor aromatic π plane.


Assuntos
Fragmentos de Peptídeos/farmacologia , Fenilalanina/farmacologia , Receptor PAR-1/antagonistas & inibidores , Relação Dose-Resposta a Droga , Voluntários Saudáveis , Humanos , Ligantes , Estrutura Molecular , Fragmentos de Peptídeos/química , Fenilalanina/química , Agregação Plaquetária/efeitos dos fármacos , Receptor PAR-1/metabolismo , Relação Estrutura-Atividade
8.
Neuroimage ; 222: 117220, 2020 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-32777357

RESUMO

Numerous studies have investigated grey matter (GM) volume changes in diverse patient groups. Reports of disorder-related GM reductions are common in such work, but many studies also report evidence for GM volume increases in patients. It is unclear whether these GM increases and decreases are independent or related in some way. Here, we address this question using a novel meta-analytic network mapping approach. We used a coordinate-based meta-analysis of 64 voxel-based morphometry studies of psychiatric disorders to calculate the probability of finding a GM increase or decrease in one region given an observed change in the opposite direction in another region. Estimating this co-occurrence probability for every pair of brain regions allowed us to build a network of concurrent GM changes of opposing polarity. Our analysis revealed that disorder-related GM increases and decreases are not independent; instead, a GM change in one area is often statistically related to a change of opposite polarity in other areas, highlighting distributed yet coordinated changes in GM volume as a function of brain pathology. Most regions showing GM changes linked to an opposite change in a distal area were located in salience, executive-control and default mode networks, as well as the thalamus and basal ganglia. Moreover, pairs of regions showing coupled changes of opposite polarity were more likely to belong to different canonical networks than to the same one. Our results suggest that regional GM alterations in psychiatric disorders are often accompanied by opposing changes in distal regions that belong to distinct functional networks.


Assuntos
Rede de Modo Padrão , Substância Cinzenta , Transtornos Mentais , Metanálise como Assunto , Rede Nervosa , Neuroimagem , Rede de Modo Padrão/diagnóstico por imagem , Rede de Modo Padrão/patologia , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia , Humanos , Transtornos Mentais/diagnóstico por imagem , Transtornos Mentais/patologia , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/patologia
9.
Hum Brain Mapp ; 41(15): 4155-4172, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-32829507

RESUMO

In the field of neuroimaging reverse inferences can lead us to suppose the involvement of cognitive processes from certain patterns of brain activity. However, the same reasoning holds if we substitute "brain activity" with "brain alteration" and "cognitive process" with "brain disorder." The fact that different brain disorders exhibit a high degree of overlap in their patterns of structural alterations makes forward inference-based analyses less suitable for identifying brain areas whose alteration is specific to a certain pathology. In the forward inference-based analyses, in fact, it is impossible to distinguish between areas that are altered by the majority of brain disorders and areas that are specifically affected by certain diseases. To address this issue and allow the identification of highly pathology-specific altered areas we used the Bayes' factor technique, which was employed, as a proof of concept, on voxel-based morphometry data of schizophrenia and Alzheimer's disease. This technique allows to calculate the ratio between the likelihoods of two alternative hypotheses (in our case, that the alteration of the voxel is specific for the brain disorder under scrutiny or that the alteration is not specific). We then performed temporal simulations of the alterations' spread associated with different pathologies. The Bayes' factor values calculated on these simulated data were able to reveal that the areas, which are more specific to a certain disease, are also the ones to be early altered. This study puts forward a new analytical instrument capable of innovating the methodological approach to the investigation of brain pathology.


Assuntos
Doença de Alzheimer/diagnóstico por imagem , Substância Cinzenta/diagnóstico por imagem , Neuroimagem/métodos , Esquizofrenia/diagnóstico por imagem , Doença de Alzheimer/patologia , Teorema de Bayes , Rede de Modo Padrão/diagnóstico por imagem , Rede de Modo Padrão/patologia , Diagnóstico Diferencial , Substância Cinzenta/patologia , Humanos , Modelos Teóricos , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/patologia , Neuroimagem/normas , Estudo de Prova de Conceito , Esquizofrenia/patologia
10.
Hum Brain Mapp ; 41(14): 3878-3899, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32562581

