Regulation of Irregular Neuronal Firing by Autaptic Transmission

The importance of self-feedback autaptic transmission in modulating spike-time irregularity is still poorly understood. By using a biophysical model that incorporates autaptic coupling, we here show that self-innervation of neurons participates in the modulation of irregular neuronal firing, primarily by regulating the occurrence frequency of burst firing. In particular, we find that both excitatory and electrical autapses increase the occurrence of burst firing, thus reducing neuronal firing regularity. In contrast, inhibitory autapses suppress burst firing and therefore tend to improve the regularity of neuronal firing. Importantly, we show that these findings are independent of the firing properties of individual neurons, and as such can be observed for neurons operating in different modes. Our results provide an insightful mechanistic understanding of how different types of autapses shape irregular firing at the single-neuron level, and they highlight the functional importance of autaptic self-innervation in taming and modulating neurodynamics.Comment: 27 pages, 8 figure

A Synapse-Threshold Synergistic Learning Approach for Spiking Neural Networks

Spiking neural networks (SNNs) have demonstrated excellent capabilities in various intelligent scenarios. Most existing methods for training SNNs are based on the concept of synaptic plasticity; however, learning in the realistic brain also utilizes intrinsic non-synaptic mechanisms of neurons. The spike threshold of biological neurons is a critical intrinsic neuronal feature that exhibits rich dynamics on a millisecond timescale and has been proposed as an underlying mechanism that facilitates neural information processing. In this study, we develop a novel synergistic learning approach that simultaneously trains synaptic weights and spike thresholds in SNNs. SNNs trained with synapse-threshold synergistic learning (STL-SNNs) achieve significantly higher accuracies on various static and neuromorphic datasets than SNNs trained with two single-learning models of the synaptic learning (SL) and the threshold learning (TL). During training, the synergistic learning approach optimizes neural thresholds, providing the network with stable signal transmission via appropriate firing rates. Further analysis indicates that STL-SNNs are robust to noisy data and exhibit low energy consumption for deep network structures. Additionally, the performance of STL-SNN can be further improved by introducing a generalized joint decision framework (JDF). Overall, our findings indicate that biologically plausible synergies between synaptic and intrinsic non-synaptic mechanisms may provide a promising approach for developing highly efficient SNN learning methods.Comment: 13 pages, 9 figures, submitted for publicatio

A Spatial-channel-temporal-fused Attention for Spiking Neural Networks

Spiking neural networks (SNNs) mimic brain computational strategies, and exhibit substantial capabilities in spatiotemporal information processing. As an essential factor for human perception, visual attention refers to the dynamic selection process of salient regions in biological vision systems. Although mechanisms of visual attention have achieved great success in computer vision, they are rarely introduced into SNNs. Inspired by experimental observations on predictive attentional remapping, we here propose a new spatial-channel-temporal-fused attention (SCTFA) module that can guide SNNs to efficiently capture underlying target regions by utilizing historically accumulated spatial-channel information. Through a systematic evaluation on three event stream datasets (DVS Gesture, SL-Animals-DVS and MNIST-DVS), we demonstrate that the SNN with the SCTFA module (SCTFA-SNN) not only significantly outperforms the baseline SNN (BL-SNN) and other two SNN models with degenerated attention modules, but also achieves competitive accuracy with existing state-of-the-art methods. Additionally, our detailed analysis shows that the proposed SCTFA-SNN model has strong robustness to noise and outstanding stability to incomplete data, while maintaining acceptable complexity and efficiency. Overall, these findings indicate that appropriately incorporating cognitive mechanisms of the brain may provide a promising approach to elevate the capability of SNNs.Comment: 12 pages, 8 figures, 5 tabes; This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

5-Amino-7-(4-bromo­phen­yl)-3,7-di­hydro-2H-thieno[3,2-b]pyran-6-carbo­nitrile 1,1-dioxide

