The Medial Prefrontal Cortex-Basolateral Amygdala Circuit Mediates Anxiety in Shank3 InsG3680 Knock-in Mice.

Anxiety disorder is a major symptom of autism spectrum disorder (ASD) with a comorbidity rate of ~40%. However, the neural mechanisms of the emergence of anxiety in ASD remain unclear. In our study, we found that hyperactivity of basolateral amygdala (BLA) pyramidal neurons (PNs) in Shank3 InsG3680 knock-in (InsG3680+/+) mice is involved in the development of anxiety. Electrophysiological results also showed increased excitatory input and decreased inhibitory input in BLA PNs. Chemogenetic inhibition of the excitability of PNs in the BLA rescued the anxiety phenotype of InsG3680+/+ mice. Further study found that the diminished control of the BLA by medial prefrontal cortex (mPFC) and optogenetic activation of the mPFC-BLA pathway also had a rescue effect, which increased the feedforward inhibition of the BLA. Taken together, our results suggest that hyperactivity of the BLA and alteration of the mPFC-BLA circuitry are involved in anxiety in InsG3680+/+ mice.

Zhibai dihuang pill (ZBDH) exhibits therapeutic effects on idiopathic central sexual precocity in rats by modulating the gut microflora.

To reveal the role of gut microbiota (GM) in the occurrence and development of idiopathic central precocious puberty (ICPP) using 16S rDNA sequencing and bioinformatics analysis. The Danazol-induced ICPP model was successfully constructed in this study. ZBDH and GnRHa treatments could effectively inhibit ICPP in rats, as manifested by the delayed vaginal opening time, reduced weight, decreased uterine organ coefficient, and decreased uterine wall thickness and corpus luteum number, as well as remarkably reduced serum hormone (LH, FSH, and E2) levels. According to 16S rDNA sequencing analysis results, there was no significant difference in the GM community diversity across different groups; however, the composition of the microbial community and the abundance of the dominant microbial community were dramatically different among groups. ZBDH and GnRHa treatments could effectively reduce the abundance of Muribaculateae and Lactobacillus and promote Prevotella abundance. ZBDH and GnRHa were effective in treating Danazol-induced ICPP model rats. The therapeutic effects of ZBDH and GnRHa could be related to the changes in GM in rats.

Evolutionary trajectory of TRPM2 channel activation by adenosine diphosphate ribose and calcium.

Ion channel activation upon ligand gating triggers a myriad of biological events and, therefore, evolution of ligand gating mechanism is of fundamental importance. TRPM2, a typical ancient ion channel, is activated by adenosine diphosphate ribose (ADPR) and calcium and its activation has evolved from a simple mode in invertebrates to a more complex one in vertebrates, but the evolutionary process is still unknown. Molecular evolutionary analysis of TRPM2s from more than 280 different animal species has revealed that, the C-terminal NUDT9-H domain has evolved from an enzyme to a ligand binding site for activation, while the N-terminal MHR domain maintains a conserved ligand binding site. Calcium gating pattern has also evolved, from one Ca2+-binding site as in sea anemones to three sites as in human. Importantly, we identified a new group represented by olTRPM2, which has a novel gating mode and fills the missing link of the channel gating evolution. We conclude that the TRPM2 ligand binding or activation mode evolved through at least three identifiable stages in the past billion years from simple to complicated and coordinated. Such findings benefit the evolutionary investigations of other channels and proteins.

Frontostriatal circuit dysfunction leads to cognitive inflexibility in neuroligin-3 R451C knockin mice.

