Most recent paper

Prog Neuropsychopharmacol Biol Psychiatry. 2024 Jul 19:111088. doi: 10.1016/j.pnpbp.2024.111088. Online ahead of print.

ABSTRACT

BACKGROUND: Brain aging is a complex process that involves functional alterations in multiple subnetworks and brain regions. However, most previous studies investigating aging-related functional connectivity (FC) changes using resting-state functional magnetic resonance images (rs-fMRIs) have primarily focused on the linear correlation between brain subnetworks, ignoring the nonlinear casual properties of fMRI signals.

METHODS: We introduced the neural Granger causality technique to investigate the sex-dependent nonlinear Granger connectivity (NGC) during aging on a publicly available dataset of 227 healthy participants acquired cross-sectionally in Leipzig, Germany.

RESULTS: Our findings indicate that brain aging may cause widespread declines in NGC at both regional and subnetwork scales. These findings exhibit high reproducibility across different network sparsities, demonstrating the efficacy of static and dynamic analysis strategies. Females exhibit greater heterogeneity and reduced stability in NGC compared to males during aging, especially the NGC between the visual network and other subnetworks. Besides, NGC strengths can well reflect the individual cognitive function, which may therefore work as a sensitive metric in cognition-related experiments for individual-scale or group-scale mechanism understanding.

CONCLUSION: These findings indicate that NGC analysis is a potent tool for identifying sex-dependent brain aging patterns. Our results offer valuable perspectives that could substantially enhance the understanding of sex differences in neurological diseases in the future, especially in degenerative disorders.

PMID:39033955 | DOI:10.1016/j.pnpbp.2024.111088

Sci Data. 2024 Jul 20;11(1):809. doi: 10.1038/s41597-024-03636-y.

ABSTRACT

We describe the following shared data from N = 103 healthy adults who completed a broad set of cognitive tasks, surveys, and neuroimaging measurements to examine the construct of self-regulation. The neuroimaging acquisition involved task-based fMRI, resting state fMRI, and structural MRI. Each subject completed the following ten tasks in the scanner across two 90-minute scanning sessions: attention network test (ANT), cued task switching, Columbia card task, dot pattern expectancy (DPX), delay discounting, simple and motor selective stop signal, Stroop, a towers task, and a set of survey questions. The dataset is shared openly through the OpenNeuro project, and the dataset is formatted according to the Brain Imaging Data Structure (BIDS) standard.

PMID:39033226 | DOI:10.1038/s41597-024-03636-y

Biol Psychiatry. 2024 Jul 18:S0006-3223(24)01460-4. doi: 10.1016/j.biopsych.2024.07.012. Online ahead of print.

ABSTRACT

BACKGROUND: Neurocognitive impairment is a well-known phenomenon in schizophrenia that begins prior to psychosis onset. Connectome-wide association studies have inconsistently linked cognitive performance to resting-state fMRI. We hypothesized a carefully selected cognitive instrument and refined population would allow identification of reliable brain-behavior associations with connectome-wide association studies. To test this hypothesis, we first identified brain-cognition correlations via a connectome-wide association study in early psychosis. We then asked, in an independent dataset, if these brain-cognition relationships would generalize to individuals who develop psychosis in the future.

METHODS: The Seidman Auditory Continuous Performance Task (ACPT) effectively differentiates healthy participants from those with psychosis. Our connectome-wide association study used the Human Connectome Project for Early Psychosis (n=183) to identify links between connectivity and ACPT performance. We then analyzed the North American Prodrome Longitudinal Study 2 (n=345), a multi-site prospective study of individuals at risk for psychosis. We tested the connectome-wide association study-identified cognition-connectivity relationship in both individuals at risk for psychosis and controls.

RESULTS: Our connectome-wide association study in early-course psychosis identified robust associations between better ACPT performance and higher prefrontal-somatomotor connectivity (p<.005). Prefrontal-somatomotor connectivity was also related to ACPT performance in at-risk individuals who would develop psychosis (n=17). This finding was not observed in nonconverters (n=196) or controls (n=132).

CONCLUSIONS: This connectome-wide association study identified reproducible links between connectivity and cognition in separate samples of psychosis and at-risk individuals who would later develop psychosis. A carefully selected task and population improves the ability of connectome-wide association studies to identify reliable brain-phenotype relationships.

PMID:39032726 | DOI:10.1016/j.biopsych.2024.07.012

J Psychiatr Res. 2024 Jul 15;177:211-218. doi: 10.1016/j.jpsychires.2024.07.009. Online ahead of print.

