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1.
Sci Rep ; 12(1): 2969, 2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35194054

RESUMO

Neuropsychological studies reported that shift workers show reduced cognitive performance and circadian dysfunctions which may impact structural and functional brain networks. Here we tested the hypothesis whether night shift work is associated with resting-state functional connectivity (RSFC), cortical thickness and gray matter volume in participants of the 1000BRAINS study for whom information on night shift work and imaging data were available. 13 PRESENT and 89 FORMER night shift workers as well as 430 control participants who had never worked in shift (NEVER) met these criteria and were included in our study. No associations between night shift work, three graph-theoretical measures of RSFC of 7 functional brain networks and brain morphology were found after multiple comparison correction. Preceding multiple comparison correction, our results hinted at an association between more years of shift work and higher segregation of the visual network in PRESENT shift workers and between shift work experience and lower gray matter volume of the left thalamus. Extensive neuropsychological investigations supplementing objective imaging methodology did not reveal an association between night shift work and cognition after multiple comparison correction. Our pilot study suggests that night shift work does not elicit general alterations in brain networks and affects the brain only to a limited extent. These results now need to be corroborated in studies with larger numbers of participants.


Assuntos
Encéfalo/fisiopatologia , Cognição , Rede Nervosa/fisiopatologia , Jornada de Trabalho em Turnos , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto
2.
Neural Plast ; 2022: 9941832, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35035474

RESUMO

Background: Visual symptoms are common in patients with migraine, even in interictal periods. The purpose was to assess the association between dynamic functional connectivity (dFC) of the visual cortex and clinical characteristics in migraine without aura (MwoA) patients. Methods: We enrolled fifty-five MwoA patients as well as fifty gender- and age-matched healthy controls. Regional visual cortex alterations were investigated using regional homogeneity (ReHo) and amplitude of low-frequency fluctuation (ALFF). Then, significant regions were selected as seeds for conducting dFC between the visual cortex and the whole brain. Results: Relative to healthy controls, MwoA patients exhibited decreased ReHo and ALFF values in the right lingual gyrus (LG) and increased ALFF values in the prefrontal cortex. The right LG showed abnormal dFC within the visual cortex and with other core brain networks. Additionally, ReHo values for the right LG were correlated with duration of disease and ALFF values of the right inferior frontal gyrus and middle frontal gyrus were correlated with headache frequency and anxiety scores, respectively. Moreover, the abnormal dFC of the right LG with bilateral cuneus was positively correlated with anxiety scores. Conclusions: The dFC abnormalities of the visual cortex may be involved in pain integration with multinetworks and associated with anxiety disorder in episodic MwoA patients.


Assuntos
Encéfalo/diagnóstico por imagem , Enxaqueca sem Aura/diagnóstico por imagem , Rede Nervosa/diagnóstico por imagem , Vias Visuais/diagnóstico por imagem , Adulto , Encéfalo/fisiopatologia , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Enxaqueca sem Aura/fisiopatologia , Rede Nervosa/fisiopatologia , Vias Visuais/fisiopatologia , Adulto Jovem
3.
Sci Rep ; 12(1): 114, 2022 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-34997092

RESUMO

Microglia are subject to change in tandem with the endogenously generated biological oscillations known as our circadian rhythm. Studies have shown microglia harbor an intrinsic molecular clock which regulates diurnal changes in morphology and influences inflammatory responses. In the adult brain, microglia play an important role in the regulation of condensed extracellular matrix structures called perineuronal nets (PNNs), and it has been suggested that PNNs are also regulated in a circadian and diurnal manner. We sought to determine whether microglia mediate the diurnal regulation of PNNs via CSF1R inhibitor dependent microglial depletion in C57BL/6J mice, and how the absence of microglia might affect cortical diurnal gene expression rhythms. While we observe diurnal differences in microglial morphology, where microglia are most ramified at the onset of the dark phase, we do not find diurnal differences in PNN intensity. However, PNN intensity increases across many brain regions in the absence of microglia, supporting a role for microglia in the regulation of PNNs. Here, we also show that cortical diurnal gene expression rhythms are intact, with no cycling gene changes without microglia. These findings demonstrate a role for microglia in the maintenance of PNNs, but not in the maintenance of diurnal rhythms.


