Search Results (89)

The investigation of the reward system is a fascinating domain with future applications for pain therapy and understanding addiction. We investigated interactions between tramadol use and the imidazoline system, through the modulatory effects of imidazoline receptor blockers, by behavior analysis and electroencephalography (EEG). Thirty-six male Wistar rats were placed within a conditioned place preference (CCP) setting using a three-compartment box apparatus. The transition of the six groups of subjects from one compartment to another was constantly monitored, related to preconditioning for one day, conditioning for eight days, and post-conditioning testing on day 10. During the conditioning phase, the groups received: a saline solution, efaroxan, idazoxan, tramadol, tramadol + efaroxan, and tramadol + idazoxan, respectively. The administration of efaroxan, idazoxan, or a saline solution in the non-preferred compartment did not alter the time spent by rats there. On the other hand, the administration of tramadol alone in the non-preferred compartment significantly increased the time spent by animals there (151.66 ± 11.69 s) post-conditioning as compared to preconditioning (34.5 ± 5.31 s) (p < 0.01), while the combination of efaroxan and tramadol significantly reduced its effect. After the combination with idazoxan, the effect of tramadol on increasing the time spent by the animal in the non-preferred compartment remained significantly higher than in the preconditioning phase. A significant increase in time spent in the non-preferred compartment demonstrates the existence of a CPP induction effect (by changing the preference). The effects of tramadol on the reward system can cause changes in the brain’s neuroplasticity, potentially leading to learned behaviors that promote drug seeking in previous non-preferred environments. Full article

Clinical and animal studies suggest that multiple brain systems are involved in mediating reward-motivated and related emotional behavior including the consumption of commonly used drugs and palatable food, and there is evidence that the repeated ingestion of or exposure to these rewarding substances may in turn stimulate these brain systems to produce an overconsumption of these substances along with co-occurring emotional disturbances. To understand this positive feedback loop, this review focuses on a specific population of hypothalamic peptide neurons expressing melanin-concentrating hormone (MCH), which are positively related to dopamine reward and project to forebrain areas that mediate this behavior. It also examines neurons expressing the peptide hypocretin/orexin (HCRT) that are anatomically and functionally linked to MCH neurons and the molecular systems within these peptide neurons that stimulate their development and ultimately affect behavior. This report first describes evidence in animals that exposure in adults and during adolescence to rewarding substances, such as the drugs alcohol, nicotine and cocaine and palatable fat-rich food, stimulates the expression of MCH as well as HCRT and their intracellular molecular systems. It also increases reward-seeking and emotional behavior, leading to excess consumption and abuse of these substances and neurological conditions, completing this positive feedback loop. Next, this review focuses on the model involving embryonic exposure to these rewarding substances. In addition to revealing a similar positive feedback circuit, this model greatly advances our understanding of the diverse changes that occur in these neuropeptide/molecular systems in the embryo and how they relate, perhaps causally, to the disturbances in behavior early in life that predict a later increased risk of developing substance use disorders. Studies using this model demonstrate in animals that embryonic exposure to these rewarding substances, in addition to stimulating the expression of peptide neurons, increases the intracellular molecular systems in neuroprogenitor cells that promote their development. It also alters the morphology, migration, location and neurochemical profile of the peptide neurons and causes them to develop aberrant neuronal projections to forebrain structures. Moreover, it produces disturbances in behavior at a young age, which are sex-dependent and occur in females more than in males, that can be directly linked to the neuropeptide/molecular changes in the embryo and predict the development of behavioral disorders later in life. These results supporting the close relationship between the brain and behavior are consistent with clinical studies, showing females to be more vulnerable than males to developing substance use disorders with co-occurring emotional conditions and female offspring to respond more adversely than male offspring to prenatal exposure to rewarding substances. It is concluded that the continued consumption of or exposure to rewarding substances at any stage of life can, through such peptide brain systems, significantly increase an individual’s vulnerability to developing neurological disorders such as substance use disorders, anxiety, depression, or cognitive impairments. Full article

