Regulation of Neural Circuitry under General Anesthesia: New Methods and Findings.

General anesthesia has been widely utilized since the 1840s, but its underlying neural circuits remain to be completely understood. Since both general anesthesia and sleep are reversible losses of consciousness, studies on the neural-circuit mechanisms affected by general anesthesia have mainly focused on the neural nuclei or the pathways known to regulate sleep. Three advanced technologies commonly used in neuroscience, in vivo calcium imaging, chemogenetics, and optogenetics, are used to record and modulate the activity of specific neurons or neural circuits in the brain areas of interest. Recently, they have successfully been used to study the neural nuclei and pathways of general anesthesia. This article reviews these three techniques and their applications in the brain nuclei or pathways affected by general anesthesia, to serve as a reference for further and more accurate exploration of other neural circuits under general anesthesia and to contribute to other research fields in the future.

MAMF-GCN: Multi-scale adaptive multi-channel fusion deep graph convolutional network for predicting mental disorder.

PURPOSE: Existing diagnoses of mental disorders rely on symptoms, patient descriptions, and scales, which are not objective enough. We attempt to explore an objective diagnostic method on fMRI data. Graph neural networks (GNN) have been paid more attention recently because of their advantages in processing unstructured relational data, especially for fMRI data. However, how to deeply embed and well-integrate with different modalities and scales on GNN is still a challenge. Instead of reaching a high degree of fusion, existing GCN methods simply combine image and non-image data. Most graph convolutional network (GCN) models use shallow structures, making it challenging to learn about potential information. Furthermore, current graph construction approaches usually use a single specific brain atlas, limiting the analysis and results. METHOD: In this paper, a multi-scale adaptive multi-channel fusion deep graph convolutional network based on an attention mechanism (MAMF-GCN) is proposed to better integrate features of modalities and different atlas by exploiting multi-channel correlation. An encoder automatically combines one channel with non-imaging data to generate similarity weights between subjects using a similarity perception mechanism. Other channels generate multi-scale imaging features of fMRI data after processing in the different atlas. Multi-modal information is fused using an adaptive convolution module that applies a deep graph convolutional network (GCN) to extract information from richer hidden layers. RESULTS: To demonstrate the effectiveness of our approach, we evaluate the performance of the proposed method on the Autism Brain Imaging Data Exchange (ABIDE) dataset and the Major Depressive Disorder (MDD) dataset. The experimental result shows that the proposed method outperforms many state-of-the-art methods in node classification performance. An extensive group of experiments on two disease prediction tasks demonstrates that the performance of the proposed MAMF-GCN on MDD/ABIDE dataset is improved by 3.37%-39.83% and 12.59%-32.92%, respectively. Moreover, our proposed method has also shown very effective performance in real-life clinical diagnosis. The comprehensive experiments demonstrate that our method is effective for node classification with brain disorders diagnosis. CONCLUSION: The proposed MAMF-GCN method simultaneously extracts specific and common embeddings from the topology composed of multi-scale imaging features, phenotypic information, and their combinations, then learning adaptive embedding weights by attention mechanism, which can capture and fuse the multi-scale essential embeddings to improve the classification performance of brain disorder diagnosis.

Effects of toxic apolipoprotein E fragments on Tau phosphorylation and cognitive impairment in neonatal mice under sevoflurane anesthesia.

BACKGROUND: Anesthesia induces Tau phosphorylation and cognitive impairment in young, but not adult, mice. Apolipoprotein E (ApoE) may play a protective role in neuronal activity and injury repair, whereas its toxic fragments are reported to induce neurodegeneration and neurocognitive impairment in patients with Alzheimer's disease (AD). Therefore, we set out to test the hypothesis that the difference in ApoE fragments, but not the full-length ApoE, contributes to the difference in Tau phosphorylation and neurocognitive functions following sevoflurane anesthesia in young mice. METHODS: Sevoflurane was administered to wild-type (WT), ApoE-knockout (ApoE-KO), ApoE3-targeted replacement (ApoE3 expresses both full-length and fragmented ApoE), and ApoE2-targeted replacement (ApoE2 only expresses full-length ApoE) mice. The mRNA and protein levels of ApoE, phosphorylated Tau (pTau), and cognitive function were tested in the mice. RESULTS: Sevoflurane anesthesia enhanced ApoE mRNA, total ApoE, full-length ApoE, ApoE fragments, Tau phosphorylation (AT8 and PHF1), and cognitive impairment in young mice, but not in adult mice. ApoE2, but not ApoE3 or ApoE-KO, mice showed reduced sevoflurane-induced pTau elevation and cognitive impairment. CONCLUSION: These data suggest that elevated ApoE fragments rather than full-length ApoE might be one of the underlying mechanisms of age-dependent Tau phosphorylation and cognitive impairment in young mice following sevoflurane anesthesia.

