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1.
Nat Commun ; 12(1): 882, 2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33563996

RESUMO

Photoacoustic computed tomography (PACT) has generated increasing interest for uses in preclinical research and clinical translation. However, the imaging depth, speed, and quality of existing PACT systems have previously limited the potential applications of this technology. To overcome these issues, we developed a three-dimensional photoacoustic computed tomography (3D-PACT) system that features large imaging depth, scalable field of view with isotropic spatial resolution, high imaging speed, and superior image quality. 3D-PACT allows for multipurpose imaging to reveal detailed angiographic information in biological tissues ranging from the rodent brain to the human breast. In the rat brain, we visualize whole brain vasculatures and hemodynamics. In the human breast, an in vivo imaging depth of 4 cm is achieved by scanning the breast within a single breath hold of 10 s. Here, we introduce the 3D-PACT system to provide a unique tool for preclinical research and an appealing prototype for clinical translation.


Assuntos
Imageamento Tridimensional/métodos , Técnicas Fotoacústicas/métodos , Tomografia Computadorizada por Raios X/métodos , Angiografia , Animais , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Mama/irrigação sanguínea , Mama/diagnóstico por imagem , Desenho de Equipamento , Feminino , Neuroimagem Funcional , Humanos , Imageamento Tridimensional/instrumentação , Técnicas Fotoacústicas/instrumentação , Ratos , Tomografia Computadorizada por Raios X/instrumentação
3.
Neuroimage ; 229: 117752, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33460795

RESUMO

International spread of the coronavirus SARS-CoV-2 has prompted many MRI scanning facilities to require scan subjects to wear a facial covering ("mask") during scanning as a precaution against transmission of the virus. Because wearing a mask mixes expired air with the subject's inspired air stream, the concentration of inspired carbon dioxide [CO2] is elevated, resulting in mild hypercapnia. Changes in the inspired gas mixture have been demonstrated to alter R2*-weighted Blood Oxygen Dependent (BOLD) contrast. In this study, we investigate a potential for face masking to alter BOLD contrast during a sensory-motor task designed to activate visual, auditory, and sensorimotor cortices in 8 subjects. We utilize a nasal cannula to supply air to the subject wearing a surgical mask in on-off blocks of 90s to displace expired CO2, while the subject performs the sensory-motor task. While only a small fraction (2.5%) of the sensory-motor task activation is related to nasal air modulation, a 30.0% change in gray matter BOLD signal baseline is found due to air modulation. Repeating the scan with mask removed produces a small subject-specific bias in BOLD baseline signal from nasal air supply, which may be due to cognitive influence of airflow or cannula-induced hypoxia. Measurements with capnography demonstrate wearing a mask induces an average increase in ETCO2 of 7.4%. Altogether, these results demonstrate that wearing a face mask during gradient-echo fMRI can alter BOLD baseline signal but minimally affects task activation.


Assuntos
Dióxido de Carbono/metabolismo , Neuroimagem Funcional , Substância Cinzenta/fisiologia , Imagem por Ressonância Magnética , Máscaras , Desempenho Psicomotor/fisiologia , Córtex Sensório-Motor/fisiologia , Adulto , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/metabolismo , Humanos , Córtex Sensório-Motor/diagnóstico por imagem , Córtex Sensório-Motor/metabolismo , Adulto Jovem
4.
Adv Exp Med Biol ; 1293: 471-479, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33398834

RESUMO

To elucidate the expression mechanisms of brain functions, we have developed an ultrathin fluorescence endoscope imaging system (U-FEIS) that can image cells in the brain at any depth while minimizing the invasion. The endoscope part of U-FEIS consists of a GRIN lens and a 10,000-pixel image fiber with a diameter of 450 µm. The specialized microscope of U-FEIS is within 30 cm square and includes lenses and optical filters optimized for the endoscope. Using U-FEIS, we successfully visualized neurons expressing GFP with single-cell resolution and recorded the multineuronal activities in vitro and in vivo. U-FEIS can also perform imaging and optical stimulation simultaneously. Therefore, U-FEIS should be a powerful optical tool in neuroscience research.


