RESUMO
Trauma exposure may precipitate a cascade of plastic modifications within the intrinsic activity of brain regions, but it remains unclear which regions could be responsible for the development of post-traumatic stress disorder based on intrinsic activity. To elucidate trauma-related and post-traumatic stress disorder-related alterations in cortical intrinsic activity at the whole-brain level, we recruited 47 survivors diagnosed with post-traumatic stress disorder, 64 trauma-exposed controls from a major earthquake, and 46 age- and sex-matched healthy controls. All subjects were scanned with an echo-planar imaging sequence, and 5 parameters including the amplitude of low-frequency fluctuations, fractional amplitude of low-frequency fluctuations, regional homogeneity, degree centrality, and voxel-mirrored homotopic connectivity were calculated. We found both post-traumatic stress disorder patients and trauma-exposed controls exhibited decreased amplitude of low-frequency fluctuations in the bilateral posterior cerebellum and inferior temporal gyrus, decreased fractional amplitude of low-frequency fluctuation and regional homogeneity in the bilateral anterior cerebellum, and decreased fractional amplitude of low-frequency fluctuation in the middle occipital gyrus and cuneus compared to healthy controls, and these impairments were more severe in post-traumatic stress disorder patients than in trauma-exposed controls. Additionally, fractional amplitude of low-frequency fluctuation in left cerebellum was positively correlated with Clinician-Administered PTSD Scale scores in post-traumatic stress disorder patients. We identified brain regions that might be responsible for the emergence of post-traumatic stress disorder, providing important information for the treatment of this disorder.
Assuntos
Transtornos de Estresse Pós-Traumáticos , Humanos , Transtornos de Estresse Pós-Traumáticos/fisiopatologia , Transtornos de Estresse Pós-Traumáticos/diagnóstico por imagem , Transtornos de Estresse Pós-Traumáticos/psicologia , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Córtex Cerebral/fisiopatologia , Córtex Cerebral/diagnóstico por imagem , Imagem Ecoplanar , Terremotos , Imageamento por Ressonância Magnética , Adulto Jovem , Mapeamento EncefálicoRESUMO
Dance is unique in that it is a sport and an art simultaneously. Beyond improving sensorimotor functions, dance training could benefit high-level emotional and cognitive functions. Duo dances also confer the possibility for dancers to develop the abilities to recognize, understand, and share the thoughts and feelings of their dance partners during the long-term dance training. To test this possibility, we collected high-resolution structural and resting-state functional magnetic resonance imaging (MRI) data from 43 expert-level ballroom dancers (a model of long-term exposure to duo dance training) and 40 age-matched and sex-matched nondancers, and measured their empathic ability using a self-report trait empathy scale. We found that ballroom dancers showed higher scores of empathic concern (EC) than controls. The EC scores were positively correlated with years with dance partners but negatively correlated with the number of dance partners for ballroom dancers. These behavioral results were supported by the structural and functional MRI data. Structurally, we observed that the gray matter volumes in the subgenual anterior cingulate cortex (ACC) and EC scores were positively correlated. Functionally, the connectivity between ACC and occipital gyrus was positively correlated with both EC scores and years with dance partners. In addition, the relationship between years with dance partners and EC scores was indirect-only mediated by the ACC-occipital gyrus functional connectivity. Therefore, our findings provided solid evidence for the close link between long-term ballroom dance training and empathy, which deepens our understanding of the neural mechanisms underlying this phenomenon.
