Dual Oxytocin Receptor-G Protein Signaling in the Autoregulation of Activities of Oxytocin Neurons.

Oxytocin (OT), a hypothalamic nonaneuropeptide, can extensively modulate mental and physical activities; however, the regulation of its secretion from hypothalamic OT neurons remains poorly understood. OT neuronal activity is generally modulated by neurochemical environment, synaptic inputs, astrocytic plasticity, and interneuronal interactions. By changing intracellular signals and ion channel activity, these extracellular factors dynamically regulate OT neuronal activity and OT release in a microdomain-specific manner. In this process, OT receptor (OTR) and OTR-coupled G proteins are pivotal, typically observed during lactation. Suckling-elicited somatodendritic release of OT causes sequential activation of Gq and Gs proteins to increase the firing rate gradually and trigger burst firing transiently, and then of Gi/o protein to cause post-burst inhibition as a result of potential bolus somatodendritic release of OT during the burst-like discharges. Under chronic social stress like mother-baby separation and cesarean section, excessive somatodendritic secretion of OT and over-excitation of OT neurons cause post-excitation inhibition of OT neuronal activity and reduction of OT secretion. In this process, dominance of G protein that couples to OTR is switched from Gq to Gi/o type because of inhibition of OTR-Gq signaling following negative feedback of downstream Gq signaling or crosstalk of Gq with Gs and Gi signals. This review summarizes our current understandings of OT/OTR signaling in the autoregulation of OT neuronal activity under physiological and pathological conditions.

Using case-based learning supported by role-playing situational teaching method in endocrine physiology education.

Embedding clinically relevant learning experience in basic science subjects is desired for the preclinical phase of undergraduate medical education. The present study aimed to modify case-based learning (CBL) with a role-playing situational teaching method and assess the student feedback and learning effect. One hundred seventy-six sophomore students majoring in clinical medicine from Harbin Medical University were randomly divided into two groups: the control group (n = 90), who received traditional hybrid teaching, and the experimental group (n = 86), who received the role-playing situational teaching. Students in the experimental group were given a 1-wk preclass preparation to dramatize a hyperthyroidism scenario through online autonomous learning of thyroid physiology and performed the patient's consultation process in class, followed by a student presentation about key points of lecture content and a question-driven discussion. A posttest and questionnaire survey were conducted after class. The test scores of the two groups had no statistical differences, whereas the rate of excellence (high scores) of the experimental group was significantly higher than that of the control group. Furthermore, the record of online self-directed learning engagements was significantly improved in the experimental group. In the questionnaire, >70% of the students showed positive attitudes toward the role-playing situational teaching method and were willing to participate in other chapters of the physiology course. Such results show that CBL supported by a role-playing situational teaching method encourages active learning and improves the application of basic knowledge of physiology, which can be incorporated in the preclinical curricula to bridge the gap between theory and practice.NEW & NOTEWORTHY Formal application through structured role-play is often overlooked in physiology education. In traditional case-based learning (CBL), clinical cases are the subject and unfocused discussion often occurs. The present study aimed to modify CBL with a role-playing situational teaching method and assess the student feedback and learning effect. The results show that the new teaching model encourages active learning and improves the application of basic knowledge of physiology.

Hybrid teaching after COVID-19: advantages, challenges and optimization strategies.

