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1.
Commun Biol ; 7(1): 550, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38719883

RESUMO

Perceptual and cognitive processing relies on flexible communication among cortical areas; however, the underlying neural mechanism remains unclear. Here we report a mechanism based on the realistic spatiotemporal dynamics of propagating wave patterns in neural population activity. Using a biophysically plausible, multiarea spiking neural circuit model, we demonstrate that these wave patterns, characterized by their rich and complex dynamics, can account for a wide variety of empirically observed neural processes. The coordinated interactions of these wave patterns give rise to distributed and dynamic communication (DDC) that enables flexible and rapid routing of neural activity across cortical areas. We elucidate how DDC unifies the previously proposed oscillation synchronization-based and subspace-based views of interareal communication, offering experimentally testable predictions that we validate through the analysis of Allen Institute Neuropixels data. Furthermore, we demonstrate that DDC can be effectively modulated during attention tasks through the interplay of neuromodulators and cortical feedback loops. This modulation process explains many neural effects of attention, underscoring the fundamental functional role of DDC in cognition.


Assuntos
Atenção , Modelos Neurológicos , Atenção/fisiologia , Humanos , Córtex Cerebral/fisiologia , Animais , Rede Nervosa/fisiologia , Percepção Visual/fisiologia , Neurônios/fisiologia , Cognição/fisiologia
2.
Hum Brain Mapp ; 45(7): e26666, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38726831

RESUMO

Advanced meditation such as jhana meditation can produce various altered states of consciousness (jhanas) and cultivate rewarding psychological qualities including joy, peace, compassion, and attentional stability. Mapping the neurobiological substrates of jhana meditation can inform the development and application of advanced meditation to enhance well-being. Only two prior studies have attempted to investigate the neural correlates of jhana meditation, and the rarity of adept practitioners has largely restricted the size and extent of these studies. Therefore, examining the consistency and reliability of observed brain responses associated with jhana meditation can be valuable. In this study, we aimed to characterize functional magnetic resonance imaging (fMRI) reliability within a single subject over repeated runs in canonical brain networks during jhana meditation performed by an adept practitioner over 5 days (27 fMRI runs) inside an ultra-high field 7 Tesla MRI scanner. We found that thalamus and several cortical networks, that is, the somatomotor, limbic, default-mode, control, and temporo-parietal, demonstrated good within-subject reliability across all jhanas. Additionally, we found that several other relevant brain networks (e.g., attention, salience) showed noticeable increases in reliability when fMRI measurements were adjusted for variability in self-reported phenomenology related to jhana meditation. Overall, we present a preliminary template of reliable brain areas likely underpinning core neurocognitive elements of jhana meditation, and highlight the utility of neurophenomenological experimental designs for better characterizing neuronal variability associated with advanced meditative states.


Assuntos
Imageamento por Ressonância Magnética , Meditação , Rede Nervosa , Humanos , Reprodutibilidade dos Testes , Rede Nervosa/fisiologia , Rede Nervosa/diagnóstico por imagem , Adulto , Masculino , Feminino , Encéfalo/fisiologia , Encéfalo/diagnóstico por imagem , Córtex Cerebral/fisiologia , Córtex Cerebral/diagnóstico por imagem
3.
Hum Brain Mapp ; 45(7): e26700, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38726799

RESUMO

The post-movement beta rebound has been studied extensively using magnetoencephalography (MEG) and is reliably modulated by various task parameters as well as illness. Our recent study showed that rebounds, which we generalise as "post-task responses" (PTRs), are a ubiquitous phenomenon in the brain, occurring across the cortex in theta, alpha, and beta bands. Currently, it is unknown whether PTRs following working memory are driven by transient bursts, which are moments of short-lived high amplitude activity, similar to those that drive the post-movement beta rebound. Here, we use three-state univariate hidden Markov models (HMMs), which can identify bursts without a priori knowledge of frequency content or response timings, to compare bursts that drive PTRs in working memory and visuomotor MEG datasets. Our results show that PTRs across working memory and visuomotor tasks are driven by pan-spectral transient bursts. These bursts have very similar spectral content variation over the cortex, correlating strongly between the two tasks in the alpha (R2 = .89) and beta (R2 = .53) bands. Bursts also have similar variation in duration over the cortex (e.g., long duration bursts occur in the motor cortex for both tasks), strongly correlating over cortical regions between tasks (R2 = .56), with a mean over all regions of around 300 ms in both datasets. Finally, we demonstrate the ability of HMMs to isolate signals of interest in MEG data, such that the HMM probability timecourse correlates more strongly with reaction times than frequency filtered power envelopes from the same brain regions. Overall, we show that induced PTRs across different tasks are driven by bursts with similar characteristics, which can be identified using HMMs. Given the similarity between bursts across tasks, we suggest that PTRs across the cortex may be driven by a common underlying neural phenomenon.