Assuntos
Ondas Encefálicas , Ritmo Circadiano , Microglia/patologia , Rede Nervosa/patologia , Córtex Somatossensorial/patologia , Animais , Ondas Encefálicas/efeitos dos fármacos , Ritmo Circadiano/efeitos dos fármacos , Ritmo Circadiano/genética , Peptídeos e Proteínas de Sinalização do Ritmo Circadiano/genética , Peptídeos e Proteínas de Sinalização do Ritmo Circadiano/metabolismo , Regulação da Expressão Gênica , Masculino , Camundongos Endogâmicos C57BL , Microglia/efeitos dos fármacos , Microglia/metabolismo , Rede Nervosa/efeitos dos fármacos , Rede Nervosa/metabolismo , Rede Nervosa/fisiopatologia , Compostos Orgânicos/farmacologia , Receptores de Fator Estimulador das Colônias de Granulócitos e Macrófagos/antagonistas & inibidores , Receptores de Fator Estimulador das Colônias de Granulócitos e Macrófagos/metabolismo , Córtex Somatossensorial/efeitos dos fármacos , Córtex Somatossensorial/metabolismo , Córtex Somatossensorial/fisiopatologia , Fatores de Tempo
4.
Cells ; 11(2)2022 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-35053352

RESUMO

For Alzheimer's disease (AD), aging is the main risk factor, but whether cognitive impairments due to aging resemble early AD deficits is not yet defined. When working with mouse models of AD, the situation is just as complicated, because only a few studies track the progression of the disease at different ages, and most ignore how the aging process affects control mice. In this work, we addressed this problem by comparing the aging process of PS2APP (AD) and wild-type (WT) mice at the level of spontaneous brain electrical activity under anesthesia. Using local field potential recordings, obtained with a linear probe that traverses the posterior parietal cortex and the entire hippocampus, we analyzed how multiple electrical parameters are modified by aging in AD and WT mice. With this approach, we highlighted AD specific features that appear in young AD mice prior to plaque deposition or that are delayed at 12 and 16 months of age. Furthermore, we identified aging characteristics present in WT mice but also occurring prematurely in young AD mice. In short, we found that reduction in the relative power of slow oscillations (SO) and Low/High power imbalance are linked to an AD phenotype at its onset. The loss of SO connectivity and cortico-hippocampal coupling between SO and higher frequencies as well as the increase in UP-state and burst durations are found in young AD and old WT mice. We show evidence that the aging process is accelerated by the mutant PS2 itself and discuss such changes in relation to amyloidosis and gliosis.


Assuntos
Envelhecimento/patologia , Doença de Alzheimer/patologia , Potenciais de Ação/fisiologia , Doença de Alzheimer/complicações , Doença de Alzheimer/fisiopatologia , Amiloidose/complicações , Amiloidose/patologia , Amiloidose/fisiopatologia , Animais , Ritmo Delta/fisiologia , Progressão da Doença , Gliose/complicações , Gliose/patologia , Gliose/fisiopatologia , Hipocampo/patologia , Camundongos Endogâmicos C57BL , Rede Nervosa/fisiopatologia , Placa Amiloide/complicações , Placa Amiloide/patologia , Placa Amiloide/fisiopatologia
5.
PLoS One ; 17(1): e0262310, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34986206

RESUMO

Neonatal brain injury may impact brain development and lead to lifelong functional impairments. Hypoxic-ischemic encephalopathy (HIE) and congenital heart disease (CHD) are two common causes of neonatal brain injury differing in timing and mechanism. Maturation of whole-brain neural networks can be quantified during development using diffusion magnetic resonance imaging (dMRI) in combination with graph theory metrics. DMRI of 35 subjects with CHD and 62 subjects with HIE were compared to understand differences in the effects of HIE and CHD on the development of network topological parameters and functional outcomes. CHD newborns had worse 12-18 month language (P<0.01) and 30 month cognitive (P<0.01), language (P = 0.05), motor outcomes (P = 0.01). Global efficiency, a metric of brain integration, was lower in CHD (P = 0.03) than in HIE, but transitivity, modularity and small-worldness were similar. After controlling for clinical factors known to affect neurodevelopmental outcomes, we observed that global efficiency was highly associated with 30 month motor outcomes (P = 0.02) in both groups. To explore neural correlates of adverse language outcomes in CHD, we used hypothesis-based and data-driven approaches to identify pathways with altered structural connectivity. We found that connectivity strength in the superior longitudinal fasciculus (SLF) tract 2 was inversely associated with expressive language. After false discovery rate correction, a whole connectome edge analysis identified 18 pathways that were hypoconnected in the CHD cohort as compared to HIE. In sum, our study shows that neonatal structural connectivity predicts early motor development after HIE or in subjects with CHD, and regional SLF connectivity is associated with language outcomes. Further research is needed to determine if and how brain networks change over time and whether those changes represent recovery or ongoing dysfunction. This knowledge will directly inform strategies to optimize neurologic functional outcomes after neonatal brain injury.


