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1.
Handb Clin Neurol ; 163: 147-164, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31590727

RESUMO

The frontal lobes contain a complex set of diverse anatomic regions that form multiple distinct, complex networks with cortical and subcortical regions. Damage to these cortical-subcortical networks can have dramatic behavioral consequences, ranging from apathy to impairments in executive functioning. This chapter provides a brief overview of the common syndromes caused by damage to the mediodorsal and dorsolateral prefrontal circuits, followed by a more detailed review of the syndrome-sometimes referred to as pseudopsychopathy or acquired sociopathy-associated with damage to the ventromedial prefrontal circuit.


Assuntos
Agnosia/fisiopatologia , Emoções/fisiologia , Função Executiva/fisiologia , Lobo Frontal/fisiopatologia , Demência Frontotemporal/fisiopatologia , Rede Nervosa/fisiopatologia , Apatia/fisiologia , Humanos , Motivação/fisiologia , Testes Neuropsicológicos
2.
Medicine (Baltimore) ; 98(43): e17660, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31651891

RESUMO

RATIONALE: The term crossed aphasia in dextrals (CAD) describes aphasia following a right hemisphere lesion in right-handed subjects. The diagnostic criteria for CAD, defined on the basis of clinical cases observed over the years, are aphasia; lesion in right hemisphere; strong preference for right hand use without familial history of left handedness; structural integrity of left hemisphere; and absence of brain damage in childhood. The studies of CAD have mainly been focused on the neurobiological mechanisms underlying the functional neurocognitive lateralization and organization of the brain, such as a dissociation between language and handedness, language and praxis, or other cognitive functions.Patient concerns: We described a case of a patient affected by an aphasic syndrome following cerebral hemorrhage located in right hemisphere. DIAGNOSIS: Considering the correlation between clinical data and instrumental investigations such as magnetic resonance imaging, we diagnose the patient with non-fluent aphasia. Specifically, the patient came to our attention showing a trans-cortical mixed aphasia that, later, developed in a trans-cortical motor aphasia. Contrary to most cases of CAD, our patient does not show apraxia and visuo-spatial neglect. Interventions language and visual attention when latter functions are related to right hemisphere. INTERVENTIONS: The rehabilitation program consisted in exercises stimulating verbal fluency, comprehension, reading, and writing. OUTCOMES: After 5 months of rehabilitation patient showed significant improvement in comprehension and absence of echolalia. LESSONS: At present there is no agreement about pathogenesis of CAD and neural mechanism is still unclear. Considering the clinical symptomatology, we can argue that we observed a non-fluent aphasia. However, a more large sample should be studied to asses the role of brain circuits.


Assuntos
Afasia/etiologia , Afasia/reabilitação , Hemorragia Cerebral/complicações , Adulto , Afasia/fisiopatologia , Lateralidade Funcional , Humanos , Imagem por Ressonância Magnética , Masculino , Rede Nervosa/fisiopatologia
3.
Nat Commun ; 10(1): 4096, 2019 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-31506426

RESUMO

Information about others' experiences can strongly influence our own feelings and decisions. But how does such social information affect the neural generation of affective experience, and are the brain mechanisms involved distinct from those that mediate other types of expectation effects? Here, we used fMRI to dissociate the brain mediators of social influence and associative learning effects on pain. Participants viewed symbolic depictions of other participants' pain ratings (social information) and classically conditioned pain-predictive cues before experiencing painful heat. Social information and conditioned stimuli each had significant effects on pain ratings, and both effects were mediated by self-reported expectations. Yet, these effects were mediated by largely separable brain activity patterns, involving different large-scale functional networks. These results show that learned versus socially instructed expectations modulate pain via partially different mechanisms-a distinction that should be accounted for by theories of predictive coding and related top-down influences.