Assuntos
Dança , Humanos , Dança/psicologia , Empatia , Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética , Mapeamento EncefálicoRESUMO
The ventral visual stream of the human brain is subdivided into patches with categorical stimulus preferences, like faces or scenes. However, the functional organization within these areas is less clear. Here, we used functional magnetic resonance imaging and vertex-wise tuning models to independently probe spatial and face-part preferences in the inferior occipital gyrus (IOG) of healthy adult males and females. The majority of responses were well explained by Gaussian population tuning curves for both retinotopic location and the preferred relative position within a face. Parameter maps revealed a common gradient of spatial and face-part selectivity, with the width of tuning curves drastically increasing from posterior to anterior IOG. Tuning peaks clustered more idiosyncratically but were also correlated across maps of visual and face space. Preferences for the upper visual field went along with significantly increased coverage of the upper half of the face, matching recently discovered biases in human perception. Our findings reveal a broad range of neural face-part selectivity in IOG, ranging from narrow to "holistic." IOG is functionally organized along this gradient, which in turn is correlated with retinotopy.SIGNIFICANCE STATEMENT Brain imaging has revealed a lot about the large-scale organization of the human brain and visual system. For example, occipital cortex contains map-like representations of the visual field, while neurons in ventral areas cluster into patches with categorical preferences, like faces or scenes. Much less is known about the functional organization within these areas. Here, we focused on a well established face-preferring area-the inferior occipital gyrus (IOG). A novel neuroimaging paradigm allowed us to map the retinotopic and face-part tuning of many recording sites in IOG independently. We found a steep posterior-anterior gradient of decreasing face-part selectivity, which correlated with retinotopy. This suggests the functional role of ventral areas is not uniform and may follow retinotopic "protomaps."
Assuntos
Reconhecimento Facial/fisiologia , Lobo Occipital/fisiologia , Adulto , Mapeamento Encefálico/métodos , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Vias Visuais/fisiologiaRESUMO
Uncontrolled eating-in the general population-is characterized by overeating, hedonic hunger and being drawn towards palatable foods. Theoretically, it is the result of a strong food reward signal in relation to a poor ability to exert inhibitory control. How food consumption influences inhibitory control and food cue sensitivity, and how this relates to the continued urge to eat, remains unclear. We used fMRI in order to investigate the neural mechanism underlying food cue reactivity and food-specific response inhibition (go-nogo task), by comparing women reporting high (n = 21) versus low/average (n = 19) uncontrolled eating across two sessions: during an inter-meal state and after consumption of a high-caloric snack. We found no effects of individual differences in uncontrolled eating, food consumption, nor their interaction on food cue reactivity. Differences in uncontrolled eating and food consumption did interact in modulating activity in an occipital-parietal network, extending from left lateral superior occipital cortex to visual cortex, cuneal cortex, and precuneus during response inhibition of non-food stimuli, areas previously associated with successful nogo-vs. go-trials. Yet, behavioural performance on the go-nogo task was not modulated by uncontrolled eating nor food consumption. Women with a low/average tendency for uncontrolled eating may need more cognitive resources to support successful response inhibition of non-food stimuli during food 'go' blocks in an inter-meal state, whereas women with a high tendency for uncontrolled eating showed this after food consumption. However, considering current and previous findings, it seems that individual differences in uncontrolled eating in healthy women have only limited influence on food cue reactivity and food-related inhibitory control.
Assuntos
Sinais (Psicologia) , Alimentos , Ingestão de Alimentos , Comportamento Alimentar , Feminino , Preferências Alimentares , Humanos , Fome , Hiperfagia , LanchesRESUMO
Despite being of primary importance for fundamental research and clinical studies, the relationship between local neural population activity and scalp electroencephalography (EEG) in humans remains largely unknown. Here we report simultaneous scalp and intracerebral EEG responses to face stimuli in a unique epileptic patient implanted with 27 intracerebral recording contacts in the right occipitotemporal cortex. The patient was shown images of faces appearing at a frequency of 6 Hz, which elicits neural responses at this exact frequency. Response quantification at this frequency allowed to objectively relate the neural activity measured inside and outside the brain. The patient exhibited typical 6 Hz responses on the scalp at the right occipitotemporal sites. Moreover, there was a clear spatial correspondence between these scalp responses and intracerebral signals in the right lateral inferior occipital gyrus, both in amplitude and in phase. Nevertheless, the signal measured on the scalp and inside the brain at nearby locations showed a 10-fold difference in amplitude due to electrical insulation from the head. To further quantify the relationship between the scalp and intracerebral recordings, we used an approach correlating time-varying signals at the stimulation frequency across scalp and intracerebral channels. This analysis revealed a focused and right-lateralized correspondence between the scalp and intracerebral recordings that were specific to the face stimulation is more broadly distributed in various control situations. These results demonstrate the interest of a frequency tagging approach in characterizing the electrical propagation from brain sources to scalp EEG sensors and in identifying the cortical sources of brain functions from these recordings.
