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2.
Zhongguo Zhen Jiu ; 41(10): 1074-8, 2021 Oct 12.
Artigo em Chinês | MEDLINE | ID: mdl-34628737

RESUMO

OBJECTIVE: To investigate the effect of acupuncture on default mode network (DMN) in migraine patients without aura based on functional Magnetic Resonance Imaging (fMRI). METHODS: Fifteen patients with migraine were included and treated with acupuncture based on "root-knot" theory (Zuqiaoyin [GB 44] for shaoyang headache, Lidui [ST 45] for yangming headache, Zhiyin [BL 67] for taiyang headache, and ashi point), once every other day, three times a week for 4 weeks. The patients received fMRI scanning before and after acupuncture treatment, the effect of acupuncture on DMN in patients with migraine was observed; the frequency of migraine attack, visual analogue scale (VAS) score and the using of analgesic medication before and after treatment were recorded to evaluate the curative effect of acupuncture; the migraine-specific quality of life questionnaire (MSQ), self-rating anxiety scale (SAS) and self-rating depression scale (SDS) were used to evaluate the improvements of quality of life and emotional state. RESULTS: Compared before acupuncture, the functional connections of left parahippocampal cortex (PHC) and anterior medial prefrontal cortex (aMPFC), dorsal medial prefrontal cortex (dMPFC) and lateral temporal cortex (LTC) in DMN after acupuncture were weakened (P<0.05), and the functional connections of bilateral posterior cingulate cortex (PCC) and dMPFC were weakened (P<0.05). Compared before treatment, the frequency of migraine attack, VAS, SAS and SDS scores after treatment were decreased (P<0.05), and MSQ score was increased (P<0.05). CONCLUSION: Acupuncture shows good clinical efficacy for migraine without aura, and could adjust the functional connection of DMN.


Assuntos
Terapia por Acupuntura , Transtornos de Enxaqueca , Mapeamento Encefálico , Rede de Modo Padrão , Humanos , Espectroscopia de Ressonância Magnética , Transtornos de Enxaqueca/diagnóstico por imagem , Transtornos de Enxaqueca/terapia , Qualidade de Vida
3.
BMC Neurol ; 21(1): 353, 2021 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-34517828

RESUMO

BACKGROUND: The aim of this study was to investigate whether default mode network (DMN) connectivity and brain white matter integrity at baseline were associated with severe cognitive impairments at baseline and poor cognitive outcomes after shunt placement in patients with idiopathic normal pressure hydrocephalus (iNPH). METHODS: Twenty consecutive patients with iNPH whose symptoms were followed for 6 months after shunt placement and 10 healthy controls (HCs) were enrolled. DMN connectivity and brain white matter integrity at baseline in the patients with iNPH and HCs were detected by using resting-state functional magnetic resonance imaging (MRI) with independent component analysis and diffusion tensor imaging, respectively, and these MRI indexes were compared between the patients with iNPH and HCs. Performance on neuropsychological tests for memory and executive function and on the gait test was assessed in the patients with iNPH at baseline and 6 months after shunt placement. We divided the patients with iNPH into the relatively preserved and reduced DMN connectivity groups using the MRI indexes for DMN connectivity and brain white matter integrity, and the clinical measures were compared between the relatively preserved and reduced DMN connectivity groups. RESULTS: Mean DMN connectivity in the iNPH group was significantly lower than that in the HC group and was significantly positively correlated with Rey auditory verbal learning test (RAVLT) immediate recall scores and frontal assessment battery (FAB) scores. Mean fractional anisotropy of the whole-brain white matter skeleton in the iNPH group was significantly lower than that in the HC group. The reduced DMN connectivity group showed significantly worse performance on the RAVLT at baseline and significantly worse improvement in the RAVLT immediate recall and recognition scores and the FAB scores than the preserved DMN connectivity group. Moreover, the RAVLT recognition score highly discriminated patients with relatively preserved DMN connectivity from those with relatively reduced DMN connectivity. CONCLUSIONS: Our findings indicated that iNPH patients with reduced DMN connectivity relative to the severity of brain white matter disruption have severe memory deficits at baseline and poorer cognitive outcomes after shunt placement. However, further larger-scale studies are needed to confirm these findings.