Assuntos
Encéfalo/fisiopatologia , Condicionamento Clássico , Rede Nervosa/fisiopatologia , Dor/fisiopatologia , Comportamento Social , Adolescente , Adulto , Sinais (Psicologia) , Feminino , Resposta Galvânica da Pele , Humanos , Aprendizagem , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Adulto Jovem
4.
Chaos ; 29(8): 083126, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31472487

RESUMO

We study the structural and dynamical consequences of damage in spatial neuronal networks. Inspired by real in vitro networks, we construct directed networks embedded in a two-dimensional space and follow biological rules for designing the wiring of the system. As a result, synthetic cultures display strong metric correlations similar to those observed in real experiments. In its turn, neuronal dynamics is incorporated through the Izhikevich model adopting the parameters derived from observation in real cultures. We consider two scenarios for damage, targeted attacks on those neurons with the highest out-degree and random failures. By analyzing the evolution of both the giant connected component and the dynamical patterns of the neurons as nodes are removed, we observe that network activity halts for a removal of 50% of the nodes in targeted attacks, much lower than the 70% node removal required in the case of random failures. Notably, the decrease of neuronal activity is not gradual. Both damage scenarios portray "boosts" of activity just before full silencing that are not present in equivalent random (Erdös-Rényi) graphs. These boosts correspond to small, spatially compact subnetworks that are able to maintain high levels of activity. Since these subnetworks are absent in the equivalent random graphs, we hypothesize that metric correlations facilitate the existence of local circuits sufficiently integrated to maintain activity, shaping an intrinsic mechanism for resilience.


Assuntos
Doença de Alzheimer/fisiopatologia , Encéfalo/fisiopatologia , Modelos Neurológicos , Rede Nervosa/fisiopatologia , Neurônios , Doença de Parkinson/fisiopatologia , Animais , Humanos
5.
Biomed Res ; 40(4): 125-131, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31413233

RESUMO

Hericium erinaceus has been recognized as medical mushroom since ancient time, but its scientific evidence for human health has been still uncertain. In this study, we tested a randomized, double-blind, placebo-controlled parallel-group comparative study to evaluate the improvement of the cognitive functions by taking supplements containing fruiting body of H. erinaceus for 12 weeks. We performed three kinds of tests: Mini Mental State Examination (MMSE), Benton visual retention test, and Standard verbal paired-associate learning test (S-PA). MMSE alone showed that oral intake of H. erinaceus significantly improved cognitive functions and prevented from the deterioration. We speculate that various chemical compounds, including hericenones, in the mushroom have multiple effects to the brain neural networks and improve cognitive functions. Oral intake of H.erinaceus is safe and convenient method for dementia prevention so far.


Assuntos
Agaricales , Cognição , Demência , Suplementos Nutricionais , Rede Nervosa/fisiopatologia , Idoso , Demência/fisiopatologia , Demência/prevenção & controle , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
6.
Nat Commun ; 10(1): 3830, 2019 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-31444362

RESUMO

Brain activity and connectivity alter drastically during epileptic seizures. The brain networks shift from a balanced resting state to a hyperactive and hypersynchronous state. It is, however, less clear which mechanisms underlie the state transitions. By studying neural and glial activity in zebrafish models of epileptic seizures, we observe striking differences between these networks. During the preictal period, neurons display a small increase in synchronous activity only locally, while the gap-junction-coupled glial network was highly active and strongly synchronized across large distances. The transition from a preictal state to a generalized seizure leads to an abrupt increase in neural activity and connectivity, which is accompanied by a strong alteration in glia-neuron interactions and a massive increase in extracellular glutamate. Optogenetic activation of glia excites nearby neurons through the action of glutamate and gap junctions, emphasizing a potential role for glia-glia and glia-neuron connections in the generation of epileptic seizures.