RESUMO

It is becoming clearer that the impact of brain diseases is more convincingly represented in terms of co-alterations rather than in terms of localization of alterations. In this context, areas characterized by a long mean distance of co-alteration may be considered as hubs with a crucial role in the pathology. We calculated meta-analytic transdiagnostic networks of co-alteration for the gray matter decreases and increases, and we evaluated the mean Euclidean, fiber-length, and topological distance of its nodes. We also examined the proportion of co-alterations between canonical networks, and the transdiagnostic variance of the Euclidean distance. Furthermore, disease-specific analyses were conducted on schizophrenia and Alzheimer's disease. The anterodorsal prefrontal cortices appeared to be a transdiagnostic hub of long-distance co-alterations. Also, the disease-specific analyses showed that long-distance co-alterations are more able than classic meta-analyses to identify areas involved in pathology and symptomatology. Moreover, the distance maps were correlated with the normative connectivity. Our findings substantiate the network degeneration hypothesis in brain pathology. At the same time, they suggest that the concept of co-alteration might be a useful tool for clinical neuroscience.


Assuntos
Doença de Alzheimer , Córtex Cerebral , Substância Cinzenta , Imageamento por Ressonância Magnética , Rede Nervosa , Neuroimagem , Esquizofrenia , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/patologia , Doença de Alzheimer/fisiopatologia , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/patologia , Córtex Cerebral/fisiopatologia , Bases de Dados Factuais , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia , Substância Cinzenta/fisiopatologia , Humanos , Imageamento por Ressonância Magnética/estatística & dados numéricos , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/patologia , Rede Nervosa/fisiopatologia , Neuroimagem/estatística & dados numéricos , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/patologia , Córtex Pré-Frontal/fisiopatologia , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/patologia , Esquizofrenia/fisiopatologia
11.
J Cogn Neurosci ; 31(12): 1796-1826, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31418337

RESUMO

During the last two decades, our inner sense of time has been repeatedly studied with the help of neuroimaging techniques. These investigations have suggested the specific involvement of different brain areas in temporal processing. At least two distinct neural systems are likely to play a role in measuring time: One is mainly constituted of subcortical structures and is supposed to be more related to the estimation of time intervals below the 1-sec range (subsecond timing tasks), and the other is mainly constituted of cortical areas and is supposed to be more related to the estimation of time intervals above the 1-sec range (suprasecond timing tasks). Tasks can then be performed in motor or nonmotor (perceptual) conditions, thus providing four different categories of time processing. Our meta-analytical investigation partly confirms the findings of previous meta-analytical works. Both sub- and suprasecond tasks recruit cortical and subcortical areas, but subcortical areas are more intensely activated in subsecond tasks than in suprasecond tasks, which instead receive more contributions from cortical activations. All the conditions, however, show strong activations in the SMA, whose rostral and caudal parts have an important role not only in the discrimination of different time intervals but also in relation to the nature of the task conditions. This area, along with the striatum (especially the putamen) and the claustrum, is supposed to be an essential node in the different networks engaged when the brain creates our sense of time.


Assuntos
Neuroimagem , Percepção do Tempo/fisiologia , Mapeamento Encefálico , Córtex Cerebral/fisiologia , Humanos , Modelos Neurológicos , Modelos Psicológicos , Especificidade de Órgãos , Desempenho Psicomotor/fisiologia
12.
Pflugers Arch ; 471(10): 1291-1304, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31486901

RESUMO

Nephrogenic syndrome of inappropriate antidiuresis (NSIAD) is a recently identified chromosome X-linked disease associated with gain-of-function mutations of the V2 vasopressin receptor (V2R), a G-protein-coupled receptor. It is characterized by inability to excrete a free water load, hyponatremia, and undetectable vasopressin-circulating levels. Hyponatremia can be quite severe in affected male children. To gain a deeper insight into the functional properties of the V2R active mutants and how they might translate into the pathological outcome of NSIAD, in this study, we have expressed the wild-type V2R and three constitutively active V2R mutants associated with NSIAD (R137L, R137C, and the F229V) in MCD4 cells, a cell line derived from renal mouse collecting duct, stably expressing the vasopressin-sensitive water channel aquaporin-2 (AQP2). Our findings indicate that in cells expressing each active mutant, AQP2 was constitutively localized to the apical plasma membrane in the absence of vasopressin stimulation. In line with these observations, under basal conditions, osmotic water permeability in cells expressing the constitutively active mutants was significantly higher compared to that of cells expressing the wild-type V2R. Our findings demonstrate a direct link between activating mutations of the V2R and the perturbation of water balance in NSIAD. In addition, this study provides a useful cell-based assay system to assess the functional consequences of newly discovered activating mutations of the V2R on water permeability in kidney cells and to screen the effect of drugs on the mutated receptors.


