Flow Cytometry of Synaptoneurosomes (FCS) Reveals Increased Ribosomal S6 and Calcineurin Proteins in Activated Medial Prefrontal Cortex to Nucleus Accumbens Synapses.

Learning and behavior activate cue-specific patterns of sparsely distributed cells and synapses called ensembles that undergo memory-encoding engram alterations. While Fos is often used to label selectively activated cell bodies and identify neuronal ensembles, there is no comparable endogenous marker to label activated synapses and identify synaptic ensembles. For the purpose of identifying candidate synaptic activity markers, we optimized a flow cytometry of synaptoneurosome (FCS) procedure for assessing protein alterations in activated synapses from male and female rats. After injecting yellow fluorescent protein (YFP)-expressing adeno-associated virus into medial prefrontal cortex (mPFC) to label terminals in nucleus accumbens (NAc) of rats, we injected 20 mg/kg cocaine in a novel context (cocaine+novelty) to activate synapses, and prepared NAc synaptoneurosomes 0-60 min following injections. For FCS, we used commercially available antibodies to label presynaptic and postsynaptic markers synaptophysin and PSD-95 as well as candidate markers of synaptic activity [activity-regulated cytoskeleton protein (Arc), CaMKII and phospho-CaMKII, ribosomal protein S6 (S6) and phospho-S6, and calcineurin and phospho-calcineurin] in YFP-labeled synaptoneurosomes. Cocaine+novelty increased the percentage of S6-positive synaptoneurosomes at 5-60 min and calcineurin-positive synaptoneurosomes at 5-10 min. Electron microscopy verified that S6 and calcineurin levels in synaptoneurosomes were increased 10 min after cocaine+novelty. Pretreatment with the anesthetic chloral hydrate blocked cocaine+novelty-induced S6 and calcineurin increases in synaptoneurosomes, and novel context exposure alone (without cocaine) increased S6, both of which indicate that these increases were due to neural activity per se. Overall, FCS can be used to study protein alterations in activated synapses coming from specifically labeled mPFC projections to NAc.SIGNIFICANCE STATEMENT Memories are formed during learning and are stored in the brain by long-lasting molecular and cellular alterations called engrams formed within specific patterns of cue-activated neurons called neuronal ensembles. While Fos has been used to identify activated ensemble neurons and the engrams within them, we have not had a similar marker for activated synapses that can be used to identify synaptic engrams. Here we developed a procedure for high-throughput in-line analysis of flow cytometry of synaptoneurosome (FCS) and found that ribosomal S6 protein and calcineurin were increased in activated mPFC-NAc synapses. FCS can be used to study protein alterations in activated synapses within specifically labeled circuits.

Synthesis of Ultralong Carbon Nanotubes with Ultrahigh Yields.

Ultralong carbon nanotubes (CNTs) are in huge demand in many cutting-edge fields due to their macroscale lengths, perfect structures, and extraordinary properties, while their practical application is limited by the difficulties in their mass production. Herein, we report the synthesis of ultralong CNTs with a dramatically increased yield by a simple but efficient substrate interception and direction strategy (SIDS), which couples the advantages of floating-catalyst chemical vapor deposition with the flying-kite-like growth mechanism of ultralong CNTs. The SIDS-assisted approach prominently improves the catalyst utilization and significantly increases the yield. The areal density of the ultralong CNT arrays with length of over 1 cm reached a record-breaking value of ∼6700 CNTs mm-1, which is 2-3 orders of magnitude higher than the previously reported values obtained by traditional methods. The SIDS provides a solution for synthesizing high-quality ultralong CNTs with high yields, laying the foundation for their mass production.

The exploration of shared genes and molecular mechanisms of systemic lupus erythematosus and atherosclerosis.