Assuntos
Hidrocefalia de Pressão Normal , Substância Branca , Cognição , Rede de Modo Padrão , Imagem de Tensor de Difusão , Humanos , Hidrocefalia de Pressão Normal/diagnóstico por imagem , Imageamento por Ressonância Magnética , Testes Neuropsicológicos , Substância Branca/diagnóstico por imagem
4.
Neuroscience ; 475: 93-102, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34487819

RESUMO

Two different but interacting neural systems exist in the human brain: the task positive networks and task negative networks. One of the most important task positive networks is the central executive network (CEN), while the task negative network generally refers to the default mode network (DMN), which usually demonstrates task-induced deactivation. Although previous studies have clearly shown the association of both the CEN and DMN with major depressive disorder (MDD), how the causal interactions between these two networks change in depressed patients remains unclear. In the current study, 99 subjects (43 patients with MDD and 56 healthy controls) were recruited with their resting-state fMRI data collected. After data preprocessing, spectral dynamic causal modeling (spDCM) was used to investigate the causal interactions within and between the DMN and CEN. Group commonalities and differences in causal interaction patterns within and between the CEN and DMN in patients and controls were assessed by a parametric empirical Bayes (PEB) model. Both subject groups demonstrated significant effective connectivity between regions of the CEN and DMN. In particular, we detected inhibitory influences from the CEN to the DMN with node-level PEB analyses, which may help to explain the anticorrelations between these two networks consistently reported in previous studies. Compared with healthy controls, patients with MDD showed increased effective connectivity within the CEN and decreased connectivity from regions of the CEN to DMN, suggesting impaired control of the DMN by the CEN in these patients. These findings might provide new insights into the neural substrates of MDD.


Assuntos
Transtorno Depressivo Maior , Teorema de Bayes , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Rede de Modo Padrão , Depressão , Transtorno Depressivo Maior/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Rede Nervosa/diagnóstico por imagem
5.
J Psychiatr Res ; 142: 258-262, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34392052

RESUMO

Deaths due to suicide are one of the leading causes of mortality among youths and young adults. Active suicidal ideation (SI) is considered one of the strongest risk factors for suicide. Here, we evaluated the neurocircuitry of SI in a sample of youths and young adults (aged 10-26 years) with current or past diagnosis of either major depression or bipolar disorder who were enrolled in Texas Resilience Against Depression Study (T-RAD), and had neuroimaging and SI (assessed with the 3-item Suicidal Thoughts factor of Concise Health Risk Tracking self-report scale) data available (n = 72, 53 females). Resting-state functional connectivity (FC) was computed amongst 121 cortical and subcortical regions of interest resulting in 7260 FC pairs. Mean (SD) age and SI levels of participants were 19.6 years (4.01) and 1.48 (2.36) respectively. In univariate analyses, 34 out of the 7260 FC pairs were correlated with SI (p < .005). Stronger connectivity of default mode network (DMN) with striatum was associated with higher SI. Conversely, higher SI was associated with weaker connectivity of limbic network with hippocampus, DMN, dorsal attention network, and executive control network. In multivariate analyses, these 34 FC pairs together had an average correlation of 0.54 after five-fold cross-validation. In conclusion, SI was associated with distinct patterns of resting-state functional connectivity among youths and young adults with regions in DMN and the ventral striatum as key nodes.


Assuntos
Depressão , Ideação Suicida , Adolescente , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Rede de Modo Padrão , Feminino , Humanos , Imageamento por Ressonância Magnética , Texas , Adulto Jovem
6.
Neuroimage ; 240: 118382, 2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34252524

RESUMO

Self-construal (orientations of independence and interdependence) is a fundamental concept that guides human behaviour, and it is linked to a large number of brain regions. However, understanding the connectivity of these regions and the critical principles underlying these self-functions are lacking. Because brain activity linked to self-related processes are intrinsic, the resting-state method has received substantial attention. Here, we focused on resting-state functional connectivity matrices based on brain asymmetry as indexed by the differential partition of the connectivity located in mirrored positions of the two hemispheres, hemispheric specialization measured using the intra-hemispheric (left or right) connectivity, brain communication via inter-hemispheric interactions, and global connectivity as the sum of the two intra-hemispheric connectivity. Combining machine learning techniques with hypothesis-driven network mapping approaches, we demonstrated that orientations of independence and interdependence were best predicted by the asymmetric matrix compared to brain communication, hemispheric specialization, and global connectivity matrices. The network results revealed that there were distinct asymmetric connections between the default mode network, the salience network and the executive control network which characterise independence and interdependence. These analyses shed light on the importance of brain asymmetry in understanding how complex self-functions are optimally represented in the brain networks.


