Altered static and dynamic functional network connectivity in primary angle-closure glaucoma patients.

To explore altered patterns of static and dynamic functional brain network connectivity (sFNC and dFNC) in Primary angle-closure glaucoma (PACG) patients. Clinically confirmed 34 PACG patients and 33 age- and gender-matched healthy controls (HCs) underwent evaluation using T1 anatomical and functional MRI on a 3 T scanner. Independent component analysis, sliding window, and the K-means clustering method were employed to investigate the functional network connectivity (FNC) and temporal metrics based on eight resting-state networks. Differences in FNC and temporal metrics were identified and subsequently correlated with clinical variables. For sFNC, compared with HCs, PACG patients showed three decreased interactions, including SMN-AN, SMN-VN and VN-AN pairs. For dFNC, we derived four highly structured states of FC that occurred repeatedly between individual scans and subjects, and the results are highly congruent with sFNC. In addition, PACG patients had a decreased fraction of time in state 3 and negatively correlated with IOP (p < 0.05). PACG patients exhibit abnormalities in both sFNC and dFNC. The high degree of overlap between static and dynamic results suggests the stability of functional connectivity networks in PACG patients, which provide a new perspective to understand the neuropathological mechanisms of optic nerve damage in PACG patients.

Effects of primary angle-closure glaucoma on interhemispheric functional connectivity.

Background: Previous studies on primary angle-closure glaucoma (PACG) primarily focused on local brain regions or global abnormal brain activity; however, the alteration of interhemispheric functional homotopy and its possible cause of brain-wide functional connectivity abnormalities have not been well-studied. Little is known about whether brain functional alteration could be used to differentiate from healthy controls (HCs) and its correlation with neurocognitive impairment. Methods: Forty patients with PACG and 40 age- and sex-matched healthy controls were recruited for this study; resting-state functional magnetic resonance imaging (rs-fMRI), and clinical data were collected. We used the voxel-mirrored homotopic connectivity (VMHC) method to explore between-group differences and selected brain regions with statistically significant differences as regions of interest for whole-brain functional connectivity analysis. Partial correlation was used to evaluate the association between abnormal VMHC values in significantly different regions and clinical parameters, with with age and sex as covariates. Finally, the support vector machine (SVM) model was performed in classification prediction of PACG. Results: Compared with healthy controls, patients with PACG exhibited significantly decreased VMHC values in the lingual gyrus, insula, cuneus, and pre- and post-central gyri; no regions exhibited increased VMHC values. Subsequent functional connectivity analysis revealed extensive functional changes in functional networks, particularly the default mode, salience, visual, and sensorimotor networks. The SVM model showed good performance in classification prediction of PACG, with an area under curve (AUC) of 0.85. Conclusion: Altered functional homotopy of the visual cortex, sensorimotor network, and insula may lead to impairment of visual function in PACG, suggesting that patients with PACG may have visual information interaction and integration dysfunction.

Altered Amplitude of Low-Frequency Fluctuations and Degree Centrality in Patients with Acute Subjective Tinnitus: A Resting-State Functional Magnetic Resonance Imaging Study.

BACKGROUND: The difference in spontaneous brain activity between acute subjective tinnitus patients (with or without hearing loss) and control participants was explored using the amplitude of low-frequency fluctuations and degree centrality methods through resting-state functional magnetic resonance imaging. The study aimed to provide an objective basis for clinical diagnosis and pathogenesis of patients with acute subjective tinnitus. METHODS: Fourteen acute subjective tinnitus (AST) patients with hearing loss (AST-HL), 6 AST patients with no hearing loss (AST-NHL), and 14 healthy controls (HCs) with age, sex, and education status matched were recruited for this study. Resting-state functional magnetic resonance imaging (fMRI) examinations were performed in a resting state and the amplitude of low-frequency fluctuations (ALFF) and degree centrality (DC) values of each group were acquired. Statistical analysis was performed to assess the ALFF and DC values of different brain areas of the participants (AST-HL and AST-NHL were compared with HCs, but AST-HL and AST-NHL were not). RESULTS: Patients with acute subjective tinnitus and hearing loss showed a significantly increased amplitude of low-frequency fluctuation values in the left middle temporal gyrus and bilateral frontal gyrus/marginal lobe/cingulate gyrus but a decreased amplitude of low-frequency fluctuations values in the bilateral superior temporal gyrus/anterior cerebellar lobe in comparison with healthy controls. The amplitude of low-frequency fluctuation values of patients with acute subjective tinnitus and hearing loss in the right posterior lobe of the cerebellum, bilateral temporal gyrus, bilateral lenticular nucleus, bilateral frontal gyrus, right inferior occipital gyrus, were higher, but were significantly lower in the bilateral anterior lobe of cerebellum/superior temporal gyrus and left posterior cerebellar lobe as compared with those of healthy controls. Degree centrality values in the healthy controls group were increased in the right superior marginal gyrus and decreased in the right thalamus in patients with acute subjective tinnitus and hearing loss, while patients with acute subjective tinnitus with no hearing loss presented significantly higher degree centrality values in the left frontal lobe and lower degree centrality values in the left center rear return. CONCLUSIONS: Aberrant amplitude of low-frequency fluctuations and values exist in various brain regions, indicating abnormal spontaneous brain activity in both acute subjective tinnitus and hearing loss and acute subjective tinnitus no hearing loss patients. The pathogenesis of acute subjective tinnitus may be related to abnormalities in both the auditory cortex and nonauditory cortex. These findings provide more evidence to help clarify the neuronal symptoms of acute subjective tinnitus patients.