ABSTRACT

Suicidal ideation (SI) is a common symptom of major depressive disorder (MDD), often accompanied by cognitive alterations and emotional dysregulation. However, it is unclear whether cognitive dysfunction in patients with MDD is related to the presence or absence of SI and impaired connectivity within or between large-scale neurocognitive networks. Previous studies have shown that the frontoparietal network (FPN) and default mode network (DMN) are critical for cognitive control and emotional regulation. Participants were 51 MDD patients with suicidal ideation (MDDSI), 52 MDD patients without suicidal ideation (MDDNSI), and 55 healthy controls (HC). Using areas located within FPN and DMN networks as regions of interest (ROIs), we compared the cognitive performance of the three groups and the strength of the resting state functional connections (RSFC) within and between the FPN and DMN networks. Additionally, we examined the correlation between the strength of FC within the FPN and cognitive function in the SI group. Furthermore, network-based statistics (NBS) were used to correct for the strength of FPN and DMN functional connections. The study identified significant cognitive deficits in MDD patients. Reduced strength of FC was observed within the FPN and DMN networks in the SI group compared to the NSI group. In the SI group, the strength of FC within the FPN network was positively correlated with attention/vigilance. These insights underscore the critical roles of the FPN and DMN in the suicidal ideation, shedding light on the cognitively relevant neurobiological characteristics of MDDSI, providing new insights into the neural mechanisms of MDDSI. URL: https://www.chictr.org.cn/bin/project/edit?pid=131537. Registration number: ChiCTR2100049646.

PMID:39032275 | DOI:10.1016/j.jpsychires.2024.07.009

J Affect Disord. 2024 Jul 17:S0165-0327(24)01183-2. doi: 10.1016/j.jad.2024.07.123. Online ahead of print.

ABSTRACT

BACKGROUND: Obsessive-compulsive disorder (OCD) is a disabling disorder in which the temporal variability of regional brain connectivity is not well understood. The aim of this study was to investigate alterations in static and dynamic intrinsic neural activity (INA) in first-episode OCD and whether these changes have the potential to reflect neurotransmitters.

METHODS: A total of 95 first-episode OCD patients and 106 matched healthy controls (HCs) were included in this study. Based on resting-state functional magnetic resonance imaging (rs-fMRI), the static and dynamic local connectivity coherence (calculated by static and dynamic regional homogeneity, sReHo and dReHo) were compared between the two groups. Furthermore, correlations between abnormal INA and PET- and SPECT-derived maps were performed to examine specific neurotransmitter system changes underlying INA abnormalities in OCD.

RESULTS: Compared with HCs, OCD showed decreased sReHo and dReHo values in left superior, middle temporal gyrus (STG/MTG), left Heschl gyrus (HES), left putamen, left insula, bilateral paracentral lobular (PCL), right postcentral gyrus (PoCG), right precentral gyrus (PreCG), left precuneus and right supplementary motor area (SMA). Decreased dReHo values were also found in left PoCG, left PreCG, left SMA and left middle cingulate cortex (MCC). Meanwhile, alterations in INA present in brain regions were correlated with dopamine system (D2, FDOPA), norepinephrine transporter (NAT) and the vesicular acetylcholine transporter (VAChT) maps.

CONCLUSION: Static and dynamic INA abnormalities exist in first-episode OCD, having the potential to reveal the molecular characteristics. The results help to further understand the pathophysiological mechanism and provide alternative therapeutic targets of OCD.

PMID:39029696 | DOI:10.1016/j.jad.2024.07.123

bioRxiv [Preprint]. 2024 Jul 14:2024.07.09.602725. doi: 10.1101/2024.07.09.602725.

ABSTRACT

INTRODUCTION: Trait mindfulness refers to one's disposition or tendency to pay attention to their experiences in the present moment, in a non-judgmental and accepting way. Trait mindfulness has been robustly associated with positive mental health outcomes, but its neural underpinnings are poorly understood. Prior resting-state fMRI studies have associated trait mindfulness with within- and between-network connectivity of the default-mode (DMN), fronto-parietal (FPN), and salience networks. However, it is unclear how generalizable the findings are, how they relate to different components of trait mindfulness, and how other networks and brain areas may be involved.

METHODS: To address these gaps, we conducted the largest resting-state fMRI study of trait mindfulness to-date, consisting of a pre-registered connectome predictive modeling analysis in 367 adults across three samples collected at different sites.