Assuntos
Endoscópios , Lentes , Encéfalo/diagnóstico por imagem , Neuroimagem Funcional , Microscopia
5.
Nat Med ; 27(1): 174-182, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33398159

RESUMO

Sustained pain is a major characteristic of clinical pain disorders, but it is difficult to assess in isolation from co-occurring cognitive and emotional features in patients. In this study, we developed a functional magnetic resonance imaging signature based on whole-brain functional connectivity that tracks experimentally induced tonic pain intensity and tested its sensitivity, specificity and generalizability to clinical pain across six studies (total n = 334). The signature displayed high sensitivity and specificity to tonic pain across three independent studies of orofacial tonic pain and aversive taste. It also predicted clinical pain severity and classified patients versus controls in two independent studies of clinical low back pain. Tonic and clinical pain showed similar network-level representations, particularly in somatomotor, frontoparietal and dorsal attention networks. These patterns were distinct from representations of experimental phasic pain. This study identified a brain biomarker for sustained pain with high potential for clinical translation.


Assuntos
Biomarcadores/análise , Neuroimagem Funcional/métodos , Medição da Dor/métodos , Adolescente , Adulto , Agentes Aversivos/toxicidade , Capsaicina/toxicidade , Conectoma/métodos , Conectoma/estatística & dados numéricos , Dor Facial/fisiopatologia , Feminino , Neuroimagem Funcional/estatística & dados numéricos , Humanos , Dor Lombar/fisiopatologia , Imagem por Ressonância Magnética/métodos , Imagem por Ressonância Magnética/estatística & dados numéricos , Masculino , Modelos Neurológicos , Rede Nervosa/fisiopatologia , Dor/fisiopatologia , Medição da Dor/estatística & dados numéricos , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Paladar/efeitos dos fármacos , Paladar/fisiologia , Adulto Jovem
6.
JAMA Netw Open ; 4(1): e2032236, 2021 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-33399857

RESUMO

Importance: Functional neuroimaging is a valuable tool for understanding how patients with chronic pain respond to painful stimuli. However, past studies have reported heterogenous results, highlighting opportunities for a quantitative meta-analysis to integrate existing data and delineate consistent associations across studies. Objective: To identify differential brain responses to noxious stimuli in patients with chronic pain using functional magnetic resonance imaging (fMRI) while adhering to current best practices for neuroimaging meta-analyses. Data Sources: All fMRI experiments published from January 1, 1990, to May 28, 2019, were identified in a literature search of PubMed/MEDLINE, EMBASE, Web of Science, Cochrane Library, PsycINFO, and SCOPUS. Study Selection: Experiments comparing brain responses to noxious stimuli in fMRI between patients and controls were selected if they reported whole-brain results, included at least 10 patients and 10 healthy control participants, and used adequate statistical thresholding (voxel-height P < .001 or cluster-corrected P < .05). Two independent reviewers evaluated titles and abstracts returned by the search. In total, 3682 abstracts were screened, and 1129 full-text articles were evaluated. Data Extraction and Synthesis: Thirty-seven experiments from 29 articles met inclusion criteria for meta-analysis. Coordinates reporting significant activation differences between patients with chronic pain and healthy controls were extracted. These data were meta-analyzed using activation likelihood estimation. Data were analyzed from December 2019 to February 2020. Main Outcomes and Measures: A whole-brain meta-analysis evaluated whether reported differences in brain activation in response to noxious stimuli between patients and healthy controls were spatially convergent. Follow-up analyses examined the directionality of any differences. Finally, an exploratory (nonpreregistered) region-of-interest analysis examined differences within the pain network. Results: The 37 experiments from 29 unique articles included a total of 511 patients and 433 controls (944 participants). Whole-brain meta-analyses did not reveal significant differences between patients and controls in brain responses to noxious stimuli at the preregistered statistical threshold. However, exploratory analyses restricted to the pain network revealed aberrant activity in patients. Conclusions and Relevance: In this systematic review and meta-analysis, preregistered, whole-brain analyses did not reveal aberrant fMRI activity in patients with chronic pain. Exploratory analyses suggested that subtle, spatially diffuse differences may exist within the pain network. Future work on chronic pain biomarkers may benefit from focus on this core set of pain-responsive areas.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Dor Crônica/fisiopatologia , Neuroimagem Funcional , Estimulação Física , Mapeamento Encefálico , Humanos
7.
Neuroimage ; 227: 117672, 2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-33359349