Digital franchising is increasingly recognized as a technological advancement and a specialized subset of e-commerce, yet its unique entrepreneurial dynamics remain insufficiently explored in the existing literature. Previous studies have primarily focused on platform usability or general e-commerce adoption, often overlooking the motivational, contextual, and capability-based factors that influence individuals’ willingness to engage in digital franchising as either entrepreneurs or consumers. To address this research gap, the present study applies the Motivation-Opportunity-Ability (MOA) framework to examine how personal motivations (e.g., self-expression, financial rewards), perceived platform opportunities (e.g., support, attractiveness), and individual capabilities (e.g., digital literacy, self-efficacy) shape entrepreneurial intention and, in turn, influence consumption adoption intention in digital franchising environments. An online survey was conducted using a non-probability purposive sampling method. The final sample consisted of 491 respondents from Taiwan, all of whom were either entrepreneurs operating digital franchises in the fashion industry or consumers who had purchased fashion products through digital franchising platforms, thereby ensuring contextual relevance to the study’s focus. Data were analyzed using structural equation modeling (SEM). The results indicate that expected external rewards (β = 0.456, p < 0.001) and platform support (β = 0.315, p < 0.001) are the most influential factors in shaping entrepreneurial intention. Furthermore, entrepreneurial intention significantly mediates the relationship between MOA antecedents and consumption adoption intention (β = 0.176, p < 0.001), highlighting its role as a key behavioral mechanism. These findings extend the MOA framework to a new empirical setting and offer practical implications for platform developers, franchisors, and policymakers seeking to promote participation in digital franchising. Future research is encouraged to explore cross-industry comparisons, generational differences, and longitudinal approaches to further enrich the understanding of digital franchising adoption dynamics. Full article

Background/Objectives: Obesity is a major public health challenge of the 21st century, with prevalence rates steadily rising globally. Disordered eating behaviors, particularly emotional eating (EE), complicate the clinical management of obesity and hinder long-term outcomes, such as maintaining weight loss after bariatric surgery. Studies reveal that EE affects 65–75% of overweight or obese adults, and such behavior may stem from a disrupted brain reward system linked to emotional dysregulation and impulsivity. Impulsivity in obesity involves deficient cognitive inhibitory control, creating an imbalance between impulsive and reflective systems. While problematic eating behaviors and obesity are well studied, the role of affective temperaments—innate traits influencing mood, energy, and responses to stimuli—remains underexplored. This study aims to examine the interplay between emotional eating, impulsivity, and affective temperaments in obese patients preparing for bariatric surgery. Methods: A total sample of 304 obese outpatients was consecutively enrolled at the Psychiatry Clinic of the Department of Clinical and Experimental Medicine of the University of Pisa during the presurgical mental health evaluation routinely performed before the bariatric intervention. Sociodemographic and clinical data were collected by psychiatrists during a single consultation. Assessments also included the following psychometric tests: the Structured Clinical Interview (SCID-5), the Emotional Eating Scale (EES), the Barratt Impulsivity Scale-Version 11 (BIS-11), and the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego-Auto-questionnaire (TEMPS-A). Results: A significant correlation was observed between the EES total score and the BIS total score (p = 0.003), as well as with the sub-dimensions of attentional impulsivity (p < 0.001) and motor impulsivity (p = 0.024). In addition, a significant correlation has been found between the total score of EES and the cyclothymic (p < 0.001), depressive (p < 0.001), irritable (p = 0.013), and anxious (0.020) temperaments. When comparing obese patients with EE and without EE (No-EE), higher rates of both current (p = 0.007) and lifetime (p = 0.024) psychiatric comorbidities were observed in the EE group, namely for anxiety disorders (p = 0.008) and eating disorders (p = 0.014). Conclusions: Our study highlights a significant association between EE in obese patients with the cyclothymic, irritable, anxious, and depressive temperaments, and impulsivity dimension. Thus, problematic eating behaviors and temperamental traits may have a bidirectional psychopathological influence in obese patients and need to be carefully evaluated in subjects seeking bariatric surgery. Full article

