Most recent paper

Sex differences in resting-state functional networks in awake rats

Thu, 06/01/2023 - 18:00

Brain Struct Funct. 2023 Jun 1. doi: 10.1007/s00429-023-02657-4. Online ahead of print.


Sex-related differences can be found in many brain disorders and psychophysiological traits, highlighting the importance to systematically understand the sex differences in brain function in humans and animal models. Despite emerging effort to address sex differences in behaviors and disease models in rodents, how brain-wide functional connectivity (FC) patterns differ between male and female rats remains largely unknown. Here, we used resting-state functional magnetic resonance imaging (rsfMRI) to investigate regional and systems-level differences between female and male rats. Our data show that female rats display stronger hypothalamus connectivity, whereas male rats exhibit more prominent striatum-related connectivity. At the global scale, female rats demonstrate stronger segregation within the cortical and subcortical systems, while male rats display more prominent cortico-subcortical interactions, particularly between the cortex and striatum. Taken together, these data provide a comprehensive framework of sex differences in resting-state connectivity patterns in the awake rat brain, and offer a reference for studies aiming to reveal sex-related FC differences in different animal models of brain disorders.

PMID:37261489 | DOI:10.1007/s00429-023-02657-4

Overnight Abstinence, Ventrostriatal-Insular Connectivity, and Tridimensional Personality Traits in Cigarette Smokers

Wed, 05/31/2023 - 18:00

J Integr Neurosci. 2023 May 9;22(3):66. doi: 10.31083/j.jin2203066.


BACKGROUND: Personality traits contribute to the risks of smoking. The striatum has been implicated in nicotine addiction and nicotine deprivation is associated with alterations in resting state functional connectivity (rsFC) of the ventral (VS) and dorsal (DS) striatum. However, it remains unclear how striatal rsFC may change following overnight abstinence or how these shorter-term changes in inter-regional connectivity relate to personality traits.

METHODS: In the current study, 28 smokers completed assessments with Fagerström Test of Nicotine Dependence, Tridimensional Personality Questionnaire (TPQ), as well as resting state functional magnetic resonance imaging (fMRI) scans during satiety and after overnight abstinence. We processed imaging data with published routines and evaluated the results with a corrected threshold.

RESULTS: Smokers showed increases in the VS-insula rsFC but no significant changes in the DS rsFC after overnight abstinence as compared to satiety. The difference in the VS-insula rsFC (abstinence minus satiety) was negatively correlated with harm avoidance.

CONCLUSIONS: These findings highlighted striatal connectivity correlates of very short-term abstinence from smoking and how the VS-insula rsFC may vary with individual personality traits, interlinking neural markers and personality risk factors of cigarette smoking at the earliest stage of abstinence.

PMID:37258442 | DOI:10.31083/j.jin2203066

Whole-brain analyses indicate the impairment of posterior integration and thalamo-frontotemporal broadcasting in disorders of consciousness

Wed, 05/31/2023 - 18:00

Hum Brain Mapp. 2023 May 31. doi: 10.1002/hbm.26386. Online ahead of print.


The study of the brain's dynamical activity is opening a window to help the clinical assessment of patients with disorders of consciousness. For example, glucose uptake and the dysfunctional spread of naturalistic and synthetic stimuli has proven useful to characterize hampered consciousness. However, understanding of the mechanisms behind loss of consciousness following brain injury is still missing. Here, we study the propagation of endogenous and in-silico exogenous perturbations in patients with disorders of consciousness, based upon directed and causal interactions estimated from resting-state fMRI data, fitted to a linear model of activity propagation. We found that patients with disorders of consciousness suffer decreased capacity for neural propagation and responsiveness to events, and that this can be related to severe reduction of glucose metabolism as measured with [18 F]FDG-PET. In particular, we show that loss of consciousness is related to the malfunctioning of two neural circuits: the posterior cortical regions failing to convey information, in conjunction with reduced broadcasting of information from subcortical, temporal, parietal and frontal regions. These results shed light on the mechanisms behind disorders of consciousness, triangulating network function with basic measures of brain integrity and behavior.

PMID:37254960 | DOI:10.1002/hbm.26386

The functional role of the precuneus

Wed, 05/31/2023 - 18:00

Brain. 2023 May 31:awad181. doi: 10.1093/brain/awad181. Online ahead of print.