BACKGROUND: In the post-pandemic era of higher education, hybrid teaching has emerged as a prevalent approach and is anticipated to persist as a defining trend in the future teaching reforms worldwide. However, despite its widespread adoption, certain limitations have become apparent. The objective of this study is to identify the genuine factors that impact students' performance, explore strategies that teachers can employ to enhance their teaching effectiveness and enhance students' academic self-efficacy. METHODS: The study was performed among undergraduate medical students enrolled in Physiology course at Harbin Medical University in 2020 and 2022. Since 2020, influenced by the COVID-19 pandemic, a hybrid teaching method based on an established offline teaching model called BOPPPS was implemented. A questionnaire was performed in both 2020 and 2022 to evaluate students' satisfaction and efficiency of our hybrid teaching. A comparison was also carried out on the final examination scores of students majoring in Pharmacy and Clinical Pharmacy across the years 2020 to 2022. RESULTS: The final examination scores of students in 2022 were significantly lower than those in 2020 and 2021 both in Pharmacy and Clinical Pharmacy majors. There was also a decrease of the score in students of Clinical Pharmacy in 2021 compared to 2020. The questionnaire indicated that over half (52.0%) of the students in 2022 preferred offline teaching method, in contrast to 39.1% in 2020. There were obvious changes in students from 2020 to 2022 about the disadvantages of hybrid teaching, the improvement of students' learning ability and the duration of students' autonomous learning. Through cross statistical analysis, online learning styles, learning ability improvement and students' learning burden have been identified as the primary factors influencing their preference for future teaching method. CONCLUSIONS: Hybrid teaching is still a necessary trend in the future teaching reform base on its multiple advantages. However, in order to improve the teaching outcomes and foster students' participation and learning initiatives, it is imperative to undertake additional reforms in the future teaching process.

Contribution of inwardly rectifying K+ channel 4.1 of supraoptic astrocytes to the regulation of vasopressin neuronal activity by hypotonicity.

Astrocytic morphological plasticity and its modulation of adjacent neuronal activity are largely determined by astrocytic volume regulation, in which glial fibrillary acidic protein (GFAP), aquaporin 4 (AQP4), and potassium channels including inwardly rectifying K+ channel 4.1 (Kir4.1) are essential. However, associations of astrocyte-dominant Kir4.1 with other molecules in astrocytic volume regulation and the subsequent influence on neuronal activity remain unclear. Here, we report our study on these issues using primary cultures of rat pups' hypothalamic astrocytes and male adult rat brain slices. In astrocyte culture, hyposmotic challenge (HOC) significantly decreased GFAP monomer expression and astrocytic volume at 1.5 min and increased Kir4.1 expression and inwardly rectifying currents (IRCs) at 10 min. BaCl2 (100 µmol/l) suppressed the HOC-increased IRCs, which was simulated by VU0134992 (2 µmol/l), a Kir4.1 blocker. Preincubation of the astrocyte culture with TGN-020 (10 µmol/l, a specific AQP4 blocker) made the HOC-increased Kir4.1 currents insignificant. In hypothalamic brain slices, HOC initially decreased and then increased the firing rate of vasopressin (VP) neurons in the supraoptic nucleus. In the presence of BaCl2 or VU0134992, HOC-elicited rebound increase in VP neuronal activity was blocked. GFAP was molecularly associated with Kir4.1, which was increased by HOC at 20 min; this increase was blocked by BaCl2 . These results suggest that HOC-evoked astrocytic retraction or decrease in the volume and length of its processes is associated with increased Kir4.1 activity. Kir4.1 involvement in HOC-elicited astrocytic retraction is associated with AQP4 activity and GFAP plasticity, which together determines the rebound excitation of VP neurons.

Excitatory Effects of Astrocytic Hydrogen Sulfide on the Electrical Activity of Oxytocin Neurons in the Supraoptic Nucleus.

