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1.
Epidemiol Psychiatr Sci ; 29: e166, 2020 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-32895076

RESUMO

Since its discovery in 1997, the default mode network (DMN) and its components have been extensively studied in both healthy individuals and psychiatric patients. Several studies have investigated possible DMN alterations in specific mental conditions such as bipolar disorder (BD). In this review, we describe current evidence from resting-state functional magnetic resonance imaging studies with the aim to understand possible changes in the functioning of the DMN in BD. Overall, several types of analyses including seed-based and independent component have been conducted on heterogeneous groups of patients highlighting different results. Despite the differences, findings seem to indicate that BD is associated with alterations in both frontal and posterior DMN structures, mainly in the prefrontal, posterior cingulate and inferior parietal cortices. We conclude this review by suggesting possible future research directions.


Assuntos
Transtorno Bipolar/diagnóstico por imagem , Mapeamento Encefálico/métodos , Encéfalo/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Rede Nervosa/fisiologia , Vias Neurais/diagnóstico por imagem , Transtorno Bipolar/fisiopatologia , Humanos
2.
PLoS Biol ; 18(9): e3000854, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32898172

RESUMO

Working memory is imprecise, and these imprecisions can be explained by the combined influences of random diffusive error and systematic drift toward a set of stable states ("attractors"). However, the neural correlates of diffusion and drift remain unknown. Here, we investigated how delay-period activity in frontal and parietal cortex, which is known to correlate with the decline in behavioral memory precision observed with increasing memory load, might relate to diffusion and drift. We analyzed data from an existing experiment in which subjects performed delayed recall for line orientation, at different loads, during functional magnetic resonance imaging (fMRI) scanning. To quantify the influence of drift and diffusion, we modeled subjects' behavior using a discrete attractor model and calculated within-subject correlation between frontal and parietal delay-period activity and whole-trial estimates of drift and diffusion. We found that although increases in frontal and parietal activity were associated with increases in both diffusion and drift, diffusion explained the most variance in frontal and parietal delay-period activity. In comparison, a subsequent whole-brain regression analysis showed that drift, rather than diffusion, explained the most variance in delay-period activity in lateral occipital cortex. These results are consistent with a model of the differential recruitment of general frontoparietal mechanisms in response to diffusive noise and of stimulus-specific biases in occipital cortex.


Assuntos
Lobo Frontal/fisiologia , Memória de Curto Prazo/fisiologia , Lobo Occipital/fisiologia , Lobo Parietal/fisiologia , Percepção Visual/fisiologia , Adolescente , Adulto , Viés , Mapeamento Encefálico/métodos , Feminino , Lobo Frontal/anatomia & histologia , Lobo Frontal/diagnóstico por imagem , Humanos , Imagem por Ressonância Magnética , Masculino , Rememoração Mental/fisiologia , Lobo Occipital/anatomia & histologia , Lobo Occipital/diagnóstico por imagem , Lobo Parietal/anatomia & histologia , Lobo Parietal/diagnóstico por imagem , Estimulação Luminosa , Razão Sinal-Ruído , Fatores de Tempo , Vias Visuais/anatomia & histologia , Vias Visuais/diagnóstico por imagem , Vias Visuais/fisiologia , Adulto Jovem
3.
Nat Commun ; 11(1): 4523, 2020 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-32908125

RESUMO

Thousands of functional magnetic resonance imaging (fMRI) studies have provided important insight into the human brain. However, only a handful of these studies tested infants while they were awake, because of the significant and unique methodological challenges involved. We report our efforts to address these challenges, with the goal of creating methods for awake infant fMRI that can reveal the inner workings of the developing, preverbal mind. We use these methods to collect and analyze two fMRI datasets obtained from infants during cognitive tasks, released publicly with this paper. In these datasets, we explore and evaluate data quantity and quality, task-evoked activity, and preprocessing decisions. We disseminate these methods by sharing two software packages that integrate infant-friendly cognitive tasks and eye-gaze monitoring with fMRI acquisition and analysis. These resources make fMRI a feasible and accessible technique for cognitive neuroscience in awake and behaving human infants.


