EEG Network Analysis of Depressive Emotion Interference Spatial Cognition Based on a Simulated Robotic Arm Docking Task

Depressive emotion (DE) refers to clinically relevant depressive symptoms without meeting the diagnostic criteria for depression. Studies have demonstrated that DE can cause spatial cognition impairment. However, the brain network mechanisms underlying DE interference spatial cognition remain unclear. This study aimed to reveal the differences in brain network connections between DE and healthy control (HC) groups during resting state and a spatial cognition task. The longer operation time of the DE group during spatial cognition task indicated DE interference spatial cognition. In the resting state stage, the DE group had weaker network connections in theta and alpha bands than the HC group had. Specifically, the electrodes in parietal regions were hubs of the differential networks, which are related to spatial attention. Moreover, in docking task stages, the left frontoparietal network connections in delta, beta, and gamma bands were stronger in the DE group than those of the HC group. The enhanced left frontoparietal connections in the DE group may be related to brain resource reorganization to compensate for spatial cognition decline and ensure the completion of spatial cognition tasks. Thus, these findings might provide new insights into the neural mechanisms of depressive emotion interference spatial cognition.

Frequency-specific directed interactions between whole-brain regions during sentence processing using multimodal stimulus

Neural oscillations subserve a broad range of speech processing and language comprehension functions. Using an electroencephalogram (EEG), we investigated the frequency-specific directed interactions between whole-brain regions while the participants processed Chinese sentences using different modality stimuli (i.e., auditory, visual, and audio-visual). The results indicate that low-frequency responses correspond to the process of information flow aggregation in primary sensory cortices in different modalities. Information flow dominated by high-frequency responses exhibited characteristics of bottom-up flow from left posterior temporal to left frontal regions. The network pattern of top-down information flowing out of the left frontal lobe was presented by the joint dominance of low- and high-frequency rhythms. Overall, our results suggest that the brain may be modality-independent when processing higher-order language information.

The different brain areas occupied for integrating information of hierarchical linguistic units: a study based on EEG and TMS

Human language units are hierarchical, and reading acquisition involves integrating multisensory information (typically from auditory and visual modalities) to access meaning. However, it is unclear how the brain processes and integrates language information at different linguistic units (words, phrases, and sentences) provided simultaneously in auditory and visual modalities. To address the issue, we presented participants with sequences of short Chinese sentences through auditory, visual, or combined audio-visual modalities while electroencephalographic responses were recorded. With a frequency tagging approach, we analyzed the neural representations of basic linguistic units (i.e. characters/monosyllabic words) and higher-level linguistic structures (i.e. phrases and sentences) across the 3 modalities separately. We found that audio-visual integration occurs in all linguistic units, and the brain areas involved in the integration varied across different linguistic levels. In particular, the integration of sentences activated the local left prefrontal area. Therefore, we used continuous theta-burst stimulation to verify that the left prefrontal cortex plays a vital role in the audio-visual integration of sentence information. Our findings suggest the advantage of bimodal language comprehension at hierarchical stages in language-related information processing and provide evidence for the causal role of the left prefrontal regions in processing information of audio-visual sentences.

Electroencephalographic Network Topologies Predict Antidepressant Responses in Patients with Major Depressive Disorder

Medication therapy seems to be an effective treatment for major depressive disorder (MDD). However, although the efficacies of various medicines are equal or similar on average, they vary widely among individuals. Therefore, an understanding of methods for the timely evaluation of short-term therapeutic response and prediction of symptom improvement after a specific course of medication at the individual level at the initial stage of treatment is very important. In our present study, we sought to identify a neurobiological signature of the response to short-term antidepressant treatment. Related brain network analysis was applied in resting-state electroencephalogram (EEG) datasets from patients with MDD. The corresponding EEG networks were constructed accordingly and then quantitatively measured to predict the efficacy after eight weeks of medication, as well as to distinguish the therapeutic responders from non-responders. The results of our present study revealed that the corresponding resting-state EEG networks became significantly weaker after one week of treatment, and the eventual medication efficacy was reliably predicted using the changes in those network properties within the one-week medication regimen. Moreover, the corresponding resting-state networks at baseline were also proven to precisely distinguish those responders from other individuals with an accuracy of 96.67% when using the spatial network topologies as the discriminative features. These findings consistently provide a deeper neurobiological understanding of antidepressant treatment and a reliable and quantitative approach for personalized treatment of MDD.

Forensic analysis of soman exposure using characteristic fragment ions from protein adducts

The verification of exposure to nerve agents is a serious challenge, especially in cases of soman (GD) poisoning. Protein adducts are reliable biomarkers, that provide forensic information and evidence during incidents of terrorism or sporadic poisoning. Mass spectrometry, coupled with a proteomics approach, was established for the forensic analysis of GD-based protein adducts. The fragmentation pathways of GD-based protein adducts were investigated for the first time using electrospray ionization tandem mass spectrometry. Three abundant natural loss product ions, [M+2H-54]²⁺ (loss of two carbon cations), [M+2H-72]²⁺ (loss of tert-butyl and methyl moieties), and [M+2H-84]²⁺ (loss of the pinacolyl moieties), were observed in each of the GD-labeled adducts, and the product ions were independent of protein structure and exposure route. A unique mechanism for the formation of product ions involving GD-protein adducts is proposed here. These findings support the development of a simple and precise forensic analysis technique to rapidly verify GD poisoning using these three GD-related product ions.

