Behavioral Sensitization Research Articles

From Knowledge to Practice: Design, Implementation, and Evaluation of an Evidence-Based Educational Module to Increase Cultural Awareness in Nursing Students.

Background: Educational programs for health-care providers increasingly implement culturally sensitive care. Clear methods for educating students in cultural awareness are still lacking. Research indicates that simply increasing knowledge on ethnicity, culture, or migration does not improve culturally sensitive behavior and can foster stereotypes. To overcome barriers like othering, a form of micro-racism, enhanced critical self-awareness is essential for health-care providers. Aim: A 4h module on culturally sensitive care was designed, implemented, and evaluated, with the aim of increasing nursing students' self-awareness about othering, racism, and exclusion in health care. Methods: This article describes (1) the content of the module, led by the Johari Window model and the needs and insights from nursing students and health-care providers, (2) implementation of the module, and (3) subsequent evaluation among 34 participants. Results: The survey findings were categorized into six themes: Understanding Differences and Prejudices, Applying Knowledge in the Context of Nursing Practice, Acquiring Insights through Interpersonal Engagement, Strengths of the Sessions, Weaknesses and Areas for Improvement, and Overall Impressions. The participants evaluated the module positively, identifying success factors (e.g., enhanced self-reported awareness of their own positionality) and working points (e.g., imbalance in interaction among students and time constraints). Conclusion: The study describes the design, implementation, and evaluation of a module that successfully increases nursing students' self-reported cultural competence and self-awareness, enhancing understanding of health-care inequalities and fostering open communication for more inclusive care.

Policy complexity suppresses dopamine responses.

Limits on information processing capacity impose limits on task performance. We show that male and female mice achieve performance on a perceptual decision task that is near-optimal given their capacity limits, as measured by policy complexity (the mutual information between states and actions). This behavioral profile could be achieved by reinforcement learning with a penalty on high complexity policies, realized through modulation of dopaminergic learning signals. In support of this hypothesis, we find that policy complexity suppresses midbrain dopamine responses to reward outcomes. Furthermore, neural and behavioral reward sensitivity were positively correlated across sessions. Our results suggest that policy compression shapes basic mechanisms of reinforcement learning in the brain.Significance statement Decision making relies on memory to store information about which actions to produce in which situations. This memory has limited capacity, which means that some information will be lost. The signatures of this information loss can be found in patterns of behavioral bias and randomness. However, relatively little is known about the neural mechanisms which ensure that actions achieve the highest possible reward given the limited capacity of decision memory. In this paper, we show that the neuromodulator dopamine is sensitive to the costs of memory, as predicted by a computational model of capacity-limited learning.

Lignin-reinforced eutectogel with environmentally stability for high-performance human multi-functional sensor

Intrinsic environmental instability of hydrogels has limited their practical applications as durable flexible sensors in human life. In this study, a bio-based eutectogel (BEG) with environmental tolerance was designed via deep eutectic solvent (DES), thioctic acid (TA) and lignin. Benefit from self-ring-opening polymerization of TA monomer in the ethanol and the lignin acting as free radicals, the BEG was fabricated through efficient cast-drying method. The dynamic interaction formation between DES and TA polymer network was revealed by using in-situ infrared spectroscopy during the ethanol evaporation process. The introduction of lignin not only improve the mechanical properties of the eutectogels, but also endow the BEG with moisture tolerance by activating self-aggregated dense hydrophobic layer on the surface while in high humidity environment. This bio-based eutectogels with non-volatility, board range operating temperature and proper self-adhesion could serve as long-term stable temperature-strain dual sensor with high sensitivity (GF = 1.17, TCR = 4.26 %/K) and rapid response behavior (373 ms). Furthermore, the biocompatible BEG was validated for recording human physiological signals over extended period with performance comparable to commercial hydrogel electrodes. This strategy could broaden the range of making durable stretchable eutectogels in human healthcare monitoring.