Assuntos
Mapeamento Encefálico/métodos , Encéfalo/diagnóstico por imagem , Desenvolvimento Infantil/fisiologia , Imagem por Ressonância Magnética/métodos , Vigília/fisiologia , Técnicas de Observação do Comportamento , Encéfalo/crescimento & desenvolvimento , Pré-Escolar , Cognição/fisiologia , Estudos de Coortes , Estudos de Viabilidade , Feminino , Humanos , Lactente , Masculino
4.
Nat Commun ; 11(1): 4340, 2020 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-32895386

RESUMO

Healthy cognitive ageing is a societal and public health priority. Cerebrovascular risk factors increase the likelihood of dementia in older people but their impact on cognitive ageing in younger, healthy brains is less clear. The UK Biobank provides cognition and brain imaging measures in the largest population cohort studied to date. Here we show that cognitive abilities of healthy individuals (N = 22,059) in this sample are detrimentally affected by cerebrovascular risk factors. Structural equation modelling revealed that cerebrovascular risk is associated with reduced cerebral grey matter and white matter integrity within a fronto-parietal brain network underlying executive function. Notably, higher systolic blood pressure was associated with worse executive cognitive function in mid-life (44-69 years), but not in late-life (>70 years). During mid-life this association did not occur in the systolic range of 110-140 mmHg. These findings suggest cerebrovascular risk factors impact on brain structure and cognitive function in healthy people.


Assuntos
Encéfalo/fisiopatologia , Transtornos Cerebrovasculares/fisiopatologia , Transtornos Cognitivos/fisiopatologia , Envelhecimento Saudável , Adulto , Idoso , Pressão Sanguínea , Mapeamento Encefálico/métodos , Córtex Cerebral/fisiopatologia , Estudos de Coortes , Função Executiva/fisiologia , Feminino , Substância Cinzenta/fisiopatologia , Humanos , Imagem por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Substância Branca/fisiopatologia
5.
Medicine (Baltimore) ; 99(31): e21378, 2020 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-32756127

RESUMO

BACKGROUND: A number of studies have used regional homogeneity (ReHo) to depict local functional connectivity in chronic pain (CP). However, the findings from these studies were mixed and inconsistent. METHODS: A computerized literature search will be performed in PubMed, Web of Science, Embase, China National Knowledge Infrastructure (CNKI), WanFang, and SinoMed databases until June 15, 2019 and updated on March 20, 2020. This protocol will follow the Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P). The Seed-based d Mapping with Permutation of Subject Images (SDM-PSI) software will be used for this voxel-wise meta-analysis. RESULTS: This meta-analysis will identify the most consistent ReHo alterations in CP. CONCLUSIONS: To our knowledge, this will be the first voxel-wise meta-analysis that integrates ReHo findings in CP. This meta-analysis will offer the quantitative evidence of ReHo alterations that characterize brain local functional connectivity of CP. PROSPERO REGISTRATION NUMBER: CRD42019148523.


Assuntos
Encéfalo/diagnóstico por imagem , Dor Crônica/fisiopatologia , Imagem por Ressonância Magnética , Mapeamento Encefálico/métodos , Dor Crônica/diagnóstico por imagem , Humanos , Metanálise como Assunto , Revisões Sistemáticas como Assunto
6.
PLoS One ; 15(7): e0236423, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32735611

RESUMO

BACKGROUND: Use of functional MRI (fMRI) in pre-surgical planning is a non-invasive method for pre-operative functional mapping for patients with brain tumors, especially tumors located near eloquent cortex. Currently, this practice predominantly involves task-based fMRI (T-fMRI). Resting state fMRI (RS-fMRI) offers an alternative with several methodological advantages. Here, we compare group-level analyses of RS-fMRI vs. T-fMRI as methods for language localization. PURPOSE: To contrast RS-fMRI vs. T-fMRI as techniques for localization of language function. METHODS: We analyzed data obtained in 35 patients who had both T-fMRI and RS-fMRI scans during the course of pre-surgical evaluation. The RS-fMRI data were analyzed using a previously trained resting-state network classifier. The T-fMRI data were analyzed using conventional techniques. Group-level results obtained by both methods were evaluated in terms of two outcome measures: (1) inter-subject variability of response magnitude and (2) sensitivity/specificity analysis of response topography, taking as ground truth previously reported maps of the language system based on intraoperative cortical mapping as well as meta-analytic maps of language task fMRI responses. RESULTS: Both fMRI methods localized major components of the language system (areas of Broca and Wernicke) although not with equal inter-subject consistency. Word-stem completion T-fMRI strongly activated Broca's area but also several task-general areas not specific to language. RS-fMRI provided a more specific representation of the language system. CONCLUSION: We demonstrate several advantages of classifier-based mapping of language representation in the brain. Language T-fMRI activated task-general (i.e., not language-specific) functional systems in addition to areas of Broca and Wernicke. In contrast, classifier-based analysis of RS-fMRI data generated maps confined to language-specific regions of the brain.


