Lipopolysaccharide-binding protein expression is increased by stress and inhibits monoamine synthesis to promote depressive symptoms.

Monoamine insufficiency is suggested to be associated with depressive features such as sadness, anhedonia, insomnia, and cognitive dysfunction, but the mechanisms that cause it are unclear. We found that the acute-phase protein lipopolysaccharide-binding protein (LBP) inhibits monoamine biosynthesis by acting as an endogenous inhibitor of dopamine-ß-hydroxylase (DBH) and aromatic-L-amino-acid-decarboxylase (DDC). LBP expression was increased in individuals with depression and by diverse stress challenges in mice. LBP antibodies and LBP knockdown inhibited monoamine insufficiency and depression-like features in mice, which worsened with LBP overexpression or administration. Monoamine insufficiency and depression-like symptoms were not induced by stressful stimuli in LBP-deficient mice, further highlighting a role for LBP in stress-induced depression, and a peptide we designed that blocks LBP-DBH and LBP-DDC interactions showed anti-depression effects in mice. This study reveals an important role for LBP in regulating monoamine biosynthesis and suggests that targeting LBP may have potential as a treatment for some individuals with depression.

4D label-free proteomics analysis of oxygen-induced retinopathy with or without anti-VEGF treatment.

Oxygen-induced retinopathy (OIR) animal model is widely used for retinopathy of prematurity (ROP) researches. The purpose of this study was to identify proteins and related pathways of OIR with or without anti-vascular endothelial growth factor (VEGF) treatment, for use as biomarkers in diagnosing and treating ROP. Nine samples were subjected to proteomic analysis. Retina specimens were collected from 3 OIR mice, 3 OIR mice with anti-VEGF treatment and 3 normal mice (control group). Liquid chromatography-tandem mass spectrometry analysis was performed using the 4D label-free technique. Statistically significant differentially expressed proteins, gene ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway representations, InterPro (IPR) and protein interactions were analyzed. In total, 4585 unique proteins were identified as differentially expressed proteins (DEPs). Enrichment analysis of the GO and KEGG indicated functional clusters related to peptide biosynthetic and metabolic process, cellular macromolecule biosynthetic process and nucleic acid binding in OIR group. For anti-VEGF treatment group, DEPs were clustered in DNA replication, PI3K/Akt signaling pathway and Jak/STAT signaling pathway. Proteomic profiling is useful for the exploration of molecular mechanisms of OIR and mechanisms of anti-VEGF treatment. These findings may be useful for identification of novel biomarkers for ROP pathogenesis and treatment.

A Variable Clock Underlies Internally Generated Hippocampal Sequences.

Humans have the ability to store and retrieve memories with various degrees of specificity, and recent advances in reinforcement learning have identified benefits to learning when past experience is represented at different levels of temporal abstraction. How this flexibility might be implemented in the brain remains unclear. We analyzed the temporal organization of male rat hippocampal population spiking to identify potential substrates for temporally flexible representations. We examined activity both during locomotion and during memory-associated population events known as sharp-wave ripples (SWRs). We found that spiking during SWRs is rhythmically organized with higher event-to-event variability than spiking during locomotion-associated population events. Decoding analyses using clusterless methods further indicate that a similar spatial experience can be replayed in multiple SWRs, each time with a different rhythmic structure whose periodicity is sampled from a log-normal distribution. This variability increases with experience despite the decline in SWR rates that occurs as environments become more familiar. We hypothesize that the variability in temporal organization of hippocampal spiking provides a mechanism for storing experiences with various degrees of specificity.SIGNIFICANCE STATEMENT One of the most remarkable properties of memory is its flexibility: the brain can retrieve stored representations at varying levels of detail where, for example, we can begin with a memory of an entire extended event and then zoom in on a particular episode. The neural mechanisms that support this flexibility are not understood. Here we show that hippocampal sharp-wave ripples, which mark the times of memory replay and are important for memory storage, have a highly variable temporal structure that is well suited to support the storage of memories at different levels of detail.

Genome-wide analysis of TCP transcription factor family in sunflower and identification of HaTCP1 involved in the regulation of shoot branching.