Recent advancements in computational approaches and neuroimaging techniques have refined our understanding of the precuneus. While previously believed to be largely a visual processing region, the importance of the precuneus in complex cognitive functions has been previously less familiar due to a lack of focal lesions in this deeply seated region, but also a poor understanding of its true underlying anatomy. Fortunately, recent studies have revealed significant information on the structural and functional connectivity of this region, and this data has provided a more detailed mechanistic understanding of the importance of the precuneus in healthy and pathologic states. Through improved resting-state fMRI analyses, it has become clear that the function of the precuneus can be better understood based on its functional association with large scale brain networks. Dual default mode network (DMN) systems have been well explained in recent years in supporting episodic memory and theory of mind, however a novel "para-cingulate" network, which is a subnetwork of the larger central executive network (CEN), with likely significant roles in self-referential processes and related psychiatric symptoms is introduced here and requires further clarification. Importantly, detailed anatomic studies on the precuneus structural connectivity inside and beyond the cingulate cortex has demonstrated the presence of large structural white matter connections, which provide an additional layer of meaning to the structural-functional significance of this region and its association with large scale brain networks. Together, the structural-functional connectivity of the precuneus has provided central elements which can model various neurodegenerative diseases and psychiatric disorders, such as Alzheimer's disease and depression.

PMID:37254740 | DOI:10.1093/brain/awad181

Resting-state network analysis of suicide attempt history in the UK Biobank

Wed, 05/31/2023 - 18:00

Psychol Med. 2023 May 31:1-10. doi: 10.1017/S0033291723001356. Online ahead of print.


BACKGROUND: Prior research has identified altered brain structure and function in individuals at risk for self-directed violence thoughts and behaviors. However, these studies have largely utilized healthy controls and findings have been inconsistent. Thus, this study examined differences in resting-state functional network connectivity among individuals with lifetime suicide attempt(s) v. lifetime self-directed violence thoughts alone.

METHODS: Using data from the UK Biobank, this study utilized a series of linear regressions to compare individuals with lifetime suicide attempt(s) (n = 566) v. lifetime self-directed violence thoughts alone (n = 3447) on within- and between- network resting-state functional connectivity subnetworks.

RESULTS: There were no significant between-group differences for between-network, within-network, or whole-brain functional connectivity after adjusting for age, sex, ethnicity, and body mass index and performing statistical corrections for multiple comparisons. Resting-state network measures may not differentiate between individuals with lifetime suicide attempt(s) and lifetime self-directed violence thoughts alone.

CONCLUSIONS: Null findings diverge from results reported in smaller neuroimaging studies of suicide risk, but are consistent with null findings in other large-scale studies and meta-analyses. Strengths of the study include its large sample size and stringent control group. Future research on a wider array of imaging, genetic, and psychosocial risk factors can clarify relative contributions of individual and combined variables to suicide risk and inform scientific understanding of ideation-to-action framework.

PMID:37254555 | DOI:10.1017/S0033291723001356

Effects of schema on the relationship between post-encoding brain connectivity and subsequent durable memory

Tue, 05/30/2023 - 18:00

Sci Rep. 2023 May 30;13(1):8736. doi: 10.1038/s41598-023-34822-4.


Schemas can facilitate memory consolidation. Studies have suggested that interactions between the hippocampus and the ventromedial prefrontal cortex (vmPFC) are important for schema-related memory consolidation. However, in humans, how schema accelerates the consolidation of new information and relates to durable memory remains unclear. To address these knowledge gaps, we used a human analogue of the rodent spatial schema task and resting-state fMRI to investigate how post-encoding brain networks can predict long-term memory performance in different schema conditions. After participants were trained to obtain schema-consistent or schema-inconsistent object-location associations, they learned new object-location associations. The new associations were tested after the post-encoding rest in the scanner and 24 h later outside the scanner. The Bayesian multilevel modelling was applied to analyse the post-encoding brain networks. The results showed that during the post-encoding, stronger vmPFC- anterior hippocampal connectivity was associated with durable memory in the schema-consistent condition, whereas stronger object-selective lateral occipital cortex (LOC)-ventromedial prefrontal connectivity and weaker connectivity inside the default mode network were associated with durable memory in the schema inconsistent condition. In addition, stronger LOC-anterior hippocampal connectivity was associated with memory in both schema conditions. These results shed light on how schemas reconfigure early brain networks, especially the prefrontal-hippocampal and stimuli-relevant cortical networks and influence long-term memory performance.