Assuntos
Encéfalo/diagnóstico por imagem , Área de Broca/patologia , Glioblastoma/diagnóstico , Imagem por Ressonância Magnética , Adulto , Idoso , Atenção/fisiologia , Mapeamento Encefálico/métodos , Área de Broca/diagnóstico por imagem , Feminino , Lobo Frontal/diagnóstico por imagem , Lobo Frontal/patologia , Lateralidade Funcional/fisiologia , Glioblastoma/diagnóstico por imagem , Glioblastoma/patologia , Humanos , Idioma , Masculino , Pessoa de Meia-Idade , Descanso/fisiologia , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/patologia , Adulto Jovem
7.
Yakugaku Zasshi ; 140(8): 979-983, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32741871

RESUMO

Monoamine neurotransmitters are released by specialized neurons that regulate behavioral and cognitive functions. Although localization of monoaminergic neurons in the brain is well known, the distribution, concentration, and kinetics of monoamines remain unclear. We used mass spectrometry imaging (MSI) for simultaneous and quantitative imaging of endogenous monoamines to generate a murine brain atlas of serotonin (5-HT), dopamine (DA), and norepinephrine (NE) levels. We observed several nuclei rich in both 5-HT and a catecholamine (DA or NE). Additionally, we analyzed de novo monoamine synthesis or fluctuations in those nuclei. We propose that MSI is a useful tool to gain deeper understanding of associations among the localization, levels, and turnover of monoamines in different brain areas and their role in inducing behavioral changes.


Assuntos
Monoaminas Biogênicas/análise , Monoaminas Biogênicas/metabolismo , Mapeamento Encefálico/métodos , Encéfalo/metabolismo , Espectrometria de Massas/métodos , Imagem Molecular/métodos , Neurotransmissores/metabolismo , Animais , Dopamina/análise , Dopamina/metabolismo , Camundongos , Neurônios/metabolismo , Neurotransmissores/fisiologia , Norepinefrina/análise , Norepinefrina/metabolismo , Serotonina/análise , Serotonina/metabolismo
8.
PLoS One ; 15(8): e0237511, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785278

RESUMO

Eating disorder is highly associated with obesity and it is related to brain dysfunction as well. Still, the functional substrates of the brain associated with behavioral traits of eating disorder are underexplored. Existing neuroimaging studies have explored the association between eating disorder and brain function without using all the information provided by the eating disorder related questionnaire but by adopting summary factors. Here, we aimed to investigate the multivariate association between brain function and eating disorder at fine-grained question-level information. Our study is a retrospective secondary analysis that re-analyzed resting-state functional magnetic resonance imaging of 284 participants from the enhanced Nathan Kline Institute-Rockland Sample database. Leveraging sparse canonical correlation analysis, we associated the functional connectivity of all brain regions and all questions in the eating disorder questionnaires. We found that executive- and inhibitory control-related frontoparietal networks showed positive associations with questions of restraint eating, while brain regions involved in the reward system showed negative associations. Notably, inhibitory control-related brain regions showed a positive association with the degree of obesity. Findings were well replicated in the independent validation dataset (n = 34). The results of this study might contribute to a better understanding of brain function with respect to eating disorder.


Assuntos
Mapeamento Encefálico/métodos , Encéfalo/fisiopatologia , Transtornos da Alimentação e da Ingestão de Alimentos/etiologia , Imagem por Ressonância Magnética/métodos , Neuroimagem/métodos , Adulto , Índice de Massa Corporal , Função Executiva , Comportamento Alimentar , Transtornos da Alimentação e da Ingestão de Alimentos/patologia , Feminino , Humanos , Masculino , Estudos Retrospectivos
9.
PLoS One ; 15(8): e0231294, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32853207

