From anatomy to function: the role of the somatosensory cortex in emotional regulation

Temporal characteristics of moral disgust in obsessive-compulsive disorder (OCD) from a lexical perspective: An ERPs and sLORETA study

BACKGROUND

Although many studies have hinted at the essential role of moral disgust in obsessive-compulsive disorder (OCD), few studies focused on moral disgust have been reported. Exploring the temporal characterization of moral disgust can enhance our understanding of emotional processing.

METHODS

This study included 58 patients with OCD and 45 healthy controls (HCs) and used an adapted lexical decision task paradigm (explicit LDT) combined with event-related potentials (ERPs) analysis and standardized low-resolution brain electromagnetic tomography analysis (sLORETA) to explore the performance of patients with OCD in processing moral disgust words.

RESULTS

Compared to HCs, patients with OCD showed greater EPN amplitudes (P = 0.009), which are localized the occipital lobe, when confronted with moral disgust words. In the comparison between core disgust words and moral disgust words, no difference was found in the ERP time windows of interest in patients with OCD. Furthermore, no difference between LDT and explicit LDT was detected in patients with OCD.

LIMITATIONS

We did not include word class as a variable in the study.

CONCLUSIONS

Our results showed abnormalities in processing moral disgust in the early stage (EPN) of lexical processing in patients with OCD compared to HCs. And, we found no significant difference between moral disgust and core disgust at any stage of lexical processing. This suggested that, similar to core disgust, moral disgust in patients with OCD triggered automatic attention and elicited higher levels of emotional experience and arousal compared to HCs.

Graph-constrained Analysis for Multivariate Functional Data

The manuscript considers multivariate functional data analysis with a known graphical model among the functional variables representing their conditional relationships (e.g., brain region-level fMRI data with a prespecified connectivity graph among brain regions). Functional Gaussian graphical models (GGM) used for analyzing multivariate functional data customarily estimate an unknown graphical model, and cannot preserve knowledge of a given graph. We propose a method for multivariate functional analysis that exactly conforms to a given inter-variable graph. We first show the equivalence between partially separable functional GGM and graphical Gaussian processes (GP), proposed recently for constructing optimal multivariate covariance functions that retain a given graphical model. The theoretical connection helps to design a new algorithm that leverages Dempster's covariance selection for obtaining the maximum likelihood estimate of the covariance function for multivariate functional data under graphical constraints. We also show that the finite term truncation of functional GGM basis expansion used in practice is equivalent to a low-rank graphical GP, which is known to oversmooth marginal distributions. To remedy this, we extend our algorithm to better preserve marginal distributions while respecting the graph and retaining computational scalability. The benefits of the proposed algorithms are illustrated using empirical experiments and a neuroimaging application.

The primary somatosensory sensory cortex-basolateral amygdala pathway contributes to comorbid depression in spared nerve injury-induced neuropathic pain

Comorbid depression in chronic pain is a prevalent health problem, yet the underlying neural mechanisms remain largely unexplored. This study identified a dedicated neural circuit connecting the hind limb region of the primary somatosensory cortex (S1HL) to the basolateral amygdala (BLA) that mediated neuropathic pain-induced depression. We demonstrated that depressive-like behaviors in the chronic phase of a mouse neuropathic pain model were associated with heightened activity in the S1HL and BLA. Using viral tracing and RNAscope in situ hybridization, we characterized the circuit architecture of S1HL glutamatergic projections to BLA cholecystokinin (CCK) neurons (S1HLGlu → BLACCK). In vivo fiber photometry calcium imaging revealed that both the S1HL BLA-projecting afferents and the BLA S1HL-innervating neurons exhibited hyperactivity in neuropathic pain-induced depressive states. Chemogenetic inhibition of the S1HL → BLA circuit could block neuropathic pain-induced depressive-like behaviors. In addition, specific knockdown of CCK expression in BLA S1HL-innervating neurons alleviated these depressive-like behaviors. Our findings demonstrated that the cortical-amygdala circuit S1HLGlu → BLACCK drove the transition from chronic pain to depression, thus suggesting a potential neural circuit basis for treating chronic pain-related depressive disorders.

Disrupted interhemispheric functional and structural connectivity in patients with major depressive disorder

BACKGROUND

Major depressive disorder (MDD) is associated with disrupted interhemispheric cooperation. However, the relationship between structural and functional alterations in interhemispheric cooperation in patients with MDD remains unclear. We investigated the associations between voxel-mirrored homotopic connectivity (VMHC) and radial diffusivity (RD) within the corpus callosum (CC) and their links to depressive symptoms in patients with MDD.

METHODS

Sixty patients with MDD and 38 healthy controls (HCs) were assessed using resting-state functional MRI (rs-fMRI) and diffusion MRI (dMRI) to evaluate interhemispheric functional connectivity (VMHC) and structural integrity (RD) in the CC subregions. Group comparisons, correlation analyses, and mediation analyses were conducted to identify the significant differences, relationships, and indirect effects.

RESULTS

Patients with MDD showed significantly reduced VMHC in the bilateral postcentral gyrus and lingual gyrus and increased RD in the CC subregions CC3, CC4, and CC5, indicating impaired functional and structural connectivity. Lower VMHC in the lingual gyrus was negatively correlated with depressive severity, whereas increased RD in the CC4 and CC5 was positively correlated with depressive symptoms. Mediation analysis revealed that the VMHC in the lingual gyrus fully mediated the relationship between RD in CC5 and depressive symptoms, suggesting a pathway through which structural impairments may affect mood through abnormal functional connectivity.

LIMITATIONS

The cross-sectional design limits the assessment of changes over time, and focusing solely on interhemispheric connectivity may overlook other networks involved in MDD.

CONCLUSION

These findings provide preliminary evidence for disrupted interhemispheric coordination in MDD, with both functional and structural connectivity impairments linked to depressive symptoms. The mediating effect of the VMHC in the lingual gyrus highlights the potential role of interhemispheric connectivity in the pathophysiology of MDD. Our results provide an integrative perspective on the functional and microstructural organization of the brain in patients with MDD.

Neuroimaging Changes in the Sensorimotor Network and Visual Network in Bipolar Disorder and Their Relationship with Genetic Characteristics

Objective: Patients with bipolar disorder (BD) may exhibit common and significant changes in brain activity across different networks. Our aim was to investigate the changes in functional connectivity (FC) within different brain networks in BD, as well as their neuroimaging homogeneity, heterogeneity, and genetic variation. Methods: In this study, we analyzed the seed points and whole-brain FC of the sensorimotor network (SMN) and visual network (VN) in 83 healthy controls (HCs) and 77 BD patients, along with their genetic neuroimaging associations. Results: The results showed that, compared to HCs, BD patients exhibited abnormal FC in the SMN and VN brain regions. However, after three months of treatment, there were no significant differences in SMN and VN FC in the brain regions of the patients compared to pre-treatment levels. Enrichment analysis indicated that genes associated with changes in FC were shared among different SMN seed points, but no shared genes were found among VN seed points. Conclusions: In conclusion, changes in SMN FC may serve as a potential neuroimaging marker in BD patients. Our genetic neuroimaging association analysis may help to comprehensively understand the molecular mechanisms underlying FC changes in BD patients.

Neural correlates of communication modes in medical students using fMRI

This study aims to determine if the six different types of communication (Directive, Imaginative, Reflective, Persuasive, Harmonizing, Promoting), as presented in the Process Communication Model, correlate with a respective neural pathway. Participants were 30 medical students with no past medical history. They underwent functional magnetic resonance imaging (fMRI) while watching videos typical of each communication type. By comparing each of the six experimental conditions with all the other ones, common activations were detected in the core memory network. Assertive communication styles (Directive, Imaginative) generated activations in conflict detection and resolution related areas, with a predominance in the frontal lobe. Emotive communication (Harmonizing, Promoting) highlighted activations associated with the interpretation of social and emotional cues, with a temporo-occipital predominance. There were no significant activations for the Reflective and Persuasive channel, the two channels that were most coherent with the subjects' base patterns and communication. This study indicated that out of the six communication types that were analyzed, four have a specific and congruous underlying cerebral process. This shows that neural response patterns vary across different communication styles, reflecting differences in cognitive and emotional processing.

Increased functional connectivity between brainstem substructures and cortex in treatment resistant depression

Previous functional magnetic resonance imaging (fMRI) studies showed an abnormal brainstem-to-cortex functional connectivity (FC) in major depressive disorder. However, only few studies analyzed brainstem substructures in treatment-resistant depression (TRD). In this study, we analyzed resting-state seed-based FC between midbrain, pons, medulla oblongata and cortical/subcortical brain regions in patients with TRD (n = 24) and age- and sex-matched healthy controls (n = 24). FC was analyzed in each group and compared between groups. Correlation analyses assessed the relationship between FC strength and depressive symptom severity in regions showing significant group differences in seed-based connectivity. Our findings reveal an increased FC in the midbrain and pons to the precentral gyrus, postcentral gyrus, and temporal gyrus in patients with TRD compared to healthy controls. Interestingly, in TRD patients, FC between midbrain and cortex was negatively correlated with BDI-II scores, indicating a relationship between altered connectivity and self-reported depression severity. It is essential to note that our naturalistic, cross-sectional approach precludes causal conclusions regarding the relationship between FC and pathophysiology of TRD. The small sample size necessitates confirmation in a larger cohort. Midbrain/pons-to-cortex FC was increased in patients with TRD compared to healthy controls. Future studies should explore the relationship between abnormal brainstem-to-cortex FC and depressive symptomatology in more detail.

Regulation of craving and underlying resting-state neural circuitry predict hazard of smoking lapse

Among individuals with substance use disorders, clinical outcomes may be improved by identifying brain-behavior models that predict drug re/lapse vulnerabilities such as the ability to regulate drug cravings and inhibit drug use. In a sample of nicotine-dependent adult cigarette smokers (N = 213), this laboratory study examined associations between regulation of craving (ROC) efficacy and smoking lapse, utilized functional connectivity multivariate pattern analysis (FC-MVPA) and seed-based connectivity (SBC) analyses to identify resting-state neural circuitry underlying ROC efficacy, and then examined if the identified ROC-mediated circuitry predicted hazard of smoking lapse. Regarding behavior, worse ROC efficacy predicted a greater hazard of smoking lapse. Regarding brain and behavior, FC-MVPA identified 29 brain-wide functional clusters associated with ROC efficacy. Follow-up SBC analyses using 9 of the FC-MVPA-derived clusters identified a total of 64 resting-state edges (i.e., cluster-to-cluster connections) underlying ROC efficacy, 10 of which were also associated with the hazard of smoking lapse. ROC efficacy edges also associated with smoking lapse were largely composed of connections between frontal-striatal-limbic clusters and sensory-motor clusters and better behavioral outcomes were associated with stronger resting-state FC. Findings suggest that both ROC efficacy and underlying resting-state neural circuitry may inform prediction models of re/lapse vulnerabilities and serve as treatment targets for cessation interventions.