Assuntos
Magnetoencefalografia , Memória de Curto Prazo , Humanos , Memória de Curto Prazo/fisiologia , Adulto , Masculino , Feminino , Adulto Jovem , Cadeias de Markov , Desempenho Psicomotor/fisiologia , Córtex Cerebral/fisiologia , Movimento/fisiologia , Ritmo beta/fisiologia
4.
J Headache Pain ; 25(1): 76, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38730344

RESUMO

Trigeminal neuropathic pain (TNP) is a major concern in both dentistry and medicine. The progression from normal to chronic TNP through activation of the insular cortex (IC) is thought to involve several neuroplastic changes in multiple brain regions, resulting in distorted pain perception and associated comorbidities. While the functional changes in the insula are recognized contributors to TNP, the intricate mechanisms underlying the involvement of the insula in TNP processing remain subjects of ongoing investigation. Here, we have overviewed the most recent advancements regarding the functional role of IC in regulating TNP alongside insights into the IC's connectivity with other brain regions implicated in trigeminal pain pathways. In addition, the review examines diverse modulation strategies that target the different parts of the IC, thereby suggesting novel diagnostic and therapeutic management of chronic TNP in the future.


Assuntos
Córtex Insular , Neuralgia do Trigêmeo , Humanos , Neuralgia do Trigêmeo/fisiopatologia , Neuralgia do Trigêmeo/diagnóstico , Córtex Insular/diagnóstico por imagem , Córtex Insular/fisiopatologia , Córtex Cerebral/fisiopatologia , Córtex Cerebral/diagnóstico por imagem
5.
Int J Mol Sci ; 25(9)2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38731978

RESUMO

Alzheimer's disease (AD) is the main cause of dementia worldwide. Given that learning and memory are impaired in this pathology, NMDA receptors (NMDARs) appear as key players in the onset and progression of the disease. NMDARs are glutamate receptors, mainly located at the post-synapse, which regulate voltage-dependent influx of calcium into the neurons. They are heterotetramers, and there are different subunits that can be part of the receptors, which are usually composed of two obligatory GluN1 subunits plus either two NR2A or two NR2B subunits. NR2A are mostly located at the synapse, and their activation is involved in the expression of pro-survival genes. Conversely, NR2B are mainly extrasynaptic, and their activation has been related to cell death and neurodegeneration. Thus, activation of NR2A and/or inactivation of NR2B-containing NMDARS has been proposed as a therapeutic strategy to treat AD. Here, we wanted to investigate the main differences between both subunits signalling in neuronal primary cultures of the cortex and hippocampus. It has been observed that Aß induces a significant increase in calcium release and also in MAPK phosphorylation signalling in NR2B-containing NMDAR in cortical and hippocampal neurons. However, while NR2A-containing NMDAR decreases neuronal death and favours cell viability after Aß treatment, NR2B-containing NMDAR shows higher levels of cytotoxicity and low levels of neuronal survival. Finally, it has been detected that NMDAR has no effect on pTau axonal transport. The present results demonstrate a different role between GluNA and GluNB subunits in neurodegenerative diseases such as Alzheimer's.


Assuntos
Doença de Alzheimer , Neurônios , Receptores de N-Metil-D-Aspartato , Receptores de N-Metil-D-Aspartato/metabolismo , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Animais , Neurônios/metabolismo , Hipocampo/metabolismo , Peptídeos beta-Amiloides/metabolismo , Cálcio/metabolismo , Humanos , Camundongos , Fosforilação , Células Cultivadas , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Ratos
6.
Alcohol Alcohol ; 59(4)2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38742547