The increasing emphasis on environmental sustainability in organizations has underscored the need to understand how human resource practices shape employee environmental behaviors and perceptions. This scoping review examines the relationship between Green Human Resource Management (GHRM) practices and Green Psychological Climate (GPC), analyzing their combined impact on organizational environmental outcomes through the Abilities–Motivation–Opportunities (AMO) framework. Following PRISMA-P guidelines, 16 empirical studies published between 2017 and 2024 were systematically reviewed. Findings reveal strong positive associations between GHRM and GPC, with green pay and rewards, performance management, and training emerging as key drivers. GPC acts as a critical mediating mechanism, facilitating the translation of GHRM initiatives into enhanced environmental performance and voluntary green behaviors. The effectiveness of these relationships is influenced by organizational factors (e.g., ethical leadership, green culture) and individual characteristics (e.g., environmental sensitivity, age). Through the AMO lens, the results suggest that an integrated GHRM system that enhances employees’ abilities, motivation, and opportunities creates synergistic effects, fostering a sustainability-oriented climate and reinforcing pro-environmental behaviors. These findings contribute to the theoretical understanding of sustainability-oriented HRM while offering practical insights for organizations seeking to align human resource practices with environmental objectives. Full article

Background/Objectives: Cocaine use disorder is an intersecting issue in populations with HIV-1, further exacerbating the clinical course of the disease and contributing to neurotoxicity and neuroinflammation. Cocaine and HIV neurotoxins play roles in neuronal damage during neuroHIV progression by disrupting glutamate homeostasis in the brain. Even with combined antiretroviral therapy (cART), HIV-1 Nef, an early viral protein expressed in approximately 1% of infected astrocytes, remains a key neurotoxin. This study investigates the relationship among Nef, glutamate homeostasis, and cocaine in the nucleus accumbens (NAc), a critical brain region associated with drug motivation and reward. Methods: Male and female Sprague Dawley rats were used to compare the effects of astrocytic Nef and cocaine by molecular analysis of glutamate transporters, GLT-1 and the cysteine glutamate exchanger (xCT), in the NAc. Behavioral assessments for cocaine self-administration were used to evaluate cocaine-seeking behavior. Results: The findings indicate that both cocaine and Nef independently decrease the expression of the glutamate transporter GLT-1 in the NAc. Additionally, rats with astrocytic Nef expression exhibited increased cocaine-seeking behavior but demonstrated sex-dependent molecular differences after the behavioral paradigm. Conclusions: The results suggest that the expression of Nef intensifies cocaine-induced alterations in glutamate homeostasis in the NAc, potentially underlying increased cocaine-seeking behavior. Understanding these interactions better may inform therapeutic strategies for managing cocaine use disorder in HIV-infected individuals. Full article

Background/Objectives: Learning is classically modeled to consist of an acquisition period followed by a mastery period when the skill no longer requires conscious control and becomes automatic. Dopamine neurons projecting to the ventral striatum (VS) produce a teaching signal that shifts from responding to rewarding or aversive events to anticipating cues, thus facilitating learning. However, the role of the dopamine-receptive neurons in the ventral striatum, particularly in encoding decision-making processes, remains less understood. Methods: Here, we introduce an operant conditioning paradigm using open-source microcontrollers to train mice in three sequential learning phases. Phase I employs classical conditioning, associating a 5 s sound cue (CS) with a sucrose–water reward. In Phase II, the CS is replaced by a lever press as the requirement for reward delivery, marking an operant conditioning stage. Phase III combines these elements, requiring mice to press the lever during the CS to obtain the reward. We recorded calcium signals from direct pathway spiny projection neurons (dSPNs) in the VS throughout the three phases of training. Results: We find that dSPNs are specifically engaged when the mouse makes a decision to perform a reward-seeking action in response to a CS but are largely inactive during actions taken outside the CS. Conclusions: These findings suggest that direct pathway neurons in the VS contribute to decision-making in learned action–outcome associations, indicating a specialized role in initiating operant behaviors. Full article