RESUMO

Eigenvector alignment, introduced herein to investigate human brain functional networks, is adapted from methods developed to detect influential nodes and communities in networked systems. It is used to identify differences in the brain networks of subjects with Alzheimer's disease (AD), amnestic Mild Cognitive Impairment (aMCI) and healthy controls (HC). Well-established methods exist for analysing connectivity networks composed of brain regions, including the widespread use of centrality metrics such as eigenvector centrality. However, these metrics provide only limited information on the relationship between regions, with this understanding often sought by comparing the strength of pairwise functional connectivity. Our holistic approach, eigenvector alignment, considers the impact of all functional connectivity changes before assessing the strength of the functional relationship, i.e. alignment, between any two regions. This is achieved by comparing the placement of regions in a Euclidean space defined by the network's dominant eigenvectors. Eigenvector alignment recognises the strength of bilateral connectivity in cortical areas of healthy control subjects, but also reveals degradation of this commissural system in those with AD. Surprisingly little structural change is detected for key regions in the Default Mode Network, despite significant declines in the functional connectivity of these regions. In contrast, regions in the auditory cortex display significant alignment changes that begin in aMCI and are the most prominent structural changes for those with AD. Alignment differences between aMCI and AD subjects are detected, including notable changes to the hippocampal regions. These findings suggest eigenvector alignment can play a complementary role, alongside established network analytic approaches, to capture how the brain's functional networks develop and adapt when challenged by disease processes such as AD.


Assuntos
Doença de Alzheimer/fisiopatologia , Mapeamento Encefálico/métodos , Disfunção Cognitiva/fisiopatologia , Idoso , Amnésia/fisiopatologia , Encéfalo/fisiopatologia , Córtex Cerebral/fisiopatologia , Feminino , Humanos , Imagem por Ressonância Magnética/métodos , Masculino , Modelos Teóricos , Rede Nervosa/fisiopatologia , Vias Neurais/fisiopatologia
10.
PLoS One ; 15(7): e0234255, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32726311

RESUMO

'Normal aging' in the brain refers to age-related changes that occur independent of disease, in particular Alzheimer's disease. A major barrier to mapping normal brain aging has been the difficulty in excluding the earliest preclinical stages of Alzheimer's disease. Here, before addressing this issue we first imaged a mouse model and learn that the best MRI measure of dendritic spine loss, a known pathophysiological driver of normal aging, is one that relies on the combined use of functional and structural MRI. In the primary study, we then deployed the combined functional-structural MRI measure to investigate over 100 cognitively-normal people from 20-72 years of age. Next, to cover the tail end of aging, in secondary analyses we investigated structural MRI acquired from cognitively-normal people, 60-84 years of age, who were Alzheimer's-free via biomarkers. Collectively, the results from the primary functional-structural study, and the secondary structural studies revealed that the dentate gyrus is a hippocampal region differentially affected by aging, and that the entorhinal cortex is a region most resistant to aging. Across the cortex, the primary functional-structural study revealed and that the inferior frontal gyrus is differentially affected by aging, however, the secondary structural studies implicated other frontal cortex regions. Together, the results clarify how normal aging may affect the brain and has possible mechanistic and therapeutic implications.


Assuntos
Envelhecimento/fisiologia , Encéfalo/fisiologia , Senescência Celular/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/fisiopatologia , Animais , Encéfalo/metabolismo , Mapeamento Encefálico/métodos , Disfunção Cognitiva/fisiopatologia , Espinhas Dendríticas/patologia , Giro Denteado/patologia , Córtex Entorrinal/patologia , Feminino , Humanos , Imagem por Ressonância Magnética/métodos , Masculino , Camundongos , Pessoa de Meia-Idade
11.
PLoS One ; 15(7): e0236763, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32730315

RESUMO

OBJECTIVE: Altered mental status (AMS) is one of the most common symptoms in the febrile elderly. Brain imaging tests are an important tool for diagnosing AMS patients. However, these may be prescribed unnecessarily in emergency departments, particularly for febrile patients with AMS for whom infection is suspected, leading to excessive radiation risk and cost. In this study, we investigated the factors that can predict clinically significant abnormal brain imaging (ABI) in the febrile elderly with AMS. METHODS: This retrospective multicenter study was conducted from July 2016 to June 2019. Febrile patients over the age of 65 years with AMS who visited the emergency department of two tertiary university hospitals were enrolled. Medical records were reviewed, and laboratory results were obtained. Brain imaging results with a formal reading by a radiologist were obtained. RESULTS: In all, 285 patients were enrolled, and 47 (16.49%) showed ABI. The most common diagnoses in patients admitted to the emergency department were intracranial hemorrhage and ischemic stroke for ABI, and pneumonia and urinary tract infection for non-ABI. In multivariate logistic regression analyses, higher systolic blood pressure (odds ratio [OR], 1.017; 95% confidence interval [CI], 1.006-1.028), lower body temperature (OR, 0.578; 95% CI, 0.375-0.892), the presence of lateralizing sign (OR, 45.676; 95% CI, 5.015-416.025), and lower Glasgow Coma Scale (OR, 0.718; 95% CI, 0.617-0.837) were significantly associated with ABI. CONCLUSION: Lower Glasgow Coma Scale, the presence of lateralizing sign, higher systolic blood pressure, and lower body temperature are significantly associated with ABI in febrile elderly patients with AMS.