RESULTS: In the model-training dataset, we did not find connections that predicted overall trait mindfulness, but we identified neural models of two mindfulness subscales, Acting with Awareness and Non-judging . Models included both positive networks (sets of pairwise connections that positively predicted mindfulness with increasing connectivity) and negative networks, which showed the inverse relationship. The Acting with Awareness and Non-judging positive network models showed distinct network representations involving FPN and DMN, respectively. The negative network models, which overlapped significantly across subscales, involved connections across the whole brain with prominent involvement of somatomotor, visual and DMN networks. Only the negative networks generalized to predict subscale scores out-of-sample, and not across both test datasets. Predictions from both models were also negatively correlated with predictions from a well-established mind-wandering connectome model.

CONCLUSIONS: We present preliminary neural evidence for a generalizable connectivity models of trait mindfulness based on specific affective and cognitive facets. However, the incomplete generalization of the models across all sites and scanners, limited stability of the models, as well as the substantial overlap between the models, underscores the difficulty of finding robust brain markers of mindfulness facets.

PMID:39026870 | PMC:PMC11257611 | DOI:10.1101/2024.07.09.602725

Mult Scler Relat Disord. 2024 Jul 17;89:105759. doi: 10.1016/j.msard.2024.105759. Online ahead of print.

ABSTRACT

BACKGROUND: Previous studies have investigated the influence of cannabis on cognition among people with MS (pwMS), yet the influence of sex in the context of cannabis use remains unexplored. We aim to fill this gap by investigating cannabis-sex related differences in verbal learning, memory and processing speed in association with fMRI (resting state, and task-based) metrics.

METHOD: Our sample consisted of 19 long-term, frequent cannabis users (8 males, 11 females). Assessments were conducted at baseline and after 28 days of cannabis abstinence. The tests included measures of verbal memory (Selective Reminding Test (SRT)), working memory (n-back), information processing speed (Symbol Digit Modalities Test (SDMT)) and the resting state DMN. To evaluate the effects of cannabis abstinence, we performed a group x time interaction analysis using repeated measures ANCOVA. This analysis controlled for several covariates, including the level of disability (EDSS), baseline cannabis THC metabolite levels, and cannabis withdrawal symptoms. By controlling for these variables, we aimed to isolate the impact of cannabis abstinence on cognitive performance over time. Statistical significance was set at p < 0.05.

RESULTS: There were no baseline cognitive differences between the sexes. After 28 days of cannabis abstinence, females performed better on the Selective Reminding Test (SRT) (p = 0.04), with a large effect size (η² = 0.286). The mean correct response improved over time for females, but there was no statistically significant group x time interaction on the Symbol Digit Modalities Test (SDMT) and the n-back task. Resting state default mode network data showed overall increased activation in females relative to males at day 28, which meshed with lower brain activation during task-based fMRI paradigms.

CONCLUSION: Cannabis negated sex-based cognitive differences. Functional MRI task-based paradigms revealed less cerebral activation in females compared to males, which was associated with comparable or better cognitive performance in females, particularly after cannabis abstinence.

PMID:39024968 | DOI:10.1016/j.msard.2024.105759

Mov Disord. 2024 Jul 18. doi: 10.1002/mds.29924. Online ahead of print.

ABSTRACT

BACKGROUND: Preclinical, postmortem, and positron emission tomography (PET) imaging studies have pointed to neuroinflammation as a key pathophysiological hallmark in primary 4-repeat (4R) tauopathies and its role in accelerating disease progression.

OBJECTIVE: We tested whether microglial activation (1) progresses in similar spatial patterns as the primary pathology tau spreads across interconnected brain regions, and (2) whether the degree of microglial activation parallels tau pathology spreading.

METHODS: We examined in vivo associations between tau aggregation and microglial activation in 31 patients with clinically diagnosed 4R tauopathies, using 18F-PI-2620 PET and 18F-GE180 (translocator protein [TSPO]) PET. We determined tau epicenters, defined as subcortical brain regions with highest tau PET signal, and assessed the connectivity of tau epicenters to cortical regions of interest using a 3-T resting-state functional magnetic resonance imaging template derived from age-matched healthy elderly controls.

RESULTS: In 4R tauopathy patients, we found that higher regional tau PET covaries with elevated TSPO-PET across brain regions that are functionally connected to each other (β = 0.414, P < 0.001). Microglial activation follows similar distribution patterns as tau and distributes primarily across brain regions strongly connected to patient-specific tau epicenters (β = -0.594, P < 0.001). In these regions, microglial activation spatially parallels tau distribution detectable with 18F-PI-2620 PET.