Altered Brain Activity in Strabismic Amblyopic Children as Determined by Regional Homogeneity: A Resting-State Functional Magnetic Resonance Imaging Study.

Objective: Earlier research has determined that amblyopia or strabismus may cause remarkable brain anatomical and functional variations. Nonetheless, thus far, the spontaneous changes in brain activity in children with strabismus amblyopia (SA) remain unclear. The purpose of this study was to determine the association between abnormal brain activity in children with SA and its behavioral manifestations. Patients and Methods: ?A total of 24 children with SA (10 male and 14 female children) as well as 24 healthy controls (HCs), including 10 male and 14 female children were closely matched in sex and age, and examined using resting-state functional magnetic resonance imaging (fMRI). The regional homogeneity (ReHo) technique was applied to evaluate spontaneous cerebral activity variations in children with SA and HCs. Moreover, associations between altered ReHo values in distinct cerebral areas and the degree of strabismus were assessed using Pearson correlation analysis. Results: Remarkably increased ReHo values were observed in the right lingual, right superior frontal medial, bilateral superior parietal, and right inferior parietal gyri of children with SA compared with HCs. In contrast, mean ReHo values in children with SA were lower in the right cerebellum, left superior frontal gyrus, and left putamen nucleus. Furthermore, esotropia showed a positive correlation with ReHo values of the left putamen. Conclusion: The anomalous spontaneous activity changes in several brain areas that are caused by SA may indicate neuropathologic mechanisms of visual deficits and oculomotor disorders in children with SA.

High-Quality Genome of the Medicinal Plant Strobilanthes cusia Provides Insights Into the Biosynthesis of Indole Alkaloids.

Strobilanthes cusia (Nees) Kuntze is an important plant used to process the traditional Chinese herbal medicines "Qingdai" and "Nanbanlangen". The key active ingredients are indole alkaloids (IAs) that exert antibacterial, antiviral, and antitumor pharmacological activities and serve as natural dyes. We assembled the S. cusia genome at the chromosome level through combined PacBio circular consensus sequencing (CCS) and Hi-C sequencing data. Hi-C data revealed a draft genome size of 913.74 Mb, with 904.18 Mb contigs anchored into 16 pseudo-chromosomes. Contig N50 and scaffold N50 were 35.59 and 68.44 Mb, respectively. Of the 32,974 predicted protein-coding genes, 96.52% were functionally annotated in public databases. We predicted 675.66 Mb repetitive sequences, 47.08% of sequences were long terminal repeat (LTR) retrotransposons. Moreover, 983 Strobilanthes-specific genes (SSGs) were identified for the first time, accounting for ~2.98% of all protein-coding genes. Further, 245 putative centromeric and 29 putative telomeric fragments were identified. The transcriptome analysis identified 2,975 differentially expressed genes (DEGs) enriched in phenylpropanoid, flavonoid, and triterpenoid biosynthesis. This systematic characterization of key enzyme-coding genes associated with the IA pathway and basic helix-loop-helix (bHLH) transcription factor family formed a network from the shikimate pathway to the indole alkaloid synthesis pathway in S. cusia. The high-quality S. cusia genome presented herein is an essential resource for the traditional Chinese medicine genomics studies and understanding the genetic underpinning of IA biosynthesis.

Brain Functional Connectivity Changes in Patients with Acute Eye Pain: A Resting-State Functional Magnetic Resonance Imaging (fMRI) Study.