PMID:37253795 | DOI:10.1038/s41598-023-34822-4

Decoding individual differences in self-prioritization from the resting-state functional connectome

Tue, 05/30/2023 - 18:00

Neuroimage. 2023 May 28:120205. doi: 10.1016/j.neuroimage.2023.120205. Online ahead of print.


Although the self has traditionally been viewed as a higher-order mental function by most theoretical frameworks, recent research advocates a fundamental self hypothesis, viewing the self as a baseline function of the brain embedded within its spontaneous activities, which dynamically regulates cognitive processing and subsequently guides behavior. Understanding this fundamental self hypothesis can reveal where self-biased behaviors emerge and to what extent brain signals at rest can predict such biased behaviors. To test this hypothesis, we investigated the association between spontaneous neural connectivity and robust self-bias in a perceptual matching task using resting-state functional magnetic resonance imaging (fMRI) in 348 young participants. By decoding whole-brain connectivity patterns, the support vector regression model produced the best predictions of the magnitude of self-bias in behavior, which was evaluated via a nested cross-validation procedure. The out-of-sample generalizability was further authenticated using an external dataset of older adults. The functional connectivity results demonstrated that self-biased behavior was associated with distinct connections between the default mode, cognitive control, and salience networks. Consensus network and computational lesion analyses further revealed contributing regions distributed across six networks, extending to additional nodes, such as the thalamus, whose role in self-related processing remained unclear. These results provide evidence that self-biased behavior derives from spontaneous neural connectivity, supporting the fundamental self hypothesis. Thus, we propose an integrated neural network model of this fundamental self that synthesizes previous theoretical models and portrays the brain mechanisms by which the self emerges at rest internally and regulates responses to the external environment.

PMID:37253415 | DOI:10.1016/j.neuroimage.2023.120205

Altered resting-state brain activity in functional dyspepsia patients: a coordinate-based meta-analysis

Tue, 05/30/2023 - 18:00

Front Neurosci. 2023 May 12;17:1174287. doi: 10.3389/fnins.2023.1174287. eCollection 2023.


BACKGROUND: Neuroimaging studies have identified aberrant activity patterns in multiple brain regions in functional dyspepsia (FD) patients. However, due to the differences in study design, these previous findings are inconsistent, and the underlying neuropathological characteristics of FD remain unclear.

METHODS: Eight databases were systematically searched for literature from inception to October 2022 with the keywords "Functional dyspepsia" and "Neuroimaging." Thereafter, the anisotropic effect size signed the differential mapping (AES-SDM) approach that was applied to meta-analyze the aberrant brain activity pattern of FD patients.

RESULTS: A total of 11 articles with 260 FD patients and 202 healthy controls (HCs) were included. The AES-SDM meta-analysis demonstrated that FD patients manifested increased activity in the bilateral insula, left anterior cingulate gyrus, bilateral thalamus, right precentral gyrus, left supplementary motor area, right putamen, and left rectus gyrus and decreased functional activity in the right cerebellum compared to the HCs. Sensitivity analysis showed that all these above regions were highly reproducible, and no significant publication bias was detected.

CONCLUSION: The current study demonstrated that FD patients had significantly abnormal activity patterns in several brain regions involved in visceral sensation perception, pain modulation, and emotion regulation, which provided an integrated insight into the neuropathological characteristics of FD.

PMID:37250423 | PMC:PMC10213416 | DOI:10.3389/fnins.2023.1174287

Test and re-test reliability of optimal stimulation targets and parameters for personalized neuromodulation

Tue, 05/30/2023 - 18:00

Front Neurosci. 2023 May 12;17:1153786. doi: 10.3389/fnins.2023.1153786. eCollection 2023.