Assuntos
Lesões Encefálicas/fisiopatologia , Encéfalo/fisiopatologia , Criança , Conectoma/métodos , Imagem de Difusão por Ressonância Magnética/métodos , Feminino , Cardiopatias Congênitas/fisiopatologia , Humanos , Hipóxia-Isquemia Encefálica/fisiopatologia , Recém-Nascido , Estudos Longitudinais , Imageamento por Ressonância Magnética/métodos , Masculino , Rede Nervosa/fisiopatologia , Vias Neurais/fisiopatologia , Estudos Prospectivos
6.
Brain Res ; 1779: 147787, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35041843

RESUMO

Temporal lobe epilepsy (TLE) is one of the most common focal pharmacotherapy-resistant epilepsy in adults. Previous studies have shown significantly higher numbers of neurons in the neocortical white matter in TLE patients than in controls. The aim of this work was to investigate whether white matter neurons are part of the neuronal circuitry. Therefore, we studied the distribution and density of synapses in surgically resected neocortical tissue of pharmacotherapy-resistant TLE patients. Neocortical white matter of temporal lobe from non-epileptic patients were used as controls. Synapses and neurons were visualized with immunohistochemistry using antibodies against synaptophysin and NeuN, respectively. The presence of synaptophysin in presynaptic terminals was verified by electron microscopy. Quantification of immunostaining was performed and the data of the patients' cognitive tests as well as clinical records were compared to the density of neurons and synapses. Synaptophysin density in the white matter of TLE patients was significantly higher than in controls. In TLE, a significant correlation was found between synaptophysin immunodensity and density of white matter neurons. Neuronal as well as synaptophysin density significantly correlated with scores of verbal memory of TLE patients. Neurosurgical outcome of TLE patients did not significantly correlate with histological data, although, higher neuronal and synaptophysin densities were observed in patients with favorable post-surgical outcome. Our results suggest that white matter neurons in TLE patients receive substantial synaptic input and indicate that white matter neurons may be integrated in epileptic neuronal networks responsible for the development or maintenance of seizures.


Assuntos
Epilepsia Resistente a Medicamentos/fisiopatologia , Epilepsia do Lobo Temporal/fisiopatologia , Neocórtex/fisiopatologia , Rede Nervosa/fisiopatologia , Neurônios/fisiologia , Sinapses/fisiologia , Epilepsia Resistente a Medicamentos/cirurgia , Epilepsia do Lobo Temporal/cirurgia , Humanos , Neocórtex/cirurgia , Sinaptofisina/metabolismo , Aprendizagem Verbal/fisiologia , Substância Branca
7.
Sci Rep ; 12(1): 1319, 2022 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-35079038

RESUMO

Synchronization has an important role in neural networks dynamics that is mostly accompanied by cognitive activities such as memory, learning, and perception. These activities arise from collective neural behaviors and are not totally understood yet. This paper aims to investigate a cortical model from this perspective. Historically, epilepsy has been regarded as a functional brain disorder associated with excessive synchronization of large neural populations. Epilepsy is believed to arise as a result of complex interactions between neural networks characterized by dynamic synchronization. In this paper, we investigated a network of neural populations in a way the dynamics of each node corresponded to the Jansen-Rit neural mass model. First, we study a one-column Jansen-Rit neural mass model for four different input levels. Then, we considered a Watts-Strogatz network of Jansen-Rit oscillators. We observed an epileptic activity in the weak input level. The network is considered to change various parameters. The detailed results including the mean time series, phase spaces, and power spectrum revealed a wide range of different behaviors such as epilepsy, healthy, and a transition between synchrony and asynchrony states. In some points of coupling coefficients, there is an abrupt change in the order parameters. Since the critical state is a dynamic candidate for healthy brains, we considered some measures of criticality and investigated them at these points. According to our study, some markers of criticality can occur at these points, while others may not. This occurrence is a result of the nature of the specific order parameter selected to observe these markers. In fact, The definition of a proper order parameter is key and must be defined properly. Our view is that the critical points exhibit clear characteristics and invariance of scale, instead of some types of markers. As a result, these phase transition points are not critical as they show no evidence of scaling invariance.