OBJECTIVE: Despite widespread recognition, the mechanisms underlying the relationship between systemic lupus erythematosus (SLE) and atherosclerosis (AS) are still unclear. Our study aimed to explore the shared genetic signature and molecular mechanisms of SLE and AS using a bioinformatics approach. METHODS: Gene expression profiles of GSE50772 (contains peripheral blood mononuclear cells from 61 SLE patients and 20 normal samples) and GSE100927 (contains 69 AS plaque tissue samples and 35 control samples) were downloaded from the Gene Expression Database (GEO) before the differentially expressed genes were obtained using the "limma" package in R. The differential genes were then subjected to gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis using the DAVID online platform to annotate their functions. The intersection targets of PPI and WGCNA were used as key shared genes for SLE and AS with their diagnostic value as shared genes being verified through ROC curves. Finally, Cytoscape 3.7.2 software was used to construct a miRNA-mRNA network map associated with the shared genes. RESULTS: A total of 246 DEGs were identified, including 189 upregulated genes and 57 downregulated genes, which were mainly enriched in signaling pathways such as TNF signaling pathway, IL-17 signaling pathway, and NF-kB signaling pathway. The molecular basis for the relationship between SLE and AS may be the aforementioned signaling pathways. Following ROC curve validation, the intersection of PPI and WGCNA, as well as AQP9, CCR1, CD83, CXCL1, and FCGR2A, resulted in the identification of 15 shared genes. CONCLUSION: The study provided a new perspective on the common molecular mechanisms between SLE and AS, and the key genes and pathways that were identified as being part of these pathways may offer fresh perspectives and suggestions for further experimental research.

Targeting the programmed cell death (PCD) signaling mechanism with natural substances for the treatment of diabetic cardiomyopathy (DCM).

Diabetic cardiomyopathy (DCM) is one of the severe complications of diabetes, characterized by structural and functional abnormalities in the hearts of diabetic patients without hypertension, coronary heart disease, or valvular heart disease. DCM can progress to heart failure, which is a significant cause of death in diabetic patients, but currently, there is no effective treatment available. Programmed cell death (PCD) is a genetically regulated form of cell death that includes apoptosis, autophagy, necroptosis, ferroptosis, and pyroptosis. PCD is essential for tissue homeostasis and normal development of the body. DCM is a complex condition, and abnormalities in the cascade of PCD signaling have been observed in its pathological process, suggesting that targeting PCD could be a potential therapeutic strategy. Studies have shown that natural substances can effectively modulate PCD to intervene in the treatment of DCM, and their use is safe. This review explores the role of different forms of PCD in the pathogenesis of DCM and summarizes the research progress in targeting PCD with natural substances to treat DCM. It can serve as a basis for further research and drug development to provide new treatment strategies for DCM patients.

Evaluation of Open-Source Tools for Differential Privacy.

Differential privacy (DP) defines privacy protection by promising quantified indistinguishability between individuals who consent to share their privacy-sensitive information and those who do not. DP aims to deliver this promise by including well-crafted elements of random noise in the published data, and thus there is an inherent tradeoff between the degree of privacy protection and the ability to utilize the protected data. Currently, several open-source tools have been proposed for DP provision. To the best of our knowledge, there is no comprehensive study for comparing these open-source tools with respect to their ability to balance DP's inherent tradeoff as well as the use of system resources. This work proposes an open-source evaluation framework for privacy protection solutions and offers evaluation for OpenDP Smartnoise, Google DP, PyTorch Opacus, Tensorflow Privacy, and Diffprivlib. In addition to studying their ability to balance the above tradeoff, we consider discrete and continuous attributes by quantifying their performance under different data sizes. Our results reveal several patterns that developers should have in mind when selecting tools under different application needs and criteria. This evaluation survey can be the basis for an improved selection of open-source DP tools and quicker adaptation of DP.

Klebsiella pneumoniae activates the TGF-ß signaling pathway to adhere to and invade intestinal epithelial cells via enhancing TLL1 expression.

Klebsiella pneumoniae is a gram-negative bacterium that can cause many diseases in hospitals and communities. Intestinal K. pneumoniae infections are relatively rare. Most K. pneumoniae infections begin with the colonization of the gastrointestinal system. In this study, clinically isolated K. pneumoniae strains were used to infect intestinal epithelial Caco-2 cells to study the possible intestinal translocation mechanism of K. pneumoniae. We found that of the three K. pneumoniae strains tested, KP1821 exhibited the strongest adhesive and invasive abilities and that the adhesion to Caco-2 intestinal epithelial cells was affected by the acidic environment of the stomach. Transcriptome sequencing revealed the involvement of molecules associated with the extracellular matrix and cell adhesion, inflammatory response, calcium ion and transforming growth factor ß (TGF-ß) signaling pathways, and other abnormalities in biological processes and cell signaling pathways. Additionally, tolloid-like protein 1 (TLL1) was significantly upregulated. Knocking down TLL1 with shRNA significantly reduced KP1821's ability to invade and adhere to intestinal epithelial cells. TLL1 is involved in the activation of the TGF-ß signaling pathway. Inhibition of this pathway using the inhibitor SB431542 induced significantly reduced adhesion and invasion capabilities of KP1821. Our findings demonstrate that TLL1 participates in K. pneumoniae adhesion and invasion of intestinal epithelial cells by activating the TGF-ß signaling pathway.