BACKGROUND By using functional magnetic resonance imaging (fMRI), we aimed to study the changes in potential brain function network activity in patients with acute eye pain. Also, by using the voxel-wise degree centrality (DC) method, we aimed to explore the relationship between spontaneous brain activity and the clinical features of patients with acute eye pain. MATERIAL AND METHODS A total of 15 patients with acute eye pain (5 women and 10 men; EP group) and 15 healthy controls (5 women and 10 men; HC group), were scanned by fMRI. The DC method was used to evaluate changes in spontaneous brain activity. Receiver operating characteristic (ROC) curves were analyzed, and Pearson correlation analysis was used to study the relationship between DC values and clinical manifestations in different regions of brain. RESULTS The area of the left limbic lobe showed a reduction in DC value in patients in the EP group. DC values were elevated in the left cerebellum posterior lobe, left inferior parietal lobule, left inferior temporal gyrus, left precuneus, and right cerebellum posterior lobe in the EP group. The visual analog scale value of the eyes in the EP group was negatively correlated with the left limbic lobe signal value and positively correlated with the left inferior parietal lobule signal value. Further, the scores of the hospital anxiety and depression scale and DC value of the left limbic lobe were negatively correlated. CONCLUSIONS Compared with the HC group, patients with acute eye pain had abnormal patterns of intrinsic brain activity in different brain regions, which may help reveal the potential neural mechanisms involved in eye pain.

Regional brain changes in patients with diabetic optic neuropathy: a resting-state functional magnetic resonance imaging study.

BACKGROUND: To evaluate functional connection density (FCD) in patients with diabetic optic neuropathy (DON) using the resting functional connectivity (FC) method, and to determine the abnormal areas of brain activity. METHODS: Patients with DON (n=22; 10 male, 12 female) and healthy controls (HCs; n=22; 10 male, 12 female) were included in the study. The basic characteristics of the groups were matched. Functional magnetic resonance imaging (fMRI) was conducted with participants at rest, and long- and short-range FCD (long FCD and IFCD, respectively) were measured. Receiver operating characteristic (ROC) curve analysis was also conducted to determine whether DON and HC participants could be distinguished using fMRI indicators. RESULTS: Compared with HCs, the long FCD values of the left lingual gyrus, right lingual gyrus, right fusiform gyrus, and medial and lateral cingulate gyri were decreased in patients with DON. Further, the IFCD values of the left superior temporal gyrus, left inferior temporal gyrus, right inferior temporal gyrus, left cerebellar area 8, and right cerebellar Crus2 area were higher in patients with DON than in the HCs. CONCLUSIONS: DON is associated with abnormal spontaneous brain activity. Our findings contribute to elucidating the mechanisms underlying the neuropathology of DON, and provide direction for further clinical research.

Interhemispheric Functional Connectivity Alterations in Diabetic Optic Neuropathy: A Resting-State Functional Magnetic Resonance Imaging Study.

PURPOSE: Previous research suggests that diabetic optic neuropathy (DON) can cause marked anatomical and functional variations in the brain, but to date altered functional synchronization between two functional hemispheres remains uncharacterized in DON patients. Voxel mirrored homotopic connectivity (VMHC) is a voxel-based method to evaluate the synchronism between two mirrored hemispheric by determining the functional connectivity between each voxel in one hemisphere and its counterpart. In this study, we aim to assess abnormal changes in interhemispheric functional connectivity in DON patients via the VMHC method. METHODS: The study included 28 adult DON patients (12 male, 16 female) and 28 healthy controls (12 male, 16 female) who were closely matched for sex and age. Participants were examined using resting-state functional magnetic resonance imaging. The VMHC method was applied to investigate the abnormal state in bilateral hemispheres in DON patients and the same regions in healthy controls, as well as the receiver operating characteristic (ROC) curves were used to evaluate characteristics. Associations between altered VMHC values in distinct cerebral regions and clinical features were assessed via correlational analysis. RESULTS: Markedly lower VMHC values were evident in the right temporal inferior, the left temporal inferior, the right mid-cingulum, the left mid-cingulum, the right supplementary motor region, and the left supplementary motor region in DON patients compared with healthy controls. ROC curve analysis suggested that the application of VMHC is reliable for the diagnosis of DON. CONCLUSION: Anomalous interhemispheric functional connectivity in specific brain areas caused by DON may indicate neuropathologic mechanisms of vision loss and blurry vision in patients with DON.