CONCLUSIONS: Our findings indicate that the spatial expansion of microglial activation parallels tau distribution across brain regions that are functionally connected to each other, suggesting that tau and inflammation are closely interrelated in patients with 4R tauopathies. The combination of in vivo tau and inflammatory biomarkers could therefore support the development of immunomodulatory strategies for disease-modifying treatments in these conditions. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

PMID:39022835 | DOI:10.1002/mds.29924

Mol Psychiatry. 2024 Jul 17. doi: 10.1038/s41380-024-02669-4. Online ahead of print.

ABSTRACT

Major depressive disorder (MDD) typically manifests itself in depressed affect, anhedonia, low energy, and additional symptoms. Despite its high global prevalence, its pathophysiology still gives rise to questions. Current research places alterations in functional connectivity among MDD's most promising biomarkers. However, given the heterogeneity of previous findings, the use of higher-resolution imaging techniques, like ultra-high field (UHF) fMRI (≥7 Tesla, 7T), may offer greater specificity in delineating fundamental impairments. In this study, 7T UHF fMRI scans were conducted on 31 MDD patients and 27 age-gender matched healthy controls to exploratorily contrast cerebral resting-state functional connectivity patterns between both groups. The CONN toolbox was used to generate functional network connectivity (FNC) analysis based on the region of interest (ROI)-to-ROI correlations in order to enable the identification of clusters of significantly different connections. Correction for multiple comparisons was implemented at the cluster level using a false discovery rate (FDR). The analysis revealed three significant clusters differentiating MDD patients and healthy controls. In Clusters 1 and 2, MDD patients exhibited between-network hypoconnectivity in basal ganglia-cortical pathways as well as hyperconnectivity in thalamo-cortical pathways, including several individual ROI-to-ROI connections. In Cluster 3, they showed increased occipital interhemispheric within-network connectivity. These findings suggest that alterations in basal ganglia-thalamo-cortical circuits play a substantial role in the pathophysiology of MDD. Furthermore, they indicate potential MDD-related deficits relating to a combination of perception (vision, audition, and somatosensation) as well as more complex functions, especially social-emotional processing, modulation, and regulation. It is anticipated that these findings might further inform more accurate clinical procedures for addressing MDD.

PMID:39020104 | DOI:10.1038/s41380-024-02669-4

Transl Psychiatry. 2024 Jul 17;14(1):293. doi: 10.1038/s41398-024-03007-6.

ABSTRACT

Electronic cigarettes (e-cigs) use, especially among youngsters, has been on the rise in recent years. However, little is known about the long-term effects of the use of e-cigs on brain functional activity. We acquired the resting-state functional magnetic resonance imaging (rs-fMRI) data from 93 e-cigs users with nicotine dependence and 103 health controls (HC). The local synchronization was analyzed via the regional homogeneity (ReHo) method at voxel-wise level. The functional connectivity (FC) between the nucleus accumbens (NAcc), the ventral tegmental area (VTA), and the insula was calculated at ROI-wise level. The support vector machining classification model based on rs-fMRI measures was used to identify e-cigs users from HC. Compared with HC, nicotine-dependent e-cigs users showed increased ReHo in the right rolandic operculum and the right insula (p < 0.05, FDR corrected). At the ROI-wise level, abnormal FCs between the NAcc, the VTA, and the insula were found in e-cigs users compared to HC (p < 0.05, FDR corrected). Correlation analysis found a significant negative correlation between ReHo in the left NAcc and duration of e-cigs use (r = -0.273, p = 0.008, FDR corrected). The following support vector machine model based on significant results of rs-fMRI successfully differentiates chronic e-cigs users from HC with an accuracy of 73.47%, an AUC of 0.781, a sensitivity of 67.74%, and a specificity of 78.64%. Dysregulated spontaneous activity and FC of addiction-related regions were found in e-cigs users with nicotine dependence, which provides crucial insights into the prevention of its initial use and intervention for quitting e-cigs.

PMID:39019862 | DOI:10.1038/s41398-024-03007-6

J Psychiatr Res. 2024 Jul 3;177:147-152. doi: 10.1016/j.jpsychires.2024.07.002. Online ahead of print.

ABSTRACT

OBJECTIVE: This study examines the effect of smoking on global and regional brain entropy in patients with Major Depressive Disorder (MDD), aiming to elucidate the relationship between smoking habits and brain network complexity in depression.