Ventral tegmental area GABA, glutamate, and glutamate-GABA neurons are heterogeneous in their electrophysiological and pharmacological properties.

The ventral tegmental area (VTA) contains dopamine neurons intermixed with GABA-releasing (expressing vesicular GABA transporter, VGaT), glutamate-releasing (expressing vesicular glutamate transporter 2, VGluT2), and glutamate-GABA co-releasing (co-expressing VGluT2 and VGaT) neurons. By delivering INTRSECT viral vectors into the VTA of double vglut2-Cre/vgat-Flp transgenic mice, we targeted specific VTA cell populations for ex vivo recordings. We found that VGluT2+ VGaT- and VGluT2+ VGaT+ neurons on average had relatively hyperpolarized resting membrane potential, greater rheobase, and lower spontaneous firing frequency compared to VGluT2- VGaT+ neurons, suggesting that VTA glutamate-releasing and glutamate-GABA co-releasing neurons require stronger excitatory drive to fire than GABA-releasing neurons. In addition, we detected expression of Oprm1mRNA (encoding µ opioid receptors, MOR) in VGluT2+ VGaT- and VGluT2- VGaT+ neurons, and that the MOR agonist DAMGO hyperpolarized neurons with these phenotypes. Collectively, we demonstrate the utility of the double transgenic mouse to access VTA glutamate, glutamate-GABA, and GABA neurons to determine their electrophysiological properties. SIGNIFICANT STATEMENT: Some physiological properties of VTA glutamate-releasing and glutamate-GABA co-releasing neurons are distinct from those of VTA GABA-releasing neurons. µ-opioid receptor activation hyperpolarizes some VTA glutamate-releasing and some GABA-releasing neurons.

Safety and immunogenicity of COVID-19 vaccination in patients with non-alcoholic fatty liver disease (CHESS2101): A multicenter study.

BACKGROUND & AIMS: The development of COVID-19 vaccines has progressed with encouraging safety and efficacy data. Concerns have been raised about SARS-CoV-2 vaccine responses in the large population of patients with non-alcoholic fatty liver disease (NAFLD). The study aimed to explore the safety and immunogenicity of COVID-19 vaccination in NAFLD. METHODS: This multicenter study included patients with NAFLD without a history of SARS-CoV-2 infection. All patients were vaccinated with 2 doses of inactivated vaccine against SARS-CoV-2. The primary safety outcome was the incidence of adverse reactions within 7 days after each injection and overall incidence of adverse reactions within 28 days, and the primary immunogenicity outcome was neutralizing antibody response at least 14 days after the whole-course vaccination. RESULTS: A total of 381 patients with pre-existing NAFLD were included from 11 designated centers in China. The median age was 39.0 years (IQR 33.0-48.0 years) and 179 (47.0%) were male. The median BMI was 26.1 kg/m2 (IQR 23.8-28.1 kg/m2). The number of adverse reactions within 7 days after each injection and adverse reactions within 28 days totaled 95 (24.9%) and 112 (29.4%), respectively. The most common adverse reactions were injection site pain in 70 (18.4%), followed by muscle pain in 21 (5.5%), and headache in 20 (5.2%). All adverse reactions were mild and self-limiting, and no grade 3 adverse reactions were recorded. Notably, neutralizing antibodies against SARS-CoV-2 were detected in 364 (95.5%) patients with NAFLD. The median neutralizing antibody titer was 32 (IQR 8-64), and the neutralizing antibody titers were maintained. CONCLUSIONS: The inactivated COVID-19 vaccine appears to be safe with good immunogenicity in patients with NAFLD. LAY SUMMARY: The development of vaccines against coronavirus disease 2019 (COVID-19) has progressed rapidly, with encouraging safety and efficacy data. This study now shows that the inactivated COVID-19 vaccine appears to be safe with good immunogenicity in the large population of patients with non-alcoholic fatty liver disease.