Assuntos
Aquaporina 2/metabolismo , Mutação com Ganho de Função , Doenças Genéticas Ligadas ao Cromossomo X/genética , Síndrome de Secreção Inadequada de HAD/genética , Receptores de Vasopressinas/genética , Reabsorção Renal , Animais , Linhagem Celular , Doenças Genéticas Ligadas ao Cromossomo X/metabolismo , Humanos , Síndrome de Secreção Inadequada de HAD/metabolismo , Camundongos , Receptores de Vasopressinas/metabolismo , Vasopressinas/metabolismo , Água/metabolismo , Equilíbrio Hidroeletrolítico
13.
Neuroimage ; 184: 359-371, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30237032

RESUMO

Growing evidence is challenging the assumption that brain disorders are diagnostically clear-cut categories. Transdiagnostic studies show that a set of cerebral areas is frequently altered in a variety of psychiatric as well as neurological syndromes. In order to provide a map of the altered areas in the pathological brain we devised a metric, called alteration entropy (A-entropy), capable of denoting the "structural alteration variety" of an altered region. Using the whole voxel-based morphometry database of BrainMap, we were able to differentiate the brain areas exhibiting a high degree of overlap between different neuropathologies (or high value of A-entropy) from those exhibiting a low degree of overlap (or low value of A-entropy). The former, which are parts of large-scale brain networks with attentional, emotional, salience, and premotor functions, are thought to be more vulnerable to a great range of brain diseases; while the latter, which include the sensorimotor, visual, inferior temporal, and supramarginal regions, are thought to be more informative about the specific impact of brain diseases. Since low A-entropy areas appear to be altered by a smaller number of brain disorders, they are more informative than the areas characterized by high values of A-entropy. It is also noteworthy that even the areas showing low values of A-entropy are substantially altered by a variety of brain disorders. In fact, no cerebral area appears to be only altered by a specific disorder. Our study shows that the overlap of areas with high A-entropy provides support for a transdiagnostic approach to brain disorders but, at the same time, suggests that fruitful differences can be traced among brain diseases, as some areas can exhibit an alteration profile more specific to certain disorders than to others.


Assuntos
Encefalopatias/diagnóstico por imagem , Encefalopatias/patologia , Mapeamento Encefálico/métodos , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/patologia , Conjuntos de Dados como Assunto , Entropia , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética
14.
Brain ; 141(11): 3211-3232, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30346490

RESUMO

The pathological brain is characterized by distributed morphological or structural alterations in the grey matter, which tend to follow identifiable network-like patterns. We analysed the patterns formed by these alterations (increased and decreased grey matter values detected with the voxel-based morphometry technique) conducting an extensive transdiagnostic search of voxel-based morphometry studies in a large variety of brain disorders. We devised an innovative method to construct the networks formed by the structurally co-altered brain areas, which can be considered as pathological structural co-alteration patterns, and to compare these patterns with three associated types of connectivity profiles (functional, anatomical, and genetic). Our study provides transdiagnostical evidence that structural co-alterations are influenced by connectivity constraints rather than being randomly distributed. Analyses show that although all the three types of connectivity taken together can account for and predict with good statistical accuracy, the shape and temporal development of the co-alteration patterns, functional connectivity offers the better account of the structural co-alteration, followed by anatomic and genetic connectivity. These results shed new light on the possible mechanisms at the root of neuropathological processes and open exciting prospects in the quest for a better understanding of brain disorders.