Assuntos
Córtex Cerebral/fisiologia , Sincronização Cortical/fisiologia , Epilepsia/fisiopatologia , Modelos Neurológicos , Rede Nervosa/fisiologia , Rede Nervosa/fisiopatologia , Ritmo alfa/fisiologia , Cognição/fisiologia , Humanos , Memória/fisiologia , Neurônios/fisiologia , Percepção/fisiologia
8.
Clin Neurophysiol ; 133: 94-103, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34826646

RESUMO

OBJECTIVE: Amygdala enlargement is increasingly described in association with temporal lobe epilepsies. Its significance, however, remains uncertain both in terms of etiology and its link with psychiatric disorders and of its involvement in the epileptogenic zone. We assessed the epileptogenic networks underlying drug-resistant epilepsy with amygdala enlargement and investigated correlations between clinical features, epileptogenicity and morphovolumetric amygdala characteristics. METHODS: We identified 12 consecutive patients suffering from drug-resistant epilepsy with visually suspected amygdala enlargement and available stereoelectroencephalographic recording. The epileptogenic zone was defined using the Connectivity Epileptogenicity Index. Morphovolumetric measurements were performed using automatic segmentation and co-registration on the 7TAMIbrain Amygdala atlas. RESULTS: The epileptogenic zone involved the enlarged amygdala in all but three cases and corresponded to distributed, temporal-insular, temporal-insular-prefrontal or prefrontal-temporal networks in ten cases, while only two were temporo-mesial networks. Morphovolumetrically, amygdala enlargement was bilateral in 75% of patients. Most patients presented psychiatric comorbidities (anxiety, depression, posttraumatic stress disorder). The level of depression defined by screening questionnaire was positively correlated with the extent of amygdala enlargement. CONCLUSIONS: Drug-resistant epilepsy with amygdala enlargement is heterogeneous; most cases implied "temporal plus" networks. SIGNIFICANCE: The enlarged amygdala could reflect an interaction of stress-mediated limbic network alterations and mechanisms of epileptogenesis.


Assuntos
Tonsila do Cerebelo/fisiopatologia , Epilepsia Resistente a Medicamentos/fisiopatologia , Epilepsias Parciais/fisiopatologia , Rede Nervosa/fisiopatologia , Adolescente , Adulto , Tonsila do Cerebelo/diagnóstico por imagem , Mapeamento Encefálico , Criança , Pré-Escolar , Epilepsia Resistente a Medicamentos/diagnóstico por imagem , Eletroencefalografia , Epilepsias Parciais/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Rede Nervosa/diagnóstico por imagem , Adulto Jovem
9.
Clin Neurophysiol ; 133: 83-93, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34814019

RESUMO

OBJECTIVE: In epilepsy patients, Transcranial Magnetic Stimulation (TMS) may result in the induction and modulation of epileptiform discharges (EDs). We hereby investigate the modulatory effects of TMS on brain connectivity in Genetic Generalized Epilepsy (GGE) and explore their potential as a diagnostic biomarker in GGE. METHODS: Patients with GGE (n=18) and healthy controls (n=11) were investigated with a paired-pulse TMS-EEG protocol. The brain network was studied at local and at global levels using Coherence as an EEG connectivity measure. Comparison of patients vs controls was performed in a time-resolved manner by analyzing comparatively pre- vs post-TMS brain networks. RESULTS: There was statistically significant TMS-induced modulation of connectivity at specific frequency bands within groups and difference in TMS-induced modulation between the two groups. The most significant difference between patients and controls related to connectivity modulation in the γ band at 1-3 sec post-TMS (p=0.004). CONCLUSIONS: TMS modulates the healthy and epileptic brain connectivity in different ways. Our results indicate that TMS-EEG connectivity analysis can be a basis for a diagnostic biomarker of GGE. SIGNIFICANCE: The analysis identifies specific time periods and frequency bands of interest of TMS-induced connectivity modulation and elucidates the effect of TMS on the healthy and epileptic brain connectivity.


Assuntos
Encéfalo/fisiopatologia , Epilepsia Generalizada/diagnóstico , Rede Nervosa/fisiopatologia , Adolescente , Adulto , Eletroencefalografia , Epilepsia Generalizada/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Magnética Transcraniana , Adulto Jovem
10.
Lancet Psychiatry ; 9(1): 84-96, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34774203

RESUMO

Understanding the interface between opioid use disorder (OUD) and post-traumatic stress disorder (PTSD) is challenging. By use of a dimensional framework, such as research domain criteria, convergent and targetable neurobiological processes in OUD-PTSD comorbidity can be identified. We hypothesise that, in OUD-PTSD, circuitry that is implicated in two research domain criteria systems (ie, negative valence and cognitive control) underpins dysregulation of incentive salience, negative emotionality, and executive function. We also propose that the OUD-PTSD state might be systematically investigated with approaches outlined within a neuroclinical assessment framework for addictions and PTSD. Our dimensional analysis of the OUD-PTSD state shows how first-line therapeutic approaches (ie, partial µ-type opioid receptor [MOR1] agonism) modulate overlapping neurobiological and clinical features and also provides mechanistic rationale for evaluating polytherapeutic strategies (ie, partial MOR1 agonism, κ-type opioid receptor [KOR1] antagonism, and α-2A adrenergic receptor [ADRA2A] agonism). A combination of these therapeutic mechanisms is projected to facilitate recovery in patients with OUD-PTSD by mitigating negative valence states and enhancing executive control.