In the title compound, C14H11BrN2O3S, the 2,3-dihydro­thio­phene ring is almost planar [maximum deviation = 0.006 (1) Å]. The pyran ring is in an envelope conformation [puckering parameters Q = 0.115 (2) Å, θ = 77.5 (10), ϕ = 172.9 (10)°]. The pyran and phenyl rings are approximately perpendicular, making a dihedral angle of −76.4 (2)°. The crystal packing is stabilized by inter­molecular N—H⋯O hydrogen bonds, with the sulfone O atoms acting as acceptors

H.pylori Infection inhibits Inflammatory Bowel Disease(IBD) by affecting the intestinal flora: A systematic Review

Background: Inflammatory bowel diseases (IBD) are chronic, relapsing-remitting diseases of the gastrointestinal tract, including Crohn’s disease (CD), Ulcerative Colitis (UC), and Unclassified IBD (IBDU). Their pathogenesis involves genes and the environment as cofactors in inducing autoimmunity; mainly, the interactions between enteric pathogens and immunity are studied. For example, Helicobacter pylori (HP) is a common pathogen causing gastric inflammation. However, studies found that the number of people with HP was lower than those with IBD. Therefore, it suggests that HP might protect against IBD. Methods: The search terms "helicobacter pylori," "inflammatory bowel disease," "Crohn's disease," and "ulcerative colitis" were entered into the PubMed database. Embase, Medline, Web of Science, Scopus, PubMed publisher, Cochrane, and Google Scholar were also searched. The HP prevalence rates in IBD patients, CD patients, UC patients, and IBDU patients were calculated. So its to prove that there is an inverse relationship between HP and IBD, each group was compared to a control group. Results: Even when the comparison was made separately between each group of newly diagnosed patients and controls to rule out the possibility of pharmacologic bias, the data showed an inverse relationship between the IBD group and the controls. Conclusion: The results of this review demonstrate a striking inverse association between HP infection and the prevalence of inflammatory bowel disease (IBD), regardless of the type of IBD considered across different geographic regions. Anyway, data should be interpreted with care because more research is needed on this topic that is broader, more prospective, and more consistent. This could lead to new ideas about how the environment could cause IBD. Keywords: Inflammatory bowel disease; Helicobacter pylori; Crohn’s disease; Ulcerative colitis; Colorectal cancer DOI: 10.7176/JMPB/72-04 Publication date: May 31st 202

Apoptosis-inducing effect of 6,7-dimethoxy-4'-hydroxy-8- formylflavon from Nicotiana tabacum L leaf in human hepatoma HepG2 cells via activation of mitochondriamediated apoptotic pathway

Purpose: To study the anti-proliferative and apoptotic influences of 6,7-dimethoxy-4'-hydroxy-8- formylflavon (DHF) from the leaves of Nicotiana tabacum L. in human hepatoma HepG2 cells, and the underlying mechanisms.Methods: The anti-proliferative effect of DHF (10 - 50 μg/mL) on HepG2 cells was assessed by CCK-8 assay. The pro-apoptotic effect of DHF (10, 20 and 30 μg/mL) on HepG2 cells was investigated via flow cytometry, while the mechanisms involved were studied using western blot. Xenograft assay was employed for determination of the in vivo effect of DHF (40 mg/kg/day) on HepG2 cell-induced tumor.Results: The proliferation of HepG2 cells was inhibited by DHF (IC50 = 25.87 μg/mL) due to apoptosis. In addition, xenograft assay revealed that HepG2 cell-induced tumor growth was significantly suppressed by DHF (p < 0.05 or 0.01) without any effects on mice body weights. The expressions of Survivin and Bcl-2 proteins were significantly decreased, while those of Bax, c-caspase-9, and ccaspase- 3 proteins were significantly increased by DHF (p < 0.05 or 0.01), leading to increase in cytoplasmic levels of Smac and cytochrome c proteins.Conclusion: The underlying mechanism DHF-mediated apoptotic changes in HepG2 cells in vitro and in vivo involves induction of the mitochondrial pathway of apoptosis. Thus, DHF is a good drug candidate for the development of an effective therapy for liver cancer.Keywords: 6,7-Dimethoxy-4'-hydroxy-8-formylflavon, HepG2 cells, Hepatoma, Mitochondria, Apoptosis, Bax, Cytochrome C, Survivi