Anxiety Disorders: A Narrative Review

The prevalence of anxiety disorders in the U.S. has varied between 34 and 38%. Surprisingly, this rate has only increased 1% across the last three decades. Emotional sensitivity and worrying are the only negative effects that have appeared in this recent literature. Also, only two studies have focused on risk factors including anxiety sensitivity and avoidance behavior. Most of the recent research has explored potential underlying biological mechanisms and interventions. The underlying mechanisms have included low heartrate variability, abnormal EEG patterns, altered cytokines, dysregulated neurolipids, neuroinflammation, low hippocampal volume and gray matter and a low connection between cranial hemispheres. The interventions have included metacognition, cognitive behavioral therapy, internet delivery of cognitive behavioral therapy, coloring, acupuncture, exercise, cannabidiol and pharmacology in general. Although this is an informative literature, it is unclear why limited attention has been directed at negative effects and risk factors for anxiety disorders.

Enhanced behavioural and neural sensitivity to punishments in chronic pain and fatigue.

Chronic pain and fatigue in musculoskeletal disease contribute significantly to disability, and recent studies suggest an association with reduced motivation and excessive fear avoidance. In this behavioural neuroimaging study, we aimed to identify the specific behavioral and neural changes associated with musculoskeletal pain and fatigue during reward and loss decision-making. Twenty-nine participants with chronic inflammatory arthritis and 28 healthy controls performed an instrumental learning task (4-armed bandit) during 3T brain fMRI. Computational analyses with reinforcement learning models were used to quantify the hidden variables involved in reward and loss decision-making, compare them across groups and finally relate them to brain activity. We found that participants with chronic pain had higher sensitivity to punishments and increased activity associated with the punishment prediction error in the right posterior insular cortex, putamen, pallidum, and dorsolateral prefrontal cortex. Functional network connectivity analysis showed that insula centrality correlated with subjective reports of fatigue and pain during the task. The findings of this exploratory study suggest that pain and fatigue in chronic pain relate to objective behavioural changes in loss-decision making, which can be mapped to a specific pattern of activity in brain circuits of motivation and decision-making. The proposed parametric signature, characterized most notably by increased punishment sensitivity, is distinct from patterns previously reported in psychiatric conditions and it aligns with predictions of the fear avoidance model of pain.

The effect of ACTH/MSH N-terminal fragment analogs on the anxiety level, pain sensitivity and levels of neurotrophic factors BDNF and VEGF in primary neuronal cultures of rats

ACTH/MSH-like peptides (melanocortins) have a wide range of neurotropic effects, including effects on learning and memory processes, neuroprotection, emotional state and pain sensitivity. Present work is aimed to compare the effects of peptides, the structure of which includes a natural fragment of ACTH and a stabilizing tripeptide PGP. The peptides ACTH4-7PGP (Semax), ACTH6-9PGP и ACTH7-10PGP were used in the work. The effects of these peptides on the exploratory behavior, anxiety level and pain sensitivity of white rats, as well as on the protein levels of the neurotrophic factors BDNF (brain derived neurotrophic factor) and VEGF (vascular endothelial growth factor) in primary neuron cultures were studied. A comparative study of the effects of analogs of different ACTH/MSH fragments revealed both similarities and differences in their neurotropic activity. The peptides structure of which includes a sequence of ACTH4-7 or ACTH6-9 have nootropic, anxiolytic and analgesic activity, and also cause an increase in VEGF levels in the culture of hippocampal neurons. The peptide containing the ACTH7-10 sequence in the structure exhibits anxiolytic activity, increases exploratory behavior, does not affect pain sensitivity and has a stimulating effect on BDNF and VEGF levels in neuronal cultures. The data obtained indicate that different parts of the N-terminal region of the ACTH molecule are responsible for the manifestation of certain neurotropic effects of melanocortins. The results of the study can be used in the development of therapeutics based on natural melanocortins.