Assuntos
Encéfalo , Disfunção Cognitiva/fisiopatologia , Função Executiva , Rede Nervosa , Transtornos Relacionados ao Uso de Opioides/fisiopatologia , Recompensa , Transtornos de Estresse Pós-Traumáticos/fisiopatologia , Encéfalo/metabolismo , Encéfalo/fisiopatologia , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/metabolismo , Comorbidade , Função Executiva/fisiologia , Humanos , Rede Nervosa/metabolismo , Rede Nervosa/fisiopatologia , Transtornos Relacionados ao Uso de Opioides/epidemiologia , Transtornos Relacionados ao Uso de Opioides/metabolismo , Transtornos Relacionados ao Uso de Opioides/terapia , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Transtornos de Estresse Pós-Traumáticos/metabolismo , Transtornos de Estresse Pós-Traumáticos/terapia
12.
Hum Brain Mapp ; 43(3): 1011-1031, 2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-34738280

RESUMO

The present fMRI study aimed at highlighting patterns of brain activations and autonomic activity when confronted with high mental workload and the threat of auditory stressors. Twenty participants performed a complex cognitive task in either safe or aversive conditions. Our results showed that increased mental workload induced recruitment of the lateral frontoparietal executive control network (ECN), along with disengagement of medial prefrontal and posterior cingulate regions of the default mode network (DMN). Mental workload also elicited an increase in heart rate and pupil diameter. Task performance did not decrease under the threat of stressors, most likely due to efficient inhibition of auditory regions, as reflected by a large decrement of activity in the superior temporal gyri. The threat of stressors was also accompanied with deactivations of limbic regions of the salience network (SN), possibly reflecting emotional regulation mechanisms through control from dorsal medial prefrontal and parietal regions, as indicated by functional connectivity analyses. Meanwhile, the threat of stressors induced enhanced ECN activity, likely for improved attentional and cognitive processes toward the task, as suggested by increased lateral prefrontal and parietal activations. These fMRI results suggest that measuring the balance between ECN, SN, and DMN recruitment could be used for objective mental state assessment. In this sense, an extra recruitment of task-related regions and a high ratio of lateral versus medial prefrontal activity may represent a relevant marker of increased but efficient mental effort, while the opposite may indicate a disengagement from the task due to mental overload and/or stressors.


Assuntos
Sistema Nervoso Autônomo/fisiopatologia , Córtex Cerebral/fisiopatologia , Conectoma , Rede de Modo Padrão/fisiopatologia , Regulação Emocional/fisiologia , Função Executiva/fisiologia , Rede Nervosa/fisiopatologia , Desempenho Psicomotor/fisiologia , Estresse Psicológico/fisiopatologia , Adulto , Córtex Cerebral/diagnóstico por imagem , Rede de Modo Padrão/diagnóstico por imagem , Feminino , Frequência Cardíaca/fisiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Rede Nervosa/diagnóstico por imagem , Pupila/fisiologia , Adulto Jovem
13.
Neuroimage ; 246: 118767, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34856377

RESUMO

The breakdown of rapid and accurate retrieval of words is a hallmark of aphasic speech and a prime target of therapeutic intervention. Complementary, psycho- and neurolinguistic research have developed a spectrum of models, how and by which neuronal network uncompromised speakers can rely on remarkable lexical retrieval capacities. Motivated by both lines of research we invited 32 participants with a chronic left hemispheric brain lesion to name pictures in the presence of distractor words. This picture-word-interference (PWI) paradigm is widely used in psycho- and neurolinguistic research. We find that also after brain lesion categorically related words (CAT â†’ [dog]picture) impede naming, while associatively related words (BONE â†’ [dog]picture) ease access, when compared to unrelated distractor words. The effects largely affecting latencies in neurotypical populations, are reproduced for error rate in our participants with lesions in the language network. Unsurprisingly, overall naming abilities varied greatly across patients. Notably, however, the two effects (categorical interference / associative facilitation) differ between participants. Correlating performance with lesion patterns we find support for the notion of a divergence of brain areas affording different aspects of the task: (i) lesions in the left middle temporal gyurs (MTG) deteriorate overall naming, confirming previous work; more notably, (ii) lesions comprising the inferior frontal hub (inferior frontal gyrus, IFG) of the language-network increase the interference effect for the categorical condition; on the contrary, (iii) lesions to the mid-to-posterior temporal hub (posterior middle and superior temporal gyri, pMTG/ pSTG) increase the facilitatory effect for the associative condition on error rates. The findings can be accommodated in a neuro-linguistic framework, which localizes lexical activation but also lexical interference in posterior parts of the language network (pMTG/pITG); conversely, selection between co-activated categorically related entries is afforded by frontal language areas (IFG). While purely experimental in nature our study highlights that lesion site differentially influences specific aspects of word retrieval. Since confrontational naming is a cornerstone of aphasia rehabilitation, this may be of note when designing and evaluating novel therapeutic regimes.