Limbic-Sensorimotor Tug of War for the Hippocampus: Dynamic Functional Connectivity as a Transdiagnostic Vulnerability Marker in Offspring of Emotion Dysregulation Patients

BACKGROUND

Emotion dysregulation (ED) is a key transdiagnostic symptom in several psychiatric disorders such as borderline personality disorder (BPD), bipolar disorder (BD), and attention-deficit/hyperactivity disorder (ADHD). These disorders, here defined as ED disorders (EDD), share similarities in symptoms, comorbidity, and heritability, emphasizing the importance of a transdiagnostic approach to identify markers of vulnerability to EDD in high-risk populations, such as EDD patients' offspring (EDDoff). The hippocampus, central to ED, exhibits alterations across EDD.

METHODS

We employed a state-of-the-art approach (micro-co-activation patterns, μCAPs) to study the transdiagnostic dynamic functional connectivity (dFC) of hippocampal subregions from resting-state functional MRI of 201 participants (74 EDD patients, 57 EDDoff, 70 controls). μCAPs provide a data-driven differentiation within the seed region.

RESULTS

DFC between the sensorimotor network (SMN) and the hippocampal body was lower in EDD patients (pFDR=0.0002) and EDDoff (pFDR=0.01) compared to controls, with EDDoff displaying an intermediate pattern between EDD patients and controls. dFC between the limbic network (LN) and the hippocampal head was higher in EDD patients than in controls (pFDR=0.01) and in EDDoff (pFDR=0.01). A negative correlation was found between ED and SMN (pFDR=0.01), suggesting increasing ED with decreasing SMN dFC with the hippocampus.

CONCLUSIONS

Increased dFC between the hippocampal head and the LN, at the expense of the SMN, may represent a marker of disease in EDD patients. Lower dFC between the SMN and the hippocampal body may represent a marker of vulnerability to EDD in EDDoff, correlating with ED. Such a transdiagnostic construct represents a clinically relevant target for early interventions aimed at reducing vulnerability to EDD in high-risk populations.

Exploring the interaction effects of subclinical hypothyroidism and major depressive disorder on brain networks

BACKGROUND

Major depressive disorder (MDD) often presents alongside physical illnesses, such as a high incidence of subclinical hypothyroidism (SHypo) in patients, highlighting the common occurrence of these comorbidities. Recent research has indicated that the presence of comorbid SHypo in individuals diagnosed with MDD may result in notable alterations in both brain structure and function. This study aimed was to investigate the neurological mechanisms underlying this co-occurrence using a data-driven approach to analyze brain activity patterns.

METHODS

Twenty-nine patients diagnosed with MDD without any comorbid conditions (nSHypo-MDD) were included in the study, along with 29 MDD patients who also had SHypo (SHypo-MDD), 26 patients with SHypo only, and 29 healthy individuals as controls (HCs). Each participant received resting-state functional magnetic resonance imaging scans and underwent neuropsychological evaluations.

RESULTS

We found significantly altered functional connectivity (FC) within the resting-state networks (RSNs) of the ventral and dorsal sensorimotor network (VSMN and DSMN) and occipital pole visual network (PVN) (p < 0.05, FDR corrected). A vital interaction effect between SHypo and MDD was detected in the PVN, showing that SHypo-MDD patients had higher FC values in the left cuneus than nSHypo-MDD patients. Serum-free triiodothyronine (FT3) levels in SHypo-MDD patients demonstrated an inverse relationship with FC values of the right supplementary motor area (SMA.R) (r = - 0.563, p = 0.003). Furthermore, the FC values in the left cuneus are positively associated with the Digit Symbol Substitution Test (DSST) scores (r = 0.507, p = 0.008).

CONCLUSIONS

Our study reveals significant FC changes in SHypo-MDD patients, particularly in the PVN, VSMN, and DSMN, suggesting compensatory mechanisms that mitigate cognitive deficits and highlighting the need for integrated management of SHypo and MDD to improve cognitive outcomes.

Resting-State Sensory-Motor Connectivity between Hand and Mouth as a Neural Marker of Socioeconomic Disadvantage, Psychosocial Stress, Cognitive Difficulties, Impulsivity, Depression, and Substance Use in Children

Background

The sensory-motor network is essential for integrating sensory input with motor function and higher-order cognition. Resting-state functional connectivity (rsFC) within this network undergoes significant developmental changes, and disruptions in these connections have been linked to behavioral and psychiatric outcomes. However, the relationship between sensory-motor connectivity, early-life adversity, and later health behaviors remains understudied.

Objective

This study examines the associations between rsFC within the sensory-motor network (mouth and hand regions) and key social, psychological, and behavioral factors, including baseline and past socioeconomic status (SES), trauma exposure, family conflict, impulsivity, major depressive disorder (MDD), and future substance use.

Methods

Data were drawn from the Adolescent Brain Cognitive Development (ABCD) Study, a national sample of U.S. children. Resting-state fMRI data were used to assess functional connectivity within the sensory-motor network. Bivariate analyses examined associations between rsFC in the sensory-motor mouth and hand regions and baseline SES, past SES, childhood trauma exposure, family conflict, impulsivity, and MDD. Longitudinal analyses assessed whether baseline rsFC predicted future substance use.

Results

Greater rsFC between the sensory-motor mouth and hand regions was significantly associated with lower SES, higher trauma exposure, and greater family conflict. Increased connectivity was also correlated with older age and more advanced puberty status. Higher rsFC between the sensory-motor mouth and hand regions was linked to greater impulsivity, lower cognitive function, an increased likelihood of MDD, and future marijuana use.

Conclusion

These findings suggest that sensory-motor connectivity is sensitive to socioeconomic and psychosocial stressors, with potential long-term implications for mental health and substance use risk. The results highlight the importance of early-life environmental factors in shaping neurodevelopmental trajectories and emphasize the need for targeted interventions to mitigate the effects of adversity on brain function and behavior. Future research should further explore the role of sensory-motor network alterations in behavioral health outcomes as a function of environmental stressors.

Personal Goal-Related Mental Time Travel and Its Association With Resting-State Functional Connectivity in Individuals With High Schizotypal Traits

BACKGROUND AND HYPOTHESIS

Mental time travel (MTT) is a crucial ability for daily life. Personal goal-related MTT events has stronger phenomenological characteristics than personal goal-unrelated ones, ie, the "personal goal-advantage effect". However, it remains unclear whether this effect is impacted in individuals with high schizotypal traits (HST) and the neural correlates of this effect have yet to be elucidated. The present study aimed to fill these knowledge gaps. We hypothesized that HST would show a reduced "personal goal-advantage effect" in MTT and would exhibit altered relationships with resting-state functional connectivity.

STUDY DESIGN

In Study 1, 37 HST and 40 individuals with low schizotypal traits (LST) were recruited. Participants generated MTT events with personal goal-related and personal goal-unrelated cues. In Study 2, 39 HST and 38 LST were recruited, they completed the same behavioral task and resting-state functional magnetic resonance imaging (fMRI) scanning.

STUDY RESULTS

Both Study 1 and Study 2 revealed that HST exhibited reduced "personal goal-advantage effect" on MTT specificity. Moreover, Study 2 showed that compared with LST, HST exhibited altered association between the "personal goal-advantage effect" and functional connectivity (ie, between the right precuneus and the left postcentral gyrus and "personal goal-advantage effect" on emotional valence, between the left hippocampus and the right temporal fusiform gyrus and "personal goal-advantage effect" on emotional intensity).

CONCLUSIONS

These findings suggest that HST exhibit a reduced "personal goal-advantage effect" in MTT specificity and altered neural correlates related to this effect. The "personal goal-advantage effect" may be a potential target for intervention in HST.

Effect of Different Frequencies of Transcutaneous Electrical Acupoint Stimulation (TEAS) on EEG Source Localization in Healthy Volunteers: A Semi-Randomized, Placebo-Controlled, Crossover Study

Background/Objectives: Transcutaneous electrical acupoint stimulation (TEAS), also known as transcutaneous electroacupuncture stimulation, delivers electrical pulses to the skin over acupuncture points ("acupoints") via surface electrodes. Electroencephalography (EEG) is an important tool for assessing the changes in the central nervous system (CNS) that may result from applying different TEAS frequencies peripherally-i.e., acting via the peripheral nervous system (PNS)-and determining how these influence cerebral activity and neural plasticity. Methods: A total of 48 healthy volunteers were allocated in a semi-randomized crossover study to receive four different TEAS frequencies: 2.5 pulses per second (pps); 10 pps; 80 pps; and sham (160 pps at a low, clinically ineffective amplitude). TEAS was applied for 20 min to each hand at the acupuncture point Hegu (LI4). The EEG was recorded during an initial 5 min baseline recording, then during TEAS application, and after stimulation for a further 15 min, separated into three periods of 5 min (initial, intermediate, and final) in order to assess post-stimulation changes. Source localization analysis was conducted for the traditional five EEG frequency bands: delta (0.1-3.9 Hz), theta (4-7.9 Hz), alpha (8-13 Hz), beta (14-30 Hz), and gamma (30.1-45 Hz). Results: Within-group source localization analyses of EEG data showed that during the initial 5 min post-stimulation, theta oscillations in the 2.5 pps TEAS group increased over the parahippocampal gyrus (t = 4.42, p < 0.01). The 10 pps TEAS group exhibited decreased alpha rhythms over the inferior parietal gyrus (t = -4.20, p < 0.05), whereas the sham (160 pps) TEAS group showed decreased delta rhythms over the postcentral gyrus (t = -3.97, p < 0.05). During the intermediate 5 min post-stimulation, the increased theta activity over the left parahippocampal gyrus (BA27) remained in the 2.5 pps TEAS group (t = 3.97, p < 0.05). However, diminished alpha rhythms were observed in the 10 pps TEAS group over the postcentral gyrus (t = -4.20, p < 0.01), as well as in the delta rhythms in the sham (160 pps) TEAS group in the same area (t = -4.35, p < 0.01). In the final 5 min post-stimulation, reduced alpha rhythms were exhibited over the insula in the 10 pps TEAS group (t = -4.07, p < 0.05). Interaction effects of condition by group demonstrate decreased alpha rhythms in the 10 pps TEAS group over the supramarginal gyrus during the initial 5 min post-stimulation (t = -4.31, p < 0.05), and decreased delta rhythms over the insula in the sham TEAS group during the final 5 min post-stimulation (t = -4.42, p < 0.01). Conclusions: This study revealed that low TEAS frequencies of 2.5 pps and 10 pps modulate theta and alpha oscillations over the brain areas related to emotional and attentional processes driven by external stimuli, as well as neural synchronization of delta rhythms in the sham group in brain areas related to stimulus expectation at baseline. It is hoped that these findings will stimulate further research in order to evaluate such TEAS modulation effects in clinical patients.