RESUMO

Despite decades of research, our understanding of functional brain development throughout childhood and adolescence remains limited due to the challenges posed by certain neuroimaging modalities. Recently, there has been a growing interest in using functional near-infrared spectroscopy (fNIRS) to elucidate the neural basis of cognitive and socioemotional development and identify the factors shaping these types of development. This article, focusing on the fNIRS methods, presents an up-to-date systematic review of fNIRS studies addressing the effects of age and other factors on brain functions in children and adolescents. Literature searches were conducted using PubMed and PsycINFO. A total of 79 fNIRS studies involving healthy individuals aged 3-17 years that were published in peer-reviewed journals in English before July 2020 were included. Six methodological aspects of these studies were evaluated, including the research design, experimental paradigm, fNIRS measurement, data preprocessing, statistical analysis, and result presentation. The risk of bias, such as selective outcome reporting, was assessed throughout the review. A qualitative synthesis of study findings in terms of the factor effects on changes in oxyhemoglobin concentration was also performed. This unregistered review highlights the strengths and limitations of the existing literature and suggests directions for future research to facilitate the improved use of fNIRS in developmental cognitive neuroscience research.


Assuntos
Encéfalo/anatomia & histologia , Encéfalo/fisiologia , Neuroimagem Funcional/métodos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Adolescente , Criança , Desenvolvimento Infantil/fisiologia , Pré-Escolar , Feminino , Humanos , Masculino
8.
Neuroimage ; 227: 117554, 2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-33359354

RESUMO

Letter production relies on a tight coupling between motor movements and visual feedback-each stroke of the letter is visually experienced as it is produced. Experience with letter production leads to increases in functional connectivity, a measure of neural communication, among visual and motor brain systems and leads to gains in letter recognition in preliterate children. We hypothesized that the contingency between the motor and visual experiences of the written form during production would result in both effects. Twenty literate adults were trained on four sets of novel symbols over the course of one week. Each symbol set was trained through one of four training conditions: drawing with ink, drawing without ink, watching a handwritten symbol unfold as if being drawn, and watching a static handwritten symbol. Contingency of motor and visual experiences occurred in the drawing with ink condition. The motor and visual experiences were rendered non-contingent in each of the other three conditions by controlling for visual or motor experience. Participants were presented with the trained symbols during fMRI scanning at three time points: one pre-training, one post-training, and one after a week-long no-training delay. Recognition was tested after each training session and after the third scan. We found that the contingency between visual and motor experiences during production changed the pattern of functional connectivity among visual, motor, and auditory neural communities and resulted in better recognition performance at post-training than at pre-training. Recognition gains were maintained after the no-training delay, but the functional connections observed immediately after training returned to their pre-training baselines. Our results suggest that behaviors that couple sensory and motor systems result in temporary changes in neural communication during perception that may not directly support changes in recognition.


Assuntos
Encéfalo/diagnóstico por imagem , Rede Nervosa/diagnóstico por imagem , Reconhecimento Visual de Modelos/fisiologia , Reconhecimento Psicológico/fisiologia , Adulto , Encéfalo/fisiologia , Feminino , Neuroimagem Funcional , Humanos , Imagem por Ressonância Magnética , Masculino , Rede Nervosa/fisiologia , Estimulação Luminosa , Desempenho Psicomotor/fisiologia , Adulto Jovem
9.
Elife ; 92020 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-33331819

RESUMO

The intrinsic dynamics of neuronal populations are shaped by both microscale attributes and macroscale connectome architecture. Here we comprehensively characterize the rich temporal patterns of neural activity throughout the human brain. Applying massive temporal feature extraction to regional haemodynamic activity, we systematically estimate over 6000 statistical properties of individual brain regions' time-series across the neocortex. We identify two robust spatial gradients of intrinsic dynamics, one spanning a ventromedial-dorsolateral axis and dominated by measures of signal autocorrelation, and the other spanning a unimodal-transmodal axis and dominated by measures of dynamic range. These gradients reflect spatial patterns of gene expression, intracortical myelin and cortical thickness, as well as structural and functional network embedding. Importantly, these gradients are correlated with patterns of meta-analytic functional activation, differentiating cognitive versus affective processing and sensory versus higher-order cognitive processing. Altogether, these findings demonstrate a link between microscale and macroscale architecture, intrinsic dynamics, and cognition.