RESUMO

AIMS: Continued alcohol consumption despite negative consequences is a core symptom of alcohol use disorder. This is modeled in mice by pairing negative stimuli with alcohol, such as adulterating alcohol solution with quinine. Mice consuming alcohol under these conditions are considered to be engaging in aversion-resistant intake. Previously, we have observed sex differences in this behavior, with females more readily expressing aversion-resistant consumption. We also identified three brain regions that exhibited sex differences in neuronal activation during quinine-alcohol drinking: ventromedial prefrontal cortex (vmPFC), posterior insular cortex (PIC), and ventral tegmental area (VTA). Specifically, male mice showed increased activation in vmPFC and PIC, while females exhibited increased activation in VTA. In this study, we aimed to identify what specific type of neurons are activated in these regions during quinine-alcohol drinking. METHOD: We assessed quinine-adulterated alcohol intake using the two-bottle choice procedure. We also utilized RNAscope in situ hybridization in the three brain regions that previously exhibited a sex difference to examine colocalization of Fos, glutamate, GABA, and dopamine. RESULT: Females showed increased aversion-resistant alcohol consumption compared to males. We also found that males had higher colocalization of glutamate and Fos in vmPFC and PIC, while females had greater dopamine and Fos colocalization in the VTA. CONCLUSIONS: Collectively, these experiments suggest that glutamatergic output from the vmPFC and PIC may have a role in suppressing, and dopaminergic activity in the VTA may promote, aversion-resistant alcohol consumption. Future experiments will examine neuronal circuits that contribute to sex differences in aversion resistant consumption.


Assuntos
Consumo de Bebidas Alcoólicas , Neurônios , Quinina , Caracteres Sexuais , Animais , Quinina/farmacologia , Feminino , Masculino , Camundongos , Neurônios/efeitos dos fármacos , Área Tegmentar Ventral/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Córtex Pré-Frontal/efeitos dos fármacos , Mesencéfalo/metabolismo , Mesencéfalo/efeitos dos fármacos , Córtex Insular/efeitos dos fármacos , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Etanol/farmacologia , Ácido Glutâmico/metabolismo
7.
Proc Natl Acad Sci U S A ; 121(20): e2321711121, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38713624

RESUMO

During development, neural stem cells in the cerebral cortex, also known as radial glial cells (RGCs), generate excitatory neurons, followed by production of cortical macroglia and inhibitory neurons that migrate to the olfactory bulb (OB). Understanding the mechanisms for this lineage switch is fundamental for unraveling how proper numbers of diverse neuronal and glial cell types are controlled. We and others recently showed that Sonic Hedgehog (Shh) signaling promotes the cortical RGC lineage switch to generate cortical oligodendrocytes and OB interneurons. During this process, cortical RGCs generate intermediate progenitor cells that express critical gliogenesis genes Ascl1, Egfr, and Olig2. The increased Ascl1 expression and appearance of Egfr+ and Olig2+ cortical progenitors are concurrent with the switch from excitatory neurogenesis to gliogenesis and OB interneuron neurogenesis in the cortex. While Shh signaling promotes Olig2 expression in the developing spinal cord, the exact mechanism for this transcriptional regulation is not known. Furthermore, the transcriptional regulation of Olig2 and Egfr has not been explored. Here, we show that in cortical progenitor cells, multiple regulatory programs, including Pax6 and Gli3, prevent precocious expression of Olig2, a gene essential for production of cortical oligodendrocytes and astrocytes. We identify multiple enhancers that control Olig2 expression in cortical progenitors and show that the mechanisms for regulating Olig2 expression are conserved between the mouse and human. Our study reveals evolutionarily conserved regulatory logic controlling the lineage switch of cortical neural stem cells.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos , Córtex Cerebral , Receptores ErbB , Proteínas Hedgehog , Proteínas do Tecido Nervoso , Células-Tronco Neurais , Neurogênese , Fator de Transcrição 2 de Oligodendrócitos , Fator de Transcrição PAX6 , Animais , Neurogênese/fisiologia , Córtex Cerebral/metabolismo , Córtex Cerebral/citologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Receptores ErbB/metabolismo , Receptores ErbB/genética , Camundongos , Fator de Transcrição 2 de Oligodendrócitos/metabolismo , Fator de Transcrição 2 de Oligodendrócitos/genética , Proteínas do Tecido Nervoso/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas Hedgehog/metabolismo , Proteínas Hedgehog/genética , Fator de Transcrição PAX6/metabolismo , Fator de Transcrição PAX6/genética , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/citologia , Proteínas de Homeodomínio/metabolismo , Proteínas de Homeodomínio/genética , Proteína Gli3 com Dedos de Zinco/metabolismo , Proteína Gli3 com Dedos de Zinco/genética , Proteínas do Olho/metabolismo , Proteínas do Olho/genética , Proteínas Repressoras/metabolismo , Proteínas Repressoras/genética , Fatores de Transcrição Box Pareados/metabolismo , Fatores de Transcrição Box Pareados/genética , Neuroglia/metabolismo , Neuroglia/citologia , Regulação da Expressão Gênica no Desenvolvimento , Transdução de Sinais , Bulbo Olfatório/metabolismo , Bulbo Olfatório/citologia , Linhagem da Célula , Humanos
8.
Sci Signal ; 17(835): eadj0032, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38713765