Assuntos
Afasia , Córtex Cerebral , Disfunção Cognitiva , Rede Nervosa , Reconhecimento Visual de Modelos/fisiologia , Psicolinguística , Adulto , Idoso , Afasia/diagnóstico por imagem , Afasia/patologia , Afasia/fisiopatologia , Associação , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/patologia , Córtex Cerebral/fisiopatologia , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/patologia , Disfunção Cognitiva/fisiopatologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/patologia , Rede Nervosa/fisiopatologia , Semântica
14.
J Neurophysiol ; 127(1): 99-115, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34851739

RESUMO

We explored the relationship between population interneuronal network activation and motor output in the adult, in vivo, air-stepping, spinal cat. By simultaneously measuring the activity of large numbers of spinal interneurons, we explored ensembles of coherently firing interneurons and their relation to motor output. In addition, the networks were analyzed in relation to their spatial distribution along the lumbar enlargement for evidence of localized groups driving particular phases of the locomotor step cycle. We simultaneously recorded hindlimb EMG activity during stepping and extracellular signals from 128 channels across two polytrodes inserted within lamina V-VII of two separate lumbar segments. Results indicated that spinal interneurons participate in one of two ensembles that are highly correlated with the flexor or the extensor muscle bursts during stepping. Interestingly, less than half of the isolated single units were significantly unimodally tuned during the step cycle whereas >97% of the single units of the ensembles were significantly correlated with muscle activity. These results show the importance of population scale analysis in neural studies of behavior as there is a much greater correlation between muscle activity and ensemble firing than between muscle activity and individual neurons. Finally, we show that there is no correlation between interneurons' rostrocaudal locations within the lumbar enlargement and their preferred phase of firing or ensemble participation. These findings indicate that spinal interneurons of lamina V-VII encoding for different phases of the locomotor cycle are spread throughout the lumbar enlargement in the adult spinal cord.NEW & NOTEWORTHY We report on the ensemble organization of interneuronal activity in the spinal cord during locomotor movements and show that lumbar intermediate zone interneurons organize in two groups related to the two major phases of walking: stance and swing. Ensemble organization is also shown to better correlate with muscular output than single-cell activity, although ensemble membership does not appear to be somatotopically organized within the spinal cord.


Assuntos
Interneurônios/fisiologia , Rede Nervosa/fisiopatologia , Traumatismos da Medula Espinal/fisiopatologia , Medula Espinal/fisiopatologia , Caminhada/fisiologia , Animais , Comportamento Animal/fisiologia , Gatos , Geradores de Padrão Central/fisiopatologia , Eletromiografia , Feminino , Membro Posterior/fisiopatologia , Vértebras Lombares
15.
Nat Rev Neurosci ; 23(1): 35-52, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34728833

RESUMO

Various environmental stressors, such as extreme temperatures (hot and cold), pathogens, predators and insufficient food, can threaten life. Remarkable progress has recently been made in understanding the central circuit mechanisms of physiological responses to such stressors. A hypothalamomedullary neural pathway from the dorsomedial hypothalamus (DMH) to the rostral medullary raphe region (rMR) regulates sympathetic outflows to effector organs for homeostasis. Thermal and infection stress inputs to the preoptic area dynamically alter the DMH → rMR transmission to elicit thermoregulatory, febrile and cardiovascular responses. Psychological stress signalling from a ventromedial prefrontal cortical area to the DMH drives sympathetic and behavioural responses for stress coping, representing a psychosomatic connection from the corticolimbic emotion circuit to the autonomic and somatic motor systems. Under starvation stress, medullary reticular neurons activated by hunger signalling from the hypothalamus suppress thermogenic drive from the rMR for energy saving and prime mastication to promote food intake. This Perspective presents a combined neural network for environmental stress responses, providing insights into the central circuit mechanism for the integrative regulation of systemic organs.


