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1.
Br J Sports Med ; 54(2): 110-115, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31420319

RESUMO

INTRODUCTION: The brain plays a key role in the perceptual regulation of exercise, yet neuroimaging techniques have only demonstrated superficial brain areas responses during exercise, and little is known about the modulation of the deeper brain areas at different intensities. OBJECTIVES/METHODS: Using a specially designed functional MRI (fMRI) cycling ergometer, we have determined the sequence in which the cortical and subcortical brain regions are modulated at low and high ratings perceived exertion (RPE) during an incremental exercise protocol. RESULTS: Additional to the activation of the classical motor control regions (motor, somatosensory, premotor and supplementary motor cortices and cerebellum), we found the activation of the regions associated with autonomic regulation (ie, insular cortex) (ie, positive blood-oxygen-level-dependent (BOLD) signal) during exercise. Also, we showed reduced activation (negative BOLD signal) of cognitive-related areas (prefrontal cortex), an effect that increased during exercise at a higher perceived intensity (RPE 13-17 on Borg Scale). The motor cortex remained active throughout the exercise protocol whereas the cerebellum was activated only at low intensity (RPE 6-12), not at high intensity (RPE 13-17). CONCLUSIONS: These findings describe the sequence in which different brain areas become activated or deactivated during exercise of increasing intensity, including subcortical areas measured with fMRI analysis.


Assuntos
Exercício/fisiologia , Córtex Motor/fisiologia , Adolescente , Adulto , Cerebelo/fisiologia , Córtex Cerebral/fisiologia , Ergometria/métodos , Humanos , Imagem por Ressonância Magnética , Masculino , Percepção/fisiologia , Esforço Físico/fisiologia , Córtex Pré-Frontal/fisiologia , Adulto Jovem
2.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 35(4): 339-345, 2019 Jul 28.
Artigo em Chinês | MEDLINE | ID: mdl-31701719

RESUMO

OBJECTIVE: To understand and analyze the rules of endurance exercise on the cerebral cortex adaptive mechanism in aged rats. METHODS: In this study, 3-month-old (n=20), 13-month-old (n=24) and 23-month-old (n=24) specific-pathogen free (SPF) male Sprague-Dawley Rat (SD) rats were divided into young (Y-SED), middle-aged (M-SED) and old-aged (O-SED) sedentary control group, and the corresponding Y-EX, M-EX and O-EX in the endurance exercise runner group. The 10-weeks of regular moderate-intensity aerobic exercise intervention were carried out in the endurance exercise runner group. The exercise mode is treadmill exercise (slope 0), and the exercise intensity gradually increases from 60%~65% of the maximum oxygen consumption (V·O2max) to 70%~75%, and the exercise time is 10 weeks. Hematoxylin and eosin (HE) staining was used to detect age-related morphological changes. The expressions of superoxide dismutase(SOD) and brain-derived neurotrophic factor (BDNF) and the expressions of synapsin 1 (SYN1) and Ca2+/calmodulin- dependent protein kinases IIα (CaMK IIα) / AMP-activated protein kinase α1(AMPKα1) / mammalian target of rapamycin (mTOR) pathway -related genes were detected. RESULTS: The cerebral cortex structure of the rats in each group showed age-related aging changes, the expression of SOD in the cortex showed a gradual decline, the expression of BDNF showed an age-increasing trend, and the expression levels of SYN1 and CaMK IIα were increased with age. The changes in AMPKα1 and SirT2 and IP3R, AKT1 and mTOR mRNA levels were increased slightly in middle-aged rats and decreased in aged rats. Compared with the rats in each sedentary control group, the nucleus of the cerebral cortex was tightly arranged and the number of nuclei observed under the microscope was increased significantly in each exercise group. Exercise promoted the expressions of SOD, BDNF and synaptophysin SYN1 in the cortex of rats, and the expression levels of SOD and BDNF in aged rats were up-regulated significantly (P< 0.01). The expression level of SYN1 in rats was up-regulated significantly (P<0.05) in the young and aged rats. The expression of CaMK IIα in the cortex of middle-aged and aged rats was up-regulated (P<0.01), while the expression level of CaMK IIα in young rats was down-regulated (P<0.01). Exercise could up-regulate the expression level of AMPKα1 in the cortex of young rats (P< 0.05), but not in middle-aged and old-age rats. Exercise could up-regulate the expression of SirT2 in the cortex of rats in all age groups (P<0.05). Exercise up-regulated the expression of phosphoinositide 3-kinase (IP3R)/ protein kinase B 1(AKT1) /mTOR in the cortex of rats, among which young IP3R was significantly up-regulated (P<0.01) in the young group, mTOR was significantly up-regulated in young and middle-aged group (P<0.01), and mTOR was also significantly up-regulated in the aged group (P<0.05). CONCLUSION: Endurance exercise up-regulates BDNF expression, regulates CaMKIIα signaling, activates AMPK signaling pathway and IP3R / AKT1 / mTOR signaling pathway, and improves synaptic plasticity in the cortex.