Assuntos
Encéfalo/fisiologia , Rede de Modo Padrão/fisiologia , Função Executiva/fisiologia , Lateralidade Funcional/fisiologia , Aprendizado de Máquina , Imageamento por Ressonância Magnética/métodos , Adolescente , Adulto , Encéfalo/diagnóstico por imagem , Rede de Modo Padrão/diagnóstico por imagem , Feminino , Humanos , Masculino , Adulto Jovem
7.
Neuroimage ; 240: 118379, 2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34252527

RESUMO

Mapping the structural and functional connectivity of the central nervous system has become a key area within neuroimaging research. While detailed network structures across the entire brain have been probed using animal models, non-invasive neuroimaging in humans has thus far been dominated by cortical investigations. Beyond the cortex, subcortical nuclei have traditionally been less accessible due to their smaller size and greater distance from radio frequency coils. However, major neuroimaging developments now provide improved signal and the resolution required to study these structures. Here, we present an overview of the connectivity between the amygdala, brainstem, cerebellum, spinal cord and the rest of the brain. While limitations to their imaging and analyses remain, we also provide some recommendations and considerations for mapping brain connectivity beyond the cortex.


Assuntos
Conectoma , Imageamento por Ressonância Magnética/métodos , Tonsila do Cerebelo/diagnóstico por imagem , Animais , Tronco Encefálico/diagnóstico por imagem , Cerebelo/diagnóstico por imagem , Rede de Modo Padrão , Imagem de Tensor de Difusão/métodos , Humanos , Razão Sinal-Ruído , Medula Espinal/diagnóstico por imagem
8.
Proc Natl Acad Sci U S A ; 118(27)2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34193521

RESUMO

The finding of reduced functional MRI (fMRI) activity in the default mode network (DMN) during externally focused cognitive control has been highly influential to our understanding of human brain function. However, these negative fMRI responses, measured as relative decreases in the blood-oxygenation-level-dependent (BOLD) response between rest and task, have also prompted major questions of interpretation. Using hybrid functional positron emission tomography (PET)-MRI, this study shows that task-positive and -negative BOLD responses do not reflect antagonistic patterns of synaptic metabolism. Task-positive BOLD responses in attention and control networks were accompanied by concomitant increases in glucose metabolism during cognitive control, but metabolism in widespread DMN remained high during rest and task despite negative BOLD responses. Dissociations between glucose metabolism and the BOLD response specific to the DMN reveal functional heterogeneity in this network and demonstrate that negative BOLD responses during cognitive control should not be interpreted to reflect relative increases in metabolic activity during rest. Rather, neurovascular coupling underlying BOLD response patterns during rest and task in DMN appears fundamentally different from BOLD responses in other association networks during cognitive control.


Assuntos
Rede de Modo Padrão/metabolismo , Glucose/metabolismo , Imageamento por Ressonância Magnética , Oxigênio/sangue , Tomografia por Emissão de Pósitrons , Adulto , Atenção/fisiologia , Feminino , Fluordesoxiglucose F18/metabolismo , Humanos , Masculino , Análise e Desempenho de Tarefas , Adulto Jovem
9.
Sensors (Basel) ; 21(12)2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34203578