Cognitive and behavioral rigidity are observed in various psychiatric diseases, including in autism spectrum disorder (ASD). However, the underlying mechanism remains to be elucidated. In this study, we found that neuroligin-3 (NL3) R451C knockin mouse model of autism (KI mice) exhibited deficits in behavioral flexibility in choice selection tasks. Single-unit recording of medium spiny neuron (MSN) activity in the nucleus accumbens (NAc) revealed altered encoding of decision-related cue and impaired updating of choice anticipation in KI mice. Additionally, fiber photometry demonstrated significant disruption in dynamic mesolimbic dopamine (DA) signaling for reward prediction errors (RPEs), along with reduced activity in medial prefrontal cortex (mPFC) neurons projecting to the NAc in KI mice. Interestingly, NL3 re-expression in the mPFC, but not in the NAc, rescued the deficit of flexible behaviors and simultaneously restored NAc-MSN encoding, DA dynamics, and mPFC-NAc output in KI mice. Taken together, this study reveals the frontostriatal circuit dysfunction underlying cognitive inflexibility and establishes a critical role of the mPFC NL3 deficiency in this deficit in KI mice. Therefore, these findings provide new insights into the mechanisms of cognitive and behavioral inflexibility and potential intervention strategies.

GDF11 slows excitatory neuronal senescence and brain ageing by repressing p21.

As a major neuron type in the brain, the excitatory neuron (EN) regulates the lifespan in C. elegans. How the EN acquires senescence, however, is unknown. Here, we show that growth differentiation factor 11 (GDF11) is predominantly expressed in the EN in the adult mouse, marmoset and human brain. In mice, selective knock-out of GDF11 in the post-mitotic EN shapes the brain ageing-related transcriptional profile, induces EN senescence and hyperexcitability, prunes their dendrites, impedes their synaptic input, impairs object recognition memory and shortens the lifespan, establishing a functional link between GDF11, brain ageing and cognition. In vitro GDF11 deletion causes cellular senescence in Neuro-2a cells. Mechanistically, GDF11 deletion induces neuronal senescence via Smad2-induced transcription of the pro-senescence factor p21. This work indicates that endogenous GDF11 acts as a brake on EN senescence and brain ageing.

TRPM2 as a conserved gatekeeper determines the vulnerability of DA neurons by mediating ROS sensing and calcium dyshomeostasis.

Different dopaminergic (DA) neuronal subgroups exhibit distinct vulnerability to stress, while the underlying mechanisms are elusive. Here we report that the transient receptor potential melastatin 2 (TRPM2) channel is preferentially expressed in vulnerable DA neuronal subgroups, which correlates positively with aging in Parkinson's Disease (PD) patients. Overexpression of human TRPM2 in the DA neurons of C. elegans resulted in selective death of ADE but not CEP neurons in aged worms. Mechanistically, TRPM2 activation mediates FZO-1/CED-9-dependent mitochondrial hyperfusion and mitochondrial permeability transition (MPT), leading to ADE death. In mice, TRPM2 knockout reduced vulnerable substantia nigra pars compacta (SNc) DA neuronal death induced by stress. Moreover, the TRPM2-mediated vulnerable DA neuronal death pathway is conserved from C. elegans to toxin-treated mice model and PD patient iPSC-derived DA neurons. The vulnerable SNc DA neuronal loss is the major symptom and cause of PD, and therefore the TRPM2-mediated pathway serves as a promising therapeutic target against PD.

NMDA Receptor-Dependent Synaptic Potentiation via APPL1 Signaling Is Required for the Accessibility of a Prefrontal Neuronal Assembly in Retrieving Fear Extinction.

BACKGROUND: The ventromedial prefrontal cortex has been viewed as a locus for storage and recall of extinction memory. However, the synaptic and cellular mechanisms underlying these processes remain elusive. METHODS: We combined transgenic mice, electrophysiological recording, activity-dependent cell labeling, and chemogenetic manipulation to analyze the role of adaptor protein APPL1 in the ventromedial prefrontal cortex in fear extinction retrieval. RESULTS: We found that both constitutive and conditional APPL1 knockout decreased NMDA receptor (NMDAR) function in the ventromedial prefrontal cortex and impaired fear extinction retrieval. Moreover, APPL1 undergoes nuclear translocation during extinction retrieval. Blocking APPL1 nucleocytoplasmic translocation reduced NMDAR currents and disrupted extinction retrieval. We also identified a prefrontal neuronal ensemble that is both necessary and sufficient for the storage of extinction memory. Inducible APPL1 knockout in this ensemble abolished NMDAR-dependent synaptic potentiation and disrupted extinction retrieval, while chemogenetic activation of this ensemble simultaneously rescued the impaired behaviors. CONCLUSIONS: Our results indicate that a prefrontal neuronal ensemble stores extinction memory, and APPL1 signaling supports these neurons in retrieving extinction memory by controlling NMDAR-dependent potentiation.