Assuntos
Mapeamento Encefálico , Encéfalo/anatomia & histologia , Redes Reguladoras de Genes , Modelos Neurológicos , Vias Neurais/fisiologia , Adulto , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Imagem de Tensor de Difusão , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Rede Nervosa/fisiologia , Vias Neurais/diagnóstico por imagem , Reprodutibilidade dos Testes , Adulto Jovem
15.
Cereb Cortex ; 28(7): 2647-2654, 2018 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-29722797

RESUMO

Mirror neurons have been proposed to underlie humans' ability to understand others' actions and intentions. Despite 2 decades of research, however, the exact computational and neuronal mechanisms implied in this ability remain unclear. In the current study, we investigated whether, in the absence of contextual cues, regions considered to be part of the human mirror neuron system represent intention from movement kinematics. A total of 21 participants observed reach-to-grasp movements, performed with either the intention to drink or to pour while undergoing functional magnetic resonance imaging. Multivoxel pattern analysis revealed successful decoding of intentions from distributed patterns of activity in a network of structures comprising the inferior parietal lobule, the superior parietal lobule, the inferior frontal gyrus, and the middle frontal gyrus. Consistent with the proposal that parietal regions play a key role in intention understanding, classifier weights were higher in the inferior parietal region. These results provide the first demonstration that putative mirror neuron regions represent subtle differences in movement kinematics to read the intention of an observed motor act.


Assuntos
Intenção , Neurônios-Espelho/fisiologia , Observação , Lobo Parietal/citologia , Desempenho Psicomotor/fisiologia , Adulto , Fenômenos Biomecânicos , Feminino , Força da Mão/fisiologia , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Lobo Parietal/diagnóstico por imagem , Adulto Jovem
16.
Hum Brain Mapp ; 39(5): 1898-1928, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29349864

RESUMO

By means of a novel methodology that can statistically derive patterns of co-alterations distribution from voxel-based morphological data, this study analyzes the patterns of brain alterations of three important psychiatric spectra-that is, schizophrenia spectrum disorder (SCZD), autistic spectrum disorder (ASD), and obsessive-compulsive spectrum disorder (OCSD). Our analysis provides five important results. First, in SCZD, ASD, and OCSD brain alterations do not distribute randomly but, rather, follow network-like patterns of co-alteration. Second, the clusters of co-altered areas form a net of alterations that can be defined as morphometric co-alteration network or co-atrophy network (in the case of gray matter decreases). Third, within this network certain cerebral areas can be identified as pathoconnectivity hubs, the alteration of which is supposed to enhance the development of neuronal abnormalities. Fourth, within the morphometric co-atrophy network of SCZD, ASD, and OCSD, a subnetwork composed of eleven highly connected nodes can be distinguished. This subnetwork encompasses the anterior insulae, inferior frontal areas, left superior temporal areas, left parahippocampal regions, left thalamus and right precentral gyri. Fifth, the co-altered areas also exhibit a normal structural covariance pattern which overlaps, for some of these areas (like the insulae), the co-alteration pattern. These findings reveal that, similarly to neurodegenerative diseases, psychiatric disorders are characterized by anatomical alterations that distribute according to connectivity constraints so as to form identifiable morphometric co-atrophy patterns.


Assuntos
Transtorno Autístico/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Vias Neurais/diagnóstico por imagem , Transtorno Obsessivo-Compulsivo/diagnóstico por imagem , Esquizofrenia/diagnóstico por imagem , Adolescente , Adulto , Atrofia/diagnóstico por imagem , Atrofia/etiologia , Transtorno Autístico/complicações , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Modelos Neurológicos , Transtorno Obsessivo-Compulsivo/complicações , PubMed/estatística & dados numéricos , Esquizofrenia/complicações , Adulto Jovem
17.
Neural Plast ; 2017: 1612078, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28239498

RESUMO

Introduction. The present study was intended to evaluate the effects of a rehabilitative training, the Cognitive Pragmatic Treatment (CPT), aimed at improving communicative-pragmatic abilities and the related cognitive components, on the cerebral modifications of a single case patient diagnosed with schizophrenia. Methods. The patient underwent two functional magnetic resonance imaging (fMRI) sessions, before and after the treatment. In order to assess brain changes, we calculated the Amplitude of Low Frequency Fluctuation (ALFF) index of the resting-state fMRI signal, which is interpreted as reflecting the intensity of the spontaneous regional activity of the brain. Behavioural measures of the patient's communicative performance were also gathered before and after training and at follow-up. Results. The patient improved his communicative performance in almost all tests. Posttraining stronger ALFF signal emerged in the superior, inferior, and medial frontal gyri, as well as the superior temporal gyri. Conclusions. Even if based on a single case study, these preliminary results show functional changes at the cerebral level that seem to support the patient's behavioural improvements.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Terapia Cognitivo-Comportamental/métodos , Imageamento por Ressonância Magnética/métodos , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/reabilitação , Adulto , Mapeamento Encefálico/métodos , Seguimentos , Humanos , Masculino , Esquizofrenia/fisiopatologia
18.
Cogn Affect Behav Neurosci ; 16(3): 383-92, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26912269