A Visual Analytics Approach for Structural Differences Among Graphs via Deep Learning.

Representing and analyzing structural differences among graphs help gain insight into the difference related patterns such as dynamic evolutions of graphs. Conventional solutions leverage representation learning techniques to encode structural information, but lack an intuitive way of studying structural semantics of graphs. In this article, we propose a representation-and-analysis scheme for structural differences among graphs. We propose a deep-learning-based embedding technique to encode multiple graphs while preserving semantics of structural differences. We design and implement a web-based visual analytics system to support comparative study of features learned from the embeddings. One distinctive feature of our approach is that it supports semantics-aware construction, quantification, and investigation of latent relations encoded in graphs. We validate the usability and effectiveness of our approach through case studies with three datasets.

Drinking Hydrogen-Rich Water Alleviates Chemotherapy-Induced Neuropathic Pain Through the Regulation of Gut Microbiota.

INTRODUCTION: Chemotherapy-induced neuropathic pain (CINP) is one of the most common complications of chemotherapeutic drugs which limits the dose and duration of potentially life-saving anticancer treatment and compromises the quality of life of patients. Our previous studies have reported that molecular hydrogen (H2) can be used to prevent and treat various diseases. But the underlying mechanism remains unclear. The aim of the present study was to explore the effects of hydrogen-rich water on gut microbiota in CINP. METHODS: All C57BL/6J mice were divided into 4 groups: The group fed with normal drinking water and injected with saline (H2O + Saline), the group fed with normal drinking water and injected with oxaliplatin (H2O + OXA), the group fed with hydrogen-rich water and injected with saline (HW + Saline), and the group fed with hydrogen-rich water and injected with oxaliplatin (HW + OXA). The mechanical paw withdrawal threshold of the mice was tested on days 0, 5, 10, 15 and 20 after hydrogen-rich water treatment. On day 20, feces of mice from different groups were collected for microbial community diversity and structure analysis. The levels of inflammatory cytokines (TNF-α and IL-6), oxidative stress factors (OH- and ONOO-), lipopolysaccharide (LPS) and Toll-like receptor 4 (TLR4) were detected in dorsal root ganglia (DRG), L4-6 spinal cord segments and serum by enzyme-linked immunosorbent assay. The expression of TLR4 in DRG and spinal cords was determined by Western blot. RESULTS: The results illustrated that hydrogen-rich water could alleviate oxaliplatin-induced hyperalgesia, reduce the microbial diversity and alter the structure of gut microbiota, reverse the imbalance of inflammatory cytokines and oxidative stress, and decrease the expression of LPS and TLR4. CONCLUSION: Hydrogen-rich water may alleviate CINP by affecting the diversity and structure of the gut microbiota, and then the LPS-TLR4 pathway, which provides a direction for further research.

Exemplar-based Layout Fine-tuning for Node-link Diagrams.

We design and evaluate a novel layout fine-tuning technique for node-link diagrams that facilitates exemplar-based adjustment of a group of substructures in batching mode. The key idea is to transfer user modifications on a local substructure to other substructures in the entire graph that are topologically similar to the exemplar. We first precompute a canonical representation for each substructure with node embedding techniques and then use it for on-the-fly substructure retrieval. We design and develop a light-weight interactive system to enable intuitive adjustment, modification transfer, and visual graph exploration. We also report some results of quantitative comparisons, three case studies, and a within-participant user study.

iTRAQ-based quantitative proteomic analysis of the therapeutic effects of 2% hydrogen gas inhalation on brain injury in septic mice.

Sepsis encephalopathy (SAE) has a high incidence and mortality rate in patients with sepsis; however, there is currently no effective treatment. Our previous studies have reported that 2% hydrogen (H2) gas inhalation had a protective effect on sepsis and SAE; however, the specific mechanism have not been fully elucidated. In the current study, male Institute of Cancer Research mice were either used to create the cecal ligation and puncture (CLP) model or for sham surgery, followed by 2% H2 gas inhalation for 60 min beginning at 1 and 6 h following sham or CLP surgeries. The isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomics combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, hematoxylin and eosin (H&E) staining, Nissl staining, and western blot analysis were used to investigate the effects of H2 on brain injury in mice with sepsis. The results of the H&E, and Nissl staining indicated that the CLP mice had a significant brain injury, which was characterized by aggravated pathological damage and was alleviated by 2% H2 inhalation. Quantitative proteomics based on iTRAQ combined with LC-MS/MS analysis quantified a total of 5317 proteins, of which 39 were connected with the protective mechanism of H2. In addition, H2 could regulate the immune and the coagulation systems. Furthermore, western blot analysis revealed that H2 decreased SAE in septic mice by downregulating the protein expression levels of SMAD4, DPYS, PTGDS and upregulating the expression level of CUL4A. These results provide insights into the mechanism of the positive effect of H2 on SAE and contribute to the clinical application of H2 in patients with sepsis.