Assuntos
Mapeamento Encefálico/métodos , Hemorragias Intracranianas/diagnóstico , Transtornos Mentais/diagnóstico , Neuroimagem/métodos , Pneumonia/diagnóstico , Acidente Vascular Cerebral/diagnóstico , Infecções Urinárias/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/diagnóstico por imagem , Estudos de Casos e Controles , Serviço Hospitalar de Emergência , Feminino , Seguimentos , Humanos , Hemorragias Intracranianas/diagnóstico por imagem , Masculino , Transtornos Mentais/diagnóstico por imagem , Pneumonia/diagnóstico por imagem , Prognóstico , Estudos Retrospectivos , Acidente Vascular Cerebral/diagnóstico por imagem , Infecções Urinárias/diagnóstico por imagem
12.
PLoS Comput Biol ; 16(7): e1007992, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32614826

RESUMO

Understanding how the human brain processes auditory input remains a challenge. Traditionally, a distinction between lower- and higher-level sound features is made, but their definition depends on a specific theoretical framework and might not match the neural representation of sound. Here, we postulate that constructing a data-driven neural model of auditory perception, with a minimum of theoretical assumptions about the relevant sound features, could provide an alternative approach and possibly a better match to the neural responses. We collected electrocorticography recordings from six patients who watched a long-duration feature film. The raw movie soundtrack was used to train an artificial neural network model to predict the associated neural responses. The model achieved high prediction accuracy and generalized well to a second dataset, where new participants watched a different film. The extracted bottom-up features captured acoustic properties that were specific to the type of sound and were associated with various response latency profiles and distinct cortical distributions. Specifically, several features encoded speech-related acoustic properties with some features exhibiting shorter latency profiles (associated with responses in posterior perisylvian cortex) and others exhibiting longer latency profiles (associated with responses in anterior perisylvian cortex). Our results support and extend the current view on speech perception by demonstrating the presence of temporal hierarchies in the perisylvian cortex and involvement of cortical sites outside of this region during audiovisual speech perception.


Assuntos
Córtex Auditivo/fisiologia , Percepção Auditiva , Modelos Neurológicos , Redes Neurais de Computação , Som , Adolescente , Adulto , Mapeamento Encefálico/métodos , Eletrocorticografia , Feminino , Humanos , Masculino , Filmes Cinematográficos , Fonética , Processamento de Sinais Assistido por Computador , Fala/fisiologia , Percepção da Fala , Fatores de Tempo , Adulto Jovem
13.
Medicine (Baltimore) ; 99(28): e21125, 2020 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-32664139

RESUMO

OBJECTIVE: The aim of this study was to characterize the capability of detection of the resting state networks (RSNs) with functional magnetic resonance imaging (fMRI) in healthy subjects using a 1.5T scanner in a middle-income country. MATERIALS AND METHODS: Ten subjects underwent a complete blood-oxygen-level dependent imaging (BOLD) acquisition on a 1.5T scanner. For the imaging analysis, we used the spatial independent component analysis (sICA). We designed a computer tool for 1.5 T (or above) scanners for imaging processing. We used it to separate and delineate the different components of the RSNs of the BOLD signal. The sICA was also used to differentiate the RSNs from noise artifact generated by breathing and cardiac cycles. RESULTS: For each subject, 20 independent components (IC) were computed from the sICA (a total of 200 ICs). From these ICs, a spatial pattern consistent with RSNs was identified in 161 (80.5%). From the 161, 131 (65.5%) were fit for study. The networks that were found in all subjects were: the default mode network, the right executive control network, the medial visual network, and the cerebellar network. In 90% of the subjects, the left executive control network and the sensory/motor network were observed. The occipital visual network was present in 80% of the subjects. In 39 (19.5%) of the images, no any neural network was identified. CONCLUSIONS: Reproduction and differentiation of the most representative RSNs was achieved using a 1.5T scanner acquisitions and sICA processing of BOLD imaging in healthy subjects.