NMDA receptor hypofunction underlies deficits in parvalbumin interneurons and social behavior in neuroligin 3 R451C knockin mice.

Neuroligins (NLs), a family of postsynaptic cell-adhesion molecules, have been associated with autism spectrum disorder. We have reported that dysfunction of the medial prefrontal cortex (mPFC) leads to social deficits in an NL3 R451C knockin (KI) mouse model of autism. However, the underlying molecular mechanism remains unclear. Here, we find that N-methyl-D-aspartate receptor (NMDAR) function and parvalbumin-positive (PV+) interneuron number and expression are reduced in the mPFC of the KI mice. Selective knockdown of NMDAR subunit GluN1 in the mPFC PV+ interneuron decreases its intrinsic excitability. Restoring NMDAR function by its partial agonist D-cycloserine rescues the PV+ interneuron dysfunction and social deficits in the KI mice. Interestingly, early D-cycloserine administration at adolescence prevents adult KI mice from social deficits. Together, our results suggest that NMDAR hypofunction and the resultant PV+ interneuron dysfunction in the mPFC may constitute a central node in the pathogenesis of social deficits in the KI mice.

Low dinosaur biodiversity in central China 2 million years prior to the end-Cretaceous mass extinction.

Whether or not nonavian dinosaur biodiversity declined prior to the end-Cretaceous mass extinction remains controversial as the result of sampling biases in the fossil record, differences in the analytical approaches used, and the rarity of high-precision geochronological dating of dinosaur fossils. Using magnetostratigraphy, cyclostratigraphy, and biostratigraphy, we establish a high-resolution geochronological framework for the fossil-rich Late Cretaceous sedimentary sequence in the Shanyang Basin of central China. We have found only three dinosaurian eggshell taxa (Macroolithus yaotunensis, Elongatoolithus elongatus, and Stromatoolithus pinglingensis) representing two clades (Oviraptoridae and Hadrosauridae) in sediments deposited between ∼68.2 and ∼66.4 million y ago, indicating sustained low dinosaur biodiversity, and that assessment is consistent with the known skeletal remains in the Shanyang and surrounding basins of central China. Along with the dinosaur eggshell records from eastern and southern China, we find a decline in dinosaur biodiversity from the Campanian to the Maastrichtian. Our results support a long-term decline in global dinosaur biodiversity prior to 66 million y ago, which likely set the stage for the end-Cretaceous nonavian dinosaur mass extinction.

A short period of early life oxytocin treatment rescues social behavior dysfunction via suppression of hippocampal hyperactivity in male mice.

Early sensory experiences interact with genes to shape precise neural circuits during development. This process is vital for proper brain function in adulthood. Neurological dysfunctions caused by environmental alterations and/or genetic mutation may share the same molecular or cellular mechanisms. Here, we show that early life bilateral whisker trimming (BWT) subsequently affects social discrimination in adult male mice. Enhanced activation of the hippocampal dorsal CA3 (dCA3) in BWT mice was observed during social preference tests. Optogenetic activation of dCA3 in naive mice impaired social discrimination, whereas chemogenetic silencing of dCA3 rescued social discrimination deficit in BWT mice. Hippocampal oxytocin (OXT) is reduced after whisker trimming. Neonatal intraventricular compensation of OXT relieved dCA3 over-activation and prevented social dysfunction. Neonatal knockdown of OXT receptor in dCA3 mimics the effects of BWT, and cannot be rescued by OXT treatment. Social behavior deficits in a fragile X syndrome mouse model (Fmr1 KO mice) could also be recovered by early life OXT treatment, through negating dCA3 over-activation. Here, a possible avenue to prevent social dysfunction is uncovered.