Altered hypothalamus functional connectivity and psychological stress in patients with alopecia areata

Background

Alopecia areata (AA) is a nonscarring chronic inflammatory hair loss disease with a complex etiology. Psychological stress and dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis have been strongly linked to the etiology of AA, but the associated changes in intrinsic brain activity remain unknown. We hypothesized that patients with AA exhibit altered hypothalamic activity that is linked to psychological stress. This study aimed to characterize the altered hypothalamic activity in patients with AA and its relationship to psychological stress.

Methods

A total of 102 patients with AA and 84 age- and sex-matched healthy controls (HCs) were recruited. All participants underwent resting-state functional magnetic resonance imaging (rs-fMRI) to assess brain activity and completed neuropsychological evaluations, including the Hamilton Anxiety Rating Scale (HAM-A) score and the Hamilton Depression Rating Scale (HAM-D). Additionally, patients with AA were assessed using the Dermatology Life Quality Index (DLQI), and blood samples were obtained to measure total serum immunoglobulin E (IgE) levels. We chose the hypothalamus as the region of interest (ROI) to compare alterations in hypothalamic of amplitude of low-frequency fluctuation (ALFF) and whole-brain functional connectivity (FC) between patients with AA and HCs. Analyses of the correlation of brain activity and clinical data were conducted, including neuropsychological tests, DLQI, and blood samples.

Results

The HAM-A score, the HAM-D score, and the altered ALFF in the hypothalamus showed a statistically significant difference between patients with AA and HCs (P<0.05). Patients with AA exhibited increased FC between the hypothalamus, the left postcentral gyrus, and right inferior temporal gyrus (Gaussian random field-corrected: voxel <0.001 and cluster <0.05). Moreover, increased FC between the hypothalamus and left postcentral gyrus was positively correlated with HAM-D score (r=0.296; P=0.020), while increased FC between the hypothalamus and the right inferior temporal gyrus was negatively correlated with both DLQI (r=-0.256; P=0.012) and total serum IgE (r=-0.203; P=0.048).

Conclusions

Patients with AA exhibited altered hypothalamus activity and connectivity. These alterations may underlie the neurophysiological basis of psychological stress experienced by patients with AA.

Soma and neurite density imaging detects brain microstructural impairments in amyotrophic lateral sclerosis

OBJECTIVE

To investigate whole-brain microstructural changes in amyotrophic lateral sclerosis (ALS) using soma and neurite density imaging (SANDI), a novel multicompartment model of diffusion-weighted imaging that estimates apparent soma and neurite density.

METHODS

This study consists of 41 healthy controls and 43 patients with ALS, whose diffusion-weighted data were acquired. The SANDI-derived (including signal fractions of soma (fsoma), neurite (fneurite), and extra-cellular space (fextra)) and diffusion tensor imaging (DTI)-derived metrics were obtained. Voxel-based analyses were performed to evaluate intergroup differences and the correlation of SANDI and DTI metrics with clinical parameters.

RESULTS

In ALS patients, fneurite reduction involved both gray matter (primarily the bilateral precentral gyri, supplementary motor area, medial frontal gyrus, anterior cingulate cortex, inferior frontal gyrus, orbital gyrus, paracentral lobule, postcentral gyrus, middle cingulate cortex, hippocampus and parahippocampal gyrus, and insula, and left anterior parts of the temporal lobe) and white matter (primarily the bilateral corticospinal tract, body of corpus callosum, and brainstem) (P <0.05 after false discovery rate correction). The fextra increment showed a similar spatial distribution in ALS patients. Interestingly, the decreased fsoma in ALS primarily located in gray matter; while, the increased fsoma primarily involved white matter. The spatial distribution of fneurite/fextra/fsoma changes was larger than that detected by conventional DTI metrics, and the fneurite/fextra/fsoma were correlated with disease severity.

CONCLUSIONS

SANDI may serve as a clinically relevant model, superior to conventional DTI, for characterizing microstructural impairments such as neurite degeneration and soma alteration in ALS.

Comparison of cortical gyrification patterns in patients with panic disorder with and without comorbid generalized anxiety disorder

BACKGROUND

Lower functioning and higher symptom severity are observed when panic disorder (PD) co-occurs with generalized anxiety disorder (PD + GAD). No research on cortical gyrification patterns in the PD + GAD group has been conducted to date, which could show the alterations in brain connectivity in the extended fear network (EFN). This study aimed to investigate the characteristics of cortical gyrification in the PD + GAD group, compared to that in the PD without comorbid GAD (PD-GAD) group.

METHODS

This study included 90 patients with PD, with propensity score matching between the PD + GAD (n = 30) and PD-GAD groups (n = 60), and 65 healthy controls (HC). For clinical evaluation, we assessed the anxiety symptomatology, suicidality, and harm avoidance. The local gyrification index (LGI) was obtained from T1-weighted brain MRI data using FreeSurfer.

RESULTS

In the PD group compared to the HC, the hypergyrification involved the EFN. In the PD + GAD group compared to the PD-GAD group, hypergyrification was shown in the pathological worry-related brain regions. Within the PD + GAD group, significant positive correlations were observed between the superior frontal gyrus LGI values and suicidality scores, as well as between the superior parietal gyrus LGI values and harm avoidance levels.

LIMITATIONS

Given the variability in cortical gyrification patterns, longitudinal studies are needed to assess the occurrence of hypergyrification in specific brain regions.

CONCLUSIONS

This study is the first to demonstrate cortical gyrification patterns in the PD + GAD group compared to those in the PD-GAD group. Notably, the EFN and pathological worry-related brain regions have been implicated in the pathology of PD + GAD.

Pde4b-regulated cAMP signaling pathway in the AUDGABA-S1TrSst circuit underlies acute-stress-induced anxiety-like behavior

Acute-stress-induced anxiety helps animals avoid danger, but the neural and molecular mechanisms controlling this behavior remain largely elusive. Here, we find that acute physical stress activates many neurons in the primary somatosensory cortex, trunk region (S1Tr). Single-cell sequencing reveals that the S1Tr c-fos-positive neurons activated by acute stress are largely GABAergic somatostatin (Sst) neurons. These S1TrSst neurons desensitize during subsequent anxiety-like behavior tests. Inhibiting or inducing apoptosis of S1TrSst neurons mimics acute-stress effects and induces anxiety, while activating these neurons reduces acute-stress-induced anxiety. S1TrSst cells receive inputs from secondary auditory cortex, dorsal area (AUD) GABAergic neurons to modulate this anxiety. Spatial transcriptome sequencing and targeted Pde4b protein knockdown show that acute stress reduces Pde4b-regulated cAMP signaling in AUDGABA-S1TrSst projections, leading to decreased S1TrSst neuron activity in subsequent behavioral tests. Our study reports a neural and molecular mechanism for acute-stress-induced anxiety, providing a basis for treating anxiety disorders.

Aberrant Resting-State Effective Connectivity Between the Insula and Other Regions of the Whole Brain in Children With Obstructive Sleep Apnea

To investigate the effective connectivity between the bilateral insulae and other regions of the whole brain in children with obstructive sleep apnea (OSA), and to reveal the relationships between these abnormal connections and cognitive dysfunction in this condition. Resting-state functional magnetic resonance imaging (rs-fMRI) data and clinical variables were collected from 55 children with OSA [5.0 (5.0, 8.0) years, 32 males, 28 pre-school children] and 25 healthy controls [6.0 (5.0, 9.0) years, 11 males, 9 pre-school children], matched for age, gender, and education. Rs-fMRI data were analysed to investigative group-difference in the effective connectivity between the bilateral insulae and other regions of the brain of children with OSA with those of controls. Spearman correlation analysis was conducted between these abnormal connections and clinical variables among children with OSA. Compared with controls, children with OSA showed abnormal clinical variables (i.e., increased OAHI, AHI, OAI, HI, ODI, time of SpO2 < 90%, total AI, and respiratory-related AI, while decreased minimal SpO2, FIQ, VIQ, and PIQ). Additionally, significant alterations were observed in the effective connectivity between the bilateral insulae and other regions of brain, such as frontal, parietal, occipital, and cerebellum and so forth. Furthermore, the mean values of the effective connectivity in children with OSA were significantly correlated with several sleep-related and neurocognitive parameters. There exist abnormal causal interactions between the bilateral insulae and other regions throughout the brain in OSA children, accompanied by impaired cognitive function, suggesting that the former may be a potential neural mechanism underlying the latter.

Early life psychosocial stress increases binge-like ethanol consumption and CSF1R inhibition prevents stress-induced alterations in microglia and brain macrophage population density

Early life stress (ELS) has lasting consequences on microglia and brain macrophage function. During ELS, microglia and brain macrophages alter their engagement with synapses leading to changes in neuronal excitability. Further, ELS can induce innate immune memory formation in microglia and brain macrophages resulting in altered responsivity to future environmental stimuli. These alterations can result in lasting adaptations in circuit function and may mediate the relationship between ELS and the risk to develop alcohol use disorder (AUD). Whether microglia and brain macrophages truly mediate this relationship remains elusive. Here, we report: 1) an ELS model, psychosocial stress (PSS), increases binge-like ethanol consumption in early adulthood. 2) Repeated binge-like ethanol consumption increases microglia and brain macrophage population densities across the brain. 3) PSS may elicit innate immune memory formation in microglia and brain macrophages leading to altered population densities following repeated binge-like ethanol consumption. 4) Microglia and brain macrophage inhibition trended towards preventing PSS-evoked changes in binge-like ethanol consumption and normalized microglia and brain macrophage population densities. Therefore, our study suggests that acutely inhibiting microglia and brain macrophage function during periods of early life PSS may prevent innate immune memory formation and assist in reducing the risk to develop AUD.