RESUMO

Although very difficult to define, happiness is becoming a core concept within contemporary psychology and affective neuroscience. In the last two decades, the increased use of neuroimaging techniques has facilitated empirical study of the neural correlates of happiness. This area of research utilizes procedures that induce positive emotion and mood, and autobiographical recall is one of the most widely used and effective approaches. In this article, we review eight positron emission tomography and seven functional magnetic resonance imaging studies that have investigated happiness by using autobiographical recall to induce emotion. Regardless of the neuroimaging technique used, the studies conducted so far have shown that remembering happy events is primarily associated with the activation of many areas, including anterior cingulate cortex, prefrontal cortex, and insula. Importantly, these areas are also found to be connected with other basic emotions, such as sadness and anger. In the conclusion, we integrate these findings, discussing important limitations of the extant literature and suggesting new research directions.


Assuntos
Afeto/fisiologia , Córtex Cerebral/patologia , Emoções/fisiologia , Rememoração Mental/fisiologia , Neuroimagem , Córtex Pré-Frontal/patologia , Animais , Córtex Cerebral/fisiopatologia , Humanos , Córtex Pré-Frontal/fisiopatologia
19.
Biopolymers ; 106(4): 460-9, 2016 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-27271345

RESUMO

We previously showed that an antagonist-based peptide ligand, H-Cys(Npys)-Arg-Tyr-Tyr-Arg- Ile-Lys-NH2 , captures the free thiol groups in the ligand-binding site of the nociceptin receptor ORL1. However, the exact receptor sites of this thiol-disulfide exchange reaction have not been uncovered, although such identification would help to clarify the ligand recognition site. Since the Cys→Ala substitution prevents the reaction, we performed the so-called Ala scanning for all the Cys residues in the transmembrane (TM) domains of the ORL1 receptor. Seven different mutant receptors were soundly expressed in the COS-7 cells and examined for their specific affinity labeling by a competitive binding assay using nociceptin and [(3) H]nociceptin. The results of in vitro Ala scanning analyses revealed that the labeled residues were Cys59 in TM1, Cys215 and Cys231 in TM5, and Cys310 in TM7. The present study has provided a novel method of Cys(Npys)-affinity labeling for identification of the ligand-binding sites in the ORL1 receptor. © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 460-469, 2016.


Assuntos
Peptídeos/química , Receptores Opioides , Coloração e Rotulagem/métodos , Substituição de Aminoácidos , Animais , Sítios de Ligação , Células COS , Chlorocebus aethiops , Humanos , Ligantes , Mutação de Sentido Incorreto , Receptores Opioides/biossíntese , Receptores Opioides/química , Receptores Opioides/genética , Receptor de Nociceptina
20.
Conscious Cogn ; 40: 67-78, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26752605

RESUMO

Although mindfulness meditation has been practiced in the East for more than two millennia, Western scientific research and healthcare programs have only recently drawn their attention to it. Basically, the concept of mindfulness hinges on focusing on one's own awareness at the present moment. In this review we analyze different hypotheses about the functioning and the cerebral correlates of mindfulness meditation. Since mindfulness is strictly associated with a particular state of consciousness, we also examine some of the most relevant theories that have been proposed as accounts of consciousness. Finally, we suggest that consciousness and mindfulness meditation can be integrated within a neuroscientific perspective, by identifying the brain areas which seem to play an essential role in both, namely the anterior cingulate cortex, posterior cingulate cortex, insula and thalamus.


Assuntos
Córtex Cerebral/fisiologia , Estado de Consciência/fisiologia , Meditação , Atenção Plena , Tálamo/fisiologia , Humanos
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