The Ventral Tegmental Area has calbindin neurons with the capability to co-release glutamate and dopamine into the nucleus accumbens.

The ventral tegmental area (VTA) has three major classes of neurons: dopaminergic (expressing tyrosine hydroxylase; TH), GABAergic (expressing vesicular GABA transporter; VGaT) and glutamatergic (expressing vesicular glutamate transporter 2; VGluT2). While VTA dopaminergic and GABAergic neurons have been further characterized by expression of calcium-binding proteins (calbindin, CB; calretinin, CR or parvalbumin, PV), it is unclear whether these proteins are expressed in rat VTA glutamatergic neurons. Here, by a combination of in situ hybridization (for VGluT2 mRNA detection) and immunohistochemistry (for CB-, CR- or PV-detection), we found that among the total population of VGluT2 neurons, 30% coexpressed CB, 3% coexpressed PV and <1% coexpressed CR. Given that some VGluT2 neurons coexpress TH or VGaT, we examined whether these neurons coexpress CB, and found that about 20% of VGluT2-CB neurons coexpressed TH and about 13% coexpressed VGaT. Because VTA TH-CB neurons are known to target the nucleus accumbens (nAcc), we determined whether VGluT2-CB-TH neurons innervate nAcc, and found that about 80% of VGluT2-CB neurons innervating the nAcc shell coexpressed TH. In summary, (a) CB, PV and CR are detected in subpopulations of VTA-VGluT2 neurons; (b) CB is the main calcium-binding protein present in VTA-VGluT2 neurons; (c) one-third of VTA-VGluT2 neurons coexpress CB; (d) some VTA-VGluT2-CB neurons have the capability to co-release dopamine or GABA, and (e) a subpopulation of VTA glutamatergic-dopaminergic neurons innervates nAcc shell. These findings further provide evidence for molecular diversity among VTA-VGluT2 neurons, neurons that may play a role in specific circuitry and behaviours.

Effects of Puerarin on Clinical Parameters, Vascular Endothelial Function, and Inflammatory Factors in Patients with Coronary Artery Disease.

BACKGROUND The aim of this study was to investigate the effects of puerarin on vascular endothelial function and inflammatory factors in coronary artery disease (CAD) patients with stable angina pectoris (SAP). MATERIAL AND METHODS To evaluate the effects of angina pectoris, the differences of scores of the Seattle angina questionnaire (SAQ), vascular endothelial function [endothelial progenitor cells (EPCs), nitric oxide (NO) and endothelin 1 (ET-1)], and inflammatory factors [tumor necrosis factor a (TNF-α), hypersensitive C-reactive protein (hs-CRP), interleukin-6 (IL-6)] in 2 groups were assessed before and after treatment. RESULTS Regarding the curative effect of angina pectoris, the total effective rate of the treatment group was significantly superior to that of the control group (89% vs. 65%, P<0.05). The duration of angina pectoris, the number of abnormal leads, the improvement of the ST segment depression of electrocardiogram, and the scores of SAQ life quality indexes in the treatment group were better than those of the control group (P<0.05). In the 2 groups, EPCs and NO were both elevated, while ET-1 was decreased, and the improvements of the treatment group were superior to those of the control group (P<0.05). After treatment, the average levels of serum TNF-α, hs-CRP and IL-6 in the 2 groups were all decreased, which the treatment group showed a much sharper decrease than in the control group (P<0.05). CONCLUSIONS Puerarin effectively improves clinical symptoms and vascular endothelial function and reduces the levels of inflammatory factors in patients with CAD.

Prevalence and predictors of seizure clusters: A prospective observational study of adult patients with epilepsy.