Effects of Dispositional and Contextual Moral Sensitivity in Moral Decision‐Making: A Cross‐Sectional Study Among Nursing Students

ABSTRACTAimBased on Rest's Four Stage Model (moral sensitivity, moral judgement, moral intention and moral behaviour), we aim to compare the effects of dispositional moral sensitivity and contextual moral sensitivity on moral decision‐making among nursing students.DesignA cross‐sectional study.MethodsThe participants were from nursing colleges in Shijiazhuang, Guangzhou and Chongqing, China. A total of 354 nursing students were recruited via the convenience sampling method. Data were collected via the dispositional moral sensitivity scale and a scenario experiment. Structural equation modeling (SEM) was used to test the relationships among the variables in the structural model via Mplus.ResultsWhile dispositional moral sensitivity and contextual moral sensitivity both influence moral intention, they do so in opposite directions. Moral judgement has a positive impact on moral intention and acts as a mediator between dispositional moral sensitivity/contextual moral sensitivity and moral intention.ConclusionThis study compares the various influence paths and mechanisms of dispositional moral sensitivity and contextual moral sensitivity in moral decision‐making, thereby advancing research on nursing ethics education.ImpactOur findings suggest that nursing colleges should adopt diverse strategies to cultivate the dispositional moral sensitivity of nursing students, thus facilitating their ability to make moral decisions. These insights have valuable implications for the advancement of nursing ethics education.Reporting MethodWe adhered to the STROBE guidelines.Patient or Public ContributionNo patient or public contribution.

In vivo changes in zebrafish anesthetic sensitivity in response to the loss of kif5Aa are associated with the alteration of mitochondrial motility.

Anesthetic and sedative drugs are small compounds known to bind to hundreds of proteins. One intriguing binding partner of propofol is the kinesin motor domain, kif5A, a neuronal mitochondrial transport protein. Here, we used zebrafish WT and kif5Aa KO larval behavioral assays to assess anesthetic sensitivity and combined that with zebrafish primary neuronal cell culture to probe for alteration in mitochondrial motility. We found that the loss of kif5Aa increases behavioral sensitivity to propofol and etomidate, with etomidate hypersensitivity greater than propofol. In contrast, kif5Aa KO animals were resistant to the behavioral effects of dexmedetomidine. Finally, WT and kif5Aa KO larvae responded similarly to the behavioral effects of ketamine. Propofol inhibited the anterograde motility of mitochondria in WT zebrafish neurons, while etomidate inhibited mitochondrial motility in both anterograde and retrograde directions; neither drug altered mitochondrial motility in the kif5Aa knockout (KO) neurons. In contrast, dexmedetomidine enhanced retrograde mitochondrial motility in both WT and kif5Aa KO animals. Finally, ketamine had little significant effect on mitochondrial motility in either mutant or WT animals. These data demonstrate that each anesthetic/sedative drug affects the motor protein machinery uniquely and is associated with unique changes in behavior. Understanding how different anesthetic compounds alter neuron motor proteins will be important in defining how anesthetics alter neuronal signaling and energetic dynamics.

A sex-specific effect of M4 muscarinic cholinergic autoreceptor deletion on locomotor stimulation by cocaine and scopolamine.

Acetylcholine modulates the activity of the direct and indirect pathways within the striatum through interaction with muscarinic M4 and M1 receptors. M4 receptors are uniquely positioned to regulate plasticity within the direct pathway and play a substantial role in reward and addiction-related behaviors. However, the role of M4 receptors on cholinergic neurons has been less explored. This study aims to fill this gap by addressing the role of M4 receptors on cholinergic neurons in these behaviors. To investigate the significance of M4-dependent inhibitory signaling in cholinergic neurons we created mutant mice that lack M4 receptors on cholinergic neurons. Cholinergic neuron-specific depletion was confirmed using in situ hybridization. We aimed to untangle the possible contribution of M4 autoreceptors to the effects of the global M4 knockout by examining aspects of basal locomotion and dose-dependent reactivity to the psychostimulant and rewarding properties of cocaine, haloperidol-induced catalepsy, and examined both the anti-cataleptic and locomotion-inducing effects of the non-selective anticholinergic drug scopolamine. Basal phenotype assessment revealed no developmental deficits in knockout mice. Cocaine stimulated locomotion in both genotypes, with no differences observed at lower doses. However, at the highest cocaine dose tested, male knockout mice displayed significantly less activity compared to wild type littermates (p = 0.0084). Behavioral sensitization to cocaine was similar between knockout and wild type mice. Conditioned place preference tests indicated no differences in the rewarding effects of cocaine between genotypes. In food-reinforced operant tasks knockout and wild type mice successfully acquired the tasks with comparable performance results. M4 receptor depletion did not affect haloperidol-induced catalepsy and scopolamine reversal of catalepsy but attenuated scopolamine-induced locomotion in females (p = 0.04). Our results show that M4 receptor depletion attenuated the locomotor response to high doses of cocaine in males and scopolamine in females, suggesting sex-specific regulation of cholinergic activity. Depletion of M4 receptors on cholinergic neurons does not significantly impact basal behavior or cocaine-induced hyperactivity but may modulate the response to high doses of cocaine in male mice and the response to scopolamine in female mice. Overall, our findings suggest that M4-dependent autoregulation plays a minor but delicate role in modulating specific behavioral responses to pharmacological challenges, possibly in a sex-dependent manner.