Assuntos
Eletrodos Implantados , Eletroencefalografia , Reconhecimento Facial/fisiologia , Lobo Occipital/fisiologia , Lobo Temporal/fisiologia , Adulto , Eletrocorticografia , Epilepsia/fisiopatologia , Feminino , Humanos , Estimulação LuminosaRESUMO
BACKGROUND: Women are more susceptible to major depressive disorder (MDD). A possible explanation is that women have a trait tendency to engage in a ruminative response style. Depending on cognitive model of depression, attention bias, memory bias and self-referential bias were closely related among depressed patients. Previous studies have explored the neural mechanism of the cognitive biases by using amplitude of low frequency fluctuations (ALFF) or functional connectivity (FC), and few combined these two metrics, especially focusing on female patients. METHODS: We assessed 25 female patients diagnosed with MDD and 13 well matched healthy controls (HCs) using Rs-fMRI. Two metrics ALFF and FC based on abnormal ALFF were explored and made comparisons. RESULTS: Compared with HCs, female patients with MDD showed that one cluster with significantly decreased ALFF in the left middle occipital gyrus(L-MOG). Furtherly we founded depressed female subjects showed significantly lower FC between the L-MOG seed and left orbitofrontal cortex, and significantly higher FC between the L-MOG seed and left medial prefrontal gyrus and left hippocampus. CONCLUSIONS: Our results showed L-MOG may act as a connection, which involved in the processing of cognitive biases of MDD by connected with limbic-cortical regions in resting state. These findings may enhance the understanding of the neurobiological mechanism in female patients with MDD.
Assuntos
Transtorno Depressivo Maior/fisiopatologia , Lobo Occipital/fisiopatologia , Adulto , Estudos de Casos e Controles , Feminino , Lobo Frontal/fisiopatologia , Neuroimagem Funcional , Hipocampo/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Adulto JovemRESUMO
Debate continues over whether the inferior occipital gyrus (IOG) or the fusiform gyrus (FG) represents the first stage of face processing and what role these brain regions play. We investigated this issue by combining functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG) in normal adults. Participants passively observed upright and inverted faces and houses. First, we identified the IOG and FG as face-specific regions using fMRI. We applied beamforming source reconstruction and time-frequency analysis to MEG source signals to reveal the time course of gamma-band activations in these regions. The results revealed that the right IOG showed higher gamma-band activation in response to upright faces than to upright houses at 100 ms from the stimulus onset. Subsequently, the right FG showed greater gamma-band response to upright faces versus upright houses at around 170 ms. The gamma-band activation in the right IOG and right FG was larger in response to inverted faces than to upright faces at the later time window. These results suggest that (1) the gamma-band activities occurs rapidly first in the IOG and next in the FG and (2) the gamma-band activity in the right IOG at later time stages is involved in configuration processing for faces. Hum Brain Mapp 38:2067-2079, 2017. © 2017 Wiley Periodicals, Inc.