Assuntos
Encéfalo/fisiopatologia , Comunicação Celular , Excitabilidade Cortical/fisiologia , Epilepsia/fisiopatologia , Convulsões/fisiopatologia , Animais , Animais Geneticamente Modificados , Encéfalo/citologia , Encéfalo/diagnóstico por imagem , Modelos Animais de Doenças , Junções Comunicantes/fisiologia , Ácido Glutâmico/metabolismo , Humanos , Microscopia Confocal , Rede Nervosa/citologia , Rede Nervosa/fisiopatologia , Neuroglia/fisiologia , Neurônios/fisiologia , Imagem Óptica , Optogenética , Técnicas de Patch-Clamp , Peixe-Zebra
7.
J Autism Dev Disord ; 49(12): 4751-4760, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31444629

RESUMO

Evidence on neurophysiological correlates of coexisting autism spectrum disorders (ASD) and overweight/obesity may elucidate mechanisms leading to the observed greater risk of obesity in children with ASD. An exploratory secondary data analysis was performed on resting state functional magnetic resonance imaging (rs-fMRI) data of children downloaded from the ABIDE Preprocessed database (n = 81). Children with isolated ASD showed hypo-connectivity between anterior and posterior default mode network (DMN) (p = 0.003; FWER). Children with coexisting ASD and overweight/obesity showed hyper-connectivity between anterior and posterior DMN (p = 0.015; FWER). More evidence is needed to confirm these contrasting rs-fMRI connectivity profiles and to explicate causal inferences regarding neurophysiological mechanisms associated with coexisting ASD and overweight/obesity.


Assuntos
Transtorno do Espectro Autista/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Rede Nervosa/diagnóstico por imagem , Obesidade Pediátrica/diagnóstico por imagem , Adolescente , Transtorno do Espectro Autista/epidemiologia , Transtorno do Espectro Autista/fisiopatologia , Encéfalo/fisiopatologia , Mapeamento Encefálico/métodos , Criança , Feminino , Humanos , Imagem por Ressonância Magnética/métodos , Masculino , Rede Nervosa/fisiopatologia , Vias Neurais/diagnóstico por imagem , Vias Neurais/fisiopatologia , Sobrepeso/diagnóstico por imagem , Sobrepeso/epidemiologia , Sobrepeso/fisiopatologia , Obesidade Pediátrica/epidemiologia , Obesidade Pediátrica/fisiopatologia
8.
Neurology ; 93(11): e1112-e1122, 2019 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-31405905

RESUMO

OBJECTIVE: To study the intrinsic organization of the thalamocortical circuitry in patients with generalized epilepsy with tonic-clonic seizures (GTCS) via resting-state fMRI (rs-fMRI) connectome analysis and to evaluate its relation to drug response. METHODS: In a prospectively followed-up sample of 41 patients and 27 healthy controls, we obtained rs-fMRI and structural MRI. After 1 year of follow-up, 27 patients were classified as seizure-free and 14 as drug-resistant. We examined connectivity within and between resting-state communities in cortical and thalamic subregions. In addition to comparing patients to controls, we examined associations with seizure control. We assessed reproducibility in an independent cohort of 21 patients. RESULTS: Compared to controls, patients showed a more constrained network embedding of the thalamus, while frontocentral neocortical regions expressed increased functional diversity. Findings remained significant after regressing out thalamic volume and cortical thickness, suggesting independence from structural alterations. We observed more marked network imbalances in drug-resistant compared to seizure-free patients. Findings were similar in the reproducibility dataset. CONCLUSIONS: Our findings suggest a pathoconnectomic mechanism of generalized epilepsy centered on diverging changes in cortical and thalamic connectivity. More restricted thalamic connectivity could reflect the tendency to engage in recursive thalamocortical loops, which may contribute to hyperexcitability. Conversely, increased connectional diversity of frontocentral networks may relay abnormal activity to an extended bilateral territory. Network imbalances were observed shortly after diagnosis and related to future drug response, suggesting clinical utility.