BACKGROUND: Sunflower is an important ornamental plant, which can be used for fresh cut flowers and potted plants. Plant architecture regulation is an important agronomic operation in its cultivation and production. As an important aspect of plant architecture formation, shoot branching has become an important research direction of sunflower. RESULTS: TEOSINTE-BRANCHED1/CYCLOIDEA/PCF (TCP) transcription factors are essential in regulating various development process. However, the role of TCPs in sunflowers has not yet been studied. This study, 34 HaTCP genes were identified and classified into three subfamilies based on the conservative domain and phylogenetic analysis. Most of the HaTCPs in the same subfamily displayed similar gene and motif structures. Promoter sequence analysis has demonstrated the presence of multiple stress and hormone-related cis-elements in the HaTCP family. Expression patterns of HaTCPs revealed several HaTCP genes expressed highest in buds and could respond to decapitation. Subcellular localization analysis showed that HaTCP1 was located in the nucleus. Paclobutrazol (PAC) and 1-naphthylphthalamic acid (NPA) administration significantly delayed the formation of axillary buds after decapitation, and this suppression was partially accomplished by enhancing the expression of HaTCP1. Furthermore, HaTCP1 overexpressed in Arabidopsis caused a significant decrease in branch number, indicating that HaTCP1 played a key role in negatively regulating sunflower branching. CONCLUSIONS: This study not only provided the systematic analysis for the HaTCP members, including classification, conserved domain and gene structure, expansion pattern of different tissues or after decapitation. But also studied the expression, subcellular localization and function of HaTCP1. These findings could lay a critical foundation for further exploring the functions of HaTCPs.

Heat wave exposure and semen quality in sperm donation volunteers: A retrospective longitudinal study in south China.

BACKGROUND: Previous studies have suggested an association between non-optimum ambient temperature and decreased semen quality. However, the effect of exposure to heat waves on semen quality remains unclear. METHODS: Volunteers who intended to donate sperm in Guangdong provincial human sperm bank enrolled. Heat waves were defined by temperature threshold and duration, with a total of 9 definitions were employed, specifying daily mean temperature exceeding the 85th, 90th, or 95th percentile for at least 2, 3, or 4 consecutive days. Residential exposure to heat waves during 0-90 days before ejaculation was evaluated using a validated gridded dataset on ambient temperature. Association and potential windows of susceptibility were evaluated and identified using linear mixed models and distributed lag non-linear models. RESULTS: A total of 2183 sperm donation volunteers underwent 8632 semen analyses from 2018 to 2019. Exposure to heat wave defined as daily mean temperature exceeding the 95th percentile for at least 4 consecutive days (P95-D4) was significantly associated with a 0.11 (95% confidence interval [CI]: 0.03, 0.18) ml, 3.36 (1.35, 5.38) × 106/ml, 16.93 (7.95, 25.91) × 106, and 2.11% (1.4%, 2.83%) reduction in semen volume, sperm concentration, total sperm number, and normal forms, respectively; whereas exposure to heat wave defined as P90-D4 was significantly associated with a 1.98% (1.47%, 2.48%) and 2.08% (1.57%, 2.58%) reduction in total motility and progressive motility, respectively. Sperm count and morphology were susceptible to heat wave exposure during the early stage of spermatogenesis, while sperm motility was susceptible to exposure during the late stage. CONCLUSION: Heat wave exposure was significantly associated with a reduction in semen quality. The windows of susceptibility during 0-90 days before ejaculation varied across sperm count, motility, and morphology. Our findings suggest that reducing heat wave exposure before ejaculation may benefit sperm donation volunteers and those attempting to conceive.

Characteristics of Leaf Spot Disease Caused by Didymella Species and the Influence of Infection on Tea Quality.

Leaf spots are the most damaging and common foliar diseases of tea and are caused by several species of fungi. During 2018 to 2020, leaf spot diseases showing different symptoms (large and small spots) were observed in commercial tea plantations in Guizhou and Sichuan provinces of China. The pathogen causing the two different sized leaf spots was identified as the same species (Didymella segeticola) based on morphological characteristics, pathogenicity, and multilocus phylogenetic analysis using the combined ITS, TUB, LSU, and RPB2 gene regions. Microbial diversity analysis of lesion tissues from small spots on naturally infected tea leaves further confirmed Didymella to be present as the main pathogen. Results of sensory evaluation and quality-related metabolite analysis of tea shoots infected with the small leaf spot symptom indicated that D. segeticola negatively affected the quality and flavor of tea by changing the composition and content of caffeine, catechins, and amino acids. In addition, the significantly reduced amino acid derivatives in tea are confirmed to be positively associated with the enhanced bitter taste. The results improve our understanding of the pathogenicity of Didymella species and the influence of Didymella on the host plant, Camellia sinensis.