METHODS: The study enrolled 24 MDD patients, divided into smokers and non-smokers, from Alanya Alaaddin Keykubat University and Istanbul Medipol University. Resting-state fMRI data were acquired and processed. The complexity of neuronal activity was assessed using dispersion entropy, with statistical significance determined by a suite of tests including Kolmogorov-Smirnov, Student's t-test, and Mann-Whitney U test.

RESULTS: The smoking cohort exhibited higher global brain entropy compared to the non-smoking group (p = 0.033), with significant differences in various brain networks, indicating that smoking may alter global brain activity and network dynamics in individuals with MDD.

CONCLUSION: The study provides evidence that smoking is associated with increased brain entropy in MDD patients, suggesting that chronic smoking may influence cognitive and emotional networks. This underscores the importance of considering smoking history in the treatment and prognosis of MDD. The findings call for further research to understand the mechanistic links between smoking, brain entropy, and depression.

PMID:39018709 | DOI:10.1016/j.jpsychires.2024.07.002

Wellcome Open Res. 2024 Jan 3;9:4. doi: 10.12688/wellcomeopenres.19392.1. eCollection 2024.

ABSTRACT

BACKGROUND: The proposed research aims to test the effects and mechanisms of a six-month yoga-based intervention as an add-on to standard treatment in opioid use disorder (OUD) by conducting a randomized controlled study with the following primary outcome variables: 1) clinical: abstinence (opioid negative urine test), and reductions in pain and craving, and 2) mechanisms: reward circuit activation in response to opioid visual cue craving paradigm, activation in response to a cognitive control task, and resting state functional connectivity through fMRI, and plasma beta-endorphin levels. Secondary outcome variables are perceived stress, anxiety, sleep quality, cognitive performance, pain threshold, buprenorphine dosage and side effects, withdrawal symptoms, socio-occupational functioning, vedic personality traits, heart rate variability, serum cortisol, and brain GABA levels through magnetic resonance spectroscopy (MRS).

METHODS: In this single-blinded, randomized, controlled, parallel-group superiority trial with 1:1 allocation ratio, 164 patients with OUD availing the outpatient/ inpatient clinical services at a tertiary mental healthcare hospital in India will be enrolled after giving informed consent. Consecutive consenting patients will be randomly allotted to one of the two groups - yoga arm (standard treatment + yoga-based intervention), or waitlist group (standard treatment alone). Allocation concealment will be followed, the clinicians, outcome assessors and data analysts will remain blind to subject-group allocation. A validated and standardized yoga program for OUD will be used as an intervention. Participants in the yoga arm will receive 10 supervised in-person sessions of yoga in the initial two weeks followed by tele-yoga sessions thrice a week for the next 22 weeks. The wait-list control group will continue the standard treatment alone for 24 weeks. Assessments will be done at baseline, two weeks, 12 weeks, and 24 weeks. Data from all randomized subjects will be analysed using intent-to-treat analysis and mixed model multivariate analysis.

DISSEMINATION: Findings will be disseminated through peer-reviewed publication, conference presentations, and social media.

TRIAL REGISTRATION NUMBER: The trial has been registered under Clinical Trials Registry-India with registration number CTRI/2023/03/050737.

PMID:39015614 | PMC:PMC11249518 | DOI:10.12688/wellcomeopenres.19392.1

J Neurophysiol. 2024 Jul 17. doi: 10.1152/jn.00027.2024. Online ahead of print.

ABSTRACT

Alzheimer's disease (AD) is a neurodegenerative disease, and mild cognitive impairment (MCI) is considered a transitional stage between healthy aging and dementia. Early detection of MCI can help slow down the progression of AD. At present, there are few studies exploring the characteristics of abnormal dynamic brain activity in AD. This article uses a method called Leading Eigenvector Dynamics Analysis (LEiDA) to study resting-state functional magnetic resonance imaging (rs-fMRI) data of AD, MCI, and cognitively normal (CN) participants. By identifying repetitive states of phase coherence, inter group differences in brain dynamic activity indicators are examined. And the neurobehavioral scales were used to assess the relationship between abnormal dynamic activities and cognitive function. The results showed that in the indicators of occurrence probability and lifetime, the globally synchronized state of the patient group decreased. The activity state of the limbic regions significantly detected the difference between AD and the other two groups. Compared to CN, AD and MCI have varying degrees of increase in default and visual regions activity states. In addition, in the analysis related to the cognitive scales, it was found that individuals with poorer cognitive abilities were less active in the globally synchronized state, and more active in limbic regions activity state and visual regions activity state. Taken together, these findings reveal abnormal dynamic activity of resting-state networks in patients with AD and MCI, provide new insights into the dynamic analysis of brain networks, and contribute to a deeper understanding of abnormal spatial dynamic patterns in AD patients.