RESUMO

Serum response factor (SRF) is an essential transcription factor for brain development and function. Here, we explored how an SRF cofactor, the actin monomer-sensing myocardin-related transcription factor MRTF, is regulated in mouse cortical neurons. We found that MRTF-dependent SRF activity in vitro and in vivo was repressed by cyclase-associated protein CAP1. Inactivation of the actin-binding protein CAP1 reduced the amount of actin monomers in the cytoplasm, which promoted nuclear MRTF translocation and MRTF-SRF activation. This function was independent of cofilin1 and actin-depolymerizing factor, and CAP1 loss of function in cortical neurons was not compensated by endogenous CAP2. Transcriptomic and proteomic analyses of cerebral cortex lysates from wild-type and Cap1 knockout mice supported the role of CAP1 in repressing MRTF-SRF-dependent signaling in vivo. Bioinformatic analysis identified likely MRTF-SRF target genes, which aligned with the transcriptomic and proteomic results. Together with our previous studies that implicated CAP1 in axonal growth cone function as well as the morphology and plasticity of excitatory synapses, our findings establish CAP1 as a crucial actin regulator in the brain relevant for formation of neuronal networks.


Assuntos
Actinas , Proteínas de Transporte , Córtex Cerebral , Camundongos Knockout , Fator de Resposta Sérica , Transativadores , Animais , Córtex Cerebral/metabolismo , Transativadores/metabolismo , Transativadores/genética , Fator de Resposta Sérica/metabolismo , Fator de Resposta Sérica/genética , Camundongos , Actinas/metabolismo , Actinas/genética , Neurônios/metabolismo , Proteínas dos Microfilamentos/metabolismo , Proteínas dos Microfilamentos/genética , Regulação da Expressão Gênica , Transdução de Sinais
9.
Brain Behav ; 14(5): e3529, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38747741

RESUMO

BACKGROUND AND AIMS: Stress ulcer (SU) is a common complication in patients with acute ischemic stroke. The relationship of infarction location and the incidence of SU was unclear. Herein, we aim to investigate the association between ischemic insular damage and the development of SU. METHODS: Data were retrieved from the SPARK study (Effect of Cardiac Function on Short-Term Functional Prognosis in Patients with Acute Ischemic Stroke). We included the patients who had experienced an ischemic stroke within 7 days. The diagnosis of SU was based on clinical manifestations, including hematemesis, bloody nasogastric tube aspirate, or hematochezia. Evaluation of ischemic insular damage was conducted through magnetic resonance imaging. Cyclo-oxygenase regression analysis and Kaplan-Meier survival curves were used to assess the relationship between ischemic insular damage and the occurrence of SU. RESULTS: Among the 1357 patients analyzed, 110 (8.1%) developed SUs during hospitalization, with 69 (6.7%) experiencing infarctions in the anterior circulation. After adjusting for potential confounders, patients with ischemic insular damage exhibited a 2.16-fold higher risk of developing SUs compared to those without insular damage (p = .0206). Notably, among patients with infarctions in the anterior circulation, those with insular damage had a 2.21-fold increased risk of SUs (p = .0387). Moreover, right insular damage was associated with a higher risk of SUs compared to left insular damage or no insular damage (p for trend = .0117). Kaplan-Meier curves demonstrated early separation among groups, persisting throughout the follow-up period (all p < .0001). CONCLUSIONS: This study identified a significant independent correlation between ischemic insular damage, particularly on the right side, and the development of SU during hospitalization, indicating the need to consider prophylactic acid-suppressive treatment for patients with ischemic insular damage.


Assuntos
AVC Isquêmico , Humanos , Masculino , Feminino , AVC Isquêmico/complicações , AVC Isquêmico/epidemiologia , AVC Isquêmico/diagnóstico por imagem , Idoso , Pessoa de Meia-Idade , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/patologia , Imageamento por Ressonância Magnética , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/epidemiologia , Úlcera/patologia
10.
PLoS Comput Biol ; 20(5): e1012074, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38696532