Correlation Analysis of EEG Brain Network With Modulated Acoustic Stimulation for Chronic Tinnitus Patients

The acoustic stimulation influences of the brain is still unveiled, especially from the brain network point, which can reveal how interaction is propagated and integrated between different brain zones for chronic tinnitus patients. We specifically designed a paradigm to record the electroencephalograms (EEGs) for tinnitus patients when they were treated with consecutive acoustic stimulation neuromodulation therapy for up to 75 days, using the tinnitus handicap inventory (THI) to evaluate the tinnitus severity or the acoustic stimulation treatment efficacy, and the EEG to record the brain activities every 2 weeks. Then, we used an EEG-based coherence analysis to investigate if the changes in brain network consistent with the clinical outcomes can be observed during 75-days acoustic treatment. Finally, correlation analysis was conducted to study potential relationships between network properties and tinnitus handicap inventory score change. The EEG network became significantly weaker after long-term periodic acoustic stimulation treatment, and tinnitus handicap inventory score changes or the acoustic stimulation treatment efficacy are strongly correlated with the varying brain network properties. Long-term acoustic stimulation neuromodulation intervention can improve the rehabilitation of chronic tinnitus patients, and the EEG network provides a relatively reliable and quantitative analysis approach for objective evaluation of tinnitus clinical diagnosis and treatment.

[The expression of transcription factors Snail and Slug in epithelial-mesenchymal transition of human lens epithelial cells induced by transforming growth factor-β2]

OBJECTIVE

To investigate the expression of transcription factors snail and slug in epithelial mesenchymal transition (EMT) of human lens epithelial cells (HLEC) induced by transforming growth factor-β2 (TGF-β2).

METHODS

Experimental research. HLEC were treated with different concentrations of TGF-β2 (1.0 and 10.0 μg/L) for different time. The morphological changes were observed under inverted microscope. The expression and cellular localization of snail and slug were evaluated by immunofluorescence. Expressions of snail, slug, E-Cadherin and α-SMA were further determined by Western blot analysis. Single factor analysis of variance, rank sum test and Pearson correlation were used for statistical analysis.

RESULTS

Cultured HLEC were polygonal monolayer cells with tight intercellular adhesion closely and patchy distribution. After treatment of different doses of TGF-β2 for 24 h, HLEC became isolated, exhibited long spindle-like shape as fibroblastic phenotype. The immunofluorescence staining indicated that snail and slug were localized in the nuclei. The expressions of snail and slug appeared to be positive correlative to TGF-β2 dose (snail protein expression: 0.74±0.16, 1.13±0.03, 1.54±0.18 and slug protein expression: 1.96±0.02, 3.12±0.09, 4.07±0.12 in HLEC treated with 0.1, 1.0 and 10 μg/L TGF-β2 respectively) (χ(2)=9.62,P=0.022;F=241.10,P<0.01). In addition, the expression of α-SMA and E-Cadherin showed the similar form (α-SMA protein expression: 0.87±0.04, 1.42±0.11, 2.17±0.36 and E-Cadherin protein expression: 2.50±0.36, 1.65±0.32, 0.41±0.14 in HLEC treated with 0.1, 1.0 and 10.0 μg/L TGF-β2 respectively) (χ(2)=9.97,P=0.019;F=19.99,P<0.01). All Pearson correlation coefficient were close to 1. The expression of snail and slug in HLEC were also increased with extending duration of TGF-β2 (1.0 μg/L). The expression levels of both proteins were modestly up-regulated at 8 hours, robustly increased at 24 h, reached peak at 48h and began to decline at 72 h (snail protein expression: 0.90±0.13, 1.43±0.14, 1.96±0.27, 1.57±0.16 and slug protein expression: 0.91±0.36, 1.24±0.16, 2.44±0.26, 1.43±0.16 in HLEC treated with 1.0 μg/L TGF-β2 for 8 h, 24 h, 48 h and 72 h respectively) (F=12.49,P=0.001;F=14.03,P<0.01).

CONCLUSION

Transcription factors snail and slug might be time and dose-dependently involved in in-vitro TGF-β2-induced EMT of HLEC. (Chin J Ophthalmol, 2016, 52: 285-290).

Neurobehavioral study of prenatal exposure to hyperthermia combined with irradiation in mice

Thirty-two pregnant adult LACA mice were randomly assigned to one of five exposure groups: control, 38 degrees C, 42 degrees C, irradiation, and 42 degrees C + irradiation. Animals were exposed on gestation day 9 to either 38 degrees C waterbath for 5 min, 42 degrees C waterbath for 5 min, treatment with 0.5 Gy of 60Co gamma irradiation, or pretreatment at 42 degrees C waterbath for 5 min following by 0.5 Gy of 60CO gamma irradiation. On postnatal day 7, litters were reduced to a maximum of eight pups per litter, with equal members of male and female offspring whenever possible. A total of 216 pups were observed for the age of acquisition of four physiological landmarks (pinna detachment, incisor eruption, eye opening, testes descent), six developmental reflexes (surface righting, cliff avoidance, auditory startle, air righting, visual placing, hindlimb splaying), and examination of learning and memory function. These studies, at threshold exposure levels to hyperthermia and ionizing radiation, indicate there is no consistent significant additional postnatal effect when pregnant mice are exposed to both of these agents. These studies are important for our understanding of the relative long-range effects of prenatal exposure to hyperthermia and acute dose irradiation early in gestation on neurobehavioral teratogenesis.