Hippocampal temporal dynamics and spatial heterogeneity unveil vulnerability markers in the offspring of bipolar patients

OBJECTIVES

Bipolar disorder (BD) is a highly heritable disorder characterized by emotion dysregulation and recurrent oscillations between mood states. Despite the proven efficacy of early interventions, vulnerability markers in high-risk individuals are still lacking. BD patients present structural alterations of the hippocampus, a pivotal hub of emotion regulation networks composed of multiple subregions with different projections. However, the hippocampal dynamic functional connectivity (dFC) in BD remains unclear. We aim to investigate whether the dFC of hippocampal subdivisions differentiates BD patients, offspring of BD patients (BDoff), and healthy controls (HC); and whether it correlates with symptoms differently between these groups.

METHODS

We studied for the first time the dFC of the hippocampus through a cutting-edge micro-co-activation patterns (μCAPs) analysis of resting-state functional MRI data of 97 subjects (26 BD, 18 BDoff, 53 HC). μCAPs allow a data-driven differentiation within the seed region.

RESULTS

dFC between the hippocampal body and a somatomotor-μCAP was lower both in BD patients (p-valueFDR:0.00015) and in BDoff (p-valueFDR:0.020) than in HC. Inversely, dFC between the hippocampal head and a limbic-μCAP was higher in BD patients than in HC (p-valueFDR: 0.005). Furthermore, the correlations between a frontoparietal-μCAP and both depression and emotion dysregulation symptoms were significantly higher in BD than HC (p-valueFDR <0.02).

CONCLUSION

Overall, we observed alterations of large-scale functional brain networks associated with decreased cognitive control flexibility and disrupted somatomotor, saliency, and emotion processing in BD. Interestingly, BDoff presented an intermediate phenotype between BD and HC, suggesting that dFC of hippocampal subregions might represent a marker of vulnerability to BD.

Altered local spontaneous activity and functional connectivity density in major depressive disorder patients with anhedonia

OBJECTIVE

The purpose of this study was to investigate the alterations of intrinsic brain function in major depressive disorder (MDD) patients with and without anhedonia based on whole-brain level by using two novel measures, four-dimensional spatial-temporal consistency of local neural activity (FOCA) and local functional connectivity density (lFCD).

METHODS

A total of 26 MDD patients with anhedonia (MDD-WA), 29 MDD patients without anhedonia (MDD-WoA), and 30 healthy controls (HCs) were recruited and underwent resting-state functional magnetic resonance imaging (rs-fMRI) scanning and intrinsic brain function was explored by FOCA and lFCD. A two-sample t-test was conducted to explore FOCA and lFCD differences between MDD patients and HCs, then analysis of covariance (ANCOVA) and post hoc tests were performed to obtain brain regions with significant differences among three groups. Finally, the diagnostic performance of FOCA and lFCD values with significant inter-group difference was evaluated using receiver operating characteristic (ROC) curves.

RESULTS

Compared to HCs, MDD patients showed decreased FOCA in the right cuneus (CUN) and left postcentral gyrus (PoCG), as well as diminished lFCD in the right CUN and left calcarine fissure and surrounding cortex (CAL). Interestingly, the MDD-WA group was more likely to exhibit decreased FOCA in the left PoCG and reduced lFCD in the left CAL after consideration for the effect of anhedonia in MDD patients. The MDD-WA group further showed increased FOCA in the bilateral caudate (CAU) and right ventral anterior nucleus (VA) when comparing to HCs. Additionally, as compared with MDD-WoA group, the MDD-WA group presented decreased FOCA in the right middle occipital gyrus (MOG), which was also negatively associated with the severity of anhedonia in MDD patients. Finally, FOCA values of the right MOG exhibited excellent discriminant validity in differentiating MDD-WA from MDD-WoA, and the other individual or combined indices of FOCA or lFCD values in the aforementioned distinct brain regions presented significant utility in distinguishing between MDD or MDD-WA and HCs.

CONCLUSIONS

The present findings suggest that aberrant intrinsic brain function in the left CAL, left PoCG, bilateral CAU, right VA, and, especially the right MOG may be associated with anhedonia in patients with MDD. Altered FOCA in the right MOG may have the potential to be a diagnostic neuroimaging biomarker for MDD patients with anhedonia.

Gray matter and cognitive alteration related to chronic obstructive pulmonary disease patients: combining ALE meta-analysis and MACM analysis

Chronic obstructive pulmonary disease (COPD) is frequently comorbid with cognitive impairment, but it has not been paid enough attention, and its neuroanatomical characteristics have not been fully identified. Voxel-based morphometric (VBM) studies comparing gray matter (GM) abnormalities in COPD patients with healthy controls (HCs) were searched using 8 electronic databases from the inception to March 2023. Stereotactic data were extracted and tested for convergence and differences using the activation likelihood estimation (ALE) method. Moreover, based on the ALE results, a structural meta-analytic connectivity modeling (MACM) was conducted to explore the co-atrophy pattern in patients with COPD. Last, behavioral analysis was performed to assess the functional roles of the regions affected by COPD. In total, 11 studies on COPD with 949 participants were included. Voxel-based meta-analysis revealed significant GM abnormalities in the right postcentral gyrus (including inferior parietal lobule), left precentral gyrus, and left cingulate gyrus (including paracentral lobule) in patients with COPD compared with HCs. Further MACM analysis revealed a deeper co-atrophy pattern between the brain regions with abnormal GM structure and the insula in COPD patients. Behavioral analysis showed that the abnormal GM structure in the left cingulate gyrus (including paracentral lobule) was strongly associated with cognitive function, especially executive function. COPD comorbid with cognitive impairment has a specific neurostructural basis of GM structural abnormalities, which may also involve a deeper co-atrophy pattern between the insula. These findings enhance our understanding of the underlying neuropathogenesis and suggest potential imaging markers for cognitive impairment in COPD patients. PROSPERO registration number: CRD42022298722.

Temporoparietal structural-functional coupling abnormalities in drug-naïve first-episode major depressive disorder

INTRODUCTION

Major depressive disorder (MDD) is a debilitating and heterogeneous disease. Many MDD patients experience concurrent anxiety symptoms, often referred to as anxious depression (MDD-ANX). The relationships between network alterations in structural connectivity (SC) and functional connectivity (FC) in MDD and its anxiety-related subtype remain areas that require further investigation.

METHODS

We investigated SC-FC coupling at the system and regional levels in 80 never-treated first-episode MDD patients and 80 healthy control (HC) subjects. For brain systems and regions showing significant between-group coupling differences, we further conducted subgroup comparisons between MDD-ANX, non-anxious depression (MDD-NANX) and HC. We also investigated topological features at the corresponding levels, and assessed the correlation patterns between significant coupling alterations and the topological and clinical characteristics.

RESULTS

Relative to HC, MDD patients showed increased SC-FC coupling in the temporal system (right hippocampus and left superior temporal gyrus [STG]) but decreased coupling in the parietal system (right postcentral gyrus and left angular gyrus). These systems and regions were further characterized by disturbed inter-module connections and impaired structural network efficiency in MDD. Notably, SC-FC coupling of the right hippocampus was significantly increased in MDD-ANX compared to MDD-NANX, which further showed distinct correlation patterns with structural network efficiency.

CONCLUSIONS

Alterations in both SC-FC coupling and topological properties in the temporal and parietal regions provide insights into the interplay between the structural and functional network abnormalities in MDD. SC-FC coupling alterations in the right hippocampus, associated with structural nodal efficiency, may be implicated in the neuropathology of anxious depression.

Efferent compared to afferent neural substrates of the vergence eye movement system evoked via fMRI

Introduction

The vergence neural system was stimulated to dissect the afferent and efferent components of symmetrical vergence eye movement step responses. The hypothesis tested was whether the afferent regions of interest would differ from the efferent regions to serve as comparative data for future clinical patient population studies.

Methods

Thirty binocularly normal participants participated in an oculomotor symmetrical vergence step block task within a functional MRI experiment compared to a similar sensory task where the participants did not elicit vergence eye movements.

Results

For the oculomotor vergence task, functional activation was observed within the parietal eye field, supplemental eye field, frontal eye field, and cerebellar vermis, and activation in these regions was significantly diminished during the sensory task. Differences between the afferent sensory and efferent oculomotor experiments were also observed within the visual cortex.

Discussion

Differences between the vergence oculomotor and sensory tasks provide a protocol to delineate the afferent and efferent portion of the vergence neural circuit. Implications with clinical populations and future therapeutic intervention studies are discussed.

Altered Functional Connectivity of Prefrontal Cortex-Related Circuitry and Trait Impulsivity in Patients With Bipolar Disorder and History of Suicide Attempts

BACKGROUND

The neurobiological basis of impulsivity and its role in suicide attempt (SA) in BD remains underexplored. This study aimed to examine the functional connectivity (FC) within the prefrontal cortex (PFC) in BD patients with and without a history of SA, focusing on the role of trait impulsivity.

METHODS

Seventy-two euthymic BD patients (34 with a history of SA, BDSA; and 38 without, BDNS) and 55 age- and sex-matched healthy controls underwent resting-state functional MRI. FC analyses were conducted on four PFC regions: superior frontal gyrus (SFG), middle frontal gyrus (MFG), inferior frontal gyrus (IFG), and orbitofrontal cortex (OFC). Trait impulsivity was assessed using the Barratt Impulsiveness Scale (BIS-11), and its association with FC was analyzed using a general linear model, adjusting for demographic and clinical variables.

RESULTS

BDSA had higher trait impulsivity than BDNS and the controls. BDSA exhibited reduced FC between the PFC and sensorimotor (postcentral and precentral gyri) and thalamic regions compared to BDNS. These reductions in FC of the fronto-thalamic and fronto-sensorimotor circuits were significantly associated with higher trait impulsivity scores.

CONCLUSION

The findings highlight specific PFC-based FC alterations associated with suicide attempts and trait impulsivity in BD, offering potential neurobiological markers for suicide risk in this population.