Salivary vitamin D levels in children with autism in relation to oral health status and disease severity

Background: Autism spectrum disorder is characterized by difficulties with social interaction and communication, as well as limited patterns of behavior and atypical sensory sensitivity. Although vitamin D insufficiency has previously been observed in autistic children, evidence on the link between vitamin D deficiency, oral health condition, and autism severity is scarce. The purpose of this study was to investigate vitamin D levels in relation to oral health status of children with autism, as well as the relationship between vitamin D and disease severity. Materials and methods: Two groups were included in this study: 40 institutionalized autistic children as a study group and 40 apparently healthy children as a control group with age range (3-12) years. Depending on the severity of autistic symptoms, the group was classified into three subgroups: mild, moderate, and severe. The oral examination was performed using simplified oral hygiene and decayed, missing and filled tooth indices to measure oral health status for both groups. Three millilitres of un-stimulated salivary sample was taken by drooling technique, the salivary level of vitamin D assessed by enzyme-linked immunosorbent assay. The data from the current study were analysed using SPSS version 21. Results: Salivary vitamin D levels were found to be significantly lower in the study group than in the control group. This reduction was not correlated with the severity of autism. 37.5% of the autistic patient group had fair oral hygiene, compared to 20% of the control group; simplified oral hygiene index shows negative significant correlation with vitamin D level while caries experience was significantly higher in patient group and there was a negative non-significant correlation with vitamin D level. Conclusion: The vitamin D level was significantly lower in the patient group with no correlation with disease severity, fair oral hygiene and more caries in both primary and permanent dentition was observed in autistic patients with significant negative correlation between the simplified oral hygiene index and vitamin D, while negative non-significant correlation with dental caries

Comparative Analysis of Physico-Chemical and Potassium Sorption Properties of Sensitive Clays

The paper analyses physico-chemical and geotechnical characteristics of four Scandinavian sensitive soils formed under different environmental depositional conditions, with the main aims to contribute to the knowledge of sensitive soils and assess the potassium sorption capacity among the investigated soils, as a basic characteristic to evaluate the effectiveness of treatment with KCl and to analyse potassium migration in such soils. The results show that, although the chemical composition of the four soils is very similar, their sensitivity is significantly different. The correlation from literature linking the specific surface, mineralogy, and plasticity in sensitive clays of Eastern Canada, was found to be qualitatively valid for the investigated Scandinavian sensitive clays, too. The highest value of the sensitivity index among the tested soils was found to be related to the lowest cation exchange capacity and to a limited amount of amorphous minerals. These characteristics contribute to explaining the highly sensitive behaviour of that soil affecting the structure formation during the deposition stage. The potassium sorption capacity has been experimentally investigated through batch tests specifically performed on the sensitive soils, as the first step to quantify the maximum sorption capacity and identify the main factors affecting it. The maximum potassium sorption capacity was always lower than that estimated by the cation exchange capacity, and it increased with the cation exchange capacity, plasticity index, and activity of the soils, as well as with the amount of phyllosilicates and amorphous minerals.