RESUMO

We investigate the ability of the pairwise maximum entropy (PME) model to describe the spiking activity of large populations of neurons recorded from the visual, auditory, motor, and somatosensory cortices. To quantify this performance, we use (1) Kullback-Leibler (KL) divergences, (2) the extent to which the pairwise model predicts third-order correlations, and (3) its ability to predict the probability that multiple neurons are simultaneously active. We compare these with the performance of a model with independent neurons and study the relationship between the different performance measures, while varying the population size, mean firing rate of the chosen population, and the bin size used for binarizing the data. We confirm the previously reported excellent performance of the PME model for small population sizes N < 20. But we also find that larger mean firing rates and bin sizes generally decreases performance. The performance for larger populations were generally not as good. For large populations, pairwise models may be good in terms of predicting third-order correlations and the probability of multiple neurons being active, but still significantly worse than small populations in terms of their improvement over the independent model in KL-divergence. We show that these results are independent of the cortical area and of whether approximate methods or Boltzmann learning are used for inferring the pairwise couplings. We compared the scaling of the inferred couplings with N and find it to be well explained by the Sherrington-Kirkpatrick (SK) model, whose strong coupling regime shows a complex phase with many metastable states. We find that, up to the maximum population size studied here, the fitted PME model remains outside its complex phase. However, the standard deviation of the couplings compared to their mean increases, and the model gets closer to the boundary of the complex phase as the population size grows.


Assuntos
Entropia , Modelos Neurológicos , Neurônios , Animais , Neurônios/fisiologia , Córtex Cerebral/fisiologia , Potenciais de Ação/fisiologia , Biologia Computacional , Simulação por Computador
11.
PeerJ ; 12: e17313, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38708344

RESUMO

Background: Humans continuously maintain and adjust posture during gait, standing, and sitting. The difficulty of postural control is reportedly increased during unstable stances, such as unipedal standing and with closed eyes. Although balance is slightly impaired in healthy young adults in such unstable stances, they rarely fall. The brain recognizes the change in sensory inputs and outputs motor commands to the musculoskeletal system. However, such changes in cortical activity associated with the maintenance of balance following periods of instability require further clarified. Methods: In this study, a total of 15 male participants performed two postural control tasks and the center of pressure displacement and electroencephalogram were simultaneously measured. In addition, the correlation between amplitude of center of pressure displacement and power spectral density of electroencephalogram was analyzed. Results: The movement of the center of pressure was larger in unipedal standing than in bipedal standing under both eye open and eye closed conditions. It was also larger under the eye closed condition compared with when the eyes were open in unipedal standing. The amplitude of high-frequency bandwidth (1-3 Hz) of the center of pressure displacement was larger during more difficult postural tasks than during easier ones, suggesting that the continuous maintenance of posture was required. The power spectral densities of the theta activity in the frontal area and the gamma activity in the parietal area were higher during more difficult postural tasks than during easier ones across two postural control tasks, and these correlate with the increase in amplitude of high-frequency bandwidth of the center of pressure displacement. Conclusions: Taken together, specific activation patterns of the neocortex are suggested to be important for the postural maintenance during unstable stances.


Assuntos
Eletroencefalografia , Equilíbrio Postural , Humanos , Equilíbrio Postural/fisiologia , Masculino , Adulto Jovem , Adulto , Postura/fisiologia , Córtex Cerebral/fisiologia , Posição Ortostática
12.
Biomed Khim ; 70(2): 83-88, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38711407

RESUMO

The toxic effect of ethanol on the cerebral cortex and protective effects of omega-3 fatty acids against this neurotoxicity were investigated. Twenty eight male Wistar-albino rats were divided into 4 groups. Rats of the ethanol and ethanol withdrawal groups were treated with ethanol (6 g/kg/day) for 15 days. Animals of the ethanol+omega-3 group received omega-3 fatty acids (400 mg/kg daily) and ethanol. In rats of the ethanol group SOD activity was lower than in animals of the control group. In rats treated with omega-3 fatty acids along with ethanol SOD, activity increased. GSH-Px activity and MDA levels in animals of all groups were similar. In ethanol treated rats NO levels significantly decreased as compared to the animals of the control group (6.45±0.24 nmol/g vs 11.05±0.53 nmol/g, p.


Assuntos
Córtex Cerebral , Etanol , Ácidos Graxos Ômega-3 , Óxido Nítrico , Ratos Wistar , Superóxido Dismutase , Animais , Masculino , Ratos , Ácidos Graxos Ômega-3/farmacologia , Córtex Cerebral/metabolismo , Córtex Cerebral/efeitos dos fármacos , Óxido Nítrico/metabolismo , Superóxido Dismutase/metabolismo , Glutationa Peroxidase/metabolismo , Antioxidantes/farmacologia , Malondialdeído/metabolismo
13.
Hum Brain Mapp ; 45(7): e26703, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38716714