Assuntos
Córtex Cerebral/fisiologia , Plasticidade Neuronal , Condicionamento Físico Animal , Resistência Física , Transdução de Sinais , Fatores Etários , Animais , Masculino , Ratos , Ratos Sprague-Dawley
3.
PLoS Comput Biol ; 15(11): e1007316, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31730613

RESUMO

Predicting future brain signal is highly sought-after, yet difficult to achieve. To predict the future phase of cortical activity at localized ECoG and MEG recording sites, we exploit its predominant, large-scale, spatiotemporal dynamics. The dynamics are extracted from the brain signal through Fourier analysis and principal components analysis (PCA) only, and cast in a data model that predicts future signal at each site and frequency of interest. The dominant eigenvectors of the PCA that map the large-scale patterns of past cortical phase to future ones take the form of smoothly propagating waves over the entire measurement array. In ECoG data from 3 subjects and MEG data from 20 subjects collected during a self-initiated motor task, mean phase prediction errors were as low as 0.5 radians at local sites, surpassing state-of-the-art methods of within-time-series or event-related models. Prediction accuracy was highest in delta to beta bands, depending on the subject, was more accurate during episodes of high global power, but was not strongly dependent on the time-course of the task. Prediction results did not require past data from the to-be-predicted site. Rather, best accuracy depended on the availability in the model of long wavelength information. The utility of large-scale, low spatial frequency traveling waves in predicting future phase activity at local sites allows estimation of the error introduced by failing to account for irreducible trajectories in the activity dynamics.


Assuntos
Mapeamento Encefálico/métodos , Previsões/métodos , Adulto , Encéfalo/fisiologia , Córtex Cerebral/fisiologia , Eletrocorticografia/métodos , Eletroencefalografia/métodos , Feminino , Humanos , Masculino , Análise de Componente Principal/métodos , Adulto Jovem
4.
Elife ; 82019 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-31591965

RESUMO

Sleep deprivation has marked effects on food intake, shifting food choices toward energy-dense options. Here we test the hypothesis that neural processing in central olfactory circuits, in tandem with the endocannabinoid system (ECS), plays a key role in mediating this relationship. We combined a partial sleep-deprivation protocol, pattern-based olfactory neuroimaging, and ad libitum food intake to test how central olfactory mechanisms alter food intake after sleep deprivation. We found that sleep restriction increased levels of the ECS compound 2-oleoylglycerol (2-OG), enhanced encoding of food odors in piriform cortex, and shifted food choices toward energy-dense food items. Importantly, the relationship between changes in 2-OG and food choices was formally mediated by odor-evoked connectivity between the piriform cortex and insula, a region involved in integrating feeding-related signals. These findings describe a potential neurobiological pathway by which state-dependent changes in the ECS may modulate chemosensory processing to regulate food choices.


Assuntos
Córtex Cerebral/fisiologia , Preferências Alimentares , Condutos Olfatórios/fisiologia , Córtex Piriforme/fisiologia , Sono , Adulto , Feminino , Glicerídeos/análise , Humanos , Masculino , Neuroimagem , Privação do Sono , Olfato , Adulto Jovem
5.
Nat Commun ; 10(1): 4798, 2019 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-31641118