Assuntos
Córtex Cerebral/diagnóstico por imagem , Conectoma/métodos , Epilepsia Generalizada/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Rede Nervosa/diagnóstico por imagem , Tálamo/diagnóstico por imagem , Adolescente , Adulto , Córtex Cerebral/fisiopatologia , Epilepsia Generalizada/fisiopatologia , Feminino , Seguimentos , Humanos , Masculino , Rede Nervosa/fisiopatologia , Estudos Prospectivos , Tálamo/fisiopatologia , Adulto Jovem
9.
Zhonghua Nei Ke Za Zhi ; 58(9): 662-667, 2019 Sep 01.
Artigo em Chinês | MEDLINE | ID: mdl-31461817

RESUMO

Objective: To investigate the correlation of functional connectivity (FC) and the integrity of connective fibres between hippocampus and thalamus in Alzheimer's disease(AD) and amnestic mild cognitive impairment (aMCI). Methods: Both resting-state functional magnetic resonance imaging (rs-fMRI) and diffusion tensor imaging (DTI) data of 40 AD patients, 37 aMCI patients and 41 normal control subjects matching with age and educational level were collected. These subjects were all recruited from outpatient Department of Neurology in the Second Medical Center of Chinese PLA General Hospital, as well as poster, from May 2016 to January 2018. The FC strength between bilateral hippocampus and thalamus, as well as the parameters representing integrity of connective fibres, including fractional anisotropy (FA) and mean diffusivity(MD),were analyzed. Also, the correlations between FC strength and FA or MD strength were analyzed in the study. Results: Compared to that of normal control subjects, the FC strength between billateral hippocampus and thalamus in patients with AD, aMCI were not significantly different(P>0.05). The integrity of bilateral connective fibres between hippocampus and thalamus were damaged in AD patients when compared to normal control subjects(P<0.01). A positive correlation of connective fibres integrity with FC strength between hippocampus and thalamus was found in the left side(r=0.25,P<0.05) but rather in the right side. Conclusion: In AD and aMCI patients, structural connectivity between left hippocampus and thalamus affects the functional connectivity between them.


Assuntos
Doença de Alzheimer/fisiopatologia , Amnésia/complicações , Disfunção Cognitiva/fisiopatologia , Hipocampo/diagnóstico por imagem , Rede Nervosa/fisiopatologia , Tálamo/diagnóstico por imagem , Doença de Alzheimer/diagnóstico por imagem , Encéfalo/patologia , Estudos de Casos e Controles , Disfunção Cognitiva/diagnóstico por imagem , Imagem de Tensor de Difusão/métodos , Humanos , Imagem por Ressonância Magnética/métodos
10.
Biol Aujourdhui ; 213(1-2): 43-49, 2019.
Artigo em Francês | MEDLINE | ID: mdl-31274102

RESUMO

A large body of clinical and pre-clinical evidence has shown complex interactions between bottom-up and top-down mechanisms that are essential for the discrimination of noxious information and pain perception. These endogenous systems, mainly originating from the brainstem, hypothalamus and cerebral cortex, are strongly influenced by behavioral, cognitive and emotional factors that are relevant for the survival of the individual. Under pathological conditions, however, dysfunctional engagement of these descending pathways certainly contributes to the transformation from acute into chronic pain states. In disorders such as primary headaches, dysfunctions affecting brain regulation mechanisms contribute to the generation of episodic painful states in susceptible individuals, and to the evolution from acute to chronic migraine or cluster headache. Taken together, these studies support the concept that CNS mechanisms that process trigemino-vascular pain do not consist only of a bottom-up process, whereby a painful focus modifies the inputs to the next higher level. Indeed, several CNS regions mediate subtle forms of plasticity by adjusting neural maps downstream and, consequently, altering all the modulatory mechanisms as a result of sensory, autonomic, endocrine, cognitive and emotional influences. Disturbances in normal sensory processing within these loops could lead to maladaptive changes and impaired craniofacial functions at the origin of primary headaches.