OBJECTIVE: The purpose of this prospective observational study was to describe the prevalence and adverse outcomes associated with seizure clusters (defined as ≥2 seizures in a 6-hour period) in a large sample of adult patients with a range of epilepsy severities and to identify clinical characteristics predictive of clustering. METHODS: Patients maintained a seizure diary and were contacted monthly to verify compliance and data accuracy. Logistic regression models were utilized to test associations between individual patient demographic/clinical characteristics and seizure clustering. Fisher's exact test was utilized to test associations between rescue medication use and adverse seizure-related outcomes. RESULTS: A total of 300 patients were followed prospectively for one year; 247 patients qualified for final analysis. Six-hour seizure clusters occurred in 45.8% of patients with active epilepsy at enrollment, including 62.7% of those with prior day-clusters and 30.0% of those without prior day-clusters. The odds of clustering were markedly greater among patients who reported a higher seizure frequency (>4 seizures per year vs. 1-4 seizures per year) (adjusted odds ratio (OR): 8.9; 95% confidence interval (CI): 3.2-24.6; p < 0.0001) and among patients with prior day-clusters (adjusted OR: 11.0; 95% CI: 1.2-104.2; p = 0.036). Rescue medication use was associated with significantly fewer injuries and emergency department visits, but rescue medication was underutilized. CONCLUSIONS: Seizure clusters are common, occurring in nearly half of adult patients with active epilepsy followed prospectively over one year, and are more frequent in those with higher seizure frequencies and prior day-clusters. Although underutilized, rescue medication was associated with fewer injuries and emergency department visit.

Optogenetic excitation in the ventral tegmental area of glutamatergic or cholinergic inputs from the laterodorsal tegmental area drives reward.

Converging evidence shows that ventral tegmental area (VTA) dopamine neurons receive laterodorsal tegmental nucleus (LDTg) cholinergic and glutamatergic inputs. To test the behavioral consequences of selectively driving the two sources of excitatory LDTg input to the VTA, channelrhodopsin-2 (ChR2) was expressed in LDTg cholinergic neurons of ChAT::Cre mice (ChAT-ChR2 mice) or in LDTg glutamatergic neurons of VGluT2::Cre mice (VGluT2-ChR2 mice). Mice were tested in a 3-chamber place preference apparatus where entry into a light-paired chamber resulted in VTA light stimulation of LDTg-cholinergic or LDTg-glutamatergic axons for the duration of a chamber stay. ChAT-ChR2 mice spent more time in the light-paired chamber and subsequently showed conditioned place preference for the light-paired chamber in the absence of light. VGluT2-ChR2 mice, entered the light-paired chamber significantly more times than a light-unpaired chamber, but remained in the light-paired chamber for short time periods and did not show a conditioned place preference. When each entry into the light-paired chamber resulted in a single train of VTA light stimulation, VGluT2-ChR2 mice entered the light-paired chamber significantly more times than the light-unpaired chamber, but spent approximately equal amounts of time in the two chambers. VTA excitation of LDTg-glutamatergic inputs may be more important for reinforcement of initial chamber entry while VTA excitation of LDTg-cholinergic inputs may be more important for the rewarding effects of chamber stays. We suggest that LDTg-cholinergic and LDTg-glutamatergic inputs to the VTA each contribute to the net rewarding effects of exciting LDTg axons in the VTA.

Controlled Synthesis of MOF-Encapsulated NiPt Nanoparticles toward Efficient and Complete Hydrogen Evolution from Hydrazine Borane and Hydrazine.

The catalytic dehydrogenation of hydrazine borane (N2H4BH3) and hydrous hydrazine (N2H4·H2O) for H2 evolution is considered as two of the pivotal reactions for the implementation of the hydrogen-based economy. A reduction rate controlled strategy is successfully applied for the encapsulating of uniform tiny NiPt alloy nanoclusters within the opening porous channels of MOFs in this work. The resultant Ni0.9Pt0.1/MOF core-shell composite with a low Pt content exerted exceedingly high activity and durability for complete H2 evolution (100% hydrogen selectivity) from alkaline N2H4BH3 and N2H4·H2O solution. The features of small NiPt alloy NPs, strong synergistic effect between NiPt alloy NPs and the MOF, and open pore structure for freely mass transfer made NiPt/MIL-101 an excellent catalyst for highly efficient H2 evolution from N2H4BH3 or N2H4·H2O.

Rewarding Effects of Optical Stimulation of Ventral Tegmental Area Glutamatergic Neurons.