Tissue-Specific Regulation of Reactive Oxygen Species by an ATP-Responsive Nanoregulator Enhances Anticancer Efficacy and Reduces Anthracycline-Induced Cardiotoxicity.

Chemotherapy plays an important role in cancer treatment, yet its clinical application is inhibited by side effects. Chemotherapeutic agents accumulate at nonspecific sites and induce oxidative stress damage in noncancer tissues. A selective approach would be ideal, which would not only enhance anticancer efficacy in the tumor sites but also reduce chemotherapy-induced adverse effects on normal tissues. Therefore, we reported an adenosine-5'-triphosphate (ATP)-responsive oxidative stress nanoregulator (DePQu-DOX) to achieve the tissue-specific therapy. The DePQu-DOX NPs coloading doxorubicin (DOX) and quercetin (Qu) enhanced oxidative stress in murine breast cancer cells and scavenged DOX-induced oxygen free radicals in normal cardiac myocytes and podocytes. The released Qu could accelerate free radical scavenging more efficiently in oxygen-rich myocardium than in hypoxic tumors. Additionally, the ATP-specific responsiveness of nanocarriers enable cargos to selectively accumulate at tumor sites and decline the accumulation amount at normal tissues, resulting in lower system toxicity and improved anticancer effects. In vitro and in vivo experiments showed that this oxidative stress nanoregulator could efficiently protect normal tissues and significantly inhibit tumor growth. This study suggests that nanomedicine-mediated oxidative stress regulation could provide selective tumor therapeutics and reduce anthracycline-induced system toxicity.

Identification of suitable reference genes for gene expression studies in rat skeletal muscle following sciatic nerve crush injury.

Reverse transcription­quantitative polymerase chain reaction (RT­qPCR) is a molecular biological method used to assess gene expression characterized by high simplicity, effectiveness, specificity and sensitivity. The selection of a suitable reference gene for normalization is critical for the accuracy of quantitative results. Peripheral nerve injury is a common clinical disorder that affects multiple tissues and organs, including peripheral nerves, neurons and the innervated muscles. Numerous genes are differentially expressed in skeletal muscles during muscle denervation and reinnervation following peripheral nerve injury. The identification of a suitable reference gene in innervated muscles following nerve injury may improve the understanding of the alterations in gene expression in the processes of peripheral nerve repair and regeneration. Therefore, in the present study, by using a rat sciatic nerve crush model, the expression levels of various housekeeping genes were examined. In particular, the expression levels of 13 housekeeping genes, including 18S ribosomal RNA, actin ß, ankyrin repeat domain 27, cyclophilin A, GAPDH, hypoxanthine phosphoribosyltransferase 1 (HPRT1), mitochondrial ribosomal protein L10, phosphoglycerate kinase 1, RPTOR independent companion of mammalian target of rapamycin complex 2, TATA­box binding protein, ubiquitin C, UBX domain protein 11 and tyrosine 3­monooxygenase/tryptophan 5­monooxygenase activation protein ζ, were investigated in gastrocnemius muscles. The geNorm and NormFinder analyses suggested that the expression level of HPRT1 was particularly stable in gastrocnemius muscles following rat sciatic nerve crush injury. Therefore, HPRT1 may be used as a reference gene for the normalization of gene expression data generated by RT­qPCR.

Achyranthes bidentata polypeptides promotes migration of Schwann cells via NOX4/DUOX2-dependent ROS production in rats.

Achyranthes bidentata polypeptides (ABPP), an active polypeptides isolated from the aqueous extract of Achyranthes bidentata Blume, contributes to the regeneration of injured peripheral nerves by promoting migration of Schwann cells (SCs). In this study, we aimed to investigate the possible mechanism underlying the ABPP-induced migration of primary cultured rat SCs. Transwell migration assays indicated that ABPP promoted SCs migration in a concentration-dependent manner by inducing production of NADPH-oxidase (NOX)-derived reactive oxygen species (ROS). Inhibition of ROS production by NOXs inhibitor apocynin (APO) or diphenyleneiodonium (DPI) partially blocked ABPP-mediated SCs migration. Furthermore, by using real-time polymerase chain reaction analysis and siRNA interference technique, we verified the participation of NOX subunit 4 (NOX4) and dual oxidase 2 (DUOX2) in ABPP-induced ROS production and consequential SCs migration. Taken together, these results demonstrated that ABPP promoted SCs migration via NOX4/DUOX2-activated ROS in SCs.

miR-221-3p Inhibits Schwann Cell Myelination.