Assuntos
Encéfalo/fisiopatologia , Cefaleia/etiologia , Cefaleia/fisiopatologia , Rede Nervosa/fisiopatologia , Animais , Transtornos Cerebrovasculares/etiologia , Transtornos Cerebrovasculares/fisiopatologia , Cefaleia/psicologia , Humanos , Rede Nervosa/patologia , Dor/etiologia , Dor/fisiopatologia , Percepção da Dor/fisiologia , Ratos
11.
Neuropsychology ; 33(8): 1057-1064, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31282688

RESUMO

OBJECTIVE: Individuals with spina bifida myelomeningocele (SBM) frequently exhibit cognitive impairments on tasks mediated by brain regions involved in the posterior attention network. Although such deficits have been historically assumed to result from primary and secondary brain insults, there is a dearth of literature regarding whether sequential versus simultaneous surgical closure of neural folds and surgical shunt placement affect neuropsychological function and brain structure of attention networks that have been widely studied in individuals with SBM. The current study addressed these gaps in a large cohort of children and adults with SBM. METHOD: White matter pathways and regional brain volumes of anterior and posterior attention networks were quantified through probabilistic tractography and automated segmentation, respectively. The Child Attention Network Test measured behavioral components of posterior and anterior attention networks. RESULTS: Sequential operations were associated with reduced orienting accuracy and smaller left superior parietal and dorsolateral prefrontal cortex volumes compared to simultaneous operations, controlling for a number of shunt revisions and age. Greater number of shunt revisions was associated with higher radial diffusivity values in the parietal tectocortical pathway. Older participants had greater accuracy and faster conflict resolution performance compared to younger participants, across operation type and number of shunt revisions. CONCLUSIONS: Shunt treatment and revision history related to brain structure and functions associated with the posterior attention network. Neurosurgical history also differentiated the harmful effects of early hydrocephalus on brain structure of the posterior from the anterior attention networks in SBM. (PsycINFO Database Record (c) 2019 APA, all rights reserved).


Assuntos
Atenção/fisiologia , Córtex Cerebral , Hidrocefalia , Meningomielocele , Rede Nervosa , Disrafismo Espinal , Substância Branca/patologia , Adolescente , Adulto , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/patologia , Córtex Cerebral/fisiopatologia , Derivações do Líquido Cefalorraquidiano , Criança , Estudos de Coortes , Feminino , Humanos , Hidrocefalia/diagnóstico por imagem , Hidrocefalia/patologia , Hidrocefalia/fisiopatologia , Hidrocefalia/cirurgia , Imagem por Ressonância Magnética , Masculino , Meningomielocele/diagnóstico por imagem , Meningomielocele/patologia , Meningomielocele/fisiopatologia , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/patologia , Rede Nervosa/fisiopatologia , Reoperação , Disrafismo Espinal/diagnóstico por imagem , Disrafismo Espinal/patologia , Disrafismo Espinal/fisiopatologia , Substância Branca/diagnóstico por imagem , Adulto Jovem
13.
Handb Clin Neurol ; 160: 559-580, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31277876

RESUMO

This review presents the neurophysiologic principles and clinical applications of transcranial magnetic stimulation (TMS) and other related techniques of noninvasive cortical stimulation. TMS can serve various purposes for diagnosis or treatment. Regarding diagnosis, TMS is mainly dedicated to the recording of motor evoked potentials (MEPs). MEP recording allows investigation of corticospinal conduction time and cortical motor control in clinical practice. Especially when using image-guided neuronavigation methods, MEP recording is a reliable method to perform functional mapping of muscle representation within the motor cortex. Using various types of paired-pulse paradigms, TMS allows the assessment of brain circuit excitability or plastic changes affecting these circuits. In particular, paired-pulse TMS paradigms are able to appraise the intracortical balance between inhibitory controls mediated by GABAergic neurotransmission and excitatory controls mediated by glutamatergic neurotransmission. Finally, TMS delivered as repetitive trains of stimulation (rTMS) may activate, inhibit, or otherwise interfere with the activity of neuronal cortical networks, depending on stimulus frequency and intensity, and brain-induced electric field configuration. Therefore by modifying brain functions, with after-effects lasting beyond the time of stimulation, rTMS opens exciting perspectives for therapeutic applications, especially in the domain of depression and chronic pain syndromes.