RESUMO

Inhibitory control is fundamental to children's self-regulation and cognitive development. Here we investigate cortical-basal ganglia pathways underlying inhibitory control in children and their adult-like maturity. We first conduct a comprehensive meta-analysis of extant neurodevelopmental studies of inhibitory control and highlight important gaps in the literature. Second, we examine cortical-basal ganglia activation during inhibitory control in children ages 9-12 and demonstrate the formation of an adult-like inhibitory control network by late childhood. Third, we develop a neural maturation index (NMI), which assesses the similarity of brain activation patterns between children and adults, and demonstrate that higher NMI in children predicts better inhibitory control. Fourth, we show that activity in the subthalamic nucleus and its effective connectivity with the right anterior insula predicts children's inhibitory control. Fifth, we replicate our findings across multiple cohorts. Our findings provide insights into cortical-basal ganglia circuits and global brain organization underlying the development of inhibitory control.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Adolescente , Adulto , Gânglios da Base/fisiologia , Córtex Cerebral/fisiologia , Criança , Bases de Dados Factuais , Humanos , Imagem por Ressonância Magnética , Tempo de Reação/fisiologia , Núcleo Subtalâmico/fisiologia , Adulto Jovem
7.
Nat Commun ; 10(1): 4747, 2019 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-31628329

RESUMO

The brain is an assembly of neuronal populations interconnected by structural pathways. Brain activity is expressed on and constrained by this substrate. Therefore, statistical dependencies between functional signals in directly connected areas can be expected higher. However, the degree to which brain function is bound by the underlying wiring diagram remains a complex question that has been only partially answered. Here, we introduce the structural-decoupling index to quantify the coupling strength between structure and function, and we reveal a macroscale gradient from brain regions more strongly coupled, to regions more strongly decoupled, than expected by realistic surrogate data. This gradient spans behavioral domains from lower-level sensory function to high-level cognitive ones and shows for the first time that the strength of structure-function coupling is spatially varying in line with evidence derived from other modalities, such as functional connectivity, gene expression, microstructural properties and temporal hierarchy.


Assuntos
Encéfalo/fisiologia , Córtex Cerebral/fisiologia , Rede Nervosa/fisiologia , Neurônios/fisiologia , Algoritmos , Encéfalo/anatomia & histologia , Encéfalo/citologia , Mapeamento Encefálico/métodos , Córtex Cerebral/anatomia & histologia , Córtex Cerebral/citologia , Humanos , Imagem por Ressonância Magnética , Modelos Neurológicos , Rede Nervosa/anatomia & histologia , Rede Nervosa/citologia , Vias Neurais/anatomia & histologia , Vias Neurais/citologia , Vias Neurais/fisiologia
8.
Nat Commun ; 10(1): 4699, 2019 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-31619680

RESUMO

Regaining the function of an impaired limb is highly desirable in paralyzed individuals. One possible avenue to achieve this goal is to bridge the interrupted pathway between preserved neural structures and muscles using a brain-computer interface. Here, we demonstrate that monkeys with subcortical stroke were able to learn to use an artificial cortico-muscular connection (ACMC), which transforms cortical activity into electrical stimulation to the hand muscles, to regain volitional control of a paralysed hand. The ACMC induced an adaptive change of cortical activities throughout an extensive cortical area. In a targeted manner, modulating high-gamma activity became localized around an arbitrarily-selected cortical site controlling stimulation to the muscles. This adaptive change could be reset and localized rapidly to a new cortical site. Thus, the ACMC imparts new function for muscle control to connected cortical sites and triggers cortical adaptation to regain impaired motor function after stroke.


Assuntos
Adaptação Fisiológica/fisiologia , Interfaces Cérebro-Computador , Estimulação Elétrica , Córtex Motor/fisiopatologia , Músculo Esquelético/fisiologia , Córtex Somatossensorial/fisiopatologia , Acidente Vascular Cerebral/fisiopatologia , Animais , Braço , Córtex Cerebral/fisiologia , Córtex Cerebral/fisiopatologia , Eletrocorticografia , Mãos , Macaca mulatta , Córtex Motor/fisiologia , Vias Neurais/fisiopatologia , Paralisia , Córtex Somatossensorial/fisiologia , Reabilitação do Acidente Vascular Cerebral , Punho
9.
Nat Neurosci ; 22(10): 1677-1686, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31551604