Association of altered cortical gyrification and working memory in male early abstinent alcohol-dependent individuals

BACKGROUND

Alcohol dependence (AD) is an addictive disorder with multifaceted neurobiological features. Recent research on the pathophysiological mechanisms of AD has emphasized the important role of dysconnectivity. Cortical gyrification is known to be a reliable marker of neural connectivity. This study aimed to explore cortical gyrification using the local gyrification index (LGI) between alcohol-dependent patients and controls.

METHODS

Magnetic resonance images were collected from 60 early abstinent patients with AD (5-12 days after stopping alcohol consumption) and 59 controls and preprocessed using FreeSurfer, followed by surface-based morphometry (SBM) analysis to compare the LGI between the two groups. Cognitive performance was assessed using the Spatial Working Memory (SWM) test in the Cambridge Neuropsychological Test Automated Battery (CANTAB). The relationship between LGI, cognitive performance, and clinical variables was also explored in the patient group.

RESULTS

Compared with controls, patients with AD exhibited significantly decreased LGI in several regions, including the postcentral gyrus, precentral gyrus, middle frontal, superior temporal, middle temporal, insula, superior parietal, and inferior parietal cortex. AD patients did worse than controls in several SWM measures. Furthermore, decreased LGI in the left postcentral was negatively correlated with working memory performance after multiple comparison corrections in the patient group.

CONCLUSION

Alcohol-dependent individuals exhibit abnormal patterns of cortical gyrification, which may be underlying neurobiological markers of AD. Our findings further indicate that working memory deficits may be related to abnormalities in cortical gyrification in alcohol addiction.

Phenomena of hypo- and hyperconnectivity in basal ganglia-thalamo-cortical circuits linked to major depression: a 7T fMRI study

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.

Multilayer network analysis in patients with end-stage kidney disease

This study aimed to investigate alterations in a multilayer network combining structural and functional layers in patients with end-stage kidney disease (ESKD) compared with healthy controls. In all, 38 ESKD patients and 43 healthy participants were prospectively enrolled. They exhibited normal brain magnetic resonance imaging (MRI) without any structural lesions. All participants, both ESRD patients and healthy controls, underwent T1-weighted imaging, diffusion tensor imaging (DTI), and resting-state functional MRI (rs-fMRI) using the same three-tesla MRI scanner. A structural connectivity matrix was generated using the DTI and DSI programs, and a functional connectivity matrix was created using the rs-fMRI and SPM programs in the CONN toolbox. Multilayer network analysis was conducted based on structural and functional connectivity matrices using BRAPH. Significant differences were observed at the global level in the multilayer network between patients with ESKD and healthy controls. The weighted multiplex participation was lower in patients with ESKD than in healthy controls (0.6454 vs. 0.7212, adjusted p = 0.049). However, other multilayer network measures did not differ. The weighted multiplex participation in the right subcentral gyrus, right opercular part of the inferior frontal gyrus, right occipitotemporal medial lingual gyrus, and right postcentral gyrus in patients with ESKD was lower than that in the corresponding regions in healthy controls (0.6704 vs. 0.8562, 0.8593 vs. 0.9388, 0.7778 vs. 0.8849, and 0.6825 vs. 0.8112; adjusted p < 0.05, respectively).This study demonstrated that the multilayer network combining structural and functional layers in patients with ESKD was different from that in healthy controls. The specific differences in weighted multiplex participation suggest potential disruptions in the integrated communication between different brain regions in these patients.

Sensory and motor cortices parcellations estimated via distance-weighted sparse representation with application to autism spectrum disorder

BACKGROUND

Motor impairments and sensory processing abnormalities are prevalent in autism spectrum disorder (ASD), closely related to the core functions of the primary motor cortex (M1) and the primary somatosensory cortex (S1). Currently, there is limited knowledge about potential therapeutic targets in the subregions of M1 and S1 in ASD patients. This study aims to map clinically significant functional subregions of M1 and S1.

METHODS

Resting-state functional magnetic resonance imaging data (NTD = 266) from Autism Brain Imaging Data Exchange (ABIDE) were used for subregion modeling. We proposed a distance-weighted sparse representation algorithm to construct brain functional networks. Functional subregions of M1 and S1 were identified through consensus clustering at the group level. Differences in the characteristics of functional subregions were analyzed, along with their correlation with clinical scores.

RESULTS

We observed symmetrical and continuous subregion organization from dorsal to ventral aspects in M1 and S1, with M1 subregions conforming to the functional pattern of the motor homunculus. Significant intergroup differences and clinical correlations were found in the dorsal and ventral aspects of M1 (p < 0.05/3, Bonferroni correction) and the ventromedial BA3 of S1 (p < 0.05/5). These functional characteristics were positively correlated with autism severity. All subregions showed significant results in the ROI-to-ROI intergroup differential analysis (p < 0.05/80).

LIMITATIONS

The generalizability of the segmentation model requires further evaluation.

CONCLUSIONS

This study highlights the significance of M1 and S1 in ASD treatment and may provide new insights into brain parcellation and the identification of therapeutic targets for ASD.

Effects of childhood trauma on sustained attention in major depressive disorder: the mediating role of brain activity and functional connectivity

BACKGROUND

Sustained attention deficits were reported more significant in patients with major depressive disorder (MDD) than in healthy controls (HCs), and are pivotal in both the development and aggravation of depression. Childhood trauma is also common in MDD and the exposure to childhood trauma may impede sustained attention and increase the treatment resistance in MDD. However, the underlying neuro-mechanisms link the childhood trauma to sustained attention deficits in MDD remain unclear.

METHODS

We collected resting-state functional magnetic resonance imaging data, and measured childhood trauma severity using the Childhood Trauma Questionnaire and sustained attention using the Continuous Performance Test, Identical Pairs version. After excluding subjects with significant head movement, 45 MDDs and 54 HCs were included in the analysis. We compared fractional amplitude of low-frequency fluctuation (fALFF) between the groups, conducted whole-brain correlation analysis between the fALFF and sustained attention in the MDD group, and defined significant regions as the regions of interest for the seed-to-whole brain functional connectivity (FC) analysis. We further performed mediation analyses to investigate the relationships among the childhood trauma, fALFF and FC values, and the level of sustained attention in the MDD group.

RESULTS

Compared with HCs, MDDs exhibited higher fALFF in the right middle frontal gyrus and left inferior frontal gyrus, and lower fALFF in the bilateral insular cortex, left medial orbital superior frontal gyrus and left angular gyrus (ANG.L). Whole-brain correlation analysis showed that impaired sustained attention was associated with increased fALFF in the left postcentral gyrus (PoCG.L), and FC of PoCG.L-left precentral gyrus (PreCG.L) and ANG.L-right superior temporal gyrus (STG.R) in the MDD group. Furthermore, mediation analyses showed that the fALFF in PoCG.L, and FC of PoCG.L-PreCG.L and ANG.L-STG.R mediated the relationship between the childhood trauma and sustained attention in the MDD group.

CONCLUSION

The fALFF in PoCG.L, and FC of PoCG.L-PreCG.L and ANG.L-STG.R might be potential neural substrate in the association between the childhood trauma and poor sustained attention in the MDDs, and might serve as potential intervention targets for the treatment of sustained attention deficits in MDDs with childhood trauma history.

The central regulatory effects of acupuncture in treating primary insomnia: a review

Chronic insomnia has the potential to significantly impact physical well-being, occupational performance, and overall quality of life. This review summarizes the clinical and basic research on the central regulatory mechanism of acupuncture in treating primary insomnia (PI), aiming to explore the clinical effectiveness and possible mechanism of acupuncture in treating PI. The currently available drugs for insomnia exhibit notable adverse effects and tend to induce dependence. Empirical evidence from clinical investigations has demonstrated that acupuncture has a favorable safety profile while substantially enhancing the sleep quality of individuals diagnosed with PI. The combination of acupuncture and medication has been shown to augment the therapeutic efficacy of medication while reducing the dosage and mitigating the occurrence of unwanted effects. A review of the current clinical and basic research on the effects of acupuncture on central alterations in PI patients revealed that acupuncture exerts a regulatory influence on the functional activity of brain regions implicated in cognitive and emotional processes. Additionally, acupuncture has been found to impact metabolite levels and circadian clock gene expression and enhance inflammatory responses and energy metabolism. Notably, a single acupuncture intervention had a modulatory effect on functional brain regions similar to that of cumulative acupuncture. The current clinical trials on acupuncture have been limited in scale, and basic research has focused on a single objective. With the continuous progress of brain research, extensive clinical randomized controlled trials of high quality can be combined with various neuroimaging technology modalities. Moreover, different targets and pathways can be explored through basic research. This may serve to enhance the understanding of the fundamental central nervous system mechanisms involved in the efficacy of acupuncture in treating PI.

Electroacupuncture Mitigates TRPV1 Overexpression in the Central Nervous System Associated with Fibromyalgia in Mice

BACKGROUND

Fibromyalgia (FM) is characterized by chronic pain, significantly affecting the quality of life and functional capabilities of patients. In addition to pain, patients may experience insomnia, chronic fatigue, depression, anxiety, and headaches, further complicating their overall well-being. The Transient Receptor Potential Vanilloid 1 (TRPV1) receptor responds to various noxious stimuli and plays a key role in regulating pain sensitivity and inflammation. Thus, targeting TRPV1 may provide analgesic and anti-inflammatory benefits. This study investigates the efficacy of electroacupuncture (EA) in alleviating chronic pain in FM through TRPV1 and its downstream molecules in the central nervous system (CNS).

METHODS

To model FM, we subjected mice to intermittent cold stress (ICS) for three days. The study comprised five rodent groups: Control (CON), ICS, ICS + EA, ICS + Sham EA, and ICS + KO (TRPV1 knockout mice).

RESULTS

Our findings revealed that ICS induced allodynia and hyperalgesia in mice by day four, persisting until day 21. EA at 2 Hz and TRPV1 KO significantly decreased both mechanical and thermal hypersensitivity (Withdrawal-Day 14: 2.43 ± 0.19 g; Day 21: 5.88 ± 0.47 g, n = 6, p < 0.05; Latency-Day 14: 2.77 ± 0.22 s; Day 21: 5.85 ± 0.41 s, n = 6, p < 0.05). In contrast, sham EA did not produce significant effects. Additionally, TRPV1 and several pain-related proteins were significantly elevated in the thalamus, somatosensory cortex (SSC), medial prefrontal cortex (mPFC), hippocampus, hypothalamus, cerebellum regions V (CB V), VI (CB VI) and VII (CB VII) after the ICS model. Both EA at the ST36 acupoint and TRPV1 KO mice showed diminished overexpression of pain-related proteins, with the sham EA group showing no significant changes compared to the ICS group.