PMID:39015075 | DOI:10.1152/jn.00027.2024

Psychogeriatrics. 2024 Jul 16. doi: 10.1111/psyg.13161. Online ahead of print.

ABSTRACT

BACKGROUND: Computerized cognitive training (CCT) has been proposed as a potential therapy for cognitive decline. One of the benefits of CCT is a transfer effect, but its mechanism on the memory domain is unclear. This study aimed to investigate the transfer effect of non-memory multidomain CCT on the memory domain and its neural basis in patients with mild cognitive impairment (MCI) through a randomized controlled trial.

METHODS: Patients with MCI recruited from memory clinics were randomly assigned to either the CCT or the control group. The CCT group received multidomain CCT training excluding memory training, while the control group read educational books with learning-based quizzes twice a week for 8 weeks. Participants underwent memory tests yielding a composite score, other cognitive domain tests, non-cognitive scales, and resting-state functional magnetic resonance imaging (rsfMRI), at baseline and after intervention. Within- and between-group comparisons, group × time interactions, and seed-to-voxel analyses in memory-involving brain networks were performed.

RESULTS: The CCT group showed improvement over the control group in memory domain (Group × time, F = 5.87, P = 0.03, η2 = 0.31), which was related with the increased connectivity in the hippocampal-frontal and fusiform-occipital network. No other cognitive and non-cognitive symptoms differed between groups after adjusting for covariates.

CONCLUSION: Eight weeks of multidomain CCT without memory training improved memory function and restored functional network in the hippocampal and medial temporal region in MCI patients. These results can provide evidence for the transferring ability of CCT on memory functioning with its neural basis.

PMID:39014538 | DOI:10.1111/psyg.13161

Schizophr Res. 2024 Jul 15;271:47-58. doi: 10.1016/j.schres.2024.06.044. Online ahead of print.

ABSTRACT

Cognitive functioning is a crucial aspect in schizophrenia (SZ), and when altered it has devastating effects on patients' quality of life and treatment outcomes. Several studies suggested that they could result from altered communication between the cortex and cerebellum. However, the neural correlates underlying these impairments have not been identified. In this study, we investigated resting state functional connectivity (rsFC) in SZ patients, by considering the interactions between cortical networks supporting cognition and cerebellum. In addition, we investigated the relationship between SZ patients' rsFC and their symptoms. We used fMRI data from 74 SZ patients and 74 matched healthy controls (HC) downloaded from the publicly available database SchizConnect. We implemented a seed-based connectivity approach to identify altered functional connections between specific cortical networks and cerebellum. We considered ten commonly studied resting state networks, whose functioning encompasses specific cognitive functions, and the cerebellum, whose involvement in supporting cognition has been recently identified. We then explored the relationship between altered rsFC values and Positive and Negative Syndrome Scale (PANSS) scores. The SZ group showed increased connectivity values compared with HC group for cortical networks involved in attentive processes, which were also linked to PANSS items describing attention and language-related processing. We also showed decreased connectivity between cerebellar regions, and increased connectivity between them and attentive networks, suggesting the contribution of cerebellum to attentive and affective deficits. In conclusion, our findings highlighted the link between negative symptoms in SZ and altered connectivity within the cerebellum and between the same and cortical networks supporting cognition.

PMID:39013344 | DOI:10.1016/j.schres.2024.06.044

CNS Neurosci Ther. 2024 Jul;30(7):e14866. doi: 10.1111/cns.14866.

ABSTRACT

BACKGROUND: Reversible loss of consciousness is the primary therapeutic endpoint of general anesthesia; however, the drug-invariant mechanisms underlying anesthetic-induced unconsciousness are still unclear. This study aimed to investigate the static, dynamic, topological and organizational changes in functional brain network induced by five clinically-used general anesthetics in the rat brain.

METHOD: Male Sprague-Dawley rats (n = 57) were randomly allocated to received propofol, isoflurane, ketamine, dexmedetomidine, or combined isoflurane plus dexmedetomidine anesthesia. Resting-state functional magnetic resonance images were acquired under general anesthesia and analyzed for changes in dynamic functional brain networks compared to the awake state.