RESUMO

The default mode network (DMN) lies towards the heteromodal end of the principal gradient of intrinsic connectivity, maximally separated from the sensory-motor cortex. It supports memory-based cognition, including the capacity to retrieve conceptual and evaluative information from sensory inputs, and to generate meaningful states internally; however, the functional organisation of DMN that can support these distinct modes of retrieval remains unclear. We used fMRI to examine whether activation within subsystems of DMN differed as a function of retrieval demands, or the type of association to be retrieved, or both. In a picture association task, participants retrieved semantic associations that were either contextual or emotional in nature. Participants were asked to avoid generating episodic associations. In the generate phase, these associations were retrieved from a novel picture, while in the switch phase, participants retrieved a new association for the same image. Semantic context and emotion trials were associated with dissociable DMN subnetworks, indicating that a key dimension of DMN organisation relates to the type of association being accessed. The frontotemporal and medial temporal DMN showed a preference for emotional and semantic contextual associations, respectively. Relative to the generate phase, the switch phase recruited clusters closer to the heteromodal apex of the principal gradient-a cortical hierarchy separating unimodal and heteromodal regions. There were no differences in this effect between association types. Instead, memory switching was associated with a distinct subnetwork associated with controlled internal cognition. These findings delineate distinct patterns of DMN recruitment for different kinds of associations yet common responses across tasks that reflect retrieval demands.


Assuntos
Rede de Modo Padrão , Emoções , Imageamento por Ressonância Magnética , Rememoração Mental , Semântica , Humanos , Masculino , Feminino , Adulto , Adulto Jovem , Emoções/fisiologia , Rede de Modo Padrão/fisiologia , Rede de Modo Padrão/diagnóstico por imagem , Rememoração Mental/fisiologia , Córtex Cerebral/fisiologia , Córtex Cerebral/diagnóstico por imagem , Rede Nervosa/fisiologia , Rede Nervosa/diagnóstico por imagem , Mapeamento Encefálico , Reconhecimento Visual de Modelos/fisiologia
14.
Science ; 384(6696): eadk4858, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38723085

RESUMO

To fully understand how the human brain works, knowledge of its structure at high resolution is needed. Presented here is a computationally intensive reconstruction of the ultrastructure of a cubic millimeter of human temporal cortex that was surgically removed to gain access to an underlying epileptic focus. It contains about 57,000 cells, about 230 millimeters of blood vessels, and about 150 million synapses and comprises 1.4 petabytes. Our analysis showed that glia outnumber neurons 2:1, oligodendrocytes were the most common cell, deep layer excitatory neurons could be classified on the basis of dendritic orientation, and among thousands of weak connections to each neuron, there exist rare powerful axonal inputs of up to 50 synapses. Further studies using this resource may bring valuable insights into the mysteries of the human brain.


Assuntos
Neurônios , Sinapses , Lobo Temporal , Humanos , Neurônios/ultraestrutura , Sinapses/fisiologia , Sinapses/ultraestrutura , Oligodendroglia/citologia , Neuroglia , Córtex Cerebral/irrigação sanguínea , Córtex Cerebral/citologia , Córtex Cerebral/ultraestrutura , Dendritos/fisiologia , Axônios/fisiologia , Axônios/ultraestrutura
15.
Cereb Cortex ; 34(5)2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38706137

RESUMO

Schizophrenia has been considered to exhibit sex-related clinical differences that might be associated with distinctly abnormal brain asymmetries between sexes. One hundred and thirty-two antipsychotic-naïve first-episode patients with schizophrenia and 150 healthy participants were recruited in this study to investigate whether cortical asymmetry would exhibit sex-related abnormalities in schizophrenia. After a 1-yr follow-up, patients were rescanned to obtain the effect of antipsychotic treatment on cortical asymmetry. Male patients were found to show increased lateralization index while female patients were found to exhibit decreased lateralization index in widespread regions when compared with healthy participants of the corresponding sex. Specifically, the cortical asymmetry of male and female patients showed contrary trends in the cingulate, orbitofrontal, parietal, temporal, occipital, and insular cortices. This result suggested male patients showed a leftward shift of asymmetry while female patients showed a rightward shift of asymmetry in these above regions that related to language, vision, emotion, and cognition. Notably, abnormal lateralization indices remained stable after antipsychotic treatment. The contrary trends in asymmetry between female and male patients with schizophrenia together with the persistent abnormalities after antipsychotic treatment suggested the altered brain asymmetries in schizophrenia might be sex-related disturbances, intrinsic, and resistant to the effect of antipsychotic therapy.