INTRODUCTION: In the regulation of oxytocin (OT) neuronal activity, hydrogen sulfide (H2S), a gaseous neurotransmitter, likely exerts an excitatory role. This role is associated with increased expression of astrocytic cystathionine-ß-synthase (CBS), the key enzyme for H2S synthesis. However, it remains unclear whether H2S is mainly produced in astrocytes and contributes to the autoregulation of OT neurons. METHODS: In hypothalamic slices of male rats, OT and H2S-associated drug effects were observed on the firing activity and spontaneous excitatory postsynaptic currents (sEPSCs) of putative OT neurons in the supraoptic nucleus (SON) in whole-cell patch-clamp recording. Expression of glial fibrillary acidic protein (GFAP) in the SON was analyzed in Western blots. In addition, changes in the length of rat pups' hypothalamic astrocytic processes were observed in primary cultures. RESULTS: In brain slices, OT significantly increased the firing rate of OT neurons, which was simulated by CBS allosteric agonist S-adenosyl-L-methionine (SAM) and H2S slow-releasing donor GYY4137 but blocked by CBS inhibitor aminooxyacetic acid (AOAA). L-α-aminoadipic acid (a gliotoxin) blocked SAM-evoked excitation. OT and SAM also increased the frequency and amplitude of sEPSCs; the effect of OT was blocked by AOAA. Both OT and GYY4137 reduced GFAP expression in the SON. Morphologically, OT or GYY4137 time-dependently reduced the length of astrocytic processes in primary cultures. CONCLUSIONS: These findings indicate that the auto-excitatory effect of OT on OT neurons is mediated by H2S from astrocytes at least partially and astrocytic H2S can elicit retraction of astrocytic processes that subsequently increase OT neuronal excitability.

Assessment of the effectiveness of BOPPPS-based hybrid teaching model in physiology education.

BACKGROUND: Online teaching has become increasingly common in higher education of the post-pandemic era. While a traditional face-to-face lecture or offline teaching remains very important and necessary for students to learn the medical knowledge systematically, guided by the BOPPPS teaching model, combination of online and offline learning approaches has become an unavoidable trend for maximizing teaching efficiency. However, in physiological education, the effectiveness of combined online teaching and offline teaching models remains poorly assessed. The present study aims at providing an assessment to the hybrid teaching model. METHODS: The study was performed among undergraduate medical students of Class 2017 ~ 2019 in the Physiology course in Harbin Medical University during 2018-2020. Based on established offline teaching model with BOPPPS components in 2018, we incorporated online teaching contents into it to form a hybrid BOPPPS teaching model (HBOPPPS, in brief), preliminarily in 2019 and completely in 2020. HBOPPPS effectiveness was assessed through comparing the final examination scores of both objective (multi-choice and single answer questions) and subjective (short and long essays) questions between classes taught with different modalities. RESULTS: The final examination score of students in Class 2019 (83.9 ± 0.5) who were taught with the HBOPPPS was significantly higher than that in Class 2017 (81.1 ± 0.6) taught with offline BOPPPS and in Class 2018 (82.0 ± 0.5) taught with immature HBOPPPS. The difference mainly attributed to the increase in average subjective scores (41.6 ± 0.3 in Class 2019, 41.4 ± 0.3 in Class 2018, and 38.2 ± 0.4 in Class 2017). In the questionnaire about the HBOPPPS among students in Class 2019, 86.2% responded positively and 79.4% perceived improvement in their learning ability. In addition, 73.5% of the students appreciated the reproducibility of learning content and 54.2% valued the flexibility of HBOPPPS. Lastly, 61.7% of the students preferred the HBOPPPS relative to BOPPPS in future learning. CONCLUSIONS: HBOPPPS is likely a more effective teaching model and useful for enhancing effectiveness of Physiology teaching. This is attributable to the reproducibility and flexibility as well as the increased learning initiatives.

Involvement of Supraoptic Astrocytes in Basilar Artery Occlusion-Evoked Differential Activation of Vasopressin Neurons and Vasopressin Secretion in Rats.

Vasopressin (VP) is a key factor in the development of brain injury in ischemic stroke. However, the regulation of VP secretion in basilar artery occlusion (BAO) remains unclear. To clarify the regulation of VP secretion in BAO and the underlying mechanisms, we performed this study in a rat model of BAO with (BC) or without common carotid artery occlusion (CCAO). The results showed that BAO and BC time-dependently increased neurological scores and that BC also increased water contents in the medulla at 2 h and in the pontine at 8 h. Moreover, plasma VP level increased significantly at BAO-8 h, CCAO and BC-2 h but not at BC-8 h; however, VP expressions increased in the supraoptic nucleus (SON) at BC-8 h. The neurological scores were highly correlated with pontine water contents and plasma VP levels. The number of phosphorylated extracellular signal-regulated protein kinase1/2-positive VP neurons increased significantly in the SON at BC-8 h. Similarly, the number of c-Fos-positive VP neurons increased significantly in the SON at BAO-8 h and BC-8 h. In addition, the length of glial fibrillary acidic protein (GFAP) filaments increased significantly in BC compared to BAO only. Aquaporin 4 (AQP4) puncta around VP neurons increased significantly at BC-8 h relative to BC-2 h, which had negative correlation with plasma VP levels. These findings indicate that BAO facilitates VP secretion and increases VP neuronal activity in the SON. The peripheral VP release is possibly under a negative feedback regulation of central VP neuronal activity through increasing GFAP and AQP4 expression in astrocytic processes.