Association between ambient temperatures and injuries: a time series analysis using emergency ambulance dispatches in Chongqing, China.

BACKGROUND: Global warming and increasing extreme weather have become a severe problem in recent years, posing a significant threat to human health worldwide. Research exploring the link between injury as one of the leading causes of death globally and ambient temperature was lacking. Based on the hourly injury emergency ambulance dispatch (IEAD) records from 2019-2021 in the main urban area of Chongqing, this study explored the role of temperature extremes on the pathogenesis of injury by different mechanisms and identified sensitive populations for different mechanisms of injury. METHODS: In this study, we collected hourly injury emergency ambulance dispatch (IEAD) records from Chongqing Emergency Dispatch Center in the main urban area of Chongqing from 2019 to 2021, and used a distributed lagged nonlinear model (DLNM) with quasi-Poisson distribution to evaluate the association between ambient temperature and IEADs. And the stratified analysis was performed by gender, age and different injury mechanisms to identify susceptible groups. Finally, the attributable burden of ambient extreme temperatures was also investigated. RESULTS: The risk for total IEADs increased significantly at high temperature (32 °C) compared with optimal temperature (9 °C) (CRR: 1.210; 95%CI[1.127,1.300]). The risks of traffic accident injury (CRR: 1.346; 95%CI[1.167,1.552]), beating injury (CRR: 1.508; 95%CI[1.165,1.952]), fall-height injury (CRR: 1.871; 95%CI[1.196-2.926]) and injury of sharp penetration (CRR: 2.112; 95%CI[1.388-3.213]) were significantly increased. At low temperature (7 °C), the risk of fall injury (CRR: 1.220; 95% CI [1.063,1.400]) increased significantly. Lag for 24 hours at extreme low temperature (5 °C), the risk of 18-45 years (RR: 1.016; 95%CI[1.009,1.024]) and over 60 years of age (RR: 1.019; 95%CI[1.011,1.025]) increased significantly. The effect of 0 h delay in extreme high temperature (36 °C) on males aged 18-45 years (RR: 1.115; 95%CI[1.071,1.162]) and 46-59 years (RR: 1.069; 95%CI[1.023,1.115]) had significant impact on injury risk. CONCLUSIONS: This study showed that ambient temperature was significantly related to the risk of injury, and different mechanisms of injury were affected differently by extreme temperature. The increasing risk of traffic accident injury, beating injury, fall-height injury and sharp penetrating injury was associated with extreme heat, while fall injury was associated with extreme cold. The risk of injury in high temperature environment was mainly concentrated in males and young adults. The results of this study can help to identify the sensitive population with different injury mechanisms in extreme temperature environment, and provide reference for public health emergency departments to respond to relevant strategies in extreme temperature environment to minimize the potential risk to the public.

Antimicrobial peptides, conventional antibiotics, and their synergistic utility for the treatment of drug-resistant infections.

Antimicrobial peptides (AMPs), also known as host defense peptides (HDPs), are important effector immune defense molecules in multicellular organisms. AMPs exert their antimicrobial activities through several mechanisms; thus far, induction of drug resistance through AMPs has been regarded as unlikely. Therefore, they have great potential as new generation antimicrobial agents. To date, more than 30 AMP-related drugs are in the clinical trial phase. In recent years, studies show that some AMPs and conventional antibiotics have synergistic effects. The combined use of AMPs and antibiotics can kill drug-resistant pathogens, prevent drug resistance, and significantly improve the therapeutic effects of antibiotics. In this review, we discuss the progress in synergistic studies on AMPs and conventional antibiotics. An overview of the current understanding of the functional scope of AMPs, ongoing clinical trials, and challenges in the development processes are also presented.

Protein tyrosine phosphatase 1B regulates fibroblasts proliferation, motility and extracellular matrix synthesis via the MAPK/ERK signalling pathway in keloid.