Assuntos
Potencial Evocado Motor/fisiologia , Córtex Motor/fisiologia , Rede Nervosa/fisiologia , Doenças do Sistema Nervoso/diagnóstico , Doenças do Sistema Nervoso/terapia , Estimulação Magnética Transcraniana/métodos , Humanos , Córtex Motor/fisiopatologia , Rede Nervosa/fisiopatologia , Doenças do Sistema Nervoso/fisiopatologia
14.
Transl Psychiatry ; 9(1): 172, 2019 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-31253763

RESUMO

Ketamine acts as a rapid clinical antidepressant at 25 min after injection with effects sustained for 7 days. As dissociative effects emerging acutely after injection are not entirely discernible from therapeutic action, we aimed to dissect the differences between short-term and long-term response to ketamine to elucidate potential imaging biomarkers of ketamine's antidepressant effect. We used a genetical model of depression, in which we bred depressed negative cognitive state (NC) and non-depressed positive cognitive state (PC) rat strains. Four parallel rat groups underwent stress-escape testing and a week later received either S-ketamine (12 NC, 13 PC) or saline (12 NC, 12 PC). We acquired resting-state functional magnetic resonance imaging time series before injection and at 30 min and 48 h after injection. Graph analysis was used to calculate brain network properties. We identified ketamine's distinct action over time in a qualitative manner. The rapid response entailed robust and strain-independent topological modifications in cognitive, sensory, emotion, and reward-related circuitry, including regions that exhibited correlation of connectivity metrics with depressive behavior, and which could explain ketamine's dissociative and antidepressant properties. At 48 h ketamine had mainly strain-specific action normalizing habenula, midline thalamus, and hippocampal connectivity measures in depressed rats. As these nodes mediate cognitive flexibility impaired in depression, action within this circuitry presumably reflects ketamine's procognitive effects induced only in depressed patients. This finding is especially valid, as our model represents cognitive aspects of depression. These empirically defined circuits explain ketamine's distinct action over time and might serve as translational imaging correlates of antidepressant response in preclinical testing.


Assuntos
Antidepressivos/farmacologia , Cérebro/efeitos dos fármacos , Conectoma , Depressão/tratamento farmacológico , Ketamina/farmacologia , Rede Nervosa/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/fisiopatologia , Cérebro/diagnóstico por imagem , Cérebro/fisiopatologia , Modelos Animais de Doenças , Habenula/diagnóstico por imagem , Habenula/efeitos dos fármacos , Habenula/fisiopatologia , Hipocampo/diagnóstico por imagem , Hipocampo/efeitos dos fármacos , Hipocampo/fisiopatologia , Imagem por Ressonância Magnética , Masculino , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/fisiopatologia , Ratos , Ratos Sprague-Dawley , Tálamo/diagnóstico por imagem , Tálamo/efeitos dos fármacos , Tálamo/fisiopatologia
15.
Neuroimage ; 199: 570-584, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31181333

RESUMO

The organization of brain areas in functionally connected networks, their dynamic changes, and perturbations in disease states are subject of extensive investigations. Research on functional networks in humans predominantly uses functional magnetic resonance imaging (fMRI). However, adopting fMRI and other functional imaging methods to mice, the most widely used model to study brain physiology and disease, poses major technical challenges and faces important limitations. Hence, there is great demand for alternative imaging modalities for network characterization. Here, we present a refined protocol for in vivo widefield calcium imaging of both cerebral hemispheres in mice expressing a calcium sensor in excitatory neurons. We implemented a stringent protocol for minimizing anesthesia and excluding movement artifacts which both imposed problems in previous approaches. We further adopted a method for unbiased identification of functional cortical areas using independent component analysis (ICA) on resting-state imaging data. Biological relevance of identified components was confirmed using stimulus-dependent cortical activation. To explore this novel approach in a model of focal brain injury, we induced photothrombotic lesions of the motor cortex, determined changes in inter- and intrahemispheric connectivity at multiple time points up to 56 days post-stroke and correlated them with behavioral deficits. We observed a severe loss in interhemispheric connectivity after stroke, which was partially restored in the chronic phase and associated with corresponding behavioral motor deficits. Taken together, we present an improved widefield calcium imaging tool accounting for anesthesia and movement artifacts, adopting an advanced analysis pipeline based on human fMRI algorithms and with superior sensitivity to recovery mechanisms in mouse models compared to behavioral tests. This tool will enable new studies on interhemispheric connectivity in murine models with comparability to human imaging studies for a wide spectrum of neuroscience applications in health and disease.