CONCLUSIONS

Chronic widespread pain was reduced by EA and TRPV1 KO, with the effects of EA on the TRPV1 pain pathway clearly evident in the CNS after 21 days.

Association of inflammatory cytokines with magnetic resonance imaging features of the brain in patients with depression

There is growing evidence that the imbalance of inflammatory cytokines plays an important role in the pathophysiological mechanism of depression. However, the effects of inflammatory cytokines on the whole brain in patients with depression are still not fully elucidated. The present study aimed to investigate the relationship between inflammatory cytokines and cerebral magnetic resonance imaging (MRI) features using voxel-based whole-brain analysis in patients with depression. A total of 60 patients with depression and 60 healthy controls (HCs) were included. Interleukin-1 was positively correlated with gray matter volume (GMV) in the left putamen and negatively correlated with regional homogeneity (ReHo) and degree centrality (DC) in the left anterior cingulate cortex. Interleukin-6 was positively correlated with GMV in the right superior parietal lobule and ReHo in the left pallidum and putamen. Interferon-α was negatively correlated with DC in the left postcentral gyrus. The ReHo in the left pallidum in depressed patients was lower than that in HCs. The FCs based on the left pallidum as the seed in depressed patients were significantly reduced. The imaging features of the left pallidum had good performance (area under the curve: 0.891) for identifying depressed patients. Inflammatory cytokines are associated with cerebral imaging features in patients with depression and in particular, the abnormal imaging features of the left pallidum may be a potential neuroimaging biomarker of depression.

Identification of neural alterations in patients with Crohn's disease with a novel multiparametric brain MRI-based radiomics model

OBJECTIVES

Gut-brain axis dysfunction has emerged as a key contributor to the pathogenesis of Crohn's disease (CD). The elucidation of neural alterations may provide novel insights into its management. We aimed to develop a multiparameter brain MRI-based radiomics model (RM) for characterizing neural alterations in CD patients and to interpret these alterations using multiomics traits.

METHODS

This prospective study enrolled 230 CD patients and 46 healthy controls (HCs). Participants voluntarily underwent brain MRI and psychological assessment (n = 155), blood metabolomics analysis (n = 260), and/or fecal 16S rRNA sequencing (n = 182). The RM was developed using 13 features selected from 13,870 first-order features extracted from multiparameter brain MRI in training cohort (CD, n = 75; HCs, n = 32) and validated in test cohort (CD, n = 34; HCs, n = 14). Multiomics data (including gut microbiomics, blood metabolomics, and brain radiomics) were compared between CD patients and HCs.

RESULTS

In the training cohort, area under the receiver operating characteristic curve (AUC) of RM for distinguishing CD patients from HCs was 0.991 (95% confidence interval (CI), 0.975-1.000). In test cohort, RM showed an AUC of 0.956 (95% CI, 0.881-1.000). CD-enriched blood metabolites such as triacylglycerol (TAG) exhibited significant correlations with both brain features detected by RM and CD-enriched microbiota (e.g., Veillonella). One notable correlation was found between Veillonella and Ctx-Lh-Middle-Temporal-CBF-p90 (r = 0.41). Mediation analysis further revealed that dysbiosis, such as of Veillonella, may regulate the blood flow in the middle temporal cortex through TAG.

CONCLUSION

We developed a multiparameter MRI-based RM that characterized the neural alterations of CD patients, and multiomics data offer potential evidence to support the validity of our model. Our study may offer clues to help provide potential therapeutic targets.

CRITICAL RELEVANCE STATEMENT

Our brain-gut axis study developed a novel model using multiparameter MRI and radiomics to characterize brain changes in patients with Crohn's disease. We validated this model's effectiveness using multiomics data, making it a potential biomarker for better patient management.

KEY POINTS

Utilizing multiparametric MRI and radiomics techniques could unveil Crohn's disease's neurophenotype. The neurophenotype radiomics model is interpreted using multiomics data. This model may serve as a novel biomarker for Crohn's disease management.

Static and temporal dynamic changes of intrinsic brain activity in early-onset and adult-onset schizophrenia: a fMRI study of interaction effects

Background

Schizophrenia is characterized by altered static and dynamic spontaneous brain activity. However, the conclusions regarding this are inconsistent. Evidence has revealed that this inconsistency could be due to mixed effects of age of onset.

Methods

We enrolled 66/84 drug-naïve first-episode patients with early-onset/adult-onset schizophrenia (EOS/AOS) and matched normal controls (NCs) (46 adolescents, 73 adults), undergoing resting-state functional magnetic resonance imaging. Two-way ANOVA was used to determine the amplitude of low-frequency fluctuation (ALFF) and dynamic ALFF (dALFF) among the four groups.

Result

Compared to NCs, EOS had a higher ALFF in inferior frontal gyrus bilateral triangular part (IFG-tri), left opercular part (IFG-oper), left orbital part (IFG-orb), and left middle frontal gyrus (MFG). The AOS had a lower ALFF in left IFG-tri, IFG-oper, and lower dALFF in left IFG-tri. Compared to AOS, EOS had a higher ALFF in the left IFG-orb, and MFG, and higher dALFF in IFG-tri. Adult NCs had higher ALFF and dALFF in the prefrontal cortex (PFC) than adolescent NCs. The main effects of diagnosis were found in the PFC, medial temporal structures, cerebrum, visual and sensorimotor networks, the main effects of age were found in the visual and motor networks of ALFF and PFC of dALFF.

Conclusion

Our findings unveil the static and dynamic neural activity mechanisms involved in the interaction between disorder and age in schizophrenia. Our results underscore age-related abnormalities in the neural activity of the PFC, shedding new light on the neurobiological mechanisms underlying the development of schizophrenia. This insight may offer valuable perspectives for the specific treatment of EOS in clinical settings.

Enhanced generalization and specialization of brain representations of semantic knowledge in healthy aging

Aging is often associated with a decrease in cognitive capacities. However, semantic memory appears relatively well preserved in healthy aging. Both behavioral and neuroimaging studies support the view that changes in brain networks contribute to this preservation of semantic cognition. However, little is known about the role of healthy aging in the brain representation of semantic categories. Here we used pattern classification analyses and computational models to examine the neural representations of living and non-living word concepts. The results demonstrate that brain representations of animacy in healthy aging exhibit increased similarity across categories, even across different task contexts. This pattern of results aligns with the neural dedifferentiation hypothesis that proposes that aging is associated with decreased specificity in brain activity patterns and less efficient neural resource allocation. However, the loss in neural specificity for different categories was accompanied by increased dissimilarity of item-based conceptual representations within each category. Taken together, the age-related patterns of increased generalization and specialization in the brain representations of semantic knowledge may reflect a compensatory mechanism that enables a more efficient coding scheme characterized by both compression and sparsity, thereby helping to optimize the limited neural resources and maintain semantic processing in the healthy aging brain.

Depression and metabolic connectivity: insights into the locus coeruleus, HF-rTMS, and anxiety

The use of repetitive Transcranial Magnetic Stimulation (rTMS) in treating major depressive disorder (MDD) is increasingly being explored in precision medicine. However, there's a notable lack of understanding of the underlying neurobiological effects, which limits our ability to correlate specific imaging features with treatment efficacy. As one possible neurobiological mechanism, clinical research has already shown that in MDD, lower norepinephrine release in the locus coeruleus (LC) triggers depressive symptoms, and pharmacological approaches that block norepinephrine reuptake boost its levels, easing depression. Surprisingly, the LC has not received a more pronounced focus in contemporary rTMS research. This study investigates the role of the LC in MDD and its response to high-frequency (HF)-rTMS using 18FDG-PET imaging. We compared LC metabolic connectivity between MDD patients (n = 43) and healthy controls (n = 32). Additionally, we evaluated the predictive value of LC connectivity for HF-rTMS treatment outcomes and examined post-treatment changes in LC metabolic connectivity. Our findings revealed significant differences in LC metabolic connectivity between MDD patients and controls. Baseline LC metabolic connectivity did not predict HF-rTMS treatment outcomes. However, post-treatment analyses showed a significant correlation between improved clinical outcomes and attenuation of LC metabolic connectivity in regions associated with cognitive control and the default mode network. Notably, a reduction in state anxiety moderated this relationship, highlighting the role of anxiety in HF-rTMS efficacy for MDD treatment. Our findings suggest that LC metabolic connectivity, influenced by state anxiety levels, may be crucial in HF-rTMS efficacy, offering further insights for personalized MDD treatment strategies.

Exploring spontaneous brain activity changes in high-altitude smokers: Insights from ALFF/fALFF analysis

INTRODUCTION

This study aims to explore the impact of smoking on intrinsic brain activity among high-altitude (HA) populations. Smoking is associated with various neural alterations, but it remains unclear whether smokers in HA environments exhibit specific neural characteristics.

METHODS

We employed ALFF and fALFF methods across different frequency bands to investigate differences in brain functional activity between high-altitude smokers and non-smokers. 31 smokers and 31 non-smokers from HA regions participated, undergoing resting-state functional magnetic resonance imaging (rs-fMRI) scans. ALFF/fALFF values were compared between the two groups. Correlation analyses explored relationships between brain activity and clinical data.

RESULTS

Smokers showed increased ALFF values in the right superior frontal gyrus (R-SFG), right middle frontal gyrus (R-MFG), right anterior cingulate cortex (R-ACC), right inferior frontal gyrus (R-IFG), right superior/medial frontal gyrus (R-MSFG), and left SFG compared to non-smokers in HA. In sub-frequency bands (0.01-0.027 Hz and 0.027-0.073 Hz), smokers showed increased ALFF values in R-SFG, R-MFG, right middle cingulate cortex (R-MCC), R-MSFG, Right precentral gyrus and L-SFG while decreased fALFF values were noted in the right postcentral and precentral gyrus in the 0.01-0.027 Hz band. Negative correlations were found between ALFF values in the R-SFG and smoking years.