Assuntos
Encéfalo/diagnóstico por imagem , Processamento de Imagem Assistida por Computador , Imagem por Ressonância Magnética/instrumentação , Rede Nervosa/diagnóstico por imagem , Descanso/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Mapeamento Encefálico/métodos , Desenho de Equipamento , Feminino , Seguimentos , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos
14.
PLoS One ; 15(7): e0234104, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32609778

RESUMO

Advances in computer and communications technology have deeply affected the way we communicate. Social media have emerged as a major means of human communication. However, a major limitation in such media is the lack of non-verbal stimuli, which sometimes hinders the understanding of the message, and in particular the associated emotional content. In an effort to compensate for this, people started to use emoticons, which are combinations of keyboard characters that resemble facial expressions, and more recently their evolution: emojis, namely, small colorful images that resemble faces, actions and daily life objects. This paper presents evidence of the effect of emojis on memory retrieval through a functional Magnetic Resonance Imaging (fMRI) study. A total number of fifteen healthy volunteers were recruited for the experiment, during which successive stimuli were presented, containing words with intense emotional content combined with emojis, either with congruent or incongruent emotional content. Volunteers were asked to recall a memory related to the stimulus. The study of the reaction times showed that emotional incongruity among word+emoji combinations led to longer reaction times in memory retrieval compared to congruent combinations. General Linear Model (GLM) and Blind Source Separation (BSS) methods have been tested in assessing the influence of the emojis on the process of memory retrieval. The analysis of the fMRI data showed that emotional incongruity among word+emoji combinations activated the Broca's area (BA44 and BA45) in both hemispheres, the Supplementary Motor Area (SMA) and the inferior prefrontal cortex (BA47), compared to congruent combinations. Furthermore, compared to pseudowords, word+emoji combinations activated the left Broca's area (BA44 and BA45), the amygdala, the right temporal pole (BA48) and several frontal regions including the SMA and the inferior prefrontal cortex.


Assuntos
Memória Episódica , Rememoração Mental/fisiologia , Simbolismo , Adulto , Encéfalo/fisiologia , Mapeamento Encefálico/métodos , Comunicação , Compreensão , Emoções , Expressão Facial , Feminino , Voluntários Saudáveis , Humanos , Imagem por Ressonância Magnética/métodos , Masculino , Memória/fisiologia , Córtex Motor/fisiologia , Comunicação não Verbal/psicologia , Córtex Pré-Frontal/fisiologia , Leitura , Lobo Temporal/fisiologia , Redação , Adulto Jovem
15.
PLoS One ; 15(7): e0235039, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32707574

RESUMO

Functional brain network (FBN), estimated with functional magnetic resonance imaging (fMRI), has become a potentially useful way of diagnosing neurological disorders in their early stages by comparing the connectivity patterns between different brain regions across subjects. However, this depends, to a great extent, on the quality of the estimated FBNs, indicating that FBN estimation is a key step for the subsequent task of disorder identification. In the past decades, researchers have developed many methods to estimate FBNs, including Pearson's correlation and (regularized) partial correlation, etc. Despite their widespread applications in current studies, most of the existing methods estimate FBNs only based on the dependency between the measured blood oxygen level dependent (BOLD) signals, which ignores spatial relationship of signals associated with different brain regions. Due to the space and material parsimony principle of our brain, we believe that the spatial distance between brain regions has an important influence on FBN topology. Therefore, in this paper, we assume that spatially neighboring brain regions tend to have stronger connections and/or share similar connections with others; based on this assumption, we propose two novel methods to estimate FBNs by incorporating the information of brain region distance into the estimation model. To validate the effectiveness of the proposed methods, we use the estimated FBNs to identify subjects with mild cognitive impairment (MCI) from normal controls (NCs). Experimental results show that the proposed methods are better than the baseline methods in the sense of MCI identification accuracy.


Assuntos
Disfunção Cognitiva/diagnóstico , Conectoma/métodos , Imagem por Ressonância Magnética/métodos , Rede Nervosa , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Mapeamento Encefálico/métodos , Disfunção Cognitiva/diagnóstico por imagem , Feminino , Humanos , Masculino , Modelos Teóricos , Rede Nervosa/diagnóstico por imagem , Análise Espacial
16.
Obesity (Silver Spring) ; 28(7): 1283-1291, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32510870