RESUMO

Recent brain imaging findings by using different methods (e.g., fMRI and PET) have suggested that social anxiety disorder (SAD) is correlated with alterations in regional or network-level brain function. However, due to many limitations associated with these methods, such as poor temporal resolution and limited number of samples per second, neuroscientists could not quantify the fast dynamic connectivity of causal information networks in SAD. In this study, SAD-related changes in brain connections within the default mode network (DMN) were investigated using eight electroencephalographic (EEG) regions of interest. Partial directed coherence (PDC) was used to assess the causal influences of DMN regions on each other and indicate the changes in the DMN effective network related to SAD severity. The DMN is a large-scale brain network basically composed of the mesial prefrontal cortex (mPFC), posterior cingulate cortex (PCC)/precuneus, and lateral parietal cortex (LPC). The EEG data were collected from 88 subjects (22 control, 22 mild, 22 moderate, 22 severe) and used to estimate the effective connectivity between DMN regions at different frequency bands: delta (1-3 Hz), theta (4-8 Hz), alpha (8-12 Hz), low beta (13-21 Hz), and high beta (22-30 Hz). Among the healthy control (HC) and the three considered levels of severity of SAD, the results indicated a higher level of causal interactions for the mild and moderate SAD groups than for the severe and HC groups. Between the control and the severe SAD groups, the results indicated a higher level of causal connections for the control throughout all the DMN regions. We found significant increases in the mean PDC in the delta (p = 0.009) and alpha (p = 0.001) bands between the SAD groups. Among the DMN regions, the precuneus exhibited a higher level of causal influence than other regions. Therefore, it was suggested to be a major source hub that contributes to the mental exploration and emotional content of SAD. In contrast to the severe group, HC exhibited higher resting-state connectivity at the mPFC, providing evidence for mPFC dysfunction in the severe SAD group. Furthermore, the total Social Interaction Anxiety Scale (SIAS) was positively correlated with the mean values of the PDC of the severe SAD group, r (22) = 0.576, p = 0.006 and negatively correlated with those of the HC group, r (22) = -0.689, p = 0.001. The reported results may facilitate greater comprehension of the underlying potential SAD neural biomarkers and can be used to characterize possible targets for further medication.


Assuntos
Fobia Social , Encéfalo , Mapeamento Encefálico , Rede de Modo Padrão , Eletroencefalografia , Humanos , Imageamento por Ressonância Magnética , Rede Nervosa
10.
Nat Rev Neurosci ; 22(8): 503-513, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34226715

RESUMO

The default mode network (DMN) is a set of widely distributed brain regions in the parietal, temporal and frontal cortex. These regions often show reductions in activity during attention-demanding tasks but increase their activity across multiple forms of complex cognition, many of which are linked to memory or abstract thought. Within the cortex, the DMN has been shown to be located in regions furthest away from those contributing to sensory and motor systems. Here, we consider how our knowledge of the topographic characteristics of the DMN can be leveraged to better understand how this network contributes to cognition and behaviour.


Assuntos
Encéfalo/fisiologia , Cognição/fisiologia , Rede de Modo Padrão/fisiologia , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Rede de Modo Padrão/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética
11.
J Alzheimers Dis ; 82(4): 1797-1808, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34219733

RESUMO

BACKGROUND: Previous studies reported default mode network (DMN) and limbic network (LIN) brain perfusion deficits in patients with amnestic mild cognitive impairment (aMCI), frequently a prodromal stage of Alzheimer's disease (AD). However, the validity of these measures as AD markers has not yet been tested using MRI arterial spin labeling (ASL). OBJECTIVE: To investigate the convergent and discriminant validity of DMN and LIN perfusion in aMCI. METHODS: We collected core AD markers (amyloid-ß 42 [Aß42], phosphorylated tau 181 levels in cerebrospinal fluid [CSF]), neurodegenerative (hippocampal volumes and CSF total tau), vascular (white matter hyperintensities), genetic (apolipoprotein E [APOE] status), and cognitive features (memory functioning on Paired Associate Learning test [PAL]) in 14 aMCI patients. Cerebral blood flow (CBF) was extracted from DMN and LIN using ASL and correlated with AD features to assess convergent validity. Discriminant validity was assessed carrying out the same analysis with AD-unrelated features, i.e., somatomotor and visual networks' perfusion, cerebellar volume, and processing speed. RESULTS: Perfusion was reduced in the DMN (F = 5.486, p = 0.039) and LIN (F = 12.678, p = 0.004) in APOE ɛ4 carriers compared to non-carriers. LIN perfusion correlated with CSF Aß42 levels (r = 0.678, p = 0.022) and memory impairment (PAL, number of errors, r = -0.779, p = 0.002). No significant correlation was detected with tau, neurodegeneration, and vascular features, nor with AD-unrelated features. CONCLUSION: Our results support the validity of DMN and LIN ASL perfusion as AD markers in aMCI, indicating a significant correlation between CBF and amyloidosis, APOE ɛ4, and memory impairment.