Ventral tegmental area (VTA) neurons play roles in reward and aversion. The VTA has three major neuronal phenotypes: dopaminergic, GABAergic, and glutamatergic. VTA glutamatergic neurons--expressing vesicular glutamate transporter-2 (VGluT2)--project to limbic and cortical regions, but also excite neighboring dopaminergic neurons. Here, we test whether local photoactivation of VTA VGluT2 neurons expressing Channelrhodopsin-2 (ChR2) under the VGluT2 promoter causes place preference and supports operant responding for the stimulation. By using a Cre-dependent viral vector, ChR2 (tethered to mCherry) was expressed in VTA glutamatergic neurons of VGluT2::Cre mice. The mCherry distribution was evaluated by immunolabeling. By confocal microscopy, we detected expression of mCherry in VTA cell bodies and local processes. In contrast, VGluT2 expression was restricted to varicosities, some of them coexpressing mCherry. By electron microscopy, we determined that mCherry-VGluT2 varicosities correspond to axon terminals, forming asymmetric synapses on neighboring dopaminergic neurons. These findings indicate that ChR2 was present in terminals containing glutamatergic synaptic vesicles and involved in local synaptic connections. Photoactivation of VTA slices from ChR2-expressing mice induced AMPA/NMDA receptor-dependent firing of dopaminergic neurons projecting to the nucleus accumbens. VTA photoactivation of ChR2-expressing mice reinforced instrumental behavior and established place preferences. VTA injections of AMPA or NMDA receptor antagonists blocked optical self-stimulation and place preference. These findings suggest a role in reward function for VTA glutamatergic neurons through local excitatory synapses on mesoaccumbens dopaminergic neurons.

Norepinephrine activates dopamine D4 receptors in the rat lateral habenula.

The lateral habenula (LHb) is involved in reward and aversion and is reciprocally connected with dopamine (DA)-containing brain regions, including the ventral tegmental area (VTA). We used a multidisciplinary approach to examine the properties of DA afferents to the LHb in the rat. We find that >90% of VTA tyrosine hydroxylase (TH) neurons projecting to the LHb lack vesicular monoamine transporter 2 (VMAT2) mRNA, and there is little coexpression of TH and VMAT2 protein in this mesohabenular pathway. Consistent with this, electrical stimulation of LHb did not evoke DA-like signals, assessed with fast-scan cyclic voltammetry. However, electrophysiological currents that were inhibited by L741,742, a DA-D4-receptor antagonist, were observed in LHb neurons when DA uptake or degradation was blocked. To prevent DA activation of D4 receptors, we repeated this experiment in LHb slices from DA-depleted rats. However, this did not disrupt D4 receptor activation initiated by the dopamine transporter inhibitor, GBR12935. As the LHb is also targeted by noradrenergic afferents, we examined whether GBR12935 activation of DA-D4 receptors occurred in slices depleted of norepinephrine (NE). Unlike DA, NE depletion prevented the activation of DA-D4 receptors. Moreover, direct application of NE elicited currents in LHb neurons that were blocked by L741,742, and GBR12935 was found to be a more effective blocker of NE uptake than the NE-selective transport inhibitor nisoxetine. These findings demonstrate that NE is released in the rat LHb under basal conditions and that it activates DA-D4 receptors. Therefore, NE may be an important regulator of LHb function.

Hypoxia-inducible factor 1a is a Tsc1-regulated survival factor in newborn neurons in tuberous sclerosis complex.

Tuberous sclerosis complex (TSC) is a genetic disorder caused by mutations in TSC1 or TSC2 resulting in hyperactivity of the mammalian target of rapamycin and disabling brain lesions. These lesions contain misplaced neurons enriched in hypoxia-inducible factor 1a (HIF1a). However, the relationship between TSC1/2 and HIF1a and the function of HIF1a in TSC neurons remain unexplored. Here, we examine the degree of HIF1a activity and its function in newborn Tsc1(null) neurons in a mouse model of TSC. Using single cell electroporation in the neurogenic subventricular zone (SVZ) of neonatal mice, we deleted Tsc1 and generated olfactory lesions containing misplaced Tsc1(null) neurons as previously reported. These newborn neurons displayed elevated HIF1a-mediated transcriptional activity when compared with Tsc1 heterozygote neurons and a marked resistance to cell death induced by a HIF1a antagonist. Electroporation of Hif1a targeting short hairpin RNA (shRNA) or dominant negative HIF1a constructs resulted in 80-90% loss of Tsc1(null) newborn neurons although sparing SVZ stem cells. Consistent with this later finding, induction of Hif1a shRNA expression during synaptic integration thus bypassing neuron production also resulted in newborn neuron death. Collectively, these results suggest that HIF1a acts as a molecular determinant of newborn neuron survival and that its TSC1-dependent up-regulation gave Tsc1(null) neurons a survival advantage, despite their misplacement in a novel microenvironment.

Glutamatergic and dopaminergic neurons in the mouse ventral tegmental area.