Assuntos
Neocórtex/fisiologia , Conectoma , Neuroimagem Funcional , Humanos , Imagem por Ressonância Magnética , Neocórtex/anatomia & histologia , Neocórtex/diagnóstico por imagem , Vias Neurais/anatomia & histologia , Vias Neurais/fisiologia
13.
Neuron ; 108(1): 66-92, 2020 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-33058767

RESUMO

We propose a new paradigm for dense functional imaging of brain activity to surmount the limitations of present methodologies. We term this approach "integrated neurophotonics"; it combines recent advances in microchip-based integrated photonic and electronic circuitry with those from optogenetics. This approach has the potential to enable lens-less functional imaging from within the brain itself to achieve dense, large-scale stimulation and recording of brain activity with cellular resolution at arbitrary depths. We perform a computational study of several prototype 3D architectures for implantable probe-array modules that are designed to provide fast and dense single-cell resolution (e.g., within a 1-mm3 volume of mouse cortex comprising ∼100,000 neurons). We describe progress toward realizing integrated neurophotonic imaging modules, which can be produced en masse with current semiconductor foundry protocols for chip manufacturing. Implantation of multiple modules can cover extended brain regions.


Assuntos
Encéfalo/diagnóstico por imagem , Neuroimagem Funcional/métodos , Neurônios/patologia , Imagem Óptica/métodos , Animais , Encéfalo/patologia , Encéfalo/fisiologia , Simulação por Computador , Sistemas Computacionais , Neuroimagem Funcional/instrumentação , Procedimentos Analíticos em Microchip , Vias Neurais/diagnóstico por imagem , Vias Neurais/patologia , Vias Neurais/fisiologia , Neurônios/fisiologia , Imagem Óptica/instrumentação , Óptica e Fotônica , Optogenética
14.
Neuron ; 108(1): 93-110, 2020 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-33058769

RESUMO

Visualizing and perturbing neural activity on a brain-wide scale in model animals and humans is a major goal of neuroscience technology development. Established electrical and optical techniques typically break down at this scale due to inherent physical limitations. In contrast, ultrasound readily permeates the brain, and in some cases the skull, and interacts with tissue with a fundamental resolution on the order of 100 µm and 1 ms. This basic ability has motivated major efforts to harness ultrasound as a modality for large-scale brain imaging and modulation. These efforts have resulted in already-useful neuroscience tools, including high-resolution hemodynamic functional imaging, focused ultrasound neuromodulation, and local drug delivery. Furthermore, recent breakthroughs promise to connect ultrasound to neurons at the genetic level for biomolecular imaging and sonogenetic control. In this article, we review the state of the art and ongoing developments in ultrasonic neurotechnology, building from fundamental principles to current utility, open questions, and future potential.


Assuntos
Encéfalo/diagnóstico por imagem , Sistemas de Liberação de Medicamentos/métodos , Ecoencefalografia/métodos , Imagem Molecular/métodos , Ondas Ultrassônicas , Animais , Barreira Hematoencefálica/efeitos da radiação , Encéfalo/fisiologia , Encéfalo/efeitos da radiação , Neuroimagem Funcional , Hemodinâmica , Humanos , Proteínas , Terapia por Ultrassom , Ultrassonografia , Ultrassonografia Doppler Transcraniana/métodos
16.
Neurology ; 95(19): e2635-e2647, 2020 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-32963103

RESUMO

OBJECTIVE: To determine whether intranasal oxytocin, alone or in combination with instructed mimicry of facial expressions, would augment neural activity in patients with frontotemporal dementia (FTD) in brain regions associated with empathy, emotion processing, and the simulation network, as indexed by blood oxygen-level dependent (BOLD) signal during fMRI. METHODS: In a placebo-controlled, randomized crossover design, 28 patients with FTD received 72 IU intranasal oxytocin or placebo and then completed an fMRI facial expression mimicry task. RESULTS: Oxytocin alone and in combination with instructed mimicry increased activity in regions of the simulation network and in limbic regions associated with emotional expression processing. CONCLUSIONS: The findings demonstrate latent capacity to augment neural activity in affected limbic and other frontal and temporal regions during social cognition in patients with FTD, and support the promise and need for further investigation of these interventions as therapeutics in FTD. CLINICALTRIALSGOV IDENTIFIER: NCT01937013. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that a single dose of 72 IU intranasal oxytocin augments BOLD signal in patients with FTD during viewing of emotional facial expressions.