Activation of the proton-sensing GPCR, GPR65 on fibroblast-like synoviocytes contributes to inflammatory joint pain

Inflammation is associated with localized acidosis, however, attributing physiological and pathological roles to proton-sensitive receptors is challenging due to their diversity and widespread expression. Here, agonists of the proton-sensing GPCR, GPR65, were systematically characterized. The synthetic agonist BTB09089 (BTB) recapitulated many proton-induced signaling events and demonstrated selectivity for GPR65. BTB was used to show that GPR65 activation on fibroblast-like synoviocytes (FLS), cells that line synovial joints, results in the secretion of proinflammatory mediators capable of recruiting immune cells and sensitizing sensory neurons. Intra-articular injection of BTB resulted in GPR65-dependent sensitization of knee-innervating neurons and nocifensive behaviors in mice. Stimulation of GPR65 on human FLS also triggered the release of inflammatory mediators and synovial fluid samples from human osteoarthritis patients were shown to activate GPR65. These results suggest a role of GPR65 in mediating cell-cell interactions that drive inflammatory joint pain in both mice and humans.

Disgust sensitivity and psychopathic behavior: A narrative review.

Humans live under constant threat from pathogenic microorganisms and minimizing such threat has been a major evolutionary selective force in shaping human behavior and health. A particular adaptive mechanism against the harm caused by parasites and their infectiousness is disgust sensitivity, which has evolved to detect and avoid poisonous foods as well as bodily secretions harboring virulent microorganisms. This ubiquitous and reflexive behavior requires the integration of several internal and external sensory signals between the brain, the autonomic nervous system (ANS), and the gastrointestinal tract. Although the emotional expression of disgust is experienced by almost all individuals, the neural mechanisms of sensory signals underlying disgust sensitivity may differ in certain psychiatric conditions. Psychopathy, for instance, is a personality disorder in which disgust sensitivity to contagious bodily secretions is apparently absent or downregulated from its atypical personality temperament. In this review, we provide convergent behavioral, anatomical, and cellular evidence to suggest that a fractured experience of disgust sensitivity might be an additional feature of psychopathic behavior. First, we discuss the neural networks of certain brain regions mediating the emotional states of disgust and then discuss the intersection of the ANS and gastrointestinal tract in the processing of disgust and its relevance to aberrant antisocial behavior. Together, this work highlights the interconnections between the brain and the bilateral body plan as an integrated cell network that is relevant for understanding common principles underlying function and dysfunction of disgust levels in psychiatric domains.

Feedback Sensitivity, Scholastic Adjustment and Prosocial Behavior: The Mediation Effect of Academic Self-Efficacy

Empirical findings support the important role played by prosocial behavior and scholastic performance in significantly affecting adolescents’ long-term psychosocial adjustment. Furthermore, several studies showed the positive impact of academic self-efficacy in affecting adolescents’ social and academic functioning; however, no studies have investigated the effect of other important personality structures, such as students’ feedback sensitivity. The present study aims to investigate the effects of adolescents’ feedback sensitivity (reward sensitivity/punishment sensitivity) on their prosocial behavior and scholastic performance, also examining the potential indirect effect of academic self-efficacy on the association between reward/punishment sensitivity and prosocial behavior/scholastic performance. The participants were 132 adolescents from Rome (Italy). A structural equation model showed a positive and significant effect of academic self-efficacy on scholastic performance and prosocial behavior, a positive significant effect of punishment sensitivity on prosocial behavior, a positive significant effect of reward sensitivity on academic self-efficacy and a significant indirect effect of academic self-efficacy on the association between reward sensitivity and scholastic performance. The results of this study are useful in terms of practical implications to promote students’ adjustment.

Efficient value synthesis in the orbitofrontal cortex explains how loss aversion adapts to the ranges of gain and loss prospects.

Is irrational behavior the incidental outcome of biological constraints imposed on neural information processing? In this work, we consider the paradigmatic case of gamble decisions, where gamble values integrate prospective gains and losses. Under the assumption that neurons have a limited firing response range, we show that mitigating the ensuing information loss within artificial neural networks that synthetize value involves a specific form of self-organized plasticity. We demonstrate that the ensuing efficient value synthesis mechanism induces value range adaptation. We also reveal how the ranges of prospective gains and/or losses eventually determine both the behavioral sensitivity to gains and losses and the information content of the network. We test these predictions on two fMRI datasets from the OpenNeuro.org initiative that probe gamble decision-making but differ in terms of the range of gain prospects. First, we show that peoples' loss aversion eventually adapts to the range of gain prospects they are exposed to. Second, we show that the strength with which the orbitofrontal cortex (in particular: Brodmann area 11) encodes gains and expected value also depends upon the range of gain prospects. Third, we show that, when fitted to participant's gambling choices, self-organizing artificial neural networks generalize across gain range contexts and predict the geometry of information content within the orbitofrontal cortex. Our results demonstrate how self-organizing plasticity aiming at mitigating information loss induced by neurons' limited response range may result in value range adaptation, eventually yielding irrational behavior.