Protocols have been proposed to optimize neuromodulation targets and parameters to increase treatment efficacies for different neuropsychiatric diseases. However, no study has investigated the temporal effects of optimal neuromodulation targets and parameters simultaneously via exploring the test-retest reliability of the optimal neuromodulation protocols. In this study, we employed a publicly available structural and resting-state functional magnetic resonance imaging (fMRI) dataset to investigate the temporal effects of the optimal neuromodulation targets and parameters inferred from our customized neuromodulation protocol and examine the test-retest reliability over scanning time. 57 healthy young subjects were included in this study. Each subject underwent a repeated structural and resting state fMRI scan in two visits with an interval of 6 weeks between two scanning visits. Brain controllability analysis was performed to determine the optimal neuromodulation targets and optimal control analysis was further applied to calculate the optimal neuromodulation parameters for specific brain states transition. Intra-class correlation (ICC) measure was utilized to examine the test-retest reliability. Our results demonstrated that the optimal neuromodulation targets and parameters had excellent test-retest reliability (both ICCs > 0.80). The test-retest reliability of model fitting accuracies between the actual final state and the simulated final state also showed a good test-retest reliability (ICC > 0.65). Our results indicated the validity of our customized neuromodulation protocol to reliably identify the optimal neuromodulation targets and parameters between visits, which may be reliably extended to optimize the neuromodulation protocols to efficiently treat different neuropsychiatric disorders.

PMID:37250412 | PMC:PMC10213310 | DOI:10.3389/fnins.2023.1153786

Dynamic alterations of spontaneous neural activity in post-stroke aphasia: a resting-state functional magnetic resonance imaging study

Tue, 05/30/2023 - 18:00

Front Neurosci. 2023 May 11;17:1177930. doi: 10.3389/fnins.2023.1177930. eCollection 2023.


BACKGROUND AND PURPOSE: The dynamic alterations in spontaneous neural activity of the brain during the acute phase of post-stroke aphasia (PSA) remain unclear. Therefore, in this study, dynamic amplitude of low-frequency fluctuation (dALFF) was applied to explore abnormal temporal variability in local functional activity of the brain during acute PSA.

MATERIALS AND METHODS: Resting-state functional magnetic resonance imaging (rs-fMRI) data from 26 patients with PSA and 25 healthy controls (HCs) were acquired. The sliding window method was used to assess dALFF, with the k-means clustering method used to identify dALFF states. The two-sample t-test was applied to compare differences in dALFF variability and state metrics between the PSA and HC groups.

RESULTS: (1) In the PSA group, greater variance of dALFF in the cerebellar network (CBN) and left fronto-temporo-parietal network (FTPN) was observed. (2) Three dALFF states were identified among all subjects. States 1 and 2 were identified in the PSA patients, and the two dALFF states shared a similar proportion. Moreover, the number of transitions between the two dALFF states was higher in the patients compared with that in HCs.

CONCLUSION: The results of this study provide valuable insights into brain dysfunction that occurs during the acute phase (6.00 ± 3.52 days) of PSA. The observed increase in variability of local functional activities in CBN and left FTPN may be related to the spontaneous functional recovery of language during acute PSA, and it also suggests that cerebellum plays an important role in language.

PMID:37250389 | PMC:PMC10213748 | DOI:10.3389/fnins.2023.1177930

Abnormal changes of static and dynamic functional connectivity of dopaminergic midbrain in patients with first-episode schizophrenia and their correlations with clinical symptoms

Mon, 05/29/2023 - 18:00

Zhonghua Yi Xue Za Zhi. 2023 Jun 6;103(21):1623-1630. doi: 10.3760/cma.j.cn112137-20221118-02428.