Assuntos
Hipotálamo/fisiologia , Hipotálamo/fisiopatologia , Bulbo/fisiologia , Bulbo/fisiopatologia , Rede Nervosa/fisiologia , Rede Nervosa/fisiopatologia , Estresse Fisiológico , Estresse Psicológico/fisiopatologia , Animais , Regulação da Temperatura Corporal/fisiologia , Transtornos de Estresse por Calor/fisiopatologia , Humanos , Vias Neurais/fisiologia
16.
Hum Brain Mapp ; 43(2): 581-592, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34729858

RESUMO

Lifelong bilingualism is associated with delayed dementia onset, suggesting a protective effect on the brain. Here, we aim to study the effects of lifelong bilingualism as a dichotomous and continuous phenomenon, on brain metabolism and connectivity in individuals with Alzheimer's dementia. Ninety-eight patients with Alzheimer's dementia (56 monolinguals; 42 bilinguals) from three centers entered the study. All underwent an [18F]-fluorodeoxyglucose positron emission tomography (PET) imaging session. A language background questionnaire measured the level of language use for conversation and reading. Severity of brain hypometabolism and strength of connectivity of the major neurocognitive networks was compared across monolingual and bilingual individuals, and tested against the frequency of second language life-long usage. Age, years of education, and MMSE score were included in all above mentioned analyses as nuisance covariates. Cerebral hypometabolism was more severe in bilingual compared to monolingual patients; severity of hypometabolism positively correlated with the degree of second language use. The metabolic connectivity analyses showed increased connectivity in the executive, language, and anterior default mode networks in bilingual compared to monolingual patients. The change in neuronal connectivity was stronger in subjects with higher second language use. All effects were most pronounced in the left cerebral hemisphere. The neuroprotective effects of lifelong bilingualism act both against neurodegenerative processes and through the modulation of brain networks connectivity. These findings highlight the relevance of lifelong bilingualism in brain reserve and compensation, supporting bilingual education and social interventions aimed at usage, and maintenance of two or more languages, including dialects, especially crucial in the elderly people.


Assuntos
Doença de Alzheimer/fisiopatologia , Córtex Cerebral/fisiopatologia , Conectoma , Multilinguismo , Rede Nervosa/fisiopatologia , Neuroproteção/fisiologia , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico por imagem , Córtex Cerebral/diagnóstico por imagem , Feminino , Humanos , Masculino , Rede Nervosa/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Fatores de Proteção
17.
Hum Brain Mapp ; 43(2): 844-859, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34716740

RESUMO

Sensorimotor abnormalities are common in autism spectrum disorder (ASD) and predictive of functional outcomes, though their neural underpinnings remain poorly understood. Using functional magnetic resonance imaging, we examined both brain activation and functional connectivity during visuomotor behavior in 27 individuals with ASD and 30 typically developing (TD) controls (ages 9-35 years). Participants maintained a constant grip force while receiving visual feedback at three different visual gain levels. Relative to controls, ASD participants showed increased force variability, especially at high gain, and reduced entropy. Brain activation was greater in individuals with ASD than controls in supplementary motor area, bilateral superior parietal lobules, and contralateral middle frontal gyrus at high gain. During motor action, functional connectivity was reduced between parietal-premotor and parietal-putamen in individuals with ASD compared to controls. Individuals with ASD also showed greater age-associated increases in functional connectivity between cerebellum and visual, motor, and prefrontal cortical areas relative to controls. These results indicate that visuomotor deficits in ASD are associated with atypical activation and functional connectivity of posterior parietal, premotor, and striatal circuits involved in translating sensory feedback information into precision motor behaviors, and that functional connectivity of cerebellar-cortical sensorimotor and nonsensorimotor networks show delayed maturation.


Assuntos
Transtorno do Espectro Autista/fisiopatologia , Encéfalo/fisiopatologia , Conectoma , Rede Nervosa/fisiopatologia , Desempenho Psicomotor/fisiologia , Adolescente , Adulto , Transtorno do Espectro Autista/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Criança , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Rede Nervosa/diagnóstico por imagem , Adulto Jovem
18.
Urology ; 159: 133-138, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34688769