RESUMO

When experts are immersed in a task, do their brains prioritize task-related activity? Most efforts to understand neural activity during well-learned tasks focus on cognitive computations and task-related movements. We wondered whether task-performing animals explore a broader movement landscape and how this impacts neural activity. We characterized movements using video and other sensors and measured neural activity using widefield and two-photon imaging. Cortex-wide activity was dominated by movements, especially uninstructed movements not required for the task. Some uninstructed movements were aligned to trial events. Accounting for them revealed that neurons with similar trial-averaged activity often reflected utterly different combinations of cognitive and movement variables. Other movements occurred idiosyncratically, accounting for trial-by-trial fluctuations that are often considered 'noise'. This held true throughout task-learning and for extracellular Neuropixels recordings that included subcortical areas. Our observations argue that animals execute expert decisions while performing richly varied, uninstructed movements that profoundly shape neural activity.


Assuntos
Cognição/fisiologia , Movimento/fisiologia , Neurônios/fisiologia , Animais , Percepção Auditiva/fisiologia , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/fisiologia , Tomada de Decisões/fisiologia , Modelos Lineares , Camundongos , Camundongos Endogâmicos C57BL , Neuroimagem , Desempenho Psicomotor/fisiologia , Percepção Visual/fisiologia
10.
Elife ; 82019 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-31502539

RESUMO

Humans navigate across a range of spatial scales, from rooms to continents, but the brain systems underlying spatial cognition are usually investigated only in small-scale environments. Do the same brain systems represent and process larger spaces? Here we asked subjects to compare distances between real-world items at six different spatial scales (room, building, neighborhood, city, country, continent) under functional MRI. Cortical activity showed a gradual progression from small to large scale processing, along three gradients extending anteriorly from the parahippocampal place area (PPA), retrosplenial complex (RSC) and occipital place area (OPA), and along the hippocampus posterior-anterior axis. Each of the cortical gradients overlapped with the visual system posteriorly and the default-mode network (DMN) anteriorly. These results suggest a progression from concrete to abstract processing with increasing spatial scale, and offer a new organizational framework for the brain's spatial system, that may also apply to conceptual spaces beyond the spatial domain.


Assuntos
Córtex Cerebral/fisiologia , Orientação Espacial , Percepção Espacial , Adulto , Mapeamento Encefálico , Feminino , Voluntários Saudáveis , Humanos , Imagem por Ressonância Magnética , Masculino , Adulto Jovem
11.
Nat Neurosci ; 22(11): 1925-1935, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31527803

RESUMO

The thalamus is the central communication hub of the forebrain and provides the cerebral cortex with inputs from sensory organs, subcortical systems and the cortex itself. Multiple thalamic regions send convergent information to each cortical region, but the organizational logic of thalamic projections has remained elusive. Through comprehensive transcriptional analyses of retrogradely labeled thalamic neurons in adult mice, we identify three major profiles of thalamic pathways. These profiles exist along a continuum that is repeated across all major projection systems, such as those for vision, motor control and cognition. The largest component of gene expression variation in the mouse thalamus is topographically organized, with features conserved in humans. Transcriptional differences between these thalamic neuronal identities are tied to cellular features that are critical for function, such as axonal morphology and membrane properties. Molecular profiling therefore reveals covariation in the properties of thalamic pathways serving all major input modalities and output targets, thus establishing a molecular framework for understanding the thalamus.


Assuntos
Córtex Cerebral/anatomia & histologia , Tálamo/anatomia & histologia , Potenciais de Ação , Animais , Atlas como Assunto , Córtex Cerebral/metabolismo , Córtex Cerebral/fisiologia , Humanos , Camundongos , Camundongos Transgênicos , Vias Neurais/anatomia & histologia , Vias Neurais/metabolismo , Vias Neurais/fisiologia , Tálamo/metabolismo , Tálamo/fisiologia , Transcriptoma
12.
Dev Cogn Neurosci ; 39: 100704, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31476670

RESUMO

The humans' brain asymmetry is observed in the early stages of life and known to change further with age. The developmental trajectory of such an asymmetry has been observed for language, as one of the most lateralized cognitive functions. However, it remains unclear how these age-related changes in structural asymmetry are related to changes in language performance. We collected longitudinal structural magnetic resonance imaging data of children from 5 to 6 years to investigate structural asymmetry development and its linkage to the improvement of language comprehension abilities. Our results showed substantial changes of language performance across time, which were associated with changes of cortical thickness asymmetry in the triangular part of the inferior frontal gyrus (IFG), constituting a portion of Broca's area. This suggests that language improvement is influenced by larger cortical thinning in the left triangular IFG compared to the right. This asymmetry in children's brain at age 5 and 6 years was further associated with the language performance at 7 years. To our knowledge, this is the first longitudinal study to demonstrate that children's improvement in sentence comprehension seems to depend on structural asymmetry changes in the IFG, further highlighting its crucial role in language acquisition.