Keloid is a fibroproliferative disorder resulting from trauma, characterized by abnormal activation of keloid fibroblasts and excessive deposition of extracellular matrix (ECM). It affects life quality of patients and lacks of effective therapeutic targets. Protein tyrosine phosphatase 1B (PTP1B) belongs to the protein tyrosine phosphatases and participates in many cellular processes such as metabolism, proliferation and motility. It has been reported that PTP1B negatively regulated diabetic wound healing and tumor progression. However, its effects in keloid remain unclear. Here, we aimed to evaluate the effects of PTP1B on keloid fibroblasts which play essential roles in keloids pathogenesis. Our results revealed that PTP1B expression was decreased both in keloid tissues and in keloid fibroblasts compared to healthy controls. Keloid fibroblasts (KFs) showed higher cell proliferation, motility, ECM production and ERK activity than normal fibroblasts (NFs). Overexpression of PTP1B in KFs and NFs inhibited cell proliferation, motility, ECM synthesis and the MAPK/ERK signalling pathway while knockdown of PTP1B showed converse effects. The rescue experiments with ERK inhibitor further verified that MAPK/ERK signalling pathway involved in PTP1B regulatory network. Taken together, our findings indicated that overexpression of PTP1B suppressed keloid fibroblasts bio-behaviours and promoted their phenotype switch to normal cells via inhibiting the MAPK/ERK signalling pathway, suggesting it may be a potential anti-keloid therapy.

The effect of daily mean temperature on hand, foot and mouth disease and the source of regional heterogeneity in Chongqing, China, 2010-2019.

BACKGROUND: Hand, foot and mouth disease (HFMD) is a serious infectious disease which has become a public health problem. A multi-regional study was conducted in this study to explore the relationship between temperature and HFMD in different regions and the source of heterogeneity, and further detect the effect modifiers such as socio-economic factors, medical and health factors and meteorological factors. METHODS: The data on daily reported HFMD cases and meteorological data from 2010 to 2019 in Chongqing were collected. Thirty-eight districts and counties of Chongqing were divided into 6 regions. The distributed lag nonlinear model (DLNM) was applied to assess the effect of daily mean temperature on HFMD at region level with the pooled effect estimates from multivariate meta-regression model analysis. Stratified analyses by gender, age and children's type were also conducted. Potential modifiers were considered in meta regression to explore the source of heterogeneity. RESULTS: There were nonlinear relationships with an inverted V-shape between temperature and HFMD. A maximum cumulative relative risk (CRR) of 1.22 (95% confidence interval (CI): 1.12-1.34) peaked at 23.8 °C, and the risk appeared immediately and lasted for the whole 14 days. Compared with other groups, warm temperature had a stronger effect on children aged 0-1 and scattered children, while cold temperature had a stronger effect on female, children aged 3-6 and childcare children with an M-shape. We found that socio-economic factors, medical health factors and meteorological factors were significantly associated with heterogeneity. Density of medical technical personnel, urbanization rate and density of health care institutions were the main modifiers for explaining heterogeneity of 26.10%, 24.90% and 24.86% respectively which were revealed by meta-analysis. CONCLUSIONS: There was a significant nonlinear correlation between temperature and HFMD. Compared with other groups, children aged 0-1 and scattered children were more susceptible to warm temperature, while female, children aged 3-6 and childcare children were more susceptible to cold temperature. Socio-economic factors, medical health factors and meteorological factors may be the source of the heterogeneity. Therefore, local governments should consider different temperature-HFMD relationships between different regions and populations when formulating appropriate preventive measures.

Transcriptomic and metabolomic analyses of non-structural carbohydrates in red maple leaves.

Plant sugars serve to balance nutrition, regulate development, and respond to biotic and abiotic stresses, whereas non-structural carbohydrates (NSCs) are essential energy sources that facilitate plant growth, metabolism, and environmental adaptation. To better elucidate the mechanisms of NSCs in red maple, ultrahigh-performance liquid chromatograph Q extractive mass spectrometry (UHPLC-QE-MS) and high-throughput RNA-sequencing were performed on green, red, and yellow leaves from a selected red maple mutant. In green leaves, the fructose phosphorylation process exhibited greater flux. In yellow leaves, sucrose and starch had a stronger capacity for synthesis and degradation, whereas in red leaves, there was a greater accumulation of trehalose and manninotriose. ArTPS5 positively regulated amylose, which was negatively regulated by ArFBP2, whereas ArFRK2 and ArFBP13 played a positive role in the biosynthesis of Sucrose-6P. Sucrose-6P also regulated anthocyanins and abscisic acid in red maple by affecting transcription factors. The results of this paper can assist with the control and optimization of the biosynthesis of NSCs in red maple, which may ultimately provide the foundation for influencing sugar production in Acer.