A facile and effective strategy to develop a super-hydrophobic/super-oleophilic fiberglass filter membrane for efficient micron-scale water-in-oil emulsion separation.

In order to achieve efficient micron-scale water-in-oil emulsion separation, a facile and effective strategy is developed to prepare a super-hydrophobic/super-oleophilic fiberglass filter membrane (FGm). Methyl-trichlorosilane (MTS) is successfully cross-linked on the surface of the fiberglass filter membrane (FGm) and aggregates into a 3D nanowire array to provide low surface energy. Nano fumed hydrophobic silica (SH-SiO2) is used to construct the well-defined nanosphere structure on the surface of FGm and enhance the ability of the membrane to resist extreme conditions. The optimally modified membrane displays outstanding super-hydrophobic properties with a contact angle of 156.2°. It is impressive to find that the MTS@SH-SiO2@FGm not only demonstrates the ability to separate water-in-oil emulsions with a particle size of less than 20 µm, but also the removal efficiency of separation has reached 99.98%. More attractively, the membrane still has stable super-hydrophobic features and reusable water-in-oil emulsion separation performance even under exposure to diverse harsh conditions, including extremely acidic corrosive solutions and ultra-high temperature systems.

Application analysis of omental flap isolation and modified pancreaticojejunostomy in pancreaticoduodenectomy (175 cases).

BACKGROUND: To explore the application value of free omental wrapping and modified pancreaticojejunostomy in pancreaticoduodenectomy (PD). METHODS: The clinical data of 175 patients who underwent pancreaticoduodenectomy from January 2015 to December 2020 were retrospectively analysed. In total, 86 cases were divided into Group A (omental wrapping and modified pancreaticojejunostomy) and 89 cases were divided into Group B (control group). The incidences of postoperative pancreatic fistula and other complications were compared between the two groups, and univariate and multivariate logistic regression analyses were used to determine the potential risk factors for postoperative pancreatic fistula. Risk factors associated with postoperative overall survival were identified using Cox regression. RESULTS: The incidences of grade B/C pancreatic fistula, bile leakage, delayed bleeding, and reoperation in Group A were lower than those in Group B, and the differences were statistically significant (P < 0.05). Group A had an earlier drainage tube extubation time, earlier return to normal diet time and shorter postoperative hospital stay than the control group (P < 0.05). The levels of C-reactive protein (CRP), interleukin-6 (IL-6), and procalcitonin (PCT) inflammatory factors 1, 3 and 7 days after surgery also showed significant. Univariate and multivariate logistic regression analyses showed that a body mass index (BMI) ≥ 24, pancreatic duct diameter less than 3 mm, no isolation of the greater omental flap and modified pancreaticojejunostomy were independent risk factors for pancreatic fistula (P < 0.05). Cox regression analysis showed that age ≥ 65 years old, body mass index ≥ 24, pancreatic duct diameter less than 3 mm, no isolation of the greater omental flap isolation and modified pancreaticojejunostomy, and malignant postoperative pathology were independent risk factors associated with postoperative overall survival (P < 0.05). CONCLUSIONS: Wrapping and isolating the modified pancreaticojejunostomy with free greater omentum can significantly reduce the incidence of postoperative pancreatic fistula and related complications, inhibit the development of inflammation, and favourably affect prognosis.

KIF2C regulates synaptic plasticity and cognition in mice through dynamic microtubule depolymerization.