The ventral tegmental area (VTA) comprises dopamine (DA), γ-aminobutyric acid (GABA) and glutamate (Glu) neurons. Some rat VTA Glu neurons, expressing vesicular glutamate transporter 2 (VGluT2), co-express tyrosine hydroxylase (TH). While transgenic mice are now being used in attempts to determine the role of VGluT2/TH neurons in reward and neuronal signaling, such neurons have not been characterized in mouse tissue. By cellular detection of VGluT2 mRNA and TH immunoreactivity (TH-IR), we determined the cellular expression of VGluT2 mRNA within VTA TH-IR neurons in the mouse. We found that some mouse VGluT2 neurons coexpressed TH-IR, but their frequency was lower than in the rat. To determine whether low expression of TH mRNA or TH-IR accounts for this low frequency, we evaluated VTA cellular coexpression of TH transcripts and TH protein. Within the medial aspects of the VTA, some neurons expressed TH mRNA but lacked TH-IR; among them a subset coexpressed VGluT2 mRNA. To determine if lack of VTA TH-IR was due to TH trafficking, we tagged VTA TH neurons by Cre-inducible expression of mCherry in TH::Cre mice. By dual immunofluorescence, we detected axons containing mCherry, but lacking TH-IR, in the lateral habenula, indicating that low frequency of VGluT2 mRNA (+)/TH-IR (+) neurons in the mouse is due to lack of synthesis of TH protein, rather than TH protein trafficking. In conclusion, VGluT2 neurons are present in the rat and mouse VTA, but they differ in the populations of VGluT2/TH and TH neurons. Under normal conditions, the translation of TH protein is suppressed in the mouse mesohabenular TH neurons.

Robust Fine-Grained Visual Recognition With Neighbor-Attention Label Correction.

Existing deep learning methods for fine-grained visual recognition often rely on large-scale, well-annotated training data. Obtaining fine-grained annotations in the wild typically requires concentration and expertise, such as fine category annotation for species recognition, instance annotation for person re-identification (re-id) and dense annotation for segmentation, which inevitably leads to label noise. This paper aims to tackle label noise in deep model training for fine-grained visual recognition. We propose a Neighbor-Attention Label Correction (NALC) model to correct labels during the training stage. NALC samples a training batch and a validation batch from the training set. It hence leverages a meta-learning framework to correct labels in the training batch based on the validation batch. To enhance the optimization efficiency, we introduce a novel nested optimization algorithm for the meta-learning framework. The proposed training procedure consistently improves label accuracy in the training batch, consequently enhancing the learned image representation. Experimental results demonstrate that our method significantly increases label accuracy from 70% to over 98% and outperforms recent approaches by up to 13.4% in mean Average Precision (mAP) on various fine-grained image retrieval (FGIR) tasks, including instance retrieval on CUB200 and person re-id on Market1501. We also demonstrate the efficacy of NALC on noisy semantic segmentation datasets generated from Cityscapes, where it achieves a significant 7.8% improvement in mIOU score. NALC also exhibits robustness to different types of noise, including simulated noise such as Asymmetric, Pair-Flip, and Pattern noise, as well as practical noisy labels generated by tracklets and clustering.

Graph-based social relation inference with multi-level conditional attention.

Social relation inference intrinsically requires high-level semantic understanding. In order to accurately infer relations of persons in images, one needs not only to understand scenes and objects in images, but also to adaptively attend to important clues. Unlike prior works of classifying social relations using attention on detected objects, we propose a MUlti-level Conditional Attention (MUCA) mechanism for social relation inference, which attends to scenes, objects and human interactions based on each person pair. Then, we develop a transformer-style network to achieve the MUCA mechanism. The novel network named as Graph-based Relation Inference Transformer (i.e., GRIT) consists of two modules, i.e., a Conditional Query Module (CQM) and a Relation Attention Module (RAM). Specifically, we design a graph-based CQM to generate informative relation queries for all person pairs, which fuses local features and global context for each person pair. Moreover, we fully take advantage of transformer-style networks in RAM for multi-level attentions in classifying social relations. To our best knowledge, GRIT is the first for inferring social relations with multi-level conditional attention. GRIT is end-to-end trainable and significantly outperforms existing methods on two benchmark datasets, e.g., with performance improvement of 7.8% on PIPA and 9.6% on PISC.