Assuntos
Face , Ritmo Gama/fisiologia , Lobo Occipital/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Lobo Temporal/fisiologia , Adolescente , Adulto , Eletroencefalografia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Magnetoencefalografia , Masculino , Lobo Occipital/diagnóstico por imagem , Oxigênio/sangue , Estimulação Luminosa , Lobo Temporal/diagnóstico por imagem , Fatores de Tempo , Adulto JovemRESUMO
Faces contain multifaceted information that is important for human communication. Neuroimaging studies have revealed face-specific activation in multiple brain regions, including the inferior occipital gyrus (IOG) and amygdala; it is often assumed that these regions constitute the neural network responsible for the processing of faces. However, it remains unknown whether and how these brain regions transmit information during face processing. This study investigated these questions by applying dynamic causal modeling of induced responses to human intracranial electroencephalography data recorded from the IOG and amygdala during the observation of faces, mosaics, and houses in upright and inverted orientations. Model comparisons assessing the experimental effects of upright faces versus upright houses and upright faces versus upright mosaics consistently indicated that the model having face-specific bidirectional modulatory effects between the IOG and amygdala was the most probable. The experimental effect between upright versus inverted faces also favored the model with bidirectional modulatory effects between the IOG and amygdala. The spectral profiles of modulatory effects revealed both same-frequency (e.g., gamma-gamma) and cross-frequency (e.g., theta-gamma) couplings. These results suggest that the IOG and amygdala communicate rapidly with each other using various types of oscillations for the efficient processing of faces. Hum Brain Mapp 38:4511-4524, 2017. © 2017 Wiley Periodicals, Inc.
Assuntos
Tonsila do Cerebelo/fisiologia , Eletrocorticografia , Reconhecimento Facial/fisiologia , Lobo Occipital/fisiologia , Adulto , Tonsila do Cerebelo/fisiopatologia , Epilepsia Resistente a Medicamentos/fisiopatologia , Eletrocorticografia/métodos , Epilepsias Parciais/fisiopatologia , Feminino , Humanos , Masculino , Modelos Neurológicos , Vias Neurais/fisiologia , Vias Neurais/fisiopatologia , Lobo Occipital/fisiopatologia , Estimulação Luminosa , Processamento de Sinais Assistido por Computador , Adulto JovemRESUMO
The brain activity of orthographic neighborhood size (N size) effect in Chinese character naming has been studied in adults, meanwhile behavioral studies have revealed a developmental trend of Chinese N-size effect in developing readers. However, it is unclear whether and how the neural mechanism of N-size effect changes in Chinese children along with development. Here we address this issue using functional magnetic resonance imaging. Forty-four students from the 3(rd) , 5(th) , and 7(th) grades were scanned during silent naming of Chinese characters. After scanning, all participants took part in an overt naming test outside the scanner, and results of the naming task showed that the 3(rd) graders named characters from large neighborhoods faster than those from small neighborhoods, revealing a facilitatory N-size effect; the 5(th) graders showed null N-size effect while the 7(th) graders showed an inhibitory N-size effect. Neuroimaging results revealed that only the 3(rd) graders exhibited a significant N-size effect in the left middle occipital activity, with greater activation for large N-size characters. Results of 5(th) and 7(th) graders showed significant N-size effects in the left middle frontal gyrus, in which 5(th) graders induced greater activation in large N-size condition than in small N-size condition, while 7(th) graders exhibited an opposite effect which was similar to the adult pattern reported in a previous study. The current findings suggested the transition from broadly tuned to finely tuned orthographic representation with reading development, and the inhibition from neighbors' phonology for higher graders. Hum Brain Mapp 37:632-647, 2016. © 2015 Wiley Periodicals, Inc.
Assuntos
Encéfalo/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Leitura , Adolescente , Mapeamento Encefálico , Criança , Linguagem Infantil , China , Feminino , Humanos , Testes de Linguagem , Imageamento por Ressonância Magnética , Masculino , Testes Neuropsicológicos , Estimulação Luminosa , Tempo de ReaçãoRESUMO
This study investigates specific changes in brain function during cognitive and emotional tasks in patients with schizophrenia and a history of violence (VSCZ) compared with non-violent patients with schizophrenia and healthy controls. A comprehensive literature search was conducted at the Web of Science, Medline, and PubMed. Ten studies met the inclusion criteria. In which, eight studies compared brain activation between patients with VSCZ and non-violent patients with schizophrenia, and the former exhibited increased activation at the middle occipital gyrus and rectus compared with the latter. Seven studies compared brain activation between patients with VSCZ and controls, and the former exhibited increased activation at the anterior cingulate cortex, cerebellum VI region, lingual gyrus and fusiform. Subgroup analysis in five studies performing emotional tasks revealed that patients with VSCZ showed increased activation at the middle occipital gyrus compared with non-violent patients with schizophrenia. Our findings suggest that abnormal emotion perception and regulation significantly contribute to the increased risk of violence in patients with schizophrenia. Notably, the middle occipital gyrus and rectus emerge as key neurophysiological correlates associated with this phenomenon.