RESULTS: Different general anesthetics induced distinct patterns of functional connectivity inhibition within brain-wide networks, resulting in multi-level network reorganization primarily by impairing the functional connectivity of cortico-subcortical networks as well as by reducing information transmission capacity, intrinsic connectivity, and network architecture stability of subcortical regions. Conversely, functional connectivity and topological properties were preserved within cortico-cortical networks, albeit with fewer dynamic fluctuations under general anesthesia.

CONCLUSIONS: Our findings highlighted the effects of different general anesthetics on functional brain network reorganization, which might shed light on the drug-invariant mechanism of anesthetic-induced unconsciousness.

PMID:39014472 | DOI:10.1111/cns.14866

Front Neurosci. 2024 Jul 1;18:1388213. doi: 10.3389/fnins.2024.1388213. eCollection 2024.

ABSTRACT

OBJECTIVE: Acute unilateral vestibulopathy (AUVP) is the second leading cause of peripheral vestibular vertigo. Full recovery of AUVP is related to sufficient central vestibular compensation. It has been confirmed that the vestibular nucleus and vestibular cortex are involved in the process of vestibular compensatory in AUVP patients. However, few studies have focused on the functional compensation of thalamus in patients with AUVP. This study aimed to explore the alterations of resting-state functional connectivity (FC) focused on thalamus using functional magnetic resonance imaging (fMRI) in AUVP patients.

METHODS: Data of 3D-T1 and resting-state fMRI were collected from 40 AUVP patients and 35 healthy controls (HC). Seeds-based (bilateral thalamus) FC was analyzed to investigate the changes in FC between the two groups. Furthermore, we evaluated the associations between altered thalamus FC and clinical features in AUVP patients using Pearson's partial correlation.

RESULTS: Compared with HC, AUVP patients showed decreased FC between bilateral thalamus and left insula. We also observed decreased FC between right thalamus and left supramarginal gyrus. Additionally, we found increased FC between left thalamus and right postcentral gyrus (PCG), as well as increased FC between right thalamus and regions of bilateral PCG, right middle frontal gyrus and right middle occipital gyrus in AUVP patients. Furthermore, the FC between left thalamus and left insula was negatively correlated with values of canal paresis in patients with AUVP (p = 0.010, r = -0.434).

CONCLUSION: Our results provided first evidence for the decreased thalamo-vestibular cortex pathway, as well as increased thalamo-somatosensory and thalamo-visual cortex pathway in AUVP patients. These findings help us better understand the underlying mechanisms of central dynamic compensatory following an acute unilateral peripheral vestibular damage.

PMID:39010942 | PMC:PMC11246849 | DOI:10.3389/fnins.2024.1388213

J Sports Med Phys Fitness. 2024 Jul 15. doi: 10.23736/S0022-4707.24.15947-6. Online ahead of print.

ABSTRACT

BACKGROUND: Limited research has been conducted on the neural mechanisms of visuospatial attention in closed skill sports. This research aimed to delve into the unique visuospatial attention abilities of skaters and elucidate the underlying neural mechanisms.

METHODS: This cross-sectional study employed an expert-novice paradigm, applying a purely data-driven approach to analyze and compare the resting-state networks (RSNs) associated with visuospatial attention in 15 elite skaters and 15 control subjects.

RESULTS: From the 38 components identified by independent component analysis (ICA) algorithm, five RSNs were selected, including the dorsal attention network (DAN), left and right fronto-parietal network (FPN), somatomotor network (SMN) and visual network (VIS). Elite skaters exhibited heightened functional connectivity (FC) in the right angular gyrus and left precuneus within DAN, left fusiform gyrus within left FPN, right primary motor cortex within right FPN, left supplementary motor area within SMN, and right primary visual cortex within VIS compared to the control group. Conversely, skaters demonstrated diminished FC in the bilateral superior temporal gyrus within DAN and right prefrontal cortex within the right FPN.

CONCLUSIONS: Statistical results demonstrated significant differences in RSNs related to visuospatial functions in a wide range of brain regions between elite skaters and controls. We further speculate that these variances could be attributable to alterations in visuospatial abilities resulting from years of devoted skating training. The findings of this study offer novel perspectives on the neural reorganization linked to motor training, contributing to an enriched comprehension of the neuroplasticity changes inherent in prolonged engagement in motor skill development.

PMID:39008282 | DOI:10.23736/S0022-4707.24.15947-6

Am J Transl Res. 2024 Jun 15;16(6):2423-2434. doi: 10.62347/GTVB7800. eCollection 2024.