Assuntos
Amnésia/fisiopatologia , Disfunção Cognitiva/fisiopatologia , Rede de Modo Padrão , Sistema Límbico , Perfusão , Idoso , Doença de Alzheimer/fisiopatologia , Biomarcadores/líquido cefalorraquidiano , Circulação Cerebrovascular , Feminino , Hipocampo/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Masculino
12.
J Affect Disord ; 293: 347-354, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34229288

RESUMO

Aberrant DMN connectivity and activity have been robustly linked to Major Depressive Disorder (MDD) and risk for depression. This link has mostly been explained in terms of rumination, a form of negative, repetitive cognitive processing. Yet, accumulating findings are indicating altered DMN dynamics during emotional processing in MDD, pointing at a potential emotion-related DMN pathology in depression linked to inflexibly sustained emotional responses. Such a link might be especially important in understanding risk of depression. However, whether inflexible emotional processing (i.e. emotional inertia) is connecting aberrant DMN organization to risk of depression as well as how this might relate to rumination remains unclear. Addressing this gap, 34 participants underwent a resting-state fMRI and a 7-day Experience Sampling phase. Using regression and multiple mediation analysis we investigated the relations between negative emotional inertia, rumination, DMN organization and risk of depression as indicated by high subclinical depressive symptoms. The findings indicated that DMN efficiency at rest was positively associated with depressive symptoms and risk of depression. Both negative emotional inertia in daily life and rumination were independently mediating this relationship. While negative emotional inertia was connected to a broad increase in the coupling of DMN regions, rumination was only related to an increase in node strength of the dorsomedial Prefrontal Cortex. These findings are pointing towards an emotional-related DMN pathology contributing to risk of depression. Furthermore the findings are indicating that this relationship is independent from the rumination-related link between the DMN and depression - representing different aspects of DMN organization.


Assuntos
Depressão , Transtorno Depressivo Maior , Encéfalo , Mapeamento Encefálico , Rede de Modo Padrão , Depressão/diagnóstico por imagem , Transtorno Depressivo Maior/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Vias Neurais
13.
Neuroimage ; 241: 118427, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34311069

RESUMO

The neural underpinnings of rumination can be characterized by its specific dynamic nature. Temporal stability is the stable and consistent representation of information by a distributed neural activity and connectivity pattern across brain regions. Although stability is a key feature of the brain's functional architecture, its profiles supporting rumination remain elusive. We characterized the stability of the whole-brain functional architecture during an induced, continuous rumination state and compared it with a well-constrained distraction state as the control condition in a group of healthy participants (N = 40). We further examined the relationship between stability in regions showing a significant effect on the rumination vs. distraction contrast and rumination traits. The variability of dynamic functional connectivities (FCs) among these regions was also explored to determine the potential coupling regions that drove the altered stability pattern during rumination. The results showed that rumination was characterized by a similar but altered stability profile compared with distraction and resting states. Comparison between rumination and distraction revealed that key regions of the default mode network (DMN), such as the medial prefrontal cortex (MPFC) and bilateral parahippocampal gyrus (PHG), which showed decreased stability while frontoparietal control network (FPCN) regions, including the inferior parietal lobule (IPL) and dorsal lateral prefrontal cortex (DLPFC), showed significantly enhanced stability in rumination compared with distraction. Additionally, stability in the MPFC and IPL was related to individual differences in rumination traits. Exploratory analysis of the variation in dynamic FCs suggested that higher stability in the IPL may be related to its less variable FCs with the PHG. Together, these findings implicated that rumination may be supported by the dissociated dynamic nature of hypostability in the DMN and hyperstability in the FPCN.