Rheological properties and 3D printability of SBS/CR-modified asphalt binder with C9 petroleum resin for crack filling

IntroductionThis study investigates rheological behavior and 3D printability of SBS-, CR-, SBS/CR-modified asphalt binder with C9 petroleum resin (C9PR) for crack filling.MethodsThirteen types of modified asphalt binders with respective C9PR of 0 wt%, 1 wt%, 2 wt%, 3 wt% were prepared and evaluated for their microstructure, physical properties, compatibility, rheological properties, and 3D printability.ResultsThe results show that SBS, CR, and C9PR influenced significantly on rheological properties and 3D printability of modified asphalt binders. Physical blending and improved storage stability of modified asphalt binders were observed with the addition of C9PR. In addition, the combination of SBS and CR showed enhanced viscoelastic behavior and temperature sensitivity compared to the base asphalt binder due to the increased swelling behavior of SBS and CR in asphalt binders by C9PR.DiscussionAsphalt binder with 3 wt% SBS, 15 wt% CR, and 1 wt% C9PR showed improved viscosity, elasticity, compatibility, high-temperature rutting resistance, and fatigue resistance. Additionally, C9PR expanded 3D printable temperature range of modified asphalt binder, leading to its potential use as an additive in 3D printed asphalt binders.

The elderly population's social networks and HIV perceptions: Evidence from China.

Previous studies have found that people with low participation in social activities and living alone were prone to have risky sexual behaviors, while people with high participation in social activities were less prone to have risky sexual behaviors. Based on the above assumptions, we conducted an analysis on elderly population's social networks and human immunodeficiency virus (HIV) risky behaviors in China. In the survey study, considering the sensitivity of sexual behavior, HIV risk behavior of the elderly population is more difficult to measure, so the intermediate variable of HIV perceptions was used instead of the sexual behavioral variable. A cross-sectional study was conducted in July to September 2023 among the elderly aged ≥ 50 years in China to measure the social networks with the Social Support Rate Scale (SSRS) and to measure the HIV perceptions of the elderly with the degree of knowledge of acquired immunodeficiency syndrome (AIDS) prevention and treatment and the degree of discrimination of HIV/AIDS patients, and the data were statistically analyzed with SPSS 27.0 software. Statistical analysis methods included descriptive analyses such as frequency, percentage, mean ± standard deviation, and median, two independent samples t-test analysis, and multivariate logistic regression model analysis. Among the 1022 elderly people surveyed, the proportion of those with weak and strong levels of social support was 46.9% and 53.1%, respectively; the proportion of those with low, medium, and high levels of HIV knowledge perceptions was 4.8%, 5.9%, and 89.3%, respectively; and the proportion of those with low, medium, and high levels of attitudinal perceptions was 24.7%, 35.0%, and 40.3%, respectively. Based on the Goodman-Kruskal Gamma test, it was found that there was a positive correlation between social support and HIV knowledge perceptions in the elderly population, and there was a negative correlation between social support and HIV attitudinal perceptions in the elderly population. Ethnicity, current occupation or pre-retirement occupation, personal average after-tax monthly income, attitudinal perceptions, and social support were the influencing factors for the knowledge perceptions in the elderly population (P < 0.05); literacy, number of children, mode of residence, personal average monthly income after tax, knowledge perceptions, and social support were the influencing factors of attitudinal perceptions in the elderly population (P < 0.05). There is a correlation between social networks and HIV perceptions in China's elderly population, which is positively correlated with HIV knowledge perceptions and negatively correlated with HIV attitudinal perceptions, and it is important to improve the HIV prevention and knowledge of the elderly population and reduce their HIV-related discrimination.