Objective: To investigate the abnormal changes of static functional connectivity (sFC) and dynamic functional connectivity (dFC) in the dopaminergic midbrain (ventral dorsal tegmental area and bilateral substantia nigra compacta, VTA/SNc) in patients with first-episode schizophrenia(SCH), and their correlation with the Positive and Negative Symptom Scale (PANSS). Methods: The data of 198 first-episode untreated schizophrenia patients and 199 healthy controls (HC) matched by age, sex and years of education who were admitted to the First Affiliated Hospital of Zhengzhou University from January 2019 to May 2022 were prospectively collected. All subjects underwent high resolution structural MRI and resting state functional magnetic resonance imaging (rs-fMRI) scanning. The dopaminergic midbrain (VTA/SNc) was defined as three regions of interest (ROI). The sFC and dFC analyses with VTA/SNc as seeds were performed to produce a whole-brain diagram initially, which subsequently were compared between schizophrenia group and HC group. Finally, the correlation analysis of sFC and dFC values with the PANSS scores were performed, including the positive scale score, negative scale score, general psychopathology scale score, total score and symptom scores. Results: There were 86 males and 112 females in SCH group, and aged (23±9) years. Meanwhile, there were 95 males and 104 females in HC group, and aged (22±5) years. In the SCH group, the positive (P), the negative (N) and the general psychopathology (G) scale scores and the total score (T) of the PANSS scale was 20±7, 21±7, 41±11 and 82±22, respectively. Compared with the HC group, the VTA showed decreased sFC with four clusters including cerebellar vermis 7/9, left putamen, right thalamus and left middle cingulate gyrus in the schizophrenia group (peak center, t=-4.35, -4.81, -4.35 and -4.65; voxel P<0.005; cluster P<0.05), the right SNc showed decreased sFC with four clusters including left cerebellar hemisphere 4/5/8, right putamen, right medial orbitofrontal gyrus and the left putamen in the schizophrenia group (peak center, t=-4.91, -5.15, -4.77 and -5.21; voxel P<0.005; cluster P<0.05), and the left SNc showed decreased sFC with four clusters including the left putamen, right putamen, right medial orbitofrontal gyrus and left middle cingulate gyrus in the schizophrenia group (peak center, t=-5.82, -4.83 and -4.65; voxel P<0.005; cluster P<0.05). Compared with the HC group, the VTA showed decreased dFC with the right inferior parietal gyrus, right angular gyrus and right superior parietal gyrus in schizophrenia group (t=-4.17). In the schizophrenia group, the sFC value of cluster 2 (left putamen) with VTA as seed and cluster 4 (left putamen) with right SNc as seed were positively correlated with the positive scale scores in PANSS (r=0.141, 0.169, both P<0.05). The sFC and dFC values of significant regions were also correlated with hallucination, delusion, suspicion, hostility, communication disorder, passivity/indifference, lack of communication, stereotyped thinking, depression, non-cooperation, lack of judgment and insight, impulse control disorder, active social avoidance (all P<0.05). Conclusion: The static and dynamic functional connectivity (stability) of VTA/SNc to cerebellum, thalamus, striatum, prefrontal lobe and cingulate gyrus in first-episode schizophrenia patients were decreased, which were closely related to the positive and negative symptoms of schizophrenia.

PMID:37248062 | DOI:10.3760/cma.j.cn112137-20221118-02428

Cardiovascular and metabolic health is associated with functional brain connectivity in middle-aged and older adults: Results from the Human Connectome Project-Aging study

Mon, 05/29/2023 - 18:00

Neuroimage. 2023 May 27:120192. doi: 10.1016/j.neuroimage.2023.120192. Online ahead of print.


Several cardiovascular and metabolic indicators, such as cholesterol and blood pressure have been associated with altered neural and cognitive health as well as increased risk of dementia and Alzheimer's disease in later life. In this cross-sectional study, we examined how an aggregate index of cardiovascular and metabolic risk factor measures was associated with correlation-based estimates of resting-state functional connectivity (FC) across a broad adult age-span (36-100+ years) from 930 volunteers in the Human Connectome Project Aging (HCP-A). Increased (i.e., worse) aggregate cardiometabolic scores were associated with reduced FC globally, with especially strong effects in insular, medial frontal, medial parietal, and superior temporal regions. Additionally, at the network-level, FC between core brain networks, such as default-mode and cingulo-opercular, as well as dorsal attention networks, showed strong effects of cardiometabolic risk. These findings highlight the lifespan impact of cardiovascular and metabolic health on whole-brain functional integrity and how these conditions may disrupt higher-order network integrity.

PMID:37247763 | DOI:10.1016/j.neuroimage.2023.120192

Altered spontaneous brain activities in maintenance hemodialysis patients with cognitive impairment and the construction of cognitive function prediction models

Mon, 05/29/2023 - 18:00

Ren Fail. 2023 Dec;45(1):2217276. doi: 10.1080/0886022X.2023.2217276.


OBJECTIVE: The brain neuromechanism in maintenance hemodialysis patients (MHD) with cognitive impairment (CI) remains unclear. The study aimed to probe the relationship between spontaneous brain activity and CI by using resting-state functional magnetic resonance imaging (rs-fMRI) data.

METHODS: Here, 55 MHD patients with CI and 28 healthy controls were recruited. For baseline data, qualitative data were compared between groups using the χ2 test; quantitative data were compared between groups using the independent samples t-test, ANOVA test, Mann-Whitney U-test, or Kruskal-Wallis test. Comparisons of ALFF/fALFF/ReHo values among the three groups were calculated by using the DPABI toolbox, and then analyzing the correlation with clinical variables. p < .05 was considered a statistically significant difference. Furthermore, back propagation neural network (BPNN) was utilized to predict cognitive function.