Assuntos
Cálcio , Córtex Cerebral/fisiologia , Conectoma/métodos , Rede Nervosa/fisiologia , Neuroimagem/métodos , Imagem Óptica/métodos , Prosencéfalo/fisiologia , Acidente Vascular Cerebral/fisiopatologia , Animais , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/fisiopatologia , Modelos Animais de Doenças , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Córtex Motor/lesões , Córtex Motor/fisiopatologia , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/fisiopatologia , Prosencéfalo/diagnóstico por imagem , Prosencéfalo/fisiopatologia , Acidente Vascular Cerebral/diagnóstico por imagem
17.
Lancet Psychiatry ; 6(7): 610-619, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31196794

RESUMO

Catatonia is a psychomotor syndrome associated with several psychiatric and medical conditions. Psychomotor signs range from stupor to agitation, and include pathognomonic features such as verbigeration and waxy flexibility. Disturbances of volition led to the classification of catatonia as a subtype of schizophrenia, but changes in nosology now recognise the high prevalence in mood disorders, overlap with delirium, and comorbidity with medical conditions. Initial psychometric studies have revealed three behavioural factors, but the structure of catatonia is still unknown. Evidence from brain imaging studies of patients with psychotic disorders indicates increased neural activity in premotor areas in patients with hypokinetic catatonia. However, whether this localised hyperactivity is due to corticocortical inhibition or excess activity of inhibitory corticobasal ganglia loops is unclear. Current treatment of catatonia relies on benzodiazepines and electroconvulsive therapy-both effective, yet unspecific in their modes of action. Longitudinal research and treatment studies, with neuroimaging and brain stimulation techniques, are needed to advance our understanding of catatonia.


Assuntos
Encéfalo/fisiopatologia , Catatonia/fisiopatologia , Rede Nervosa/fisiopatologia , Catatonia/diagnóstico , Humanos , Vias Neurais/fisiopatologia
18.
Gut ; 68(9): 1701-1715, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31175206

RESUMO

Imaging of the living human brain is a powerful tool to probe the interactions between brain, gut and microbiome in health and in disorders of brain-gut interactions, in particular IBS. While altered signals from the viscera contribute to clinical symptoms, the brain integrates these interoceptive signals with emotional, cognitive and memory related inputs in a non-linear fashion to produce symptoms. Tremendous progress has occurred in the development of new imaging techniques that look at structural, functional and metabolic properties of brain regions and networks. Standardisation in image acquisition and advances in computational approaches has made it possible to study large data sets of imaging studies, identify network properties and integrate them with non-imaging data. These approaches are beginning to generate brain signatures in IBS that share some features with those obtained in other often overlapping chronic pain disorders such as urological pelvic pain syndromes and vulvodynia, suggesting shared mechanisms. Despite this progress, the identification of preclinical vulnerability factors and outcome predictors has been slow. To overcome current obstacles, the creation of consortia and the generation of standardised multisite repositories for brain imaging and metadata from multisite studies are required.