Assuntos
Esquizofrenia , Violência , Humanos , Esquizofrenia/fisiopatologia , Encéfalo/fisiopatologia , Encéfalo/diagnóstico por imagem , Imageamento por Ressonância MagnéticaRESUMO
Aggression can be categorized into reactive aggression (RA) and proactive aggression (PA) based on their underlying motivations. However, previous research has rarely identified the relationship between femininity and RA/PA, and there is a lack of understanding regarding the femininity-related neurofunctional basis of these aggressive behaviors. Thus, this study first examined the relationships between femininity and aggression, then explored the aggression-by-femininity interactions on the fractional amplitude of low-frequency fluctuations using resting-state fMRI among 705 university participants (mean age = 19.14 ± 0.99). The behavioral data indicated that femininity was more negatively associated with RA and PA when masculinity was controlled for. Additionally, the neural data revealed that femininity-specific relationships of RA in the left middle occipital gyrus (i.e. individuals with low femininity had positive relationships between RA and the left middle occipital gyrus, whereas those with high femininity had negative relationships) as well as of PA in the left middle frontal gyrus (i.e. individuals with high femininity showed significant negative relationships, whereas those with low femininity did not exhibit significant relationships). These findings reflect that individuals with varying levels of femininity exhibit distinct neural bases when expressing different subtypes of aggression, which are associated with societal expectations of gender.
Assuntos
Agressão , Mapeamento Encefálico , Encéfalo , Feminilidade , Imageamento por Ressonância Magnética , Humanos , Feminino , Agressão/fisiologia , Adulto Jovem , Masculino , Encéfalo/fisiologia , Encéfalo/diagnóstico por imagem , Adolescente , AdultoRESUMO
Visual perception can be strongly biased due to exposure to specific stimuli in the environment, often causing neural adaptation and visual aftereffects. In this study, we investigated whether adaptation to certain body shapes biases the perception of the own body shape. Furthermore, we aimed to evoke neural adaptation to certain body shapes. Participants completed a behavioral experiment (n = 14) to rate manipulated pictures of their own bodies after adaptation to demonstratively thin or fat pictures of their own bodies. The same stimuli were used in a second experiment (n = 16) using functional magnetic resonance imaging (fMRI) adaptation. In the behavioral experiment, after adapting to a thin picture of the own body participants also judged a thinner than actual body picture to be the most realistic and vice versa, resembling a typical aftereffect. The fusiform body area (FBA) and the right middle occipital gyrus (rMOG) show neural adaptation to specific body shapes while the extrastriate body area (EBA) bilaterally does not. The rMOG cluster is highly selective for bodies and perhaps body parts. The findings of the behavioral experiment support the existence of a perceptual body shape aftereffect, resulting from a specific adaptation to thin and fat pictures of one's own body. The fMRI results imply that body shape adaptation occurs in the FBA and the rMOG. The role of the EBA in body shape processing remains unclear. The results are also discussed in the light of clinical body image disturbances.