RESULTS: Compared with the MHD-NCI group, the patients with MHD-CI had more severe anemia and higher urea nitrogen levels, lower mALFF values in the left postcentral gyrus, lower mfALFF values in the left inferior temporal gyrus, and greater mALFF values in the right caudate nucleus (p < .05). The above-altered indicators were correlated with MOCA scores. BPNN prediction models indicated that the diagnostic efficacy of the model which inputs were hemoglobin, urea nitrogen, and mALFF value in the left central posterior gyrus was optimal (R2 = 0.8054), validation cohort (R2 = 0.7328).

CONCLUSION: The rs-fMRI can reveal the neurophysiological mechanism of cognitive impairment in MHD patients. In addition, it can serve as a neuroimaging marker for diagnosing and evaluating cognitive impairment in MHD patients.

PMID:37246750 | DOI:10.1080/0886022X.2023.2217276

Resting state functional connectivity differentiation of neuropathic and nociceptive pain in individuals with chronic spinal cord injury

Sat, 05/27/2023 - 18:00

Neuroimage Clin. 2023 Apr 20;38:103414. doi: 10.1016/j.nicl.2023.103414. Online ahead of print.


Many individuals with spinal cord injury live with debilitating chronic pain that may be neuropathic, nociceptive, or a combination of both in nature. Identification of brain regions demonstrating altered connectivity associated with the type and severity of pain experience may elucidate underlying mechanisms, as well as treatment targets. Resting state and sensorimotor task-based magnetic resonance imaging data were collected in 37 individuals with chronic spinal cord injury. Seed-based correlations were utilized to identify resting state functional connectivity of regions with established roles in pain processing: the primary motor and somatosensory cortices, cingulate, insula, hippocampus, parahippocampal gyri, thalamus, amygdala, caudate, putamen, and periaqueductal gray matter. Resting state functional connectivity alterations and task-based activation associated with individuals' pain type and intensity ratings on the International Spinal Cord Injury Basic Pain Dataset (0-10 scale) were evaluated. We found that intralimbic and limbostriatal resting state connectivity alterations are uniquely associated with neuropathic pain severity, whereas thalamocortical and thalamolimbic connectivity alterations are associated specifically with nociceptive pain severity. The joint effect and contrast of both pain types were associated with altered limbocortical connectivity. No significant differences in task-based activation were identified. These findings suggest that the experience of pain in individuals with spinal cord injury may be associated with unique alterations in resting state functional connectivity dependent upon pain type.

PMID:37244076 | DOI:10.1016/j.nicl.2023.103414

Abnormal functional connectivity density involvement in freezing of gait and its application for subtyping Parkinson's disease

Sat, 05/27/2023 - 18:00

Brain Imaging Behav. 2023 May 27. doi: 10.1007/s11682-023-00765-7. Online ahead of print.


The pathophysiological mechanisms at work in Parkinson's disease (PD) patients with freezing of gait (FOG) remain poorly understood. Functional connectivity density (FCD) could provide an unbiased way to analyse connectivity across the brain. In this study, a total of 23 PD patients with FOG (PD FOG + patients), 26 PD patients without FOG (PD FOG- patients), and 22 healthy controls (HCs) were recruited, and their resting-state functional magnetic resonance imaging (rs-fMRI) images were collected. FCD mapping was first performed to identify differences between groups. Pearson correlation analysis was used to explore relationships between FCD values and the severity of FOG. Then, a machine learning model was employed to classify each pair of groups. PD FOG + patients showed significantly increased short-range FCD in the precuneus, cingulate gyrus, and fusiform gyrus and decreased long-range FCD in the frontal gyrus, temporal gyrus, and cingulate gyrus. Short-range FCD values in the middle temporal gyrus and inferior temporal gyrus were positively correlated with FOG questionnaire (FOGQ) scores, and long-range FCD values in the middle frontal gyrus were negatively correlated with FOGQ scores. Using FCD in abnormal regions as input, a support vector machine (SVM) classifier can achieve classification with good performance. The mean accuracy values were 0.895 (PD FOG + vs. HC), 0.966 (PD FOG- vs. HC), and 0.897 (PD FOG + vs. PD FOG-). This study demonstrates that PD FOG + patients showed altered short- and long-range FCD in several brain regions involved in action planning and control, motion processing, emotion, cognition, and object recognition.