Assuntos
Rede de Modo Padrão/fisiologia , Imageamento por Ressonância Magnética/métodos , Rede Nervosa/fisiologia , Lobo Parietal/fisiologia , Córtex Pré-Frontal/fisiologia , Ruminação Cognitiva/fisiologia , Adolescente , Adulto , Rede de Modo Padrão/diagnóstico por imagem , Feminino , Humanos , Masculino , Rede Nervosa/diagnóstico por imagem , Lobo Parietal/diagnóstico por imagem , Córtex Pré-Frontal/diagnóstico por imagem , Descanso/fisiologia , Adulto Jovem
15.
Neuroimage ; 240: 118304, 2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34329959

RESUMO

Structural and functional alterations of the brain in persons genetically at-risk for Alzheimer's disease (AD) are crucial in unravelling AD development. Filippini et al. found that the default mode network (DMN) is already affected in young APOE ε4-carriers, with increased co-activation of the DMN during rest and increased hippocampal task activation. We aimed to replicate the early findings of Filippini et al, using the APOE gene, still the principal AD risk gene, and extended this with a polygenic risk score (PRS) analysis for AD, using the Human Connectome Project dataset (HCP). We included participants from the HCP S1200 dataset (age range: 22-36 years). We studied morphometric features, functional DMN co-activation and functional task activation of recollection performance. Permutation Analysis of Linear Models (PALM) was used to test for group differences between APOE ε4-carriers and non-carriers, and to test the association with PRS. PALM controls for biases induced by the family structure of the HCP sample. Results were family-wise error rate corrected at p < 0.05. Our primary analysis did not replicate the early findings of Filippini et al. (2009). However, compared with non-carriers, APOE ε4-carriers showed increased functional activation during the encoding of subsequently recollected items in areas related to facial recognition (p<0.05, t>756.11). This increased functional activation was also positively associated with PRS (APOE variants included) (p<0.05, t>647.55). Our results are supportive for none to limited genetic effects on brain structure and function in young adults. Taking the methodological considerations of replication studies into account, the true effect of APOE ε4-carriership is likely smaller than indicated in the Filippini paper. However, it still holds that we may not yet be able to detect already present measurable effects decades before a clinical expression of AD. Since the mechanistic pathway of AD is likely to encompass many different factors, further research should be focused on the interactions of genetic risk, biomarkers, aging and lifestyle factors over the life course. Sensitive functional neuroimaging as used here may help disentangling these complex interactions.


Assuntos
Apolipoproteína E4/genética , Encéfalo/fisiologia , Rede de Modo Padrão/diagnóstico por imagem , Rede de Modo Padrão/fisiologia , Heterozigoto , Memória de Curto Prazo/fisiologia , Adulto , Encéfalo/diagnóstico por imagem , Conectoma/métodos , Replicação do DNA/fisiologia , Bases de Dados Factuais , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Adulto Jovem
16.
J Psychiatr Res ; 140: 30-34, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34090100

RESUMO

Anhedonia is common in individuals with traumatic experience. Anhedonia symptoms play an important role in posttraumatic psychopathology, and are related to various adverse outcomes. The current study is a preliminary neuroimaging study of the neural correlates of posttraumatic anhedonia symptoms. Resting-state fMRI data were acquired from 88 Chinese earthquake survivors. Whole brain analyses and exploratory ROI-to-ROI analyses were performed to examine the relationship between posttraumatic anhedonia symptoms and resting-state functional connectivity (rsFC) of reward-related subcortical nucleus including nucleus accumbens and ventral pallidum. The rsFC between left ventral pallidum and areas of bilateral posterior cingulate cortex (PCC) and precuneus cortex were found lower in the high posttraumatic anhedonia group, after controlling for sex, age and other posttraumatic stress symptoms. The rsFC between left ventral pallidum and PCC and the rsFC between left ventral pallidum and lateral parietal cortex were significantly lower in the high anhedonia group. Our findings suggest that decreased functional connectivity between the ventral pallidum and the brain default mode network (DMN) regions could be the neural correlates of posttraumatic anhedonia symptoms.