Assuntos
Adaptação Fisiológica , Mapeamento Encefálico , Corpo Humano , Lobo Occipital/irrigação sanguínea , Reconhecimento Visual de Modelos/fisiologia , Adulto , Animais , Viés , Índice de Massa Corporal , Feminino , Lateralidade Funcional , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Lobo Occipital/fisiologia , Estimulação Luminosa , Adulto JovemRESUMO
The human cortical system for face perception is comprised of a network of connected regions including the middle fusiform gyrus ("fusiform face area" or FFA), the inferior occipital cortex ("occipital face area" or OFA), and the superior temporal sulcus. The traditional hierarchical feedforward model of visual processing suggests information flows from early visual cortex to the OFA for initial face feature analysis to higher order regions including the FFA for identity recognition. However, patient data suggest an alternative model. Patients with acquired prosopagnosia, an inability to visually recognize faces, have been documented with lesions to the OFA but who nevertheless show face-selective activation in the FFA. Moreover, their ability to categorize faces remains intact. This suggests that the FFA is not solely responsible for face recognition and the network is not strictly hierarchical, but may be organized in a reverse hierarchical fashion. We used transcranial magnetic stimulation (TMS) to temporarily disrupt processing in the OFA in neurologically-intact individuals and found participants' ability to categorize intact versus scrambled faces was unaffected, however face identity discrimination was significantly impaired. This suggests that face categorization but not recognition can occur without the "earlier" OFA being online and indicates that "lower level" face category processing may be assumed by other intact face network regions such as the FFA. These results are consistent with the patient data and support a non-hierarchical, global-to-local model with re-entrant connections between the OFA and other face processing areas.
Assuntos
Face , Rede Nervosa/fisiologia , Lobo Occipital/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Percepção Social , Estimulação Magnética Transcraniana/métodos , Adolescente , Adulto , Mapeamento Encefálico/instrumentação , Mapeamento Encefálico/métodos , Discriminação Psicológica/fisiologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Estimulação Magnética Transcraniana/instrumentação , Adulto JovemRESUMO
BACKGROUNDS: There have pieces of evidence of the distinct aberrant functional network topology profile in bipolar disorder (BD) across mania, depression, and euthymic episodes. However, the underlying anatomical network topology pattern in BD across different episodes is unclear. METHODS: We calculated the whole-brain probabilistic structurally connectivity across 143 subjects (72 with BD [34 depression; 13 mania; 25 euthymic] and 53 healthy controls), and used graph theory to examine the trait- and state-related topology alterations of the structural connectome in BD. The correlation analysis was further conducted to explore the relationship between detected network measures and clinical symptoms. RESULTS: There no omnibus alteration of any global network metrics were observed across all diagnostic groups. In the regional network metrics level, bipolar depression showed increased clustering coefficient in the right lingual gyrus compared with all other groups, and the increased clustering coefficient in the right lingual gyrus positively correlated with depression, anxiety, and illness burden symptoms but negatively correlated with mania symptoms; manic and euthymic patients showed decreased clustering coefficient in the left inferior occipital gyrus compared with HCs. LIMITATIONS: The moderate sample size of all patient groups (especially for subjects with mania) might have contributed to the negative findings of the trait feature in this study. CONCLUSIONS: We demonstrated the altered regional connectivity pattern in the occipital lobe of the bipolar depression and mania episode, especially the lingual gyrus. The association of the clustering coefficient in the lingual gyrus with clinical symptoms helps monitor the state of BD.
Assuntos
Transtorno Bipolar , Conectoma , Humanos , Transtorno Bipolar/diagnóstico por imagem , Mania , Depressão/diagnóstico por imagem , Imageamento por Ressonância Magnética , Encéfalo/diagnóstico por imagemRESUMO
Introduction: Several studies have reported structural and functional abnormalities of the amygdala caused by methamphetamine addiction. However, it is unknown whether abnormalities in amygdala function persist in long-term methamphetamine abstainers. Methods: In this study, 38 long-term male methamphetamine abstainers (>12 months) and 40 demographically matched male healthy controls (HCs) were recruited. Considering the heterogeneous nature of the amygdala structure and function, we chose 4 amygdala subregions (i.e., left lateral, left medial, right lateral, and right medial) as regions of interest (ROI) and compared the ROI-based resting-state functional connectivity (FC) at the whole-brain voxel-wise between the two groups. We explored the relationship between the detected abnormal connectivity, methamphetamine use factors, and the duration of withdrawal using correlation analyses. We also examined the effect of methamphetamine use factors, months of withdrawal, and sociodemographic data on detected abnormal connectivity through multiple linear regressions. Results: Compared with HCs, long-term methamphetamine abstainers showed significant hyperconnectivity between the left lateral amygdala and a continuous area extending to the left inferior/middle occipital gyrus and left middle/superior temporal gyrus. Abnormal connections negatively correlated with methamphetamine withdrawal time (r = -0.85, p < 0.001). The linear regression model further demonstrated that the months of withdrawal could identify the abnormal connectivity (ßadj = -0.86, 95%CI: -1.06 to -0.65, p < 0.001). Discussion: The use of methamphetamine can impair the neural sensory system, including the visual and auditory systems, but this abnormal connectivity can gradually recover after prolonged withdrawal of methamphetamine. From a neuroimaging perspective, our results suggest that withdrawal is an effective treatment for methamphetamine.