Assuntos
Antipsicóticos , Córtex Cerebral , Lateralidade Funcional , Imageamento por Ressonância Magnética , Esquizofrenia , Caracteres Sexuais , Humanos , Feminino , Masculino , Esquizofrenia/tratamento farmacológico , Esquizofrenia/patologia , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/fisiopatologia , Adulto , Córtex Cerebral/diagnóstico por imagem , Adulto Jovem , Antipsicóticos/uso terapêutico , Lateralidade Funcional/fisiologia , Adolescente , Mapeamento Encefálico
16.
eNeuro ; 11(5)2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38702194

RESUMO

Elicited upon violation of regularity in stimulus presentation, mismatch negativity (MMN) reflects the brain's ability to perform automatic comparisons between consecutive stimuli and provides an electrophysiological index of sensory error detection whereas P300 is associated with cognitive processes such as updating of the working memory. To date, there has been extensive research on the roles of MMN and P300 individually, because of their potential to be used as clinical markers of consciousness and attention, respectively. Here, we intend to explore with an unsupervised and rigorous source estimation approach, the underlying cortical generators of MMN and P300, in the context of prediction error propagation along the hierarchies of brain information processing in healthy human participants. The existing methods of characterizing the two ERPs involve only approximate estimations of their amplitudes and latencies based on specific sensors of interest. Our objective is twofold: first, we introduce a novel data-driven unsupervised approach to compute latencies and amplitude of ERP components accurately on an individual-subject basis and reconfirm earlier findings. Second, we demonstrate that in multisensory environments, MMN generators seem to reflect a significant overlap of "modality-specific" and "modality-independent" information processing while P300 generators mark a shift toward completely "modality-independent" processing. Advancing earlier understanding that multisensory contexts speed up early sensory processing, our study reveals that temporal facilitation extends to even the later components of prediction error processing, using EEG experiments. Such knowledge can be of value to clinical research for characterizing the key developmental stages of lifespan aging, schizophrenia, and depression.


Assuntos
Eletroencefalografia , Potenciais Evocados P300 , Humanos , Masculino , Feminino , Adulto , Eletroencefalografia/métodos , Adulto Jovem , Potenciais Evocados P300/fisiologia , Percepção Auditiva/fisiologia , Córtex Cerebral/fisiologia , Estimulação Acústica/métodos , Potenciais Evocados/fisiologia
17.
J Affect Disord ; 345: 410-418, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38706461

RESUMO

A persistent and influential barrier to effective cognitive-behavioral therapy (CBT) for patients with hoarding disorder (HD) is treatment retention and compliance. Recent research has suggested that HD patients have abnormal brain activity identified by functional magnetic resonance (fMRI) in regions often engaged for executive functioning (e.g., right superior frontal gyrus, anterior insula, and anterior cingulate), which raises questions about whether these abnormalities could relate to patients' ability to attend, understand, and engage in HD treatment. We examined data from 74 HD-diagnosed adults who completed fMRI-measured brain activity during a discarding task designed to elicit symptom-related brain dysfunction, exploring which regions' activity might predict treatment compliance variables, including treatment engagement (within-session compliance), homework completion (between-session compliance), and treatment attendance. Brain activity that was significantly related to within- and between-session compliance was found largely in insula, parietal, and premotor areas. No brain regions were associated with treatment attendance. The results add to findings from prior research that have found prefrontal, cingulate, and insula activity abnormalities in HD by suggesting that some aspects of HD brain dysfunction might play a role in preventing the engagement needed for therapeutic benefit.


Assuntos
Terapia Cognitivo-Comportamental , Transtorno de Acumulação , Imageamento por Ressonância Magnética , Psicoterapia de Grupo , Humanos , Transtorno de Acumulação/terapia , Transtorno de Acumulação/fisiopatologia , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Encéfalo/fisiopatologia , Encéfalo/diagnóstico por imagem , Cooperação do Paciente/estatística & dados numéricos , Córtex Cerebral/fisiopatologia , Córtex Cerebral/diagnóstico por imagem , Idoso , Função Executiva/fisiologia , Giro do Cíngulo/fisiopatologia , Giro do Cíngulo/diagnóstico por imagem
18.
Neuron ; 112(9): 1373-1375, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38697018

RESUMO

Maternal well-being is important for the development of the fetus, with a key influence on its nervous system. In this issue of Neuron, Krontira et al.1 implicate glucocorticoids, the stress hormones, in the regulation of neural stem cell identity and proliferation, with long-lasting consequences on brain architecture and educational attainment.