Involvement of Protein Kinase A in Oxytocin Neuronal Activity in Rat Dams with Pup Deprivation.

Oxytocin (OT) neuronal activity is the key factor for breastfeeding and it can be disrupted by mother-baby separation. To explore cellular mechanisms underlying OT neuronal activity, we studied the role of protein kinase A (PKA) in OT neuronal activity in the supraoptic nucleus (SON) using a rodent model of pup deprivation (PD) Intermittent (IPD) or continuous (CPD) PD significantly reduced suckling duration and number of milk ejections in lactating rats, particularly those with CPD. In Western blots of the SON, PD increased expressions of OT receptor (OTR) and its immediate downstream effectors, Gαq and Gß subunits, particularly IPD, but reduced the expression of catalytic subunit of PKA (cPKA). In brain slices, inhibition of PKA blocked prostaglandin E2-evoked increase in firing activity including burst firing in OT neurons. In IPD dams, filamentous actin formed ring-like structures in the cytoplasmic region of OT neurons, which was reduced in CPD. Moreover, molecular association between actin and cPKA also reduced in PD dams. Incubation of brain slices with OT reduced the expression of cPKA, which was blocked by pretreatment with atosiban, an antagonist of OTR. These results indicate that PD disrupts OT neuronal activity through dissociating the Gq proteins and PKA in OTR-associated signaling cascade, which couples with reduced interactions between filamentous actin and PKA in OT neurons in the SON. This study highlights that PKA can be a novel target treating abnormal OT neuronal activity and its associated diseases.

Astrocytic Modulation of Supraoptic Oxytocin Neuronal Activity in Rat Dams with Pup-Deprivation at Different Stages of Lactation.

Appropriate interactions between astrocytes and oxytocin neurons in the hypothalamo- neurohypophysial system are essential for normal lactation. To further explore the mechanisms underlying astrocytic modulation of oxytocin neuronal activity, we observed astrocytic plasticity in the supraoptic nucleus of lactating rats with intermittent pup-deprivation (PD, 20 h/day) at early (day 1-5) and middle (day 8-12) stages of lactation. PD at both stages decreased suckling duration and litter's body weight gain. They also significantly increased the expression of glial fibrillary acidic protein (GFAP) in Western blots while increased GFAP filaments and the colocalization of GFAP filaments with aquaporin 4 (AQP4) puncta in astrocyte processes surrounding oxytocin neuronal somata in immunohistochemistry in the supraoptic nucleus. Suckling between adjacent milk ejections but not shortly after them decreased molecular association between GFAP and AQP4. In hypothalamic slices from male rats, oxytocin treatment (0.1 nmol/L, 10 min) significantly reduced the length of GFAP filaments and AQP4 puncta in the processes but increased GFAP staining in the somata. These oxytocin effects were blocked by pretreatment of the slices with N-(1,3,4-Thiadiazolyl) nicotinamide (TGN-020, inhibitor of AQP4, 10 µmol/L, 5 min before oxytocin). In addition, inhibition of AQP4 with TGN-020 blocked excitation in oxytocin neurons evoked by prostaglandin E2, a downstream signal of oxytocin receptor and mediator of oxytocin-evoked burst firing, in whole-cell patch-clamp recordings. These results indicate that AQP4-associated astrocytic plasticity is essential for normal oxytocin neuronal activity during lactation and that PD-evoked hypogalactia is associated with astrocytic process expansion following increased GFAP and AQP4 expressions.