Research progress on supercritical CO2 thickeners.

According to the thickening principle and molecular structure of thickeners, supercritical carbon dioxide (scCO2) thickeners have been summarized and introduced by dividing into polymers, small molecular compounds and surfactants. The properties such as solubility, thickening effect, thickening condition and existing problems of scCO2 thickeners are analyzed and assessed, and the research progress and prospects of scCO2 thickeners are proposed. ScCO2 is used in both CO2 fracturing and CO2 flooding for enhanced oil recovery (EOR). However, due to its low viscosity, the proppant carrying ability and filtration control ability of scCO2 are too weak for fracturing. Also, in the process of CO2 flooding, its low viscosity not only exacerbates the gravity override but also leads to an unfavorable mobility ratio that results in viscous fingering, early breakthrough, and poor sweep efficiency. Therefore, scCO2 thickeners have good application prospects in oil and gas production for improved oil recovery (IOR).

Allicin attenuates myocardial apoptosis, inflammation and mitochondrial injury during hypoxia-reoxygenation: an in vitro study.

BACKGROUND: Myocardial ischemia-reperfusion (IR) injury is a damage due to an initial reduction in blood flow to the heart, preventing it from receiving enough oxygen, and subsequent restoration of blood flow through the opening of an occluded coronary artery producing paradoxical harmful effects. The finding of new therapies to prevent IR is of utmost importance. Allicin is a compound isolated from garlic having the ability to prevent and cure different diseases, and a protective effect on the myocardium was also demonstrated. Therefore, the aim of this study was to evaluate the in vitro protective effect of Allicin against myocardial IR injury on cardiomyocytes. METHODS: We established an in vitro hypoxia-reoxygenation (HR) model of primary porcine cardiomyocytes to simulate myocardial IR injury. Primary porcine cardiomyocytes were extracted from Mini-musk swines (1 day old). After a period of adaptation of at least 2-3 days, cardiomyocytes in good condition were selected and randomly divided into control group (normal oxygen for 5 h), HR group (2 h of hypoxia/3 h of reoxygenation), and HR + Allicin group (hypoxia/reoxygenation + Allicin treatment). RESULTS: After the induction of hypoxia/reoxygenation, Allicin treatment enhanced the cell viability. Moreover, Allicin treatment resulted in a reduction of apoptosis from 13.5 ± 1.2% to 6.11 ± 0.15% compared with the HR group (p < 0.05), and the apoptosis related proteins were regulated as well, with a decreased expression of Bax, cleaved caspase-3 and cytosolic cytochrome C and an increase in Bcl-2 expression in the HR + Allicin group (all p < 0.01). Pro-inflammatory cytokines, such as interleukin-6 and tumor necrosis factor alpha were down-regulated by the treatment with Allicin (both p < 0.01). In addition, it significantly decreased intracellular reactive oxygen species generation (p < 0.01) and reduced the loss of mitochondrial membrane potential (p < 0.01). Furthermore, the expression of PPARγ coactivator-1α and endothelial nitric oxide synthase was up-regulated (both p < 0.01), while the expression of Endothelin-1, hypoxia inducing factor-1α and transforming growth factor beta was down-regulated (all p < 0.01) by Allicin treatment. CONCLUSIONS: These results suggested that Allicin protected the cardiomyocytes against HR damage by reducing apoptosis, inflammation and mitochondrial injury, thus providing a basis for its potential use in the treatment of myocardial IR.

Macular Retinal Sensitivity and Microvasculature Changes before and after Vitrectomy in Idiopathic Macular Epiretinal Membrane with Classification.