The mesolimbic reward system originating from dopamine neurons in the ventral tegmental area (VTA) of the midbrain shows a profound reduction in function during cannabinoid withdrawal. This condition may underlie aversive states that lead to compulsive drug seeking and relapse. The lateral habenula (LHb) exerts negative control over the VTA via the GABA rostromedial tegmental nucleus (RMTg), representing a potential convergence point for drug-induced opponent processes. We hypothesized that the LHb–RMTg pathway might be causally involved in the hypodopaminergic state during cannabinoid withdrawal. To induce Δ⁹-tetrahydrocannabinol (THC) dependence, adult male Sprague–Dawley rats were treated with THC (15 mg/kg, i.p.) twice daily for 6.5–7 days. Administration of the cannabinoid antagonist rimonabant (5 mg/kg, i.p.) precipitated a robust behavioral withdrawal syndrome, while abrupt THC suspension caused milder signs of abstinence. Extracellular single unit recordings confirmed a marked decrease in the discharge frequency and burst firing of VTA dopamine neurons during THC withdrawal. The duration of RMTg-evoked inhibition was longer in THC withdrawn rats. Additionally, the spontaneous activity of RMTg neurons and of LHb neurons was strongly depressed during cannabinoid withdrawal. These findings support the hypothesis that functional changes in the habenulo–mesencephalic circuit are implicated in the mechanisms underlying substance use disorders. Full article

The reinforcement of drug-seeking motivation following drug withdrawal is recognized as a significant factor contributing to relapse. The ventral pallidum (VP) plays a crucial role in encoding and translating motivational aspects of reward. However, current research lacks a clear understanding of how the VP mediates drug-seeking motivation and the feedback modulation between the VP and the nucleus accumbens (NAc) following drug withdrawal. Therefore, utilizing a rat model of cocaine self-administration, we investigated the circuitry mechanisms underlying drug-seeking behavior post-drug withdrawal involving the NAc-VP pathway. Initially, we observed a significant enhancement in drug-seeking behavior 14 days after cocaine withdrawal. Subsequently, we identified the feedback mechanism through which the NAc-VP regulates this behavior. Immunofluorescence results indicated an increase in c-Fos expression levels in the ventral pallidum ventromedial (VPvm) and ventrolateral ventral pallidum (VPvl) following drug withdrawal. Calcium fiber photometry further elucidated that during the expression of high motivational drug-seeking behavior, there was a specific enhancement in VPvm neuronal activity, and retrograde tracing techniques suggested a weakened transmission function in the NAc-VPm pathway. Additionally, chemical genetic techniques demonstrated that inhibiting the activity of the NAc-VP pathway could increase the motivational level of drug-seeking behavior. These findings indicate that the reduced inhibitory function of the NAc-VP pathway following prolonged cocaine withdrawal forms the basis for heightened reactivity in VPvm neurons, thus regulating the expression of high motivational behavior triggered by drug-related cues. Our study results suggest that maintaining normal NAc-VP pathway functionality may decrease drug-seeking motivation post long-term drug withdrawal, offering new insights for interventions targeting relapse. Full article