PMID:37243751 | DOI:10.1007/s11682-023-00765-7

Cortex-wide neural dynamics predict behavioral states and provide a neural basis for resting-state dynamic functional connectivity

Sat, 05/27/2023 - 18:00

Cell Rep. 2023 May 26;42(6):112527. doi: 10.1016/j.celrep.2023.112527. Online ahead of print.


Although resting-state functional magnetic resonance imaging (fMRI) studies have observed dynamically changing brain-wide networks of correlated activity, fMRI's dependence on hemodynamic signals makes results challenging to interpret. Meanwhile, emerging techniques for real-time recording of large populations of neurons have revealed compelling fluctuations in neuronal activity across the brain that are obscured by traditional trial averaging. To reconcile these observations, we use wide-field optical mapping to simultaneously record pan-cortical neuronal and hemodynamic activity in awake, spontaneously behaving mice. Some components of observed neuronal activity clearly represent sensory and motor function. However, particularly during quiet rest, strongly fluctuating patterns of activity across diverse brain regions contribute greatly to interregional correlations. Dynamic changes in these correlations coincide with changes in arousal state. Simultaneously acquired hemodynamics depict similar brain-state-dependent correlation shifts. These results support a neural basis for dynamic resting-state fMRI, while highlighting the importance of brain-wide neuronal fluctuations in the study of brain state.

PMID:37243588 | DOI:10.1016/j.celrep.2023.112527

Predicting Responses to Electroconvulsive Therapy in Adolescents with Treatment-Refractory Depression Based on Resting-State fMRI

Sat, 05/27/2023 - 18:00

J Clin Med. 2023 May 19;12(10):3556. doi: 10.3390/jcm12103556.


OBJECTS: The efficacy of electroconvulsive therapy (ECT) in the treatment of adolescents with treatment-refractory depression is still unsatisfactory, and the individual differences are large. It is not clear which factors are related to the treatment effect. Resting-state fMRI may be a good tool to predict the clinical efficacy of this treatment, and it is helpful to identify the most suitable population for this treatment.

METHODS: Forty treatment-refractory depression adolescents were treated by ECT and evaluated using HAMD and BSSI scores before and after treatment, and were then divided into a treatment response group and a non-treatment group according to the reduction rate of the HAMD scale. We extracted the ALFF, fALFF, ReHo, and functional connectivity of patients as predicted features after a two-sample t-test and LASSO to establish and evaluate a prediction model of ECT in adolescents with treatment-refractory depression.

RESULTS: Twenty-seven patients achieved a clinical response; symptoms of depression and suicidal ideation were significantly improved after treatment with ECT, which was reflected in a significant decrease in the scores of HAMD and BSSI (p < 0.001). The efficacy was predicted by ALFF, fALFF, ReHo, and whole-brain-based functional connectivity. We found that models built on a subset of features of ALFF in the left insula, fALFF in the left superior parietal gyrus, right superior parietal gyrus, and right angular, and functional connectivity between the left superior frontal gyrus, dorsolateral-right paracentral lobule, right middle frontal gyrus, orbital part-left cuneus, right olfactory cortex-left hippocampus, left insula-left thalamus, and left anterior cingulate gyrus-right hippocampus to have the best predictive performance (AUC > 0.8).

CONCLUSIONS: The local brain function in the insula, superior parietal gyrus, and angular gyrus as well as characteristic changes in the functional connectivity of cortical-limbic circuits may serve as potential markers for efficacy judgment of ECT and help to provide optimized individual treatment strategies for adolescents with depression and suicidal ideation in the early stages of treatment.

PMID:37240663 | DOI:10.3390/jcm12103556

Changes in Functional Connectivity of Hippocampal Subregions in Patients with Obstructive Sleep Apnea after Six Months of Continuous Positive Airway Pressure Treatment

Sat, 05/27/2023 - 18:00

Brain Sci. 2023 May 22;13(5):838. doi: 10.3390/brainsci13050838.