PURPOSE: To observe retinal sensitivity (RS) and microvasculature changes in preoperative and postoperative idiopathic macular epiretinal membrane (iERM) with optical coherence tomography (OCT) classification by microperimetry (MP) and optical coherence tomography angiography (OCTA). METHODS: In this retrospective study, 53 eyes of 53 patients affected with iERM were enrolled and 35 iERM eyes underwent pars plana vitrectomy associated with internal limiting membrane peeling. All iERM eyes were evaluated and graded by OCT. According to the thickness of the fovea relative to the surrounding macula from OCT radial line scans, we classified iERM into 3 grades. MP was used to measure RS of macular within 20° centered on the fovea and fixation stability (FS). OCTA was used to measure the superficial and deep capillary plexus (DCP) layers using 6 mm × 6 mm scans. Measurements were taken at the baseline visit and 3-month postoperation. Evaluated factors included: best corrected visual acuity, RS, FS, vessel density. RESULTS: Eyes with iERM had worse RS than control eyes (p < 0.0001), especially in higher grade iERM eyes. And higher grade iERM eyes had a marked increase foveal vessel density (FVD) (p < 0.0001) in superficial capillary plexus (SCP) and DCP, and a significant decrease parafoveal vessel density (Para VD) in DCP. After surgery, there was no difference in RS and FS than preoperation (p > 0.05), whether in grade 1 or 2 iERM eyes. However, in OCTA analyses, grade 1 iERM eyes had less whole vessel density (WVD) and perifoveal vessel density (Peri VD) in SCP, than preoperation (p < 0.05). And grade 1 iERM eyes had higher Para VD and Peri VD in DCP (p < 0.05), than preoperative OCTA results. Grade 2 iERM eyes had less WVD, FVD, and Peri VD in SCP, than preoperation (p < 0.05). After surgery, in grade 2 iERM eyes, there was a positive correlation between whole retinal sensitivity and WVD (p < 0.05) in SCP. And there were positive correlations between Para RS and Para VD (p < 0.05), Peri RS and Peri VD (p < 0.05) in SCP. CONCLUSIONS: Classification helps to reveal different changes in iERM eyes. Higher grade iERM eyes had worse RS and microvasculature changes. MP and OCTA play an important role in assessing iERM and help surgical decisions for patients with iERM.

Telocytes inhibited inflammatory factor expression and enhanced cell migration in LPS-induced skin wound healing models in vitro and in vivo.

BACKGROUND: Cell proliferation and death are key components of wound healing and tissue repair. Telocytes (TCs) represent a newly discovered cell type that can protect tissue from acute injury via cell-cell communication with adjacent cells. The aim of this study was to use a mouse model of skin wound healing and lipopolysaccharide (LPS)-induced cell injury to evaluate the effects of TCs on skin wound healing in vivo and in vitro. MATERIAL/METHODS: Immunohistochemical staining was performed to evaluate the alteration of TCs in tissues from normal and chronic wound patients. Then, a male C57BL/6 mouse wound model of the back was established. The mice were divided randomly into three groups, and wound healing was estimated according to the wound healing rate and histology. An LPS-induced co-culture model of a mouse lung telocyte cell line (TCs) with human keratinocyte (HaCaT), human dermal microvascular endothelial cell (HDMEC) or murine fibroblast (L929) cell lines was established to analyse the effects of TCs on constitutive cell types of the skin. Cell proliferation, migration and apoptosis were examined, and reactive oxygen species (ROS) and inflammatory factors in HaCaT cells, HDMECs, and L929 cells were detected to study the mechanisms involved in TC protection in skin wounds. RESULTS: TCs were significantly increased in tissues from chronic wound patients compared with healthy controls. Wound healing was significantly improved in wound mouse models treated with exogenous TCs compared with LPS-induced models. TCs reversed the LPS-induced inhibition of HaCaT cells and HDMECs and reduced the LPS-induced apoptosis of HaCaT cells and the death ratios of HDMECs and L929 cells. TCs reversed LPS-induced ROS in HDMECs and L929 cells and decreased inflammatory factor mRNA levels in HaCaT cells, HDMECs and L929 cells. CONCLUSIONS: TCs reduce wound healing delay, and inflammatory responses caused by LPS might be mediated by inflammatory inhibition, thus restricting apoptosis and promoting migration of the main component cell types in the skin.

Rapid classification of hippocampal replay content for real-time applications.

Sharp-wave ripple (SWR) events in the hippocampus replay millisecond-timescale patterns of place cell activity related to the past experience of an animal. Interrupting SWR events leads to learning and memory impairments, but how the specific patterns of place cell spiking seen during SWRs contribute to learning and memory remains unclear. A deeper understanding of this issue will require the ability to manipulate SWR events based on their content. Accurate real-time decoding of SWR replay events requires new algorithms that are able to estimate replay content and the associated uncertainty, along with software and hardware that can execute these algorithms for biological interventions on a millisecond timescale. Here we develop an efficient estimation algorithm to categorize the content of replay from multiunit spiking activity. Specifically, we apply real-time decoding methods to each SWR event and then compute the posterior probability of the replay feature. We illustrate this approach by classifying SWR events from data recorded in the hippocampus of a rat performing a spatial memory task into four categories: whether they represent outbound or inbound trajectories and whether the activity is replayed forward or backward in time. We show that our algorithm can classify the majority of SWR events in a recording epoch within 20 ms of the replay onset with high certainty, which makes the algorithm suitable for a real-time implementation with short latencies to incorporate into content-based feedback experiments.