CONCLUSION

Our study reveals the neural characteristics of smokers in high-altitude environments, highlighting the potential impact of smoking on brain function. These results provide new insights into the neural mechanisms of high-altitude smoking addiction and may inform the development of relevant intervention measures.

Altered brain function in treatment-resistant depression patients: A resting-state functional magnetic resonance imaging study

BACKGROUND

It has been established that there are functional changes in the brain of treatment-resistant depression (TRD) patients, but previous studies of functional connectivity (FC) usually involved selection of regions of interest based on accumulated a priori knowledge of the disorder. In this study, we combine amplitude of low-frequency fluctuation (ALFF) and FC; this approach, based on the abnormal ALFF, may provide some insights into the neural basis of the disease in terms of fMRI signals of low-frequency fluctuations.

METHODS

A total of 16 TRD patients, who visited the Qingdao Mental Health Center, Shandong Province, China between March 2023 and January 2024, along with 16 normal subjects, were enrolled into this study for functional imaging. In this study, we first explored the ALFF changes of TRD patients at a baseline resting state. Second, we selected the regions that were significantly changed in the ALFF as seeds and calculated the regional activity and functional connectivity (FC) of these regions using a seed-based approach. We also calculated correlations between the percent change in the PDQ-5D scores and ALFF values in brain regions with differing activity for TRD patients.

RESULTS

During the baseline resting state, by using the ALFF, we found a significantly decreased or increased ALFF in the TRD patients relative to the controls. These regions were located in the left/right postcentral gyrus (PoCG.L/PoCG.R), right cuneus(CUN.R). We found that the ALFF values of the right hippocampus (HIP.R) in the TRD group were negatively correlated with the PDQ-5D score. Then, we selected these brain regions as seeds to investigate the FC changes in brains of TRD patients. We found abnormal functional connectivity in left/right middle frontal gyrus(MFG.L/MFG.R), the right Inferior frontal gyrus, opercular part (IFGoperc.R), the left/right Anterior cingulate and paracingulate gyri (ACC.L/ACC.R), the right supramarginal gyrus (SMG.R), and the right Calcarine fissure and surrounding cortex (CAL.R).

CONCLUSION

We found a larger range of altered brain regions in TRD patients compared to healthy controls, especially in the central executive network (CEN), salience network (SN) and default mode network (DMN).

Alterations of regional brain activity and corresponding brain circuits in drug-naïve adolescents with nonsuicidal self-injury

Nonsuicidal self-injury (NSSI) is one of the major public health problems endangering adolescents. However, the neural mechanisms of NSSI is still unclear. The purpose of this study was to explore regional brain activity and corresponding brain circuits in drug-naïve adolescents with NSSI using amplitude of low-frequency fluctuations (ALFF) combined with functional connectivity (FC) analysis. Thirty-two drug-naïve adolescents with NSSI (NSSI group) and 29 healthy controls matched for sex, age, and level of education (HC group) were enrolled in this study. ALFF and seed-based FC analyses were used to examine the alterations in regional brain activity and corresponding brain circuits. The correlation between ALFF or FC values of aberrant brain regions and clinical characteristics were detected by Pearson correlation analysis. The NSSI group showed increased ALFF in the left inferior and middle occipital gyri, lingual gyrus, and fusiform gyrus; additionally, decreased ALFF in the right medial cingulate gyrus, left anterior cingulate gyrus, and left medial superior frontal gyrus compared to those in the HC group. With the left inferior occipital gyrus as seed, the NSSI group showed increased FC between the left inferior occipital gyrus and the bilateral superior parietal gyrus, right inferior parietal angular gyrus, right inferior frontal gyrus of the insular region, and left precuneus relative to that the HC group. With the left anterior cingulate gyrus as seed, the NSSI group showed increased FC between the left anterior cingulate gyrus and right dorsolateral superior frontal gyrus. With the left lingual gyrus as seed, the NSSI group showed increased FC between the left lingual gyrus and right middle frontal gyrus, and decreased FC between the left lingual gyrus and the left superior temporal gyrus, right supplementary motor area, and left rolandic operculum. With the left fusiform gyrus as seed, the NSSI group showed increased FC between the left fusiform gyrus and left middle and inferior temporal gyrus, and decreased FC between the left fusiform gyrus and the bilateral postcentral gyrus, right precentral gyrus, right lingual gyrus, and left inferior parietal angular gyrus. Moreover, the FC value between the left fusiform gyrus and left inferior temporal gyrus was positively correlated with suicidal ideations score. This study highlights alterations in regional brain activity and corresponding brain circuits in brain regions related to visual and emotional regulation functions in drug-naïve adolescents with NSSI. These findings may facilitate better understand the underlying neural mechanisms of NSSI in adolescents.

Exploring the most discriminative brain structural abnormalities in ASD with multi-stage progressive feature refinement approach

Objective

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by increasing prevalence, diverse impairments, and unclear origins and mechanisms. To gain a better grasp of the origins of ASD, it is essential to identify the most distinctive structural brain abnormalities in individuals with ASD.

Methods

A Multi-Stage Progressive Feature Refinement Approach was employed to identify the most pivotal structural magnetic resonance imaging (MRI) features that distinguish individuals with ASD from typically developing (TD) individuals. The study included 175 individuals with ASD and 69 TD individuals, all aged between 7 and 18 years, matched in terms of age and gender. Both cortical and subcortical features were integrated, with a particular focus on hippocampal subfields.

Results

Out of 317 features, 9 had the most significant impact on distinguishing ASD from TD individuals. These structural features, which include a specific hippocampal subfield, are closely related to the brain areas associated with the reward system.

Conclusion

Structural irregularities in the reward system may play a crucial role in the pathophysiology of ASD, and specific hippocampal subfields may also contribute uniquely, warranting further investigation.

The different impacts of pain-related negative emotion and trait negative emotion on brain function in patients with inflammatory bowel disease

Inflammatory bowel diseases (IBD) are a group of chronic, non-specific intestinal diseases that could comorbid with varieties of negative emotional constructs, including pain-related negative emotions and trait negative emotions; however, the link between brain functions and different dimensions of negative emotions remains largely unknown. Ninety-eight patients with IBD and forty-six healthy subjects were scanned using a 3.0-T functional magnetic resonance imaging scanner. The amplitudes of low-frequency fluctuation (ALFF), regional homogeneity (ReHo), and degree centrality (DC) were used to assess resting-state brain activity. Partial least squares (PLS) correlation was employed to assess the relationship among abnormal brain activities, pain-related and trait negative emotions. Compared to controls, patients with IBD exhibited higher values of ALFF in the right anterior cingulate cortex (ACC), lower values of ALFF in the left postcentral gyrus, and higher values of DC in the bilateral ACC. Multivariate PLS correlation analysis revealed the brain scores of the ACC were correlated with pain-related negative emotions, the brain salience in the left postcentral gyrus was associated with the higher-order trait depression. These findings can enhance our comprehension of how pain-related negative emotion and trait negative emotion affect the brains of patients with IBD in distinct ways.

Association between sleep problems and impulsivity mediated through regional homogeneity abnormalities in male methamphetamine abstainers

Sleep problems and impulsivity frequently occur in methamphetamine (MA) abstainers and are linked to aberrant brain function. However, the interplay between these factors remains poorly understood. This study aimed to investigate the relationship between sleep, impulsivity, and regional homogeneity (ReHo) through mediation analysis in MA abstainers. 46 MA abstainers and 44 healthy controls were included. Impulsivity and sleep problems were evaluated using the Barratt Impulsivity Scale and the Pittsburgh Sleep Quality Scale, respectively. ReHo, indicative of local brain spontaneous neural activity, was assessed using resting-state functional magnetic resonance imaging. Results unveiled correlations between different dimensions of impulsivity and ReHo values in specific brain regions. Motor impulsivity correlated with ReHo values in the left postcentral gyrus and left precentral gyrus, while non-planning impulsivity was only associated with ReHo values in the left precentral gyrus. Additionally, the need for sleep medications correlated with ReHo values in the left precentral gyrus and bilateral postcentral gyrus. Also, the need for sleep medications was positively correlated with cognitive impulsivity and motor impulsivity. Mediation analysis indicated that reduced ReHo values in the left precentral gyrus mediated the association between impulsivity and the need for sleep medications. These findings imply that addressing sleep problems, especially the need for sleep medications, might augment spontaneous neural activity in specific brain regions linked to impulsivity among MA abstainers. This underscores the importance of integrating sleep interventions into comprehensive treatment strategies for MA abstainers.

Comparison of Resting-State Functional Connectivity Between Generalized Anxiety Disorder and Social Anxiety Disorder: Differences in the Nucleus Accumbens and Thalamus Network

Background: Generalized anxiety disorder (GAD) and social anxiety disorder (SAD) are distinguished by whether anxiety is limited to social situations. However, reports on the differences in brain functional networks between GAD and SAD are few. Our objective is to understand the pathogenesis of GAD and SAD by examining the differences in resting brain function between patients with GAD and SAD and healthy controls (HCs). Methods: This study included 21 patients with SAD, 17 patients with GAD, and 30 HCs. Participants underwent psychological assessments and resting-state functional magnetic resonance imaging. Whole-brain analyses were performed to compare resting-state functional connectivity (rsFC) among the groups. In addition, logistic regression analysis was conducted on the rsFC to identify significant differences between GAD and SAD. Results: Patients with SAD and GAD had significantly higher rsFC between the bilateral postcentral gyri and bilateral amygdalae/thalami than HCs. Compared with patients with SAD, those with GAD had significantly higher rsFC between the right nucleus accumbens and bilateral thalami and between the left nucleus accumbens and right thalamus. rsFC between the left nucleus accumbens and right thalamus positively correlated with state anxiety in patients with SAD and GAD, respectively. In addition, logistic regression analysis revealed that the right nucleus accumbens and the right thalamus connectivity could distinguish SAD from GAD. Conclusions: GAD and SAD were distinguished by the right nucleus accumbens and the right thalamus connectivity. Our findings offer insights into the disease-specific neural basis of SAD and GAD. Clinical Trial Registration Number: UMIN000024087. Impact Statement This study is the first to identify a resting state functional connectivity that distinguishes social anxiety disorder (SAD) from generalized anxiety disorder (GAD) and to clarify a common connectivity in both disorders. We found that the connectivity between the right nucleus accumbens and the right thalamus differentiated SAD from GAD. Furthermore, these rsFC differences suggest an underlying basis for fear overgeneralization. Our findings shed light on the pathophysiology of these conditions and could be used as a basis for further studies to improve outcomes for such patients.