Dynamic microtubules play a critical role in cell structure and function. In nervous system, microtubules are the major route for cargo protein trafficking and they specially extend into and out of synapses to regulate synaptic development and plasticity. However, the detailed depolymerization mechanism that regulates dynamic microtubules in synapses and dendrites is still unclear. In this study, we find that KIF2C, a dynamic microtubule depolymerization protein without known function in the nervous system, plays a pivotal role in the structural and functional plasticity of synapses and regulates cognitive function in mice. Through its microtubule depolymerization capability, KIF2C regulates microtubule dynamics in dendrites, and regulates microtubule invasion of spines in neurons in a neuronal activity-dependent manner. Using RNAi knockdown and conditional knockout approaches, we showed that KIF2C regulates spine morphology and synaptic membrane expression of AMPA receptors. Moreover, KIF2C deficiency leads to impaired excitatory transmission, long-term potentiation, and altered cognitive behaviors in mice. Collectively, our study explores a novel function of KIF2C in the nervous system and provides an important regulatory mechanism on how activity-dependent microtubule dynamic regulates synaptic plasticity and cognition behaviors.

Identification of Research Priorities during the COVID-19 Pandemic: Implications for Its Management.

Novel coronavirus disease 2019 (COVID-19) pandemic has had a great impact on global production and life in the past period. Countless researchers devoted themselves to rescuing patients and reducing its impact. Analyzing the literature published during the pandemic and identifying the research priorities is of great significance to quickly discover research gaps, rationally allocate scientific research resources, and promote the development of the global research platform. To understand the swing of research priorities during the pandemic, this paper proposed a research priorities identification framework for pandemic based on scientific literature text analysis. Moreover, a research priority metric model was proposed to measure the characteristics of research priorities, and the empirical analysis from COVID-19 scientific literature was conducted to identify the research priorities during the pandemic. As a result, the research priorities identified by the method proposed in this paper discovered the fine-grained dynamic characteristics along with the process in the pandemic outbreak, and based on this, the emergency scientific research response strategies were discussed to give implications for the public health emergency scientific research and management.

GRIN2A Variants Associated With Idiopathic Generalized Epilepsies.

Objective: The objective of this study is to explore the role of GRIN2A gene in idiopathic generalized epilepsies and the potential underlying mechanism for phenotypic variation. Methods: Whole-exome sequencing was performed in a cohort of 88 patients with idiopathic generalized epilepsies. Electro-physiological alterations of the recombinant N-methyl-D-aspartate receptors (NMDARs) containing GluN2A mutants were examined using two-electrode voltage-clamp recordings. The alterations of protein expression were detected by immunofluorescence staining and biotinylation. Previous studies reported that epilepsy related GRIN2A missense mutations were reviewed. The correlation among phenotypes, functional alterations, and molecular locations was analyzed. Results: Three novel heterozygous missense GRIN2A mutations (c.1770A > C/p.K590N, c.2636A > G/p.K879R, and c.3199C > T/p.R1067W) were identified in three unrelated cases. Electrophysiological analysis demonstrated R1067W significantly increased the current density of GluN1/GluN2A NMDARs. Immunofluorescence staining indicated GluN2A mutants had abundant distribution in the membrane and cytoplasm. Western blotting showed the ratios of surface and total expression of the three GluN2A-mutants were significantly increased comparing to the wild type. Further analysis on the reported missense mutations demonstrated that mutations with severe gain-of-function were associated with epileptic encephalopathy, while mutations with mild gain of function were associated with mild phenotypes, suggesting a quantitative correlation between gain-of-function and phenotypic severity. The mutations located around transmembrane domains were more frequently associated with severe phenotypes and absence seizure-related mutations were mostly located in carboxyl-terminal domain, suggesting molecular sub-regional effects. Significance: This study revealed GRIN2A gene was potentially a candidate pathogenic gene of idiopathic generalized epilepsies. The functional quantitative correlation and the molecular sub-regional implication of mutations helped in explaining the relatively mild clinical phenotypes and incomplete penetrance associated with GRIN2A variants.

Structural and functional basis of the selectivity filter as a gate in human TRPM2 channel.