Clusterless Decoding of Position from Multiunit Activity Using a Marked Point Process Filter.

Point process filters have been applied successfully to decode neural signals and track neural dynamics. Traditionally these methods assume that multiunit spiking activity has already been correctly spike-sorted. As a result, these methods are not appropriate for situations where sorting cannot be performed with high precision, such as real-time decoding for brain-computer interfaces. Because the unsupervised spike-sorting problem remains unsolved, we took an alternative approach that takes advantage of recent insights into clusterless decoding. Here we present a new point process decoding algorithm that does not require multiunit signals to be sorted into individual units. We use the theory of marked point processes to construct a function that characterizes the relationship between a covariate of interest (in this case, the location of a rat on a track) and features of the spike waveforms. In our example, we use tetrode recordings, and the marks represent a four-dimensional vector of the maximum amplitudes of the spike waveform on each of the four electrodes. In general, the marks may represent any features of the spike waveform. We then use Bayes's rule to estimate spatial location from hippocampal neural activity. We validate our approach with a simulation study and experimental data recorded in the hippocampus of a rat moving through a linear environment. Our decoding algorithm accurately reconstructs the rat's position from unsorted multiunit spiking activity. We then compare the quality of our decoding algorithm to that of a traditional spike-sorting and decoding algorithm. Our analyses show that the proposed decoding algorithm performs equivalent to or better than algorithms based on sorted single-unit activity. These results provide a path toward accurate real-time decoding of spiking patterns that could be used to carry out content-specific manipulations of population activity in hippocampus or elsewhere in the brain.

Effect of blister blight disease caused by Exobasidium on tea quality.

Blister blight, as one of the most threatening and damaging disease worldwide, mainly infects young organs and tissues seriously affecting tea growth and quality. In this study, the spread of pathogen on tea leaves were examined by toluidine blue staining, scanning electron microscope and transmission electron microscope analysis. The composition and abundance of fungal community on leaf tissues were firstly analyzed. Sensory evaluation and metabolites analysis indicated that diseased tea leaves had strong sweet taste and soluble sugars contributed significantly to the taste, while metabolites showing bitter and astringent taste (caffeine, catechins) were significantly decreased. According to the biological functions of differential metabolites, sugars including 7 monosaccharides (d-xylose, d-arabinose, d-mannose, d-glucuronic acid, glucose, d-galactose and d-fructose), 2 disaccharide (sucrose and maltose) and 1 trisaccharide (raffinose) were the main differential sugars increased in content (>2 fold change), which was of great significance to sweet taste of diseased tea.

Hainan four-eyed turtles actively select suitable stones to masquerade according to their own morphology.

Masquerade is a form of camouflage in which animals use their body size, shape, and coloration to resemble inanimate objects in their environment to deceive predators. However, there is a lack of experimental evidence to show that animals actively choose objects that match these body parameters. To explore how the Hainan four-eyed turtle, Sacalia insulensis, masquerades using suitable stones, we used indoor video surveillance technology to study the preferences of juvenile S. insulensis for stones of different sizes, shapes, and colors. The results indicated that under normal conditions, during the day, juvenile S. insulensis preferred larger oval or round stones, while at night, they preferred oval stones that were closer to their own size, with no significant preference for stone color during either time. When disturbed (by a researcher swinging their arm back and forth above the experimental setup every hour to mimic a predator), the turtles showed a preference for brown stones that were closer to their size and oval in shape. These findings suggest that juvenile S. insulensis prefer stones that resemble their carapace size and shape to masquerade when undisturbed, and that this preference is reinforced when they masquerade to reduce the risk of predation. The preference for stones that resemble their carapace color is significant only when there is a disturbance. To the best of our knowledge, this is the first study to provide evidence that vertebrates can selectively choose objects that resemble their own morphology for masquerading to reduce predation risk.