Assuntos
Encéfalo/diagnóstico por imagem , Síndrome do Intestino Irritável/diagnóstico por imagem , Neuroimagem/métodos , Big Data , Encéfalo/fisiopatologia , Humanos , Síndrome do Intestino Irritável/fisiopatologia , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/fisiopatologia , Caracteres Sexuais
19.
Neurosci Lett ; 708: 134351, 2019 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-31247225

RESUMO

Numerous neuroimaging studies have reported aberrant functional activities of the default mode network (DMN) in temporal lobe epilepsy (TLE). However, the alteration on topological organization within the DMN has not been clearly illuminated. In this study, we aimed to investigate the topological abnormalities within the DMN from a larger-scale perspective. Twenty three patients with TLE and 23 age, gender, and education matched healthy controls (HCs) were recruited in this study. All participants underwent a resting-state functional magnetic resonance imaging (rs-fMRI) scanning and completed the Attention Network Test (ANT) for executive function assessment. Specific subregions in the DMN were extracted for network construction according to the automated anatomical labelling atlas. Network properties, including global properties, nodal properties and edge analyses, were assessed using graph theory. Correlation analyses were performed between significantly different topological properties and clinical factors in patients. The ANT tests showed that executive function was impaired in the patients with TLE compared with the HCs. Furthermore, the TLE group showed decreased nodal strength in the left medial orbital superior frontal gyrus and increased nodal strength in the right inferior parietal gyrus in the DMN. Significantly increased functional connectivities between subregions in the DMN were primarily located in the bilateral superior frontal gyrus, inferior parietal gyrus, precuneus, and posterior cingulate gyrus. Moreover, the degree centrality of the right inferior parietal gyrus was positively correlated with disease duration. In conclusion, this study indicated that there existed a disrupted topological reorganization within the DMN in patients with TLE, which may further contribute to executive deficits and, to some extent, play a compensatory role.


Assuntos
Encéfalo/fisiopatologia , Epilepsia do Lobo Temporal/fisiopatologia , Rede Nervosa/fisiopatologia , Adulto , Encéfalo/diagnóstico por imagem , Estudos de Casos e Controles , Interpretação Estatística de Dados , Epilepsia do Lobo Temporal/diagnóstico por imagem , Epilepsia do Lobo Temporal/psicologia , Função Executiva , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Rede Nervosa/diagnóstico por imagem , Adulto Jovem
20.
Neuroimage ; 199: 680-690, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31173902

RESUMO

Acute stress triggers a broad psychophysiological response that is adaptive if rapidly activated and terminated. While the brain controls the stress response, it is strongly affected by it. Previous research of stress effects on brain activation and connectivity has mainly focused on pre-defined brain regions or networks, potentially missing changes in the rest of the brain. We here investigated how both stress reactivity and stress recovery are reflected in whole-brain network topology and how changes in functional connectivity relate to other stress measures. Healthy young males (n = 67) completed the Trier Social Stress Test or a control task. From 60 min before until 105 min after stress onset, blocks of resting-state fMRI were acquired. Subjective, autonomic, and endocrine measures of the stress response were assessed throughout the experiment. Whole-brain network topology was quantified using Eigenvector centrality (EC) mapping, which detects central hubs of a network. Stress influenced subjective affect, autonomic activity, and endocrine measures. EC differences between groups as well as before and after stress exposure were found in the thalamus, due to widespread connectivity changes in the brain. Stress-driven EC increases in the thalamus were significantly correlated with subjective stress ratings and showed non-significant trends for a correlation with heart rate variability and saliva cortisol. Furthermore, increases in thalamic EC and in saliva cortisol persisted until 105 min after stress onset. We conclude that thalamic areas are central for information processing after stress exposure and may provide an interface for the stress response in the rest of the body and in the mind.


Assuntos
Córtex Cerebral/fisiopatologia , Conectoma , Rede Nervosa/fisiopatologia , Estresse Psicológico/fisiopatologia , Tálamo/fisiopatologia , Adolescente , Adulto , Sistema Nervoso Autônomo/fisiopatologia , Córtex Cerebral/diagnóstico por imagem , Humanos , Hidrocortisona/metabolismo , Imagem por Ressonância Magnética , Masculino , Rede Nervosa/diagnóstico por imagem , Estresse Psicológico/diagnóstico por imagem , Estresse Psicológico/metabolismo , Tálamo/diagnóstico por imagem , Adulto Jovem
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