Assuntos
Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/fisiologia , Lateralidade Funcional/fisiologia , Desenvolvimento da Linguagem , Mapeamento Encefálico/métodos , Criança , Pré-Escolar , Feminino , Humanos , Estudos Longitudinais , Imagem por Ressonância Magnética/métodos , Masculino , Tamanho do Órgão
13.
Elife ; 82019 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-31545165

RESUMO

Enhancers are the primary DNA regulatory elements that confer cell type specificity of gene expression. Recent studies characterizing individual enhancers have revealed their potential to direct heterologous gene expression in a highly cell-type-specific manner. However, it has not yet been possible to systematically identify and test the function of enhancers for each of the many cell types in an organism. We have developed PESCA, a scalable and generalizable method that leverages ATAC- and single-cell RNA-sequencing protocols, to characterize cell-type-specific enhancers that should enable genetic access and perturbation of gene function across mammalian cell types. Focusing on the highly heterogeneous mammalian cerebral cortex, we apply PESCA to find enhancers and generate viral reagents capable of accessing and manipulating a subset of somatostatin-expressing cortical interneurons with high specificity. This study demonstrates the utility of this platform for developing new cell-type-specific viral reagents, with significant implications for both basic and translational research.


Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Biologia Molecular/métodos , Neurônios/efeitos dos fármacos , Neurofisiologia/métodos , Proteínas Recombinantes/biossíntese , Somatostatina/metabolismo , Vírus/genética , Animais , Animais Geneticamente Modificados , Córtex Cerebral/fisiologia , Genes Reguladores , Vetores Genéticos , Interneurônios/fisiologia , Camundongos , Proteínas Recombinantes/genética
14.
Behav Neurol ; 2019: 1803624, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31396292

RESUMO

In this review, we explore current literature and assess evidence linking secondary (acquired) alexithymia to aberrant humor processing, in terms of their neurobiological underpinnings. In addition, we suggest a possible common neuropathological substrate between secondary alexithymia and deficits in humor appreciation, by drawing on neurophysiologic and neuroradiological evidence, as well as on a recent and unique single-case study showing the cooccurrence of secondary alexithymia and deficit in humor appreciation. In summary, what emerges from the literature is that the cortical midline structures, in particular the medial prefrontal cortex (mPFC), the anterior cingulate cortex (ACC), and the insular cortex, seem to play a crucial role in the expression of both alexithymia and defective humor processing, while though to a lesser extent, a right hemisphere and bilateral frontoparietal contribution becomes evident. Neurobiological evidence of secondary alexithymia and aberrant humor processing points to the putative role of ACC/mPFC and the insular cortex in representing crucial processing nodes whose damage may produce both the above clinical conditions. We believe that the association of secondary alexithymia and aberrant humor processing, especially humor appreciation deficit, and their correlation with specific brain regions, mainly ACG/mPFC, as emerged from the literature, may be of some heuristic importance. Increased awareness on this topic may be of aid for neurosurgeons when accessing emotion-relevant structures, as well as for neuropsychologists to intensify their efforts to plan evidence-based neurorehabilitative interventions to alleviate the deleterious effects of such interpersonal communication deficits.


Assuntos
Sintomas Afetivos/fisiopatologia , Emoções/fisiologia , Senso de Humor e Humor como Assunto/psicologia , Sintomas Afetivos/genética , Encéfalo/fisiologia , Mapeamento Encefálico/métodos , Córtex Cerebral/fisiologia , Giro do Cíngulo/fisiologia , Humanos , Imagem por Ressonância Magnética , Transtornos Mentais/metabolismo , Transtornos Mentais/fisiopatologia , Córtex Pré-Frontal/fisiologia
15.
Brain Behav Evol ; 93(2-3): 152-165, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31416089