Assuntos
Encéfalo/diagnóstico por imagem , Emoções , Expressão Facial , Demência Frontotemporal/diagnóstico por imagem , Comportamento Imitativo/fisiologia , Ocitócicos/farmacologia , Ocitocina/farmacologia , Administração Intranasal , Idoso , Encéfalo/efeitos dos fármacos , Encéfalo/fisiopatologia , Estudos Cross-Over , Empatia , Feminino , Demência Frontotemporal/fisiopatologia , Neuroimagem Funcional , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
17.
PLoS One ; 15(9): e0238389, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32898166

RESUMO

Mapping brain functions is crucial for neurosurgical planning in patients with drug-resistant seizures. However, presurgical language mapping using either functional or structural networks can be challenging, especially in children. In fact, most of the evidence on this topic derives from cross-sectional or retrospective studies in adults submitted to anterior temporal lobectomy. In this prospective study, we used fMRI and DTI to explore patterns of language representation, their predictors and impact on cognitive performances in 29 children and young adults (mean age at surgery: 14.6 ± 4.5 years) with focal lesional epilepsy. In 20 of them, we also assessed the influence of epilepsy surgery on language lateralization. All patients were consecutively enrolled at a single epilepsy surgery center between 2009 and 2015 and assessed with preoperative structural and functional 3T brain MRI during three language tasks: Word Generation (WG), Rhyme Generation (RG) and a comprehension task. We also acquired DTI data on arcuate fasciculus in 24 patients. We first assessed patterns of language representation (relationship of activations with the epileptogenic lesion and Laterality Index (LI)) and then hypothesized a causal model to test whether selected clinical variables would influence the patterns of language representation and the ensuing impact of the latter on cognitive performances. Twenty out of 29 patients also underwent postoperative language fMRI. We analyzed possible changes of fMRI and DTI LIs and their clinical predictors. Preoperatively, we found atypical language lateralization in four patients during WG task, in one patient during RG task and in seven patients during the comprehension task. Diffuse interictal EEG abnormalities predicted a more atypical language representation on fMRI (p = 0.012), which in turn correlated with lower attention (p = 0.036) and IQ/GDQ scores (p = 0.014). Postoperative language reorganization implied shifting towards atypical language representation. Abnormal postoperative EEG (p = 0.003) and surgical failures (p = 0.015) were associated with more atypical language lateralization, in turn correlating with worsened fluency. Neither preoperative asymmetry nor postoperative DTI LI changes in the arcuate fasciculus were observed. Focal lesional epilepsy associated with diffuse EEG abnormalities may favor atypical language lateralization and worse cognitive performances, which are potentially reversible after successful surgery.


Assuntos
Mapeamento Encefálico , Epilepsias Parciais/diagnóstico por imagem , Epilepsias Parciais/psicologia , Transtornos da Linguagem/diagnóstico por imagem , Transtornos da Linguagem/psicologia , Adolescente , Criança , Cognição , Compreensão , Imagem de Tensor de Difusão , Epilepsia Resistente a Medicamentos/diagnóstico por imagem , Epilepsia Resistente a Medicamentos/psicologia , Epilepsia Resistente a Medicamentos/cirurgia , Epilepsias Parciais/cirurgia , Feminino , Lateralidade Funcional , Neuroimagem Funcional , Humanos , Imagem por Ressonância Magnética , Masculino , Estudos Prospectivos , Adulto Jovem
18.
Neuron ; 107(3): 580-589.e6, 2020 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-32778224

RESUMO

To induce brain plasticity in humans, we casted the dominant upper extremity for 2 weeks and tracked changes in functional connectivity using daily 30-min scans of resting-state functional MRI (rs-fMRI). Casting caused cortical and cerebellar regions controlling the disused extremity to functionally disconnect from the rest of the somatomotor system, while internal connectivity within the disused sub-circuit was maintained. Functional disconnection was evident within 48 h, progressed throughout the cast period, and reversed after cast removal. During the cast period, large, spontaneous pulses of activity propagated through the disused somatomotor sub-circuit. The adult brain seems to rely on regular use to maintain its functional architecture. Disuse-driven spontaneous activity pulses may help preserve functionally disconnected sub-circuits.


Assuntos
Córtex Motor/diagnóstico por imagem , Plasticidade Neuronal/fisiologia , Restrição Física , Atividades Cotidianas , Moldes Cirúrgicos , Feminino , Lateralidade Funcional , Neuroimagem Funcional , Humanos , Imagem por Ressonância Magnética , Masculino , Córtex Motor/fisiologia , Destreza Motora/fisiologia , Força Muscular/fisiologia , Vias Neurais/diagnóstico por imagem , Vias Neurais/fisiologia , Extremidade Superior
19.
PLoS Biol ; 18(8): e3000800, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32776945