Previous studies have shown that the structural and functional impairments of hippocampal subregions in patients with obstructive sleep apnea (OSA) are related to cognitive impairment. Continuous positive airway pressure (CPAP) treatment can improve the clinical symptoms of OSA. Therefore, this study aimed to investigate functional connectivity (FC) changes in hippocampal subregions of patients with OSA after six months of CPAP treatment (post-CPAP) and its relationship with neurocognitive function. We collected and analyzed baseline (pre-CPAP) and post-CPAP data from 20 patients with OSA, including sleep monitoring, clinical evaluation, and resting-state functional magnetic resonance imaging. The results showed that compared with pre-CPAP OSA patients, the FC between the right anterior hippocampal gyrus and multiple brain regions, and between the left anterior hippocampal gyrus and posterior central gyrus were reduced in post-CPAP OSA patients. By contrast, the FC between the left middle hippocampus and the left precentral gyrus was increased. The changes in FC in these brain regions were closely related to cognitive dysfunction. Therefore, our findings suggest that CPAP treatment can effectively change the FC patterns of hippocampal subregions in patients with OSA, facilitating a better understanding of the neural mechanisms of cognitive function improvement, and emphasizing the importance of early diagnosis and timely treatment of OSA.

PMID:37239310 | DOI:10.3390/brainsci13050838

Test-Retest Reliability of Resting Brain Small-World Network Properties across Different Data Processing and Modeling Strategies

Sat, 05/27/2023 - 18:00

Brain Sci. 2023 May 19;13(5):825. doi: 10.3390/brainsci13050825.


Resting-state functional magnetic resonance imaging (fMRI) with graph theoretical modeling has been increasingly applied for assessing whole brain network topological organization, yet its reproducibility remains controversial. In this study, we acquired three repeated resting-state fMRI scans from 16 healthy controls during a strictly controlled in-laboratory study and examined the test-retest reliability of seven global and three nodal brain network metrics using different data processing and modeling strategies. Among the global network metrics, the characteristic path length exhibited the highest reliability, whereas the network small-worldness performed the poorest. Nodal efficiency was the most reliable nodal metric, whereas betweenness centrality showed the lowest reliability. Weighted global network metrics provided better reliability than binary metrics, and reliability from the AAL90 atlas outweighed those from the Power264 parcellation. Although global signal regression had no consistent effects on the reliability of global network metrics, it slightly impaired the reliability of nodal metrics. These findings provide important implications for the future utility of graph theoretical modeling in brain network analyses.

PMID:37239297 | DOI:10.3390/brainsci13050825

A Systematic Review of Structural and Functional MRI Studies Investigating Social Networking Site Use

Sat, 05/27/2023 - 18:00

Brain Sci. 2023 May 11;13(5):787. doi: 10.3390/brainsci13050787.


An understanding of the neurocognitive profile underlying the use of social networking sites (SNSs) can help inform decisions about the classification of problematic SNS use as an addictive disorder and elucidate how/when 'SNS addiction' might develop. The present review aimed to synthesize structural and functional MRI research investigating problematic/compulsive forms of SNS use or regular (non-addicted) SNS use behaviours. We conducted a systematic search for research articles published in English using the Web of Science, PubMed, and Scopus databases up to October 2022. Studies meeting our inclusion criteria were assessed for quality and a narrative synthesis of the results was conducted. Twenty-eight relevant articles were identified comprising structural MRI (n = 9), resting-state fMRI (n = 6) and task-based fMRI studies (n = 13). Current evidence suggests that problematic SNS use might be characterised by (1) reduced volume of the ventral striatum, amygdala, subgenual anterior cingulate cortex, orbitofrontal cortex and posterior insula; (2) increased ventral striatum and precuneus activity in response to SNS cues; (3) abnormal functional connectivity involving the dorsal attention network; (4) inter-hemispheric communication deficits. Regular SNS use behaviours appear to recruit regions involved in the mentalising network, the self-referential cognition network, the salience network, the reward network and the default mode network. Such findings are at least partially consistent with observations from the substance addiction literature and provide some provisional support for the addictive potential of SNSs. Nonetheless, the present review is limited by the small number of eligible studies and large heterogeneity in the methods employed, and so our conclusions should remain tentative. Moreover, there is a lack of longitudinal evidence suggesting SNSs cause neuroadaptations and thus conclusions that problematic SNS use represents a disease process akin to substance use addictions are premature. More well-powered longitudinal research is needed to establish the neural consequences of excessive and problematic SNS use.

PMID:37239257 | DOI:10.3390/brainsci13050787