RESUMO

The coordination of progenitor self-renewal, neuronal production, and migration is essential to the normal development and evolution of the cerebral cortex. Numerous studies have shown that the Notch, Wnt/beta-catenin, and Neurogenin pathways contribute separately to progenitor expansion, neurogenesis, and neuronal migration, but it is unknown how these signals are coordinated. In vitro studies suggested that the mastermind-like 1 (MAML1) gene, homologue of the Drosophila mastermind, plays a role in coordinating the aforementioned signaling pathways, yet its role during cortical development remains largely unknown. Here we show that ectopic expression of dominant-negative MAML (dnMAML) causes exuberant neuronal production in the mouse cortex without disrupting neuronal migration. Comparing the transcriptional consequences of dnMAML and Neurog2 ectopic expression revealed a complex genetic network controlling the balance of progenitor expansion versus neuronal production. Manipulation of MAML and Neurog2 in cultured human cerebral stem cells exposed interactions with the same set of signaling pathways. Thus, our data suggest that evolutionary changes that affect the timing, tempo, and density of successive neuronal layers of the small lissencephalic rodent and large convoluted primate cerebral cortex depend on similar molecular mechanisms that act from the earliest developmental stages.


Assuntos
Córtex Cerebral/fisiologia , Proteínas de Ligação a DNA/fisiologia , Redes Reguladoras de Genes/fisiologia , Neurogênese/fisiologia , Proteínas Nucleares/fisiologia , Transdução de Sinais/fisiologia , Fatores de Transcrição/fisiologia , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , Diferenciação Celular/fisiologia , Movimento Celular/fisiologia , Córtex Cerebral/crescimento & desenvolvimento , Proteínas de Ligação a DNA/genética , Embrião de Mamíferos , Feminino , Feto , Regulação da Expressão Gênica , Redes Reguladoras de Genes/genética , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Proteínas do Tecido Nervoso/fisiologia , Células-Tronco Neurais , Proteínas Nucleares/genética , Gravidez , Transdução de Sinais/genética , Fatores de Transcrição/genética
16.
Proc Jpn Acad Ser B Phys Biol Sci ; 95(7): 303-311, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31406055

RESUMO

The fundamental organization of the cerebral cortical circuit is still poorly understood. In particular, it is unclear whether the diverse cell types form modular units that are repeated across the cortex. We discovered that the major cell types in cortical layer 5 form a lattice structure. Distinct types of excitatory and inhibitory neurons form cell type-specific radial clusters termed microcolumns. Microcolumns are present in diverse cortical areas, such as the visual, motor, and language areas, and are organized into periodic hexagonal lattice structures. Individual microcolumns have modular synaptic circuits and exhibit modular neuronal activity, suggesting that each of them functions as an information processing unit. Microcolumn development is suggested to be independent of cell lineage but coordinated by gap junctions. Thus, neurons in cortical layer 5 organize into a brainwide lattice structure of functional microcolumns, suggesting that parallel processing by massively repeated microcolumns underlie diverse cortical functions, such as sensory perception, motor control, and language processing.


Assuntos
Córtex Cerebral/citologia , Rede Nervosa/citologia , Animais , Córtex Cerebral/crescimento & desenvolvimento , Córtex Cerebral/fisiologia , Humanos , Rede Nervosa/fisiologia , Neurônios/citologia
17.
Nat Commun ; 10(1): 3096, 2019 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-31363096

RESUMO

Natural communication often occurs in dialogue, differentially engaging auditory and sensorimotor brain regions during listening and speaking. However, previous attempts to decode speech directly from the human brain typically consider listening or speaking tasks in isolation. Here, human participants listened to questions and responded aloud with answers while we used high-density electrocorticography (ECoG) recordings to detect when they heard or said an utterance and to then decode the utterance's identity. Because certain answers were only plausible responses to certain questions, we could dynamically update the prior probabilities of each answer using the decoded question likelihoods as context. We decode produced and perceived utterances with accuracy rates as high as 61% and 76%, respectively (chance is 7% and 20%). Contextual integration of decoded question likelihoods significantly improves answer decoding. These results demonstrate real-time decoding of speech in an interactive, conversational setting, which has important implications for patients who are unable to communicate.