ABSTRACT

BACKGROUND: Tremor-dominant (TD) and postural instability/gait difficulty (PIGD) are common subtypes of Parkinson's disease, each with distinct clinical manifestations and prognoses. The neural mechanisms underlying these subtypes remain unclear. This study aimed to investigate the altered connectivity of the frontal cortex and supplementary motor area (SMA) in different types of Parkinson's disease.

METHODS: Data of 173 participants, including 41 TD patients, 65 PIGD patients, and 67 healthy controls, were retrospectively analyzed. All subjects underwent resting-state functional magnetic resonance imaging (rs-fMRI) and clinical assessments. Differences in amplitude of low frequency fluctuation (ALFF), voxel-wise functional connectivity (FC), and functional network connectivity (FNC) among the three groups were compared, followed by partial correlation analysis.

RESULTS: Compared to healthy controls, the left dorsolateral superior frontal gyrus (DLSFG) ALFF was significantly increased in both PIGD and TD patients. The FC between the left DLSFG and the left SMA, as well as between the left paracentral lobule and the right DLSFG, was significantly decreased. Similarly, the FNC between the visual network and the auditory network was reduced. Compared to TD patients, PIGD patients showed a significantly higher ALFF in the left DLSFG and a notably reduced FC between the left DLSFG and left SMA. Additionally, the FC of the left DLSFG-SMA was inversely correlated with the PIGD score exclusively in PIGD patients. The FNC of the visual-auditory network was inversely associated with the tremor score only in TD patients.

CONCLUSION: Decreases in the left DLSFG-SMA connectivity may be a key feature of the PIGD subtype, while reduced VN-AUD connectivity may characterize the TD subtype.

PMID:39006296 | PMC:PMC11236641 | DOI:10.62347/GTVB7800

Arch Rehabil Res Clin Transl. 2024 Apr 2;6(2):100339. doi: 10.1016/j.arrct.2024.100339. eCollection 2024 Jun.

ABSTRACT

OBJECTIVE: To describe the trajectories of linguistic, cognitive-communicative, and health-related quality of life (HRQOL) outcomes after stroke in persons with aphasia.

DESIGN: Longitudinal observational study from inpatient rehabilitation to 18 months after stroke.

SETTING: Four US mid-west inpatient rehabilitation facilities (IRFs).

PARTICIPANTS: We plan to recruit 400 adult (older than 21 years) English speakers who meet the following inclusion criteria: (1) Diagnosis of aphasia after a left-hemisphere infarct confirmed by CT scan or magnetic resonance imaging (MRI); (2) first admission for inpatient rehabilitation due to a neurologic event; and (3) sufficient cognitive capacity to provide informed consent and participate in testing. Exclusion criteria include any neurologic condition other than stroke that could affect language, cognition or speech, such as Parkinson's disease, Alzheimer's disease, traumatic brain injury, or the presence of right-hemisphere lesions.

INTERVENTIONS: Not applicable.

MAIN OUTCOME MEASURES: Subjects are administered a test battery of linguistic, cognitive-communicative, and HRQOL measures. Linguistic measures include the Western Aphasia Battery-Revised and the Apraxia of Speech Rating Scale. Cognitive-communicative measures include the Communication Participation Item Bank, Connor's Continuous Performance Test-3, the Communication Confidence Rating Scale for Aphasia, the Communication Effectiveness Index, the Neurological Quality of Life measurement system (Neuro-QoL) Communication short form, and the Neuro-QoL Cognitive Function short form. HRQOL measures include the 39-item Stroke & Aphasia Quality of Life Scale, Neuro-QoL Fatigue, Sleep Disturbance, Depression, Ability to Participate in Social Roles & Activities, and Satisfaction with Social Roles & Activities tests, and the Patient-Reported Outcome Measurement and Information System 10-item Global Health short form. The test battery is administered initially during inpatient rehabilitation, and at 3-, 6-, 12-, and 18-months post-IRF discharge. Biomarker samples are collected via saliva samples at admission and a subgroup of participants also undergo resting state fMRI scans.

RESULTS: Not applicable.

CONCLUSIONS: This longitudinal observational study will develop trajectory models for recovery of clinically relevant linguistic, cognitive-communicative, and quality of life outcomes over 18 months after inpatient rehabilitation. Models will identify individual differences in the patterns of recovery based on variations in personal, genetic, imaging, and therapy characteristics. The resulting models will provide an unparalleled representation of recovery from aphasia resulting from stroke. This improved understanding of recovery will enable clinicians to better tailor and plan rehabilitation therapies to individual patient's needs.

PMID:39006119 | PMC:PMC11240047 | DOI:10.1016/j.arrct.2024.100339