RESUMO

OBJECTIVE: This study aimed to investigate regional neural activity and regulation of patterns in the reorganized neural network of obesity and explore the correlation between brain activities and eating behavior. METHODS: A total of 23 individuals with obesity and 23 controls with normal weight were enrolled. Functional magnetic resonance imaging (fMRI) data were acquired using 3.0-T MRI. Amplitude of low-frequency fluctuation and functional connectivity (FC) analyses were conducted using Data Processing Assistant for resting-state fMRI and Resting-State fMRI Data Analysis Toolkit (REST). RESULTS: The group with obesity showed increased amplitude of low-frequency values in left fusiform gyrus/amygdala, inferior temporal gyrus (ITG), hippocampus/parahippocampal gyrus, and bilateral caudate but decreased values in right superior temporal gyrus. The group with obesity showed increased FC between left caudate and right superior temporal gyrus, left fusiform gyrus/amygdala and left ITG, right caudate and left fusiform gyrus/amygdala, and right caudate and left hippocampus/parahippocampal gyrus. Dutch Eating Behavior Questionnaire-Emotional scores were positively correlated with FC between left hippocampus/parahippocampal gyrus and right caudate but negatively correlated with FC between left fusiform gyrus/amygdala and left ITG. CONCLUSIONS: The study indicated the reorganized neural network presented as a bilateral cross-regulation pattern across hemispheres between reward and various appetite-related functional processing, thus affecting emotional and external eating behavior. These results could provide further evidence for neuropsychological underpinnings of food intake and their neuromodulatory therapeutic potential in obesity.


Assuntos
Regulação do Apetite/fisiologia , Encéfalo/diagnóstico por imagem , Transtornos da Alimentação e da Ingestão de Alimentos/diagnóstico , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/patologia , Obesidade/psicologia , Adolescente , Adulto , Encéfalo/patologia , Encéfalo/fisiopatologia , Mapeamento Encefálico/métodos , Estudos de Casos e Controles , Comportamento Alimentar/fisiologia , Comportamento Alimentar/psicologia , Transtornos da Alimentação e da Ingestão de Alimentos/complicações , Transtornos da Alimentação e da Ingestão de Alimentos/fisiopatologia , Transtornos da Alimentação e da Ingestão de Alimentos/psicologia , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Obesidade/diagnóstico , Obesidade/fisiopatologia , Descanso/fisiologia , Descanso/psicologia , Adulto Jovem
17.
Proc Natl Acad Sci U S A ; 117(26): 15270-15280, 2020 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-32541017

RESUMO

The default mode network (DMN) has been defined in functional brain imaging studies as a set of highly connected brain areas, which are active during wakeful rest and inactivated during task-based stimulation. DMN function is characteristically impaired in major neuropsychiatric diseases, emphasizing its interest for translational research. However, in the mouse, a major preclinical rodent model, there is still no functional imaging evidence supporting DMN deactivation and deconnection during high-demanding cognitive/sensory tasks. Here we have developed functional ultrasound (fUS) imaging to properly visualize both activation levels and functional connectivity patterns, in head-restrained awake and behaving mice, and investigated their modulation during a sensory-task, whisker stimulation. We identified reproducible and highly symmetric resting-state networks, with overall connectivity strength directly proportional to the wakefulness level of the animal. We show that unilateral whisker stimulation leads to the expected activation of the contralateral barrel cortex in lightly sedated mice, while interhemispheric inhibition reduces activity in the ipsilateral barrel cortex. Whisker stimulation also leads to elevated bilateral connectivity in the hippocampus. Importantly, in addition to functional changes in these major hubs of tactile information processing, whisker stimulation during genuine awake resting-state periods leads to highly specific reductions both in activation and interhemispheric correlation within the restrosplenial cortex, a major hub of the DMN. These results validate an imaging technique for the study of activation and connectivity in the lightly sedated awake mouse brain and provide evidence supporting an evolutionary preserved function of the DMN, putatively improving translational relevance of preclinical models of neuropsychiatric diseases.


Assuntos
Encéfalo/diagnóstico por imagem , Neuroimagem Funcional , Rede Nervosa/fisiologia , Ultrassonografia/métodos , Animais , Mapeamento Encefálico/métodos , Masculino , Camundongos , Vibrissas/fisiologia
18.
Nat Commun ; 11(1): 2901, 2020 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-32518226

RESUMO

The hippocampal CA3 contributes to spatial working memory (SWM), but which stage of SWM the CA3 neurons act on and whether the lateralization of CA3 function occurs in SWM is also unknown. Here, we reveal increased neural activity in both sample and choice phases of SWM. Left CA3 (LCA3) neurons show higher sensitivity in the choice phase during the correct versus error trials compared with right CA3 (RCA3) neurons. LCA3 initiates firing prior to RCA3 in the choice phase. Optogenetic suppression of pyramidal neurons in LCA3 disrupts SWM only in the choice phase. Furthermore, we discover that parvalbumin (PV) neurons, rather than cholinergic neurons in the medial septum (DB were cholinergic neurons), can project directly to unilateral CA3. Selective suppression of PV neurons in the MS projecting to LCA3 impairs SWM. The findings suggest that MSPV-LCA3 projection plays a crucial role in manipulating the lateralization of LCA3 in the retrieval of SWM.