Longitudinal development of resting-state functional connectivity in adolescents with and without internalizing disorders

Longitudinal studies using resting-state functional magnetic resonance imaging (rs-fMRI) focused on adolescent internalizing psychopathology are scarce and have mostly investigated standardized treatment effects on functional connectivity (FC) of the full amygdala. The role of amygdala subregions and large resting-state networks had yet to be elucidated, and treatment is in practice often personalized. Here, longitudinal FC development of amygdala subregions and whole-brain networks are investigated in a clinically representative sample. Treatment-naïve adolescents with clinical depression and comorbid anxiety who started care-as-usual (n = 23; INT) and healthy controls (n = 24; HC) participated in rs-fMRI scans and questionnaires at baseline (before treatment) and after three months. Changes between and within groups over time in FC of the laterobasal amygdala (LBA), centromedial amygdala (CMA) and whole-brain networks derived from independent component analysis (ICA) were investigated. Groups differed significantly in FC development of the right LBA to the postcentral gyrus and the left LBA to the frontal pole. Within INT, FC to the frontal pole and postcentral gyrus changed over time while changes in FC of the right LBA were also linked to symptom change. No significant interactions were observed when considering FC from CMA bilateral seeds or within ICA-derived networks. Results in this cohort suggest divergent longitudinal development of FC from bilateral LBA subregions in adolescents with internalizing disorders compared to healthy peers, possibly reflecting nonspecific treatment effects. Moreover, associations were found with symptom change. These results highlight the importance of differentiation of amygdala subregions in neuroimaging research in adolescents.

Deficits in prefrontal metabotropic glutamate receptor 5 are associated with functional alterations during emotional processing in bipolar disorder

BACKGROUND

Elucidating biological mechanisms contributing to bipolar disorder (BD) is key to improved diagnosis and treatment development. With converging evidence implicating the metabotropic glutamate receptor 5 (mGlu5) in the pathology of BD, here, we therefore test the hypothesis that recently identified deficits in mGlu5 are associated with functional brain differences during emotion processing in BD.

METHODS

Positron emission tomography (PET) with [18F]FPEB was used to measure mGlu5 receptor availability and functional imaging (fMRI) was performed while participants completed an emotion processing task. Data were analyzed from 62 individuals (33 ± 12 years, 45 % female) who completed both PET and fMRI, including individuals with BD (n = 18), major depressive disorder (MDD: n = 20), and psychiatrically healthy comparisons (HC: n = 25).

RESULTS

Consistent with some prior reports, the BD group displayed greater activation during fear processing relative to MDD and HC, notably in right lateralized frontal and parietal brain regions. In BD, (but not MDD or HC) lower prefrontal mGlu5 availability was associated with greater activation in bilateral pre/postcentral gyri and cuneus during fear processing. Furthermore, greater prefrontal mGlu5-related brain activity in BD was associated with difficulties in psychomotor function (r≥0.904, p≤0.005) and attention (r≥0.809, p≤0.028).

LIMITATIONS

The modest sample size is the primary limitation.

CONCLUSIONS

Deficits in prefrontal mGlu5 in BD were linked to increased cortical activation during fear processing, which in turn was associated with impulsivity and attentional difficulties. These data further implicate an mGlu5-related mechanism unique to BD. More generally these data suggest integrating PET and fMRI can provide novel mechanistic insights.

Cell-Type-Specific Expression of Leptin Receptors in the Mouse Forebrain

Leptin is a hormone produced by the small intestines and adipose tissue that promotes feelings of satiety. Leptin receptors (LepRs) are highly expressed in the hypothalamus, enabling central neural control of hunger. Interestingly, LepRs are also expressed in several other regions of the body and brain, notably in the cerebral cortex and hippocampus. These brain regions mediate higher-order sensory, motor, cognitive, and memory functions, which can be profoundly altered during periods of hunger and satiety. However, LepR expression in these regions has not been fully characterized on a cell-type-specific basis, which is necessary to begin assessing their potential functional impact. Consequently, we examined LepR expression on neurons and glia in the forebrain using a LepR-Cre transgenic mouse model. LepR-positive cells were identified using a 'floxed' viral cell-filling approach and co-labeling immunohistochemically for cell-type-specific markers, i.e., NeuN, VGlut2, GAD67, parvalbumin, somatostatin, 5-HT3R, WFA, S100β, and GFAP. In the cortex, LepR-positive cells were localized to lower layers (primarily layer 6) and exhibited non-pyramidal cellular morphologies. The majority of cortical LepR-positive cells were neurons, while the remainder were identified primarily as astrocytes or other glial cells. The majority of cortical LepR-positive neurons co-expressed parvalbumin, while none expressed somatostatin or 5-HT3R. In contrast, all hippocampal LepR-positive cells were neuronal, with none co-expressing GFAP. These data suggest that leptin can potentially influence neural processing in forebrain regions associated with sensation and limbic-related functions.

Association between clinical features and decreased degree centrality and variability in dynamic functional connectivity in the obsessive-compulsive disorder

Neuroimaging studies have indicated widespread brain structural and functional disruptions in patients with obsessive-compulsive disorder (OCD). However, the underlying mechanism of these changes remains unclear. A total of 45 patients with OCD and 42 healthy controls (HC) were enrolled. The study investigated local degree centrality (DC) abnormalities and employed abnormal regions of DC as seeds to investigate variability in dynamic functional connectivity (dFC) in the whole brain using a sliding window approach to analyze resting-state functional magnetic resonance imaging. The relationship between abnormal DC and dFC as well as the clinical features of OCD were examined using correlation analysis. Our findings suggested decreased DC in the bilateral thalamus, bilateral precuneus, and bilateral cuneus in OCD patients and a nominally negative correlation between the DC value in the thalamus and illness severity measured using the Yale-Brown Obsessive Compulsive Scale (Y-BOCS). In addition, seed-based dFC analysis showed that compared to measurements in the HC, the patients had decreased dFC variability between the left thalamus and the left cuneus and right lingual gyrus, and between the bilateral cuneus and bilateral postcentral gyrus, and a nominally positive correlation between the duration of illness and dFC variability between the left cuneus and left postcentral gyrus. These results indicated that OCD patients had decreased hub importance in the bilateral thalamus and cuneus throughout the entire brain. This reduction was associated with impaired coupling with dynamic function in the visual cortex and sensorimotor network and provided novel insights into the neurophysiological mechanisms underlying OCD.

Accurate identification of individuals with subjective cognitive decline using 3D regional fractal dimensions on structural magnetic resonance imaging

BACKGROUND AND OBJECTIVE

Accurate identification of individuals with subjective cognitive decline (SCD) is crucial for early intervention and prevention of neurodegenerative diseases. Fractal dimensionality (FD) has emerged as a robust and replicable measure, surpassing traditional geometric metrics, in characterizing the intricate fractal geometrical properties of brain structure. Nevertheless, the effectiveness of FD in identifying individuals with SCD remains largely unclear. A 3D regional FD method can be suggested to characterize and quantify the spatial complexity of the precise gray matter, providing insights into cognitive aging and aiding in the automated identification of individuals with SCD.

METHODS

This study introduces a novel integer ratio based 3D box-counting fractal analysis (IRBCFA) to quantify regional fractal dimensions (FDs) in structural magnetic resonance imaging (MRI) data. The innovative method overcomes limitations of conventional box-counting techniques by accommodating arbitrary box sizes, thereby enhancing the precision of FD estimation in small, yet neurologically significant, brain regions.

RESULTS

The application of IRBCFA to two publicly available datasets, OASIS-3 and ADNI, consisting of 520 and 180 subjects, respectively. The method identified discriminative regions of interest (ROIs) predominantly within the limbic system, fronto-parietal region, occipito-temporal region, and basal ganglia-thalamus region. These ROIs exhibited significant correlations with cognitive functions, including executive functioning, memory, social cognition, and sensory perception, suggesting their potential as neuroimaging markers for SCD. The identification model trained on these ROIs demonstrated exceptional performance achieving over 93 % accuracy on the discovery dataset and exceeding 87 % on the independent testing dataset. Furthermore, an exchange experiment between datasets revealed a substantial overlap in discriminative ROIs, highlighting the robustness of our method across diverse populations.

CONCLUSION

Our findings indicate that IRBCFA can serve as a valuable tool for quantifying the spatial complexity of gray matter, providing insights into cognitive aging and aiding in the automated identification of individuals with SCD. The demonstrated generalizability and robustness of this method position it as a promising tool for neurodegenerative disease research and offer potential for clinical applications.

Neural foundation of the diathesis-stress model: longitudinal gray matter volume changes in response to stressful life events in major depressive disorder and healthy controls

Recurrences of depressive episodes in major depressive disorder (MDD) can be explained by the diathesis-stress model, suggesting that stressful life events (SLEs) can trigger MDD episodes in individuals with pre-existing vulnerabilities. However, the longitudinal neurobiological impact of SLEs on gray matter volume (GMV) in MDD and its interaction with early-life adversity remains unresolved. In 754 participants aged 18-65 years (362 MDD patients; 392 healthy controls; HCs), we assessed longitudinal associations between SLEs (Life Events Questionnaire) and whole-brain GMV changes (3 Tesla MRI) during a 2-year interval, using voxel-based morphometry in SPM12/CAT12. We also explored the potential moderating role of childhood maltreatment (Childhood Trauma Questionnaire) on these associations. Over the 2-year interval, HCs demonstrated significant GMV reductions in the middle frontal, precentral, and postcentral gyri in response to higher levels of SLEs, while MDD patients showed no such GMV changes. Childhood maltreatment did not moderate these associations in either group. However, MDD patients who had at least one depressive episode during the 2-year interval, compared to those who did not, or HCs, showed GMV increases in the middle frontal, precentral, and postcentral gyri associated with an increase in SLEs and childhood maltreatment. Our findings indicate distinct GMV changes in response to SLEs between MDD patients and HCs. GMV decreases in HCs may represent adaptive responses to stress, whereas GMV increases in MDD patients with both childhood maltreatment and a depressive episode during the 2-year interval may indicate maladaptive changes, suggesting a neural foundation for the diathesis-stress model in MDD recurrences.