Assuntos
Anedonia , Prosencéfalo Basal , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Rede de Modo Padrão , Giro do Cíngulo , Humanos , Imageamento por Ressonância Magnética , Vias Neurais/diagnóstico por imagem
17.
Neuropsychopharmacology ; 46(10): 1830-1838, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34059799

RESUMO

Neural signatures of suicide risk likely reflect a combination of specific and non-specific factors, and clarifying specific factors may facilitate development of novel treatments. Previously, we demonstrated an altered pattern of resting state connectivity between the dorsal and ventral posterior cingulate cortex (d/vPCC) and the dorsal anterior cingulate cortex (dACC), as well as altered low frequency oscillations in these regions, in individuals with a history of suicidal thoughts and behaviors (STBs) compared to healthy controls. It remains uncertain, however, whether these markers were directly related to STBs or, more generally, reflect a trait-level risk factor for depression. Here, we examined data from a 3-generational longitudinal study of depression where resting state fMRI data were analyzed from 2nd and 3rd generation offspring of probands with (FH+ = 44: STB+ = 32, STB- = 12) and without (FH- = 25: STB+ = 15, STB- = 10) a family history of major depressive disorder (MDD). Standard seed-based methods and a frequency-based analysis of intrinsic neural activity (ALFF/fALFF) were employed. FH of MDD, but not a personal history of STBs or MDD, was associated with relatively reduced dPCC-dACC, and enhanced vPCC-dACC functional connectivity. FH of MDD showed a pattern of reduced ALFF in the dPCC whereas an STB history was associated with an increase. All findings were invariant to confounding by lifetime MDD and current depression severity. Overall, contrary to predictions, resting state functional connectivity within the default mode network (DMN) was associated with FH of depression rather than STBs. These findings confirm the relevance of DMN functional connectivity for mood disorders and underscore the importance of disambiguating biological factors that differentially relate to mental disorders versus STBs.


Assuntos
Transtorno Depressivo Maior , Suicídio , Rede de Modo Padrão , Depressão , Transtorno Depressivo Maior/diagnóstico por imagem , Predisposição Genética para Doença , Humanos , Estudos Longitudinais
18.
Neurology ; 97(8): e794-e802, 2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34099528

RESUMO

OBJECTIVE: To characterize functional network changes related to conversion to cognitive impairment in a large sample of patients with multiple sclerosis (MS) over a period of 5 years. METHODS: Two hundred twenty-seven patients with MS and 59 healthy controls of the Amsterdam MS cohort underwent neuropsychological testing and resting-state fMRI at 2 time points (time interval 4.9 ± 0.9 years). At both baseline and follow-up, patients were categorized as cognitively preserved (CP; n = 123), mildly impaired (MCI; z < -1.5 on ≥2 cognitive tests, n = 32), or impaired (CI; z < -2 on ≥2 tests, n = 72), and longitudinal conversion between groups was determined. Network function was quantified with eigenvector centrality, a measure of regional network importance, which was computed for individual resting-state networks at both time points. RESULTS: Over time, 18.9% of patients converted to a worse phenotype; 22 of 123 patients who were CP (17.9%) converted from CP to MCI, 10 of 123 from CP to CI (8.1%), and 12 of 32 patients with MCI converted to CI (37.5%). At baseline, default-mode network (DMN) centrality was higher in CI individuals compared to controls (p = 0.05). Longitudinally, ventral attention network (VAN) importance increased in CP, driven by stable CP and CP-to-MCI converters (p < 0.05). CONCLUSIONS: Of all patients, 19% worsened in their cognitive status over 5 years. Conversion from intact cognition to impairment is related to an initial disturbed functioning of the VAN, then shifting toward DMN dysfunction in CI. Because the VAN normally relays information to the DMN, these results could indicate that in MS normal processes crucial for maintaining overall network stability are progressively disrupted as patients clinically progress.


Assuntos
Encéfalo , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/fisiopatologia , Rede de Modo Padrão/fisiopatologia , Progressão da Doença , Esclerose Múltipla/diagnóstico , Rede Nervosa/fisiopatologia , Adulto , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Encéfalo/fisiopatologia , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/etiologia , Rede de Modo Padrão/diagnóstico por imagem , Feminino , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/complicações , Rede Nervosa/diagnóstico por imagem , Índice de Gravidade de Doença
19.
Neuroimage ; 239: 118310, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34175424