TESOT: a teaching modality targeting the learning obstacles in global medical education.

In higher education, it is a great challenge for instructors to teach international medical students (IMSs) efficiently. These students usually have different learning obstacles and learning style preferences from domestic students. Thus it is necessary to use teaching modalities targeting the specific characteristics of IMSs. Accordingly, we have developed a teaching modality composed of classical teacher-centered approach (TCA), enriched with components of student-centered approach (SCA) and online interactions targeting the learning characteristics of IMSs, which we defined as TESOT (an acronym made of the underlined words' initials). Aside from the online interactions that provide both answers to questions raised by students and guidance throughout a course, this modality contains additional in-classroom components (i.e., pre-lecture quiz, student-led summary, and post-lecture quiz). The effectiveness of this modality was tested in the nervous system module of the Physiology course for IMSs. The final exam scores in the nervous system module in the year taught with TESOT were higher than those earned by students taught with a classical TCA modality in preceding 2 yr. The improvement of teaching effectiveness is attributable to increasing communication, bridging course contexts, and meeting diverse learning style preferences. These results indicate that TESOT as an effective teaching modality is useful for enhancing efficiency of teaching IMSs.

Neurochemical regulation of the expression and function of glial fibrillary acidic protein in astrocytes.

Glial fibrillary acidic protein (GFAP), a type III intermediate filament, is a marker of mature astrocytes. The expression of GFAP gene is regulated by many transcription factors (TFs), mainly Janus kinase-2/signal transducer and activator of transcription 3 cascade and nuclear factor κ-light-chain-enhancer of activated B cell signaling. GFAP expression is also modulated by protein kinase and other signaling molecules that are elicited by neuronal activity and hormones. Abnormal expression of GFAP proteins occurs in neuroinflammation, neurodegeneration, brain edema-eliciting diseases, traumatic brain injury, psychiatric disorders and others. GFAP, mainly in α-isoform, is the major component of cytoskeleton and the scaffold of astrocytes, which is essential for the maintenance of astrocytic structure and shape. GFAP also has highly morphological plasticity because of its quick changes in assembling and polymerizing states in response to environmental challenges. This plasticity and its corresponding cellular morphological changes endow astrocytes the functions of physical barrier between adjacent neurons and stabilizer of extracellular environment. Moreover, GFAP colocalizes and even molecularly associates with many functional molecules. This feature allows GFAP to function as a platform for direct interactions between different molecules. Last, GFAP involves transportation and localization of other functional proteins and thus serves as a protein transport guide in astrocytes. This guiding role of GFAP involves an elastic retraction and extension cytoskeletal network that couples with GFAP reassembling, transporting, and membrane protein recycling machinery. This paper reviews our current understanding of the expression and functions of GFAP as well as their regulation.

LincRNA-EPS in biomimetic vesicles targeting cerebral infarction promotes inflammatory resolution and neurogenesis.

BACKGROUND: Inflammatory damage following stroke aggravates brain damage, resulting in long-term neurological sequelae. The purpose of this study was to identify ways to reduce inflammatory reactions and to accelerate neuron regeneration after cerebral apoplexy. METHODS: We formulated a biomimetic vesicle, the leukosome, constituted by liposome, artificial long intergenic noncoding RNA (lincRNA)-EPS, and membrane proteins derived from macrophages and their physical-chemical characteristics were evaluated. Migration distance and cytotoxic levels were measured to determine the effect of lncEPS-leukosomes on lipopolysaccharide-activated microglia. An in vivo transient middle cerebral artery occlusion/reperfusion (tMCAO) model was established in mice, which were treated with lncEPS-leukosomes. Vesicle seepage, infiltration of inflammatory cells, cytotoxic levels in the cerebrospinal fluid, and neural stem cell (NSC) density were measured. RESULTS: Biomimetic vesicles with a homogeneous size increased lincRNA-EPS levels in activated microglia by 77.9%. In vitro studies showed that lincRNA-EPS inhibited the migration and cytotoxic levels of activated microglia by 63.2% and 43.6%, respectively, which promoted NSC proliferation and anti-apoptotic ability. In vivo data showed that leukosomes targeted to inflamed sites and lncEPS-leukosomes decreased the infiltration of inflammatory cells and cytotoxic levels by 81.3% and 48.7%, respectively. In addition, lncEPS-leukosomes improved neuron density in the ischemic core and boundary zone after tMCAO. CONCLUSIONS: The biomimetic vesicles formulated in this study targeted inflammatory cells and accelerated neuron regeneration by promoting inflammation resolution. This study may provide a promising treatment approach for accelerated neuron regeneration after cerebral apoplexy.