Transient receptor potential melastatin 2 (TRPM2), a Ca2+-permeable cation channel, is gated by intracellular adenosine diphosphate ribose (ADPR), Ca2+, warm temperature, and oxidative stress. It is critically involved in physiological and pathological processes ranging from inflammation to stroke to neurodegeneration. At present, the channel's gating and ion permeation mechanisms, such as the location and identity of the selectivity filter, remain ambiguous. Here, we report the cryo-electron microscopy (cryo-EM) structure of human TRPM2 in nanodisc in the ligand-free state. Cryo-EM map-guided computational modeling and patch-clamp recording further identify a quadruple-residue motif as the ion selectivity filter, which adopts a restrictive conformation in the closed state and acts as a gate, profoundly contrasting with its widely open conformation in the Nematostella vectensis TRPM2. Our study reveals the gating of human TRPM2 by the filter and demonstrates the feasibility of using cryo-EM in conjunction with computational modeling and functional studies to garner structural information for intrinsically dynamic but functionally important domains.

Disrupting phosphorylation of Tyr-1070 at GluN2B selectively produces resilience to depression-like behaviors.

Drugs targeting N-methyl-D-aspartate receptors (NMDARs) have been approved to treat major depressive disorder (MDD); however, the presence of undesirable psychotomimetic and cognitive side effects may limit their utility. In this study, we show that the phosphorylation levels of the GluN2B subunit at tyrosine (Y) 1070 increase in mice after both acute and chronic restraint stress (CRS) exposure. Preventing GluN2B-Y1070 phosphorylation via Y1070F mutation knockin produces effects similar to those of antidepressants but does not affect cognitive or anxiety-related behaviors in subject mice. Mechanistically, the Y1070F mutation selectively reduces non-synaptic NMDAR currents and increases the number of excitatory synapses in the layer 5 pyramidal neurons of medial prefrontal cortex (mPFC) but not in the hippocampus. Altogether, our study identifies phosphorylation levels of GluN2B-Y1070 in the mPFC as a dynamic, master switch guarding depressive behaviors, suggesting that disrupting the Y1070 phosphorylation of GluN2B subunit has the potential for developing new antidepressants.

cFos-ANAB: A cFos-based Web Tool for Exploring Activated Neurons and Associated Behaviors.

cFos is one of the most widely-studied genes in the field of neuroscience. Currently, there is no systematic database focusing on cFos in neuroscience. We developed a curated database-cFos-ANAB-a cFos-based web tool for exploring activated neurons and associated behaviors in rats and mice, comprising 398 brain nuclei and sub-nuclei, and five associated behaviors: pain, fear, feeding, aggression, and sexual behavior. Direct relationships among behaviors and nuclei (even cell types) under specific stimulating conditions were constructed based on cFos expression profiles extracted from original publications. Moreover, overlapping nuclei and sub-nuclei with potentially complex functions among different associated behaviors were emphasized, leading to results serving as important clues to the development of valid hypotheses for exploring as yet unknown circuits. Using the analysis function of cFos-ANAB, multi-layered pictures of networks and their relationships can quickly be explored depending on users' purposes. These features provide a useful tool and good reference for early exploration in neuroscience. The cFos-ANAB database is available at www.cfos-db.net .

Hydrothermal synthesis of a novel nanolayered tin phosphate for removing Cr(iii).

In this work, an outstanding nanolayered tin phosphate with 15.0 Å interlayer spacing, Sn (HPO4)2·3H2O (SnP-H+), has been synthesized by conventional hydrothermal method and first used in the adsorptive removal of Cr(iii) from aqueous solution. A number of factors such as contact time, initial concentration of Cr(iii), temperature, pH, and ionic strength on adsorption were investigated by batch tests. Moreover, the isothermal adsorption characteristics and kinetic model of Cr(iii) onto SnP-H+ were studied. The results showed that the adsorption of Cr(iii) by SnP-H+ was in accordance with the Langmuir adsorption isotherm model and the pseudo-second-order kinetic model. The adsorption capacity of Cr(iii) onto SnP-H+ at temperature 40.0 °C and pH 3.0 could reach 81.1 mg g-1. And the distribution coefficient K d was 23.0 g L-1. Overall, experiments certified that SnP-H+ was an excellent adsorbent that can effectively remove Cr(iii) from aqueous solution.