Following peripheral nerve injury, Schwann Cells (SCs) undergo dedifferentiation, proliferation, migration, and remyelination. Recent works demonstrated the importance of the short non-coding RNA (miRNAs) in SC dedifferentiation and remyelination after nerve injury. Previously, we found some miRNAs like miR-9, miR-221, miR-222 and miR-182 could regulate the proliferation and migration of SCs. Therefore, it is imperative to ask whether these miRNAs could regulate the myelination of SCs. Here we demonstrated that miR-221-3p could inhibit the myelination of SCs when co-cultured with dorsal root ganglion cells in vitro. In addition, NGF1-A binding protein 1 (Nab1) which was essential for SCs myelination could be downregulated by miR-221-3p. Suppressing the expression of Nab1 could reverse the promotion of miR-221-3p antagomir on SC myelination. The effects of miR-221-3p on SC myelination might be used to improve peripheral nerve regeneration, thus offering a new approach to peripheral nerve repair.

Actin Cytoskeleton Affects Schwann Cell Migration and Peripheral Nerve Regeneration.

Actin cytoskeleton regulates many essential biological functions, including cellular development, shape, polarity, and motility. The organization of actin cytoskeleton has also been associated with numerous physiological and pathological conditions, for instance, the elongation of axonal growth cone during peripheral nerve regeneration. However, the spatio-temporal expression patterns of actin cytoskeleton-related genes and the specific roles of actin cytoskeleton following peripheral nerve injury have not been fully revealed. To address this question, we made rat sciatic nerve crush surgery, collected injured sciatic nerve stumps, analyzed RNA deep sequencing outcomes, and specifically studied two significantly involved canonical pathways that were related with actin, actin cytoskeleton signaling and regulation of actin-based motility by Rho. By using bioinformatic tools and qRT-PCR, We identified and validated differentially expressed genes in these two signaling pathways. Moreover, by applying actin polymerization inhibitor cytochalasin D to sciatic nerve crushed rats, we studied the in vivo effect of cytochalasin D and demonstrated that inhibiting actin polymerization would delay the migration of Schwann cells and hinder the repair and regeneration of injured peripheral nerves. Overall, our data revealed the changes of actin cytoskeleton-related genes following peripheral nerve injury and stated the importance of actin cytoskeleton during peripheral nerve regeneration.

Mrpl10 and Tbp Are Suitable Reference Genes for Peripheral Nerve Crush Injury.

Peripheral nerve injury triggers the dysregulation of a large number of genes at multiple sites, including neurons, peripheral nerve stump, and the target organ. Housekeeping genes were frequently used as reference genes to normalize the expression values of target genes. Suitable selection of housekeeping genes that are stably expressed after nerve injury minimizes bias elicited by reference genes and thus helps to better and more sensitively reflect gene expression changes. However, many housekeeping genes have been used as reference genes without testing the expression patterns of themselves. In the current study, we calculated the expression stability of nine commonly used housekeeping genes, such as 18S (18S ribosomal RNA), Actb (ß-actin), CypA (cyclophilin A), Gapdh (glyceraldehydes-3-phosphate dehydrogenase), Hprt (hypoxanthine guanine phosphoribosyl transferase), Pgk1 (phosphoglycerate kinase 1), Tbp (TATA box binding protein), Ubc (ubiquitin C), YwhaZ (tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation), and four newly identified housekeeping genes, including Ankrd27 (Ankyrin repeat domain 27), Mrpl10 (mitochondrial ribosomal protein L10), Rictor (rapamycin-insensitive companion of mTOR, Complex 2), and Ubxn 11 (UBX domain protein 11), in both distal sciatic nerve samples and dorsal root ganglion (DRG) samples after sciatic nerve injury. Our results suggested that following peripheral nerve injury, Mrpl10 and Tbp might be used as suitable reference genes for sciatic nerve stump and DRGs, respectively.

Characterization of microparticle separation utilizing electrokinesis within an electrodeless dielectrophoresis chip.

This study demonstrated the feasibility of utilizing electrokinesis in an electrodeless dielectrophoresis chip to separate and concentrate microparticles such as biosamples. Numerical simulations and experimental observations were facilitated to investigate the phenomena of electrokinetics, i.e., electroosmosis, dielectrophoresis, and electrothermosis. Moreover, the proposed operating mode can be used to simultaneously convey microparticles through a microfluidic device by using electroosmotic flow, eliminating the need for an additional micropump. These results not only revealed that the directions of fluids could be controlled with a forward/backward electroosmotic flow but also categorized the optimum separating parameters for various microparticle sizes (0.5, 1.0 and 2.0 µm). Separation of microparticles can be achieved by tuning driving frequencies at a specific electric potential (90 Vpp·cm(-1)). Certainly, the device can be designed as a single automated device that carries out multiple functions such as transportation, separation, and detection for the realization of the envisioned Lab-on-a-Chip idea.