Research on the compressive mechanical behavior and constitutive model modification of novel refractory high-entropy alloy (Ti2Zr)1.5NbVAl0.25

Abstract In recent years, high-entropy alloys have been widely applied across various fields. To explore the mechanical properties of high-entropy alloys and their characteristics under extreme environments, ingots of a quinary high-entropy alloy (Ti2Zr)1.5NbVAl0.25 were prepared. The material’s compression mechanical properties were studied under quasi-static conditions at room temperature with strain rates ranging from 0.001s−1 to 0.1s−1, dynamic compression at strain rates ranging from 1300s−1 to 3100s−1, and compression at a strain rate of 1900s−1 and temperatures from -80°C to 400°C. Impact specimens subjected to strain rates of 1300s−1 and 3100s−1 at room temperature were recovered for metallographic analysis. The results indicate that (Ti2Zr)1.5NbVAl0.25 exhibits significant strain-hardening behavior and strain rate sensitivity. Under medium to high strain rates, the alloy undergoes a phase transformation from a single-phase BCC structure to a mixture of BCC and B2 phases upon impact, with 2500s−1 being the threshold strain rate for phase transformation. The original parameters of the Johnson-Cook constitutive model were fitted based on experimental data, and modifications were made to the strain rate hardening and temperature terms in the original model. The modified Johnson-Cook constitutive model demonstrates improved prediction of the mechanical properties of (Ti2Zr)1.5NbVAl0.25 high-entropy alloy at both room temperature and under extreme environments.

Theta and gamma modulation in the nucleus accumbens as drivers of neurophysiological responses to acute methamphetamine sensitization in mice.

Methamphetamine (METH) has well-documented long-term effects on the brain, including increased psychomotor activity and behavioral sensitization. However, its immediate effects on the brain's reward system following acute exposure, which may contribute to the development of addiction, are less understood. This study aimed to investigate the effects of acute METH on brain oscillations in the nucleus accumbens of C57BL/6 mice. Mice in the METH group received 5mg/kg of METH for 5 days during the conditioning phase, followed by an 8-day abstinence period. Afterward, they underwent a 6-minute tail suspension test and were given a 1mg/kg METH challenge. Local field potential (LFP) data were analyzed for percent total power, mean frequency indices, and phase-amplitude coupling (PAC) to assess the neural effects of METH exposure across these phases. A reduction in theta power was observed across the conditioning, abstinence, and challenge phases of METH exposure. The subsequent METH challenge enhanced gamma oscillations, and PAC analysis revealed a consistent theta-gamma coupling index during both the METH administration and challenge phases. It highlights the sensitivity of the reward system to intense, short-term drug exposure, providing new insights into how acute neural stimulation may contribute to the development of addictive behaviors, reinforcing the brain's vulnerability to drug-induced changes in neural circuitry.

Role of Rab10 in cocaine-induced behavioral effects is associated with GABAB receptor membrane expression in the nucleus accumbens.

Previous studies have demonstrated that Ras-related GTP-binding protein Rab10 (Rab10) plays a role in psychostimulant-induced behavioral effects. In this study, we showed that Rab10 in the nucleus accumbens (NAc) of male animals affects the development of cocaine-induced behavioral effects, which are associated with the plasma membrane expression of the GABAB heteroreceptor (GABABR). We performed flow cytometry, immunoendocytosis, pHluorin activity analysis, electrophysiology analysis, and open-field testing to explore the role of Rab10 in modulating the membrane expression and function of GABABR and its regulatory effect on cocaine-induced behavioral effects. Transcriptomics analysis showed that Rab10 was elevated following acute cocaine treatment. Membrane levels of Rab10 increased within day 1 of the cocaine treatment, subsequently decreasing at later time points. Rab10 deficiency in NAc regions significantly increased cocaine-inhibited membrane GABABR levels and inhibited cocaine-induced hyperlocomotion and behavioral sensitization. In addition, GAD 67 + -expressing neurons from NAc regions treated with cocaine revealed a significant decrease in Rab10 membrane expression. Furthermore, NAc neuron-specific Rab10 knockout resulted in a significant increase in the cocaine-inhibited membrane expression of GABABR, along with increased miniature inhibitory postsynaptic current (mIPSC) amplitude and attenuation of baclofen-amplified Ca2+ influx. These results uncover a new mechanism in which Rab10-GABABR signaling may serve as a potential pathway for regulating cocaine-induced behavioral effects.