Expression of glial fibrillary acidic protein in astrocytes of rat supraoptic nucleus throughout estrous cycle.

OBJECTIVE: Oxytocin (OXT) could facilitate preovulatory luteinizing hormone surge in animals and humans while brain OXT production depends on glial fibrillary acidic protein (GFAP)-associated astrocytic plasticity. Here, we examined if GFAP expressions in OXT-producing hypothalamic supraoptic nucleus (SON) correlate to special estrous stages. METHODS: 38 adult female rats were classified into diestrus, proestrus, estrus, and metestrus groups determined by vaginal smear. Rats were decapitated and the SON was dissected for detecting Fos and GFAP levels by Western Blot and immunohistochemistry. RESULTS: The result showed that Fos expression was significantly high at proestrus compared to other stages in Western blotting. No significant difference in total GFAP expression was observed between rats at different stages of the estrous cycle; however, at proestrus GFAP level at the dorsolateral portion of the SON (a region filled with OXT neurons) was significantly lower than that at the ventro-medial portion in immunohistochemistry. CONCLUSION: There is a functional correlation between supraoptic neuron activity and proestrous OXT peak during estrous cycle; it is likely that a plastic change in GFAP expression in astrocytes selectively occurs around OXT neurons at proestrus and facilitates OXT release.

Vasopressin Hypersecretion-Associated Brain Edema Formation in Ischemic Stroke: Underlying Mechanisms.

BACKGROUND: Brain edema formation is a major cause of brain damages and the high mortality of ischemic stroke. The aim of this review is to explore the relationship between ischemic brain edema formation and vasopressin (VP) hypersecretion in addition to the oxygen and glucose deprivation and the ensuing reperfusion injury. METHODS: Pertinent studies involving ischemic stroke, brain edema formation, astrocytes, and VP were identified by a search of the PubMed and the Web of Science databases in January 2016. Based on clinical findings and reports of animal experiments using ischemic stroke models, this systematic review reanalyzes the implication of individual reports in the edema formation and then establishes the inherent links among them. RESULTS: This systematic review reveals that cytotoxic edema and vasogenic brain edema in classical view are mainly under the influence of a continuous malfunction of astrocytic plasticity. Adaptive VP secretion can modulate membrane ion transport, water permeability, and blood-brain barrier integrity, which are largely via changing astrocytic plasticity. Maladaptive VP hypersecretion leads to disruptions of ion and water balance across cell membranes as well as the integrity of the blood-brain barrier. This review highlights our current understandings of the cellular mechanisms underlying ischemic brain edema formation and its association with VP hypersecretion. CONCLUSIONS: VP hypersecretion promotes brain edema formation in ischemic stroke by disrupting hydromineral balance in the neurovascular unit; suppressing VP hypersecretion has the potential to alleviate ischemic brain edema.

Involvement of the paraventricular nucleus in the occurrence of arrhythmias in middle cerebral artery occlusion rats.