RESUMO

Functional connectivity (FC) measured from functional magnetic resonance imaging (fMRI) provides a powerful tool to explore brain organization. Studies of the temporal dynamics of brain organization have shown a large temporal variability of the functional connectome, which may be associated with mental status transitions and/or adaptive process. Most dynamic studies, e.g. functional connectome and functional network connectivity (FNC), have focused on the macroscopic FC changes, i.e. the changes of temporal coherence across various brain network sources, nodes and/or regions of interest, where it is assumed within the network or node that the FC is static. In this paper, we develop a novel method to examine the spatial dynamics of FC, without the assumption of its intra-network stationarity. We applied our approach to fMRI data during an auditory oddball task (AOD) from twenty-two subjects, in an attempt to capture/validate the approach by evaluating whether spatial connectivity varies with task condition. The results showed that connectivity networks exhibit spatial variability over time, in addition to participating in conventional temporal dynamics, i.e. cross-network variability or dynamic functional network connectivity (dFNC). Furthermore, we studied the relationship of spatial dynamic in FC to cognitive processes, by performing a cluster analysis to evaluate an individual's functional correspondence towards the 'target' (oddball) detection from AOD task, and extracting cognitive task correspondence states as well as their dynamic FC spatial maps segregated by such states. We found a clear trend in different task-guided states, particularly, a prominent reduction of task stimulus synchrony state along with strong anticorrelation between default mode network (DMN) and cognitive attentional networks. We also observed an increasing occurrence of the task desynchrony state which showed an absence of DMN anticorrelation. The results highlight the impact of a well-studied cognitive task on the observed spatial dynamic structure. We also showed that the FC spatial dynamic pattern from our method largely corresponds to macroscopic dFNC patterns, but with more details and specifications over space, meanwhile the connectivity within the source itself provides novel information and varies over time. Overall, we demonstrate clear evidence of the presence of the (usually ignored) spatial dynamics of connectivity, its links to the task and implications of cognition/mental status.


Assuntos
Conectoma/métodos , Imageamento por Ressonância Magnética/métodos , Rede Nervosa/diagnóstico por imagem , Desempenho Psicomotor/fisiologia , Estimulação Acústica , Adulto , Rede de Modo Padrão/fisiologia , Imagem Ecoplanar/métodos , Feminino , Humanos , Masculino , Rede Nervosa/fisiologia , Adulto Jovem
20.
Medicine (Baltimore) ; 100(23): e26281, 2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34115028

RESUMO

BACKGROUND AND OBJECTIVE: Previous studies have shown that the default-mode network (DMN) has a substantial role in patients with major depressive disorder (MDD). However, there is a shortage of information regarding variations in the functional connectivity (FC) of the DMN of treatment-naive patients with first-episode MDD. The present study aims to explore the FC of the DMN in such patients. METHODS: The study population consisted of 33 patients and 35 controls, paired regarding age, gender, education level, and health condition. Depression severity was assessed through the Hamilton Depression Scale (HAM-D), and subjects underwent evaluation during the resting-state through functional magnetic resonance imaging (rs-fMRI). To assess the result, we used FC and ICA. We used Spearman's correlation test to detect potential correlations between anomalous FC and severity of HAM-D scores. RESULTS: We have found a decreased FC in the left medial orbitofrontal gyrus (MOFG) and right marginal gyrus (SMG) in depressive patients compared to controls. There was a negative correlation between abnormal FC in the right SMG and HAM-D scores. We have not found any increase in FC of the DMN in treatment-naive, first-episode of MDD patients. CONCLUSIONS: Our study provided evidence of a negative correlation between abnormal FC in the DMN and severity of depression symptoms measured by HAM-D in treatment-naive MDD patients. This finding could shed some light on the relevance of DMN for understanding the pathophysiology of cognitive impairment in MDD.


Assuntos
Mapeamento Encefálico/métodos , Rede de Modo Padrão/fisiopatologia , Transtorno Depressivo Maior , Imageamento por Ressonância Magnética/métodos , Córtex Pré-Frontal , Adulto , Cognição/fisiologia , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/fisiopatologia , Conectoma/métodos , Transtorno Depressivo Maior/diagnóstico , Transtorno Depressivo Maior/fisiopatologia , Transtorno Depressivo Maior/psicologia , Feminino , Humanos , Masculino , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/fisiopatologia , Escalas de Graduação Psiquiátrica
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