RESUMO
INTRODUCTION: Schizophrenia-spectrum disorders (SSD) represent one of the leading causes of disability worldwide and are usually underpinned by neurodevelopmental brain abnormalities observed on a structural and functional level. Nuclear medicine imaging studies of cerebral blood flow (CBF) have already provided insights into the pathophysiology of these disorders. Recent developments in non-invasive MRI techniques such as arterial spin labeling (ASL) have allowed broader examination of CBF across SSD prompting us to conduct an updated literature review of MRI-based perfusion studies. In addition, we conducted a focused meta-analysis of whole brain studies to provide a complete picture of the literature on the topic. METHODS: A systematic OVID search was performed in Embase, MEDLINEOvid, and PsycINFO. Studies eligible for inclusion in the review involved: 1) individuals with SSD, first-episode psychosis or clinical-high risk for psychosis, or; 2) had healthy controls for comparison; 3) involved MRI-based perfusion imaging methods; and 4) reported CBF findings. No time span was specified for the database queries (last search: 08/2022). Information related to participants, MRI techniques, CBF analyses, and results were systematically extracted. Whole-brain studies were then selected for the meta-analysis procedure. The methodological quality of each included studies was assessed. RESULTS: For the systematic review, the initial Ovid search yielded 648 publications of which 42 articles were included, representing 3480 SSD patients and controls. The most consistent finding was that negative symptoms were linked to cortical fronto-limbic hypoperfusion while positive symptoms seemed to be associated with hyperperfusion, notably in subcortical structures. The meta-analysis integrated results from 13 whole-brain studies, across 426 patients and 401 controls, and confirmed the robustness of the hypoperfusion in the left superior and middle frontal gyri and right middle occipital gyrus while hyperperfusion was found in the left putamen. CONCLUSION: This updated review of the literature supports the implication of hemodynamic correlates in the pathophysiology of psychosis symptoms and disorders. A more systematic exploration of brain perfusion could complete the search of a multimodal biomarker of SSD.
Assuntos
Transtornos Psicóticos , Esquizofrenia , Humanos , Esquizofrenia/diagnóstico por imagem , Circulação Cerebrovascular , Imageamento por Ressonância Magnética , Marcadores de SpinRESUMO
Extracellular vesicles (EVs) are released from different cell types in the central nervous system (CNS) and play roles in regulating physiological and pathological functions. Although brain-derived EVs (bdEVs) have been successfully collected from brain tissue, there is not yet a "bdEV Atlas" of EVs from different brain regions. To address this gap, we separated EVs from eight anatomical brain regions of a single individual and subsequently characterized them by count, size, morphology, and protein and RNA content. The greatest particle yield was from cerebellum, while the fewest particles were recovered from the orbitofrontal, postcentral gyrus, and thalamus regions. EV surface phenotyping indicated that CD81 and CD9 were more abundant than CD63 in all regions. Cell-enriched surface markers varied between brain regions. For example, putative neuronal markers NCAM, CD271, and NRCAM were more abundant in medulla, cerebellum, and occipital regions, respectively. These findings, while restricted to tissues from a single individual, suggest that additional studies are warranted to provide more insight into the links between EV heterogeneity and function in the CNS.