Assuntos
Glucocorticoides , Neurogênese , Humanos , Glucocorticoides/farmacologia , Neurogênese/efeitos dos fármacos , Neurogênese/fisiologia , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/citologia , Células-Tronco Neurais/efeitos dos fármacos
19.
Cereb Cortex ; 34(5)2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38741271

RESUMO

This study investigates abnormalities in cerebellar-cerebral static and dynamic functional connectivity among patients with acute pontine infarction, examining the relationship between these connectivity changes and behavioral dysfunction. Resting-state functional magnetic resonance imaging was utilized to collect data from 45 patients within seven days post-pontine infarction and 34 normal controls. Seed-based static and dynamic functional connectivity analyses identified divergences in cerebellar-cerebral connectivity features between pontine infarction patients and normal controls. Correlations between abnormal functional connectivity features and behavioral scores were explored. Compared to normal controls, left pontine infarction patients exhibited significantly increased static functional connectivity within the executive, affective-limbic, and motor networks. Conversely, right pontine infarction patients demonstrated decreased static functional connectivity in the executive, affective-limbic, and default mode networks, alongside an increase in the executive and motor networks. Decreased temporal variability of dynamic functional connectivity was observed in the executive and default mode networks among left pontine infarction patients. Furthermore, abnormalities in static and dynamic functional connectivity within the executive network correlated with motor and working memory performance in patients. These findings suggest that alterations in cerebellar-cerebral static and dynamic functional connectivity could underpin the behavioral dysfunctions observed in acute pontine infarction patients.


Assuntos
Infartos do Tronco Encefálico , Cerebelo , Imageamento por Ressonância Magnética , Vias Neurais , Ponte , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Cerebelo/fisiopatologia , Cerebelo/diagnóstico por imagem , Vias Neurais/fisiopatologia , Vias Neurais/diagnóstico por imagem , Ponte/diagnóstico por imagem , Ponte/fisiopatologia , Infartos do Tronco Encefálico/fisiopatologia , Infartos do Tronco Encefálico/diagnóstico por imagem , Idoso , Adulto , Córtex Cerebral/fisiopatologia , Córtex Cerebral/diagnóstico por imagem , Rede Nervosa/fisiopatologia , Rede Nervosa/diagnóstico por imagem
20.
Med Sci Monit ; 30: e943802, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38741355

RESUMO

BACKGROUND The thalamocortical tract (TCT) links nerve fibers between the thalamus and cerebral cortex, relaying motor/sensory information. The default mode network (DMN) comprises bilateral, symmetrical, isolated cortical regions of the lateral and medial parietal and temporal brain cortex. The Coma Recovery Scale-Revised (CRS-R) is a standardized neurobehavioral assessment of disorders of consciousness (DOC). In the present study, 31 patients with hypoxic-ischemic brain injury (HI-BI) were compared for changes in the TCT and DMN with consciousness levels assessed using the CRS-R. MATERIAL AND METHODS In this retrospective study, 31 consecutive patients with HI-BI (17 DOC,14 non-DOC) and 17 age- and sex-matched normal control subjects were recruited. Magnetic resonance imaging was used to diagnose HI-BI, and the CRS-R was used to evaluate consciousness levels at the time of diffusion tensor imaging (DTI). The fractional anisotropy (FA) values and tract volumes (TV) of the TCT and DMN were compared. RESULTS In patients with DOC, the FA values and TV of both the TCT and DMN were significantly lower compared to those of patients without DOC and the control subjects (p<0.05). When comparing the non-DOC and control groups, the TV of the TCT and DMN were significantly lower in the non-DOC group (p<0.05). Moreover, the CRS-R score had strong positive correlations with the TV of the TCT (r=0.501, p<0.05), FA of the DMN (r=0.532, p<0.05), and TV of the DMN (r=0.501, p<0.05) in the DOC group. CONCLUSIONS This study suggests that both the TCT and DMN exhibit strong correlations with consciousness levels in DOC patients with HI-BI.


Assuntos
Córtex Cerebral , Coma , Estado de Consciência , Imagem de Tensor de Difusão , Hipóxia-Isquemia Encefálica , Tálamo , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Tálamo/fisiopatologia , Tálamo/diagnóstico por imagem , Hipóxia-Isquemia Encefálica/fisiopatologia , Hipóxia-Isquemia Encefálica/diagnóstico por imagem , Adulto , Estado de Consciência/fisiologia , Imagem de Tensor de Difusão/métodos , Córtex Cerebral/fisiopatologia , Córtex Cerebral/diagnóstico por imagem , Estudos Retrospectivos , Coma/fisiopatologia , Coma/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Rede de Modo Padrão/fisiopatologia , Rede de Modo Padrão/diagnóstico por imagem , Transtornos da Consciência/fisiopatologia , Transtornos da Consciência/diagnóstico por imagem , Idoso
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