BACKGROUND: Ischemic stroke complicating with arrhythmia is one of the main causes of sudden death. To investigate the association between ischemic stroke-induced arrhythmia and the activity of paraventricular nucleus (PVN), we used Fos protein as an objective indicator to illustrate the functional state of PVN neurons in middle cerebral artery occlusion (MCAO) rats, in single intracerebroventricular injection of l-glutamate rats and in application of MK-801 before l-glutamate injection and MCAO rats. METHODS: The standard limb II electrocardiography was continuously recorded by a biological signal collecting and processing system. The experimental cerebral ischemic animal model was established by occluding the right middle cerebral artery. The Fos protein expression was detected by immunohistochemistry and Western blot. RESULTS: The incidence of arrhythmia was significantly higher than that of controls (75.89% versus 0%), and Fos protein expression in the PVN also increased significantly in MCAO rats; both of them could be blocked by prior application of MK-801. Intracerebroventricular injection of l-glutamate induced changes in Fos protein expression and arrhythmia similar to that in the stroke, which could also be blocked by prior application of MK-801. CONCLUSIONS: It was concluded that activation of the PVN in MCAO rats is likely mediated by glutamate via activation of N-methyl-D-aspartic acid (NMDA) receptors, which causes arrhythmias.

Resveratrol protects neurons and the myocardium by reducing oxidative stress and ameliorating mitochondria damage in a cerebral ischemia rat model.

BACKGROUND: Resveratrol has shown potent antioxidant activity in ischemia models. The present study was performed to determine whether resveratrol protects against cerebral ischemia-induced neuronal and myocardial injury by interfering with mitochondrial homeostasis. METHODS: Wistar rats were pretreated with resveratrol or vehicle intraperitoneally for one week and then subjected to cerebral ischemia via middle cerebral artery occlusion (MCAO) for 24 h. Oxidation was evaluated by quantitating SOD activity and MDA levels. Apoptosis and autophagy were measured based on TUNEL staining and the expression levels of Bcl-2, Bax and LC3II. Mitochondrial changes were evaluated by transmission electron microscopy and by analyzing the mitochondrial membrane potential. RESULTS: Resveratrol significantly decreased mortality, neurological deficits, infarction volume and MDA levels and increased SOD activity. Furthermore, neurocyte apoptosis was alleviated by resveratrol as indicated by the increased Bcl-2/Bax ratio, increased LC3II expression and a decreased number of TUNEL-positive neurocytes. Resveratrol preserved the mitochondria in neurons and cardiomyocytes and significantly improved cardiac function. CONCLUSION: Resveratrol protected brain tissues against ischemic damage by interfering with mitochondrial homeostasis and inhibiting apoptosis. Furthermore, resveratrol attenuated myocardial damage, suggesting that it may be a novel therapy for cerebral ischemia diseases.

Energy-saving and CO2 reduction strategies for new energy vehicles based on the integration approach of voluntary advocacy and system dynamics.

The low-carbon development of new energy vehicles (NEVs) is critical to achieving the goals of carbon peaking and carbon neutrality. As such, combining gray model theory with system dynamics (SD-GM) and based on the bidirectional-cycle prediction theory, we propose a NEV annual average mileage algorithm considering the impact of the epidemic in China, taking private cars as an example. Then, combining a voluntary advocacy strategy (VA) with the SD-GM theory (VA-SD-GM integration), we establish an energy-saving and carbon-reduction management model. To evaluate the proposed algorithm, we performed a dynamic simulation. The results indicate that the enhanced green scenario enabled significant energy-saving and CO2 reduction performance but would cause side effects in the long term. Compared with the enhanced green scenario, the linkage mode reduced the impact of parking space tension, the number of NEV trips, and the intensification of traffic congestion by approximately 33%, 50%, and 34%, respectively. It effectively suppressed the continuous increase in side effects and had a synergistic effect of carbon reduction, energy conservation, congestion alleviation, and side-effect reduction. The study provides a theoretical basis for optimizing the energy-saving and CO2 reduction path of NEVs.

Modeling and simulation analysis of vehicle pollution and carbon reduction management model based on system dynamics.