RESUMO

OBJECTIVES: To detect seed-based functional connectivity (FC) between various cortical sub-regions and the thalamus in lifelong premature ejaculation (LPE) patients and explore whether specific thalamocortical networks are significantly altered in PE patients compared to healthy controls (HCs) METHODS: Fifty non-medicated LPE patients and 40 age-matched HCs underwent a resting-state functional MRI. FC was adopted to identify specific thalamocortical connectivity between the thalamus and 6 cortical regions of interest (i.e., the motor cortex/supplementary motor, the prefrontal cortex, the temporal lobe, the posterior parietal cortex, the somatosensory cortex and the occipital lobe). In LPE patients, regression analysis was subsequently conducted to assess relationships of thalamocortical connectivity with the Premature Ejaculation Diagnostic Tool (PEDT) score and the Intravaginal Ejaculatory Latency Time (IELT). RESULTS: LPE patients had significantly decreased FC between the motor cortex and bilateral ventral thalamus, between the prefrontal cortex and left dorsomedial thalamus, as well as between the temporal cortex and bilateral ventromedial thalamus. In LPE patients, PEDT score was significantly positively associated with the thalamus-posterior parietal cortex FC, and negatively associated with the thalamus-temporal cortex FC, while IELT was positively associated with the thalamus-temporal cortex and thalamus-motor cortex FC. CONCLUSION: These results enrich the imaging evidence for the understanding of the neurobiological mechanisms and/or consequences of LPE.


Assuntos
Córtex Cerebral , Conectoma/métodos , Rede Nervosa , Ejaculação Precoce , Tálamo , Adulto , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/fisiopatologia , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Rede Nervosa/patologia , Rede Nervosa/fisiopatologia , Neurofisiologia , Ejaculação Precoce/diagnóstico , Ejaculação Precoce/fisiopatologia , Tálamo/diagnóstico por imagem , Tálamo/fisiopatologia
19.
Hum Brain Mapp ; 43(3): 974-984, 2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-34816523

RESUMO

Recent evidence suggests that presupplementary motor area (pre-SMA) and inferior frontal gyrus (IFG) play an important role in response inhibition. However, no study has investigated the relationship between these brain networks at resting-state and response inhibition in obsessive-compulsive disorder (OCD). We performed resting-state functional magnetic resonance imaging scans and then measured the response inhibition of 41 medication-free OCD patients and 49 healthy control (HC) participants by using the stop-signal task outside the scanner. We explored the differences between OCD and HC groups in the functional connectivity of pre-SMA and IFG associated with the ability of motor response inhibition. OCD patients showed a longer stop-signal reaction time (SSRT). Compared to HC, OCD patients exhibit different associations between the ability of motor response inhibition and the functional connectivity between pre-SMA and IFG, inferior parietal lobule, dorsal anterior cingulate cortex, insula, and anterior prefrontal cortex. Additional analysis to investigate the functional connectivity difference from the seed ROIs to the whole brain voxels revealed that, compared to HC, OCD exhibited greater functional connectivity between pre-SMA and IFG. Also, this functional connectivity was positively correlated with the SSRT score. These results provide additional insight into the characteristics of the resting-state functional connectivity of the regions belonging to the cortico-striato-thalamo-cortical circuit and the cingulo-opercular salience network, underlying the impaired motor response inhibition of OCD. In particular, we emphasize the importance of altered functional connectivity between pre-SMA and IFG for the pathophysiology of motor response inhibition in OCD.


Assuntos
Córtex Cerebral/fisiopatologia , Conectoma , Corpo Estriado/fisiopatologia , Inibição Psicológica , Atividade Motora/fisiologia , Córtex Motor/fisiopatologia , Rede Nervosa/fisiopatologia , Transtorno Obsessivo-Compulsivo/fisiopatologia , Tálamo/fisiopatologia , Adulto , Córtex Cerebral/diagnóstico por imagem , Corpo Estriado/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Córtex Motor/diagnóstico por imagem , Rede Nervosa/diagnóstico por imagem , Transtorno Obsessivo-Compulsivo/diagnóstico por imagem , Tálamo/diagnóstico por imagem , Adulto Jovem
20.
J Neurophysiol ; 127(1): 146-149, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34879212

RESUMO

Adolescence is a developmental period associated with major neural reorganization and the onset of many psychological disorders. Depression in particular is prevalent and impairing in adolescents and rates have been rising in recent years. Recent advances in the neurobiology of adolescent depression contribute to a better understanding of functional connectivity among neural networks and represent a promising start for determining biomarkers of depression and potential areas of intervention.


Assuntos
Encéfalo/fisiopatologia , Conectoma , Depressão/fisiopatologia , Transtorno Depressivo/fisiopatologia , Rede Nervosa/fisiopatologia , Adolescente , Encéfalo/diagnóstico por imagem , Depressão/diagnóstico por imagem , Transtorno Depressivo/diagnóstico por imagem , Humanos , Rede Nervosa/diagnóstico por imagem
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