RESUMO

Studies of neural processes underlying delay of gratification usually focus on prefrontal networks related to curbing affective impulses. Here, we provide evidence for an alternative mechanism that facilitates delaying gratification by mental orientation towards the future. Combining continuous theta-burst stimulation (cTBS) with functional neuroimaging, we tested how the right temporoparietal junction (rTPJ) facilitates processing of future events and thereby promotes delay of gratification. Participants performed an intertemporal decision task and a mental time-travel task in the MRI scanner before and after receiving cTBS over the rTPJ or the vertex (control site). rTPJ cTBS led to both stronger temporal discounting for longer delays and reduced processing of future relative to past events in the mental time-travel task. This finding suggests that the rTPJ contributes to the ability to delay gratification by facilitating mental representation of outcomes in the future. On the neural level, rTPJ cTBS led to a reduction in the extent to which connectivity of rTPJ with striatum reflected the value of delayed rewards, indicating a role of rTPJ-striatum connectivity in constructing neural representations of future rewards. Together, our findings provide evidence that the rTPJ is an integral part of a brain network that promotes delay of gratification by facilitating mental orientation to future rewards.


Assuntos
Corpo Estriado/fisiologia , Tomada de Decisões/fisiologia , Desvalorização pelo Atraso/fisiologia , Rede Nervosa/fisiologia , Lobo Parietal/fisiologia , Lobo Temporal/fisiologia , Adulto , Mapeamento Encefálico , Corpo Estriado/anatomia & histologia , Corpo Estriado/diagnóstico por imagem , Feminino , Neuroimagem Funcional , Humanos , Comportamento Impulsivo/fisiologia , Masculino , Rede Nervosa/anatomia & histologia , Rede Nervosa/diagnóstico por imagem , Lobo Parietal/anatomia & histologia , Lobo Parietal/diagnóstico por imagem , Recompensa , Lobo Temporal/anatomia & histologia , Lobo Temporal/diagnóstico por imagem , Estimulação Magnética Transcraniana
20.
PLoS One ; 15(8): e0233244, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32797080

RESUMO

The role of white matter in reading has been established by diffusion tensor imaging (DTI), but DTI cannot identify specific microstructural features driving these relationships. Neurite orientation dispersion and density imaging (NODDI), inhomogeneous magnetization transfer (ihMT) and multicomponent driven equilibrium single-pulse observation of T1/T2 (mcDESPOT) can be used to link more specific aspects of white matter microstructure and reading due to their sensitivity to axonal packing and fiber coherence (NODDI) and myelin (ihMT and mcDESPOT). We applied principal component analysis (PCA) to combine DTI, NODDI, ihMT and mcDESPOT measures (10 in total), identify major features of white matter structure, and link these features to both reading and age. Analysis was performed for nine reading-related tracts in 46 neurotypical 6-16 year olds. We identified three principal components (PCs) which explained 79.5% of variance in our dataset. PC1 probed tissue complexity, PC2 described myelin and axonal packing, while PC3 was related to axonal diameter. Mixed effects regression models did not identify any significant relationships between principal components and reading skill. Bayes factor analysis revealed that the absence of relationships was not due to low power. Increasing PC1 in the left arcuate fasciculus with age suggest increases in tissue complexity, while increases of PC2 in the bilateral arcuate, inferior longitudinal, inferior fronto-occipital fasciculi, and splenium suggest increases in myelin and axonal packing with age. Multimodal white matter imaging and PCA provide microstructurally informative, powerful principal components which can be used by future studies of development and cognition. Our findings suggest major features of white matter undergo development during childhood and adolescence, but changes are not linked to reading during this period in our typically-developing sample.


Assuntos
Neuroimagem Funcional/métodos , Imageamento por Ressonância Magnética Multiparamétrica/métodos , Leitura , Substância Branca/anatomia & histologia , Adolescente , Desenvolvimento do Adolescente/fisiologia , Axônios/ultraestrutura , Teorema de Bayes , Criança , Desenvolvimento Infantil/fisiologia , Imagem de Tensor de Difusão/estatística & dados numéricos , Feminino , Neuroimagem Funcional/estatística & dados numéricos , Voluntários Saudáveis , Humanos , Imageamento Tridimensional , Masculino , Modelos Anatômicos , Modelos Neurológicos , Imageamento por Ressonância Magnética Multiparamétrica/estatística & dados numéricos , Bainha de Mielina/metabolismo , Análise de Componente Principal/métodos , Análise de Regressão , Substância Branca/crescimento & desenvolvimento , Substância Branca/fisiologia
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