The vehicle exhaust pollution has become an important source of air pollutant and CO2 emissions, with the continuous growth of the number of vehicles. Focusing on the increasingly serious problems of vehicle exhaust pollution and CO2 emissions, a management model of vehicle pollution reduction and carbon reduction was established by using system dynamics. Taking Beijing as the case study city, different emission reduction scenarios were designed. Different scenarios are analyzed, and the results reveal the following: (1) Although the carbon tax policy for motor vehicles can play a role in vehicle pollution reduction and carbon reduction to a certain extent, but as the simulation time goes on, the policy effect is gradually weakened. The emission reduction effect of new energy vehicle promotion policy is not significant, and there is a "lag effect" and a "seesaw effect." (2) The science and technology policy has multiple effects of environmental, economic, and health. It can significantly reduce vehicle pollution and carbon emissions, and achieve the peak carbon by 2030. (3) It is not that more policies are better for CO2 emission reduction, and there is a "crowding out effect" in the CS. (4) From the perspectives of long term, the science and technology policy is a more effective way to achieve the co-control of CO2 and PM2.5 and achieve the carbon peaking goal compared with other emission reduction scenarios. These results can provide reference for relevant departments to formulate emission reduction policies and realize the management of motor vehicle pollution reduction and carbon reduction.

Evaluation of the mid- and long-term effects of a private car driving-restriction policy under the carbon emission peak target.

To investigate the medium- and long-term effects of a driving-restriction policy under the guidance of carbon emission peak goals, Beijing was taken as an example to construct a private-car energy-conservation and emission-reduction model with dual-driving factors from the perspective of the economy, environment, technology, and energy. Through causal analysis, the negative effects of a driving-restriction policy were revealed. The simulation results revealed the following. (1) A driving-restriction policy is effective in the short term, but in the long run, it cannot effectively reduce CO2 emissions and the quantity of fuel used in private cars (e.g., the increase in the amount of CO2 pollution and degree of parking space tension, as well as the rebound of air pollution). (2) Compared with the driving-restriction policy, the combined policy reduces the amount of CO2 pollution by approximately 52.45%, the PM2.5 concentration by 21.98%, and the quantity of fuel in private cars by 33.42% by 2035, while improving the air quality by approximately 144.79%. Therefore, this article provides a theoretical basis for optimizing driving-restriction policies and achieving the carbon emission peak target.

Interactions between the Astrocytic Volume-Regulated Anion Channel and Aquaporin 4 in Hyposmotic Regulation of Vasopressin Neuronal Activity in the Supraoptic Nucleus.

We assessed interactions between the astrocytic volume-regulated anion channel (VRAC) and aquaporin 4 (AQP4) in the supraoptic nucleus (SON). Acute SON slices and cultures of hypothalamic astrocytes prepared from rats received hyposmotic challenge (HOC) with/without VRAC or AQP4 blockers. In acute slices, HOC caused an early decrease with a late rebound in the neuronal firing rate of vasopressin neurons, which required activity of astrocytic AQP4 and VRAC. HOC also caused a persistent decrease in the excitatory postsynaptic current frequency, supported by VRAC and AQP4 activity in early HOC; late HOC required only VRAC activity. These events were associated with the dynamics of glial fibrillary acidic protein (GFAP) filaments, the late retraction of which was mediated by VRAC activity; this activity also mediated an HOC-evoked early increase in AQP4 expression and late subside in GFAP-AQP4 colocalization. AQP4 activity supported an early HOC-evoked increase in VRAC levels and its colocalization with GFAP. In cultured astrocytes, late HOC augmented VRAC currents, the activation of which depended on AQP4 pre-HOC/HOC activity. HOC caused an early increase in VRAC expression followed by a late rebound, requiring AQP4 and VRAC, or only AQP4 activity, respectively. Astrocytic swelling in early HOC depended on AQP4 activity, and so did the early extension of GFAP filaments. VRAC and AQP4 activity supported late regulatory volume decrease, the retraction of GFAP filaments, and subside in GFAP-VRAC colocalization. Taken together, astrocytic morphological plasticity relies on the coordinated activities of VRAC and AQP4, which are mutually regulated in the astrocytic mediation of HOC-evoked modulation of vasopressin neuronal activity.