Assuntos
Mapeamento Encefálico/métodos , Córtex Cerebral/fisiologia , Fala/fisiologia , Interfaces Cérebro-Computador , Eletrocorticografia/instrumentação , Eletrocorticografia/métodos , Eletrodos Implantados , Epilepsia/diagnóstico , Epilepsia/fisiopatologia , Feminino , Humanos , Fatores de Tempo
18.
Nat Methods ; 16(8): 778-786, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31363222

RESUMO

Point-scanning two-photon microscopy enables high-resolution imaging within scattering specimens such as the mammalian brain, but sequential acquisition of voxels fundamentally limits its speed. We developed a two-photon imaging technique that scans lines of excitation across a focal plane at multiple angles and computationally recovers high-resolution images, attaining voxel rates of over 1 billion Hz in structured samples. Using a static image as a prior for recording neural activity, we imaged visually evoked and spontaneous glutamate release across hundreds of dendritic spines in mice at depths over 250 µm and frame rates over 1 kHz. Dendritic glutamate transients in anesthetized mice are synchronized within spatially contiguous domains spanning tens of micrometers at frequencies ranging from 1-100 Hz. We demonstrate millisecond-resolved recordings of acetylcholine and voltage indicators, three-dimensional single-particle tracking and imaging in densely labeled cortex. Our method surpasses limits on the speed of raster-scanned imaging imposed by fluorescence lifetime.


Assuntos
Córtex Cerebral/fisiologia , Ácido Glutâmico/metabolismo , Neurônios/fisiologia , Tomografia/métodos , Animais , Cálcio/metabolismo , Córtex Cerebral/citologia , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/citologia , Fótons , Ratos
19.
PLoS Comput Biol ; 15(8): e1007277, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31449517

RESUMO

Despite its critical importance in experimental and clinical neuroscience, at present there is no systematic method to predict which neural elements will be activated by a given stimulation regime. Here we develop a novel approach to model the effect of cortical stimulation on spiking probability of neurons in a volume of tissue, by applying an analytical estimate of stimulation-induced activation of different cell types across cortical layers. We utilize the morphology and properties of axonal arborization profiles obtained from publicly available anatomical reconstructions of the twelve main categories of neocortical neurons to derive the dependence of activation probability on cell type, layer and distance from the source. We then propagate this activity through the local network incorporating connectivity, synaptic and cellular properties. Our work predicts that (a) intracranial cortical stimulation induces selective activation across cell types and layers; (b) superficial anodal stimulation is more effective than cathodal at cell activation; (c) cortical surface stimulation focally activates layer I axons, and (d) there is an optimal stimulation intensity capable of eliciting cell activation lasting beyond the end of stimulation. We conclude that selective effects of cortical electrical stimulation across cell types and cortical layers are largely driven by their different axonal arborization and myelination profiles.


Assuntos
Neurônios/fisiologia , Recrutamento Neurofisiológico , Animais , Córtex Cerebral/citologia , Córtex Cerebral/fisiologia , Biologia Computacional , Simulação por Computador , Estimulação Elétrica , Modelos Neurológicos , Rede Nervosa/citologia , Rede Nervosa/fisiologia , Ratos
20.
Nat Neurosci ; 22(9): 1424-1437, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31455886

RESUMO

Triggering behavioral adaptation upon the detection of adversity is crucial for survival. The insular cortex has been suggested to process emotions and homeostatic signals, but how the insular cortex detects internal states and mediates behavioral adaptation is poorly understood. By combining data from fiber photometry, optogenetics, awake two-photon calcium imaging and comprehensive whole-brain viral tracings, we here uncover a role for the posterior insula in processing aversive sensory stimuli and emotional and bodily states, as well as in exerting prominent top-down modulation of ongoing behaviors in mice. By employing projection-specific optogenetics, we describe an insula-to-central amygdala pathway to mediate anxiety-related behaviors, while an independent nucleus accumbens-projecting pathway regulates feeding upon changes in bodily state. Together, our data support a model in which the posterior insular cortex can shift behavioral strategies upon the detection of aversive internal states, providing a new entry point to understand how alterations in insula circuitry may contribute to neuropsychiatric conditions.


Assuntos
Adaptação Fisiológica/fisiologia , Comportamento Animal/fisiologia , Córtex Cerebral/fisiologia , Vias Neurais/fisiologia , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL
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