Label-free quantitative proteomic analysis of molting-related proteins of Trichinella spiralis intestinal infective larvae

International audienceAbstractMolting is a key step for body-size expansion and environmental adaptation of parasitic nematodes, and it is extremely important for Trichinella spiralis growth and development, but the molting mechanism is not fully understood. In this work, label-free LC–MS/MS was used to determine the proteome differences between T. spiralis muscle larvae (ML) at the encapsulated stage and intestinal infective larvae (IIL) at the molting stage. The results showed that a total of 2885 T. spiralis proteins were identified, 323 of which were differentially expressed. These proteins were involved in cuticle structural elements, regulation of cuticle synthesis, remodeling and degradation, and hormonal regulation of molting. These differential proteins were also involved in diverse intracellular pathways, such as fatty acid biosynthesis, arachidonic acid metabolism, and mucin type O-glycan biosynthesis. qPCR results showed that five T. spiralis genes (cuticle collagen 14, putative DOMON domain-containing protein, glutamine synthetase, cathepsin F and NADP-dependent isocitrate dehydrogenase) had significantly higher transcriptional levels in 10 h IIL than ML (P < 0.05), which were similar to their protein expression levels, suggesting that they might be T. spiralis molting-related genes. Identification and characterization of T. spiralis molting-related proteins will be helpful for developing vaccines and new drugs against the early enteral stage of T. spiralis

Identification and Nearly Full-Length Genome Characterization of Novel Porcine Bocaviruses

The genus bocavirus includes bovine parvovirus (BPV), minute virus of canines (MVC), and a group of human bocaviruses (HBoV1-4). Using sequence-independent single primer amplification (SISPA), a novel bocavirus group was discovered with high prevalence (12.59%) in piglet stool samples. Two nearly full-length genome sequences were obtained, which were approximately 5,100 nucleotides in length. Multiple alignments revealed that they share 28.7–56.8% DNA sequence identity with other members of Parvovirinae. Phylogenetic analyses indicated their closest neighbors were members of the genus bocavirus. The new viruses had a putative non-structural NP1 protein, which was unique to bocaviruses. They were provisionally named porcine bocavirus 1 and 2 (PBoV1, PBoV2). PBoV1 and PBoV2 shared 94.2% nucleotide identity in NS1 gene sequence, suggesting that they represented two different bocavirus species. Two additional samples (6V, 7V) were amplified for 2,407 bp and 2,434 bp products, respectively, including a partial NP1 gene and the complete VP1 gene; Phylogenetic analysis indicated that 6Vand 7V grouped with PBoV1 and PBoV2 in the genus of bocavirus, but were in the separate clusters. Like other parvoviruses, PBoV1, PBoV2, 6Vand 7V also contained a putative secretory phospholipase A2 (sPLA2) motif in the VP1 unique region, with a conserved HDXXY motif in the catalytic center. The conserved motif YXGXF of the Ca2+-binding loop of sPLA2 identified in human bocavirus was also found in porcine bocavirus, which differs from the YXGXG motif carried by most other parvoviruses. The observation of PBoV and potentially other new bocavirus genus members may aid in molecular and functional characterization of the genus bocavirus

Testing and Data Reduction of the Chinese Small Telescope Array (CSTAR) for Dome A, Antarctica

The Chinese Small Telescope ARray (hereinafter CSTAR) is the first Chinese astronomical instrument on the Antarctic ice cap. The low temperature and low pressure testing of the data acquisition system was carried out in a laboratory refrigerator and on the 4500m Pamirs high plateau, respectively. The results from the final four nights of test observations demonstrated that CSTAR was ready for operation at Dome A, Antarctica. In this paper we present a description of CSTAR and the performance derived from the test observations.Comment: Accepted Research in Astronomy and Astrophysics (RAA) 1 Latex file and 20 figure