Assuntos
Região CA3 Hipocampal/fisiologia , Memória de Curto Prazo , Neurônios/fisiologia , Memória Espacial , Animais , Comportamento Animal , Mapeamento Encefálico/métodos , Neurônios Colinérgicos/fisiologia , Feminino , Masculino , Aprendizagem em Labirinto , Camundongos , Camundongos Endogâmicos C57BL , Parvalbuminas/fisiologia
19.
Proc Natl Acad Sci U S A ; 117(25): 14453-14463, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32513717

RESUMO

Deep regions of the brain are not easily accessible to investigation at the mesoscale level in awake animals or humans. We have recently developed a functional ultrasound (fUS) technique that enables imaging hemodynamic responses to visual tasks. Using fUS imaging on two awake nonhuman primates performing a passive fixation task, we constructed retinotopic maps at depth in the visual cortex (V1, V2, and V3) in the calcarine and lunate sulci. The maps could be acquired in a single-hour session with relatively few presentations of the stimuli. The spatial resolution of the technology is illustrated by mapping patterns similar to ocular dominance (OD) columns within superficial and deep layers of the primary visual cortex. These acquisitions using fUS suggested that OD selectivity is mostly present in layer IV but with extensions into layers II/III and V. This imaging technology provides a new mesoscale approach to the mapping of brain activity at high spatiotemporal resolution in awake subjects within the whole depth of the cortex.


Assuntos
Mapeamento Encefálico/métodos , Córtex Visual/fisiologia , Vigília/fisiologia , Animais , Dominância Ocular/fisiologia , Feminino , Macaca mulatta , Masculino , Estimulação Luminosa , Reprodutibilidade dos Testes , Análise Espaço-Temporal , Ultrassonografia/métodos , Córtex Visual/diagnóstico por imagem
20.
PLoS One ; 15(6): e0233858, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32479547

RESUMO

PURPOSE: Low back pain (LBP) is a common ailment in most developed countries. Because most cases of LBP are known as 'non-specific', it has been challenging to develop experimental pain models of LBP which reproduce patients' clinical pain. In addition, previous models have limited applicability in a steady-pain-state neuroimaging environment. Thus, this study aims to devise a low back pain model with a simple methodology to induce experimental LBP, which has similar pain properties to patients' clinical pain, and to apply the model in a steady-pain-state neuroimaging study. METHODS: Our low back extension (LBE) pain model was tested on 217 LBP patients outside the magnetic resonance imaging (MRI) scanner to determine the reproducibility of endogenous pain and the similarity to their own clinical pain (STUDY1), and applied in a steady-pain-state functional MRI study (47 LBP patients and 23 healthy controls) to determine its applicability (induced head motions and brain functional connectivity changes; STUDY2). RESULTS: By the LBE pain model, 68.2% of the LBP patients reported increased LBP with high similarity of sensations to their own clinical pain (STUDY1), and the head motions were statistically similar to and correlated with those in resting state (STUDY2). Furthermore, the LBE model altered brain functional connectivity by decreasing the default-mode and the sensorimotor networks, and increasing the salience network, which was significantly associated with the intensity of the induced pain. Conversely, the healthy controls showed increased somatosensory network (but not of the cognitive pain processing). CONCLUSION: Our investigations suggest that our LBE pain model, which increased LBP with high similarity to the LBP patients' own pain sensation and induced patient-specific brain responses with acceptable head motion, could be applied to neuroimaging studies investigating brain responses to different levels of endogenous LBP.


Assuntos
Encéfalo/fisiopatologia , Dor Lombar/fisiopatologia , Modelos Neurológicos , Rede Nervosa/fisiopatologia , Nociceptividade/fisiologia , Adulto , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico/métodos , Feminino , Humanos , Dor Lombar/diagnóstico , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Medição da Dor , Reprodutibilidade dos Testes
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