RESUMO
Extracellular vesicles (EVs) are released from different cell types in the central nervous system (CNS) and play roles in regulating physiological and pathological functions. Although brain-derived EVs (bdEVs) have been successfully collected from brain tissue, there is not yet a "bdEV atlas" of EVs from different brain regions. To address this gap, we separated EVs from eight anatomical brain regions of a single individual and subsequently characterized them by count, size, morphology, and protein and RNA content. The greatest particle yield was from cerebellum, while the fewest particles were recovered from the orbitofrontal, postcentral gyrus, and thalamus regions. EV surface phenotyping indicated that CD81 and CD9 were more abundant than CD63 for all regions. Cell-enriched surface markers varied between brain regions. For example, putative neuronal markers NCAM, CD271, and NRCAM were more abundant in medulla, cerebellum, and occipital regions, respectively. These findings, while restricted to tissues from a single individual, suggest that additional studies are merited to lend more insight into the links between EV heterogeneity and function in the CNS.
RESUMO
Background: Previous studies have probed the brain static activity pattern in bipolar disorder across different states. However, human intrinsic brain activity is time-varying and dynamic. There is a lack of knowledge about the brain dynamical pattern in bipolar disorder across different mood states. Methods: This study used the dynamical degree centrality (dDC) to investigate the resting-state whole-brain dynamical pattern voxel-wise in a total of 62 bipolar disorder [28 bipolar depression (BD), 13 bipolar mania (BM), 21 bipolar euthymia (BE)], and 30 healthy controls (HCs). One-way analysis of variance (ANOVA) was applied to explore the omnibus differences of the dDC pattern across all groups, and Pearson's correlation analysis was used to evaluate the relationship between the dDC variability in detected regions with clinical symptom severity. Results: One-way ANOVA analysis showed the omnibus differences in the left inferior parietal lobule/middle occipital gyrus (IPL/MOG) and right precuneus/posterior cingulate cortex (PCUN/PCC) across all groups. The post hoc analysis revealed that BD showed decreased dDC in the IPL/MOG compared with all other groups, and both BD and BM exhibited decreased dDC in the PCUN/PCC compared with BE and HCs. Furthermore, correlation analysis showed that the dDC variability of the IPL/MOG and PCUN/PCC negatively correlated with the depression symptom levels in all patients with bipolar disorder. Conclusion: This study demonstrated the distinct and shared brain dynamical pattern of the depressive, manic, and euthymia states. Our findings provide new insights into the pathophysiology of bipolar disorder across different mood states from the dynamical brain network pattern perspective.
RESUMO
Background: Neovascular glaucoma (NVG) is a serious eye disease that causes irreversible damage to the eye. It can significantly increase intraocular pressure and cause severe pain, as well as abnormal activity in the cortical and pre-cortical visual systems. However, there are few studies in this area. This trial assessed the altered regional brain activity in patients with NVG using the percentage of fluctuation amplitude (PerAF) method. Methods: Resting-state functional MRI (rs-fMRI) scans were conducted in 18 individuals with NVG and 18 healthy controls (HCs), matched for education level, gender, and age. The PerAF method was applied to assess brain activity. Mean PerAF values of brain regions in NVG and HCs were compared using receiver operating characteristic (ROC) curves. Results: Lower PerAF values were found in the NVG group than in controls in the right anterior cingulate and paracingulate gyri (ACG.R), right superior occipital gyrus (SOG.R) and left superior frontal gyrus (orbital part) (ORBsup.L) (p < 0.001). In contrast, PerAF value was higher in NVG patients than in controls in the left inferior temporal gyrus (ITG.L) (p < 0.001). The hospital anxiety and depression scale (HADS) and visual analog score (VAS) were significantly and positively correlated with PerAF in ITG.L (r = 0.9331, p < 0.0001; and r = 0.7816, p = 0.0001, respectively). Conclusion: Abnormal activity in the patient's brain regions further confirms that the NVG affects the entire brain, not just the visual pathways and posterior retinal mechanisms (including the hypothalamic lateral geniculate nucleus and the primary visual cortex). This strengthens our understanding of the NVG and provides potential diagnostic and therapeutic support for patients who are difficult to diagnose and treat early.