Management factors are among the most significant causes of construction safety incidents, and there is an issue of insufficient supervision at present. The degree of diligence exhibited by relevant entities is crucial, and the payoff can influence the decision-making behaviors of involved parties. Based on this, the aim of this paper is to investigate how to enhance the initiative of enterprises in fulfilling their safety responsibilities during the construction process. By developing a tripartite evolutionary game model that involves supervision companies, general contractors, and labor subcontractors and conducting numerical simulation analysis, we reveal that simultaneous proactive investment in safety by all three parties is challenging, with labor subcontractors being relatively more prone to opt for active safety investment. Supervision companies and general contractors often struggle to fulfill their safety duties at the same time. Factors such as the rewards and penalties stipulated in a contract, rent-seeking amounts, and accident-related losses have a significant impact on the evolution of the system. Based on the findings, we propose recommendations for construction management, which include the management of labor subcontracting in construction, the control of rent-seeking behaviors, and the establishment of a cooperative safety culture during the construction process. Full article

Since game mechanics and their visual aspects have become more and more addictive, there is concern about the growing prevalence of Internet gaming disorder (IGD). In the current narrative review, we searched PubMed and Google Scholar databases for the keywords “igd biomarker gaming” and terms related to biomarker modalities. The biomarkers we found are grouped into several categories based on a measurement method and are discussed in the light of theoretical addiction models (tripartite neurocognitive model, I-PACE). Both theories point to gaming-related problems with salience and inhibition. The first dysfunction makes an individual more susceptible to game stimuli (raised reward seeking), and the second negatively impacts resistance to these stimuli (decreased cognitive control). The IGD patients’ hypersensitivity to reward manifests mostly in ventral striatum (VS) measurements. However, there is also empirical support for a ventral-to-dorsal striatal shift and transition from goal-directed to habitual behaviors. The deficits in executive control are demonstrated in parameters related to the prefrontal cortex (PFC), especially the dorsolateral prefrontal cortex (DLPFC). In general, the connection of PFC with reward under cortex nuclei seems to be dysregulated. Other biomarkers include reduced P3 amplitudes, high-frequency heart rate variability (HRV), and the number of eye blinks and saccadic eye movements during the non-resting state. A few studies propose a diagnostic (multimodal) model of IGD. The current review also comments on inconsistencies in findings in the nucleus accumbens (NAcc), anterior cingulate cortex (ACC), and precuneus and makes suggestions for future IGD studies. Full article

The incidence of obesity has markedly increased globally over the last several decades and is believed to be associated with the easier availability of energy-dense foods, including high-fat foods. The reinforcing hedonic properties of high-fat foods, including olfactory cues, activate reward centers in the brain, motivating eating behavior. Thus, there is a growing interest in the understanding of the genetic changes that occur in the brain that are associated with obesity and eating behavior. This growing interest has paralleled advances in genomic methods that enable transcriptomic-wide analyses. Here, we examined the transcriptomic-level differences in the olfactory bulb and striatum, regions of the brain associated with olfaction and hedonic food-seeking, respectively, in high-fat-diet (HFD)-fed obese mice. To isolate the dietary effects from obesity, we also examined transcriptomic changes in normal-chow-fed and limited-HFD-fed groups, with the latter being pair-fed with an HFD isocaloric to the consumption of the normal-chow-fed mice. Using RNA sequencing, we identified 274 differentially expressed genes (DEGs) in the striatum and 11 in the olfactory bulb of ad libitum HFD-fed mice compared to the chow-fed group, and thirty-eight DEGs in the striatum between the ad libitum HFD and limited-HFD-fed groups. The DEGs in both tissues were associated with inflammation and immune-related pathways, including oxidative stress and immune function, and with mitochondrial dysfunction and reward pathways in the striatum. These results shed light on potential obesity-associated genes in these regions of the brain. Full article

Oleoylethanolamide (OEA) is a lipid with anti-inflammatory activity that modulates multiple reward-related behaviors. Previous studies have shown that OEA treatment reduces alcohol self-administration (SA) while inhibiting alcohol-induced inflammatory signaling. Nevertheless, the specific mechanisms that OEA targets to achieve these effects have not been widely explored. Here, we tested the effects of OEA treatment during alcohol SA, extinction or previous to cue-induced reinstatement of alcohol seeking. In addition, we measured gene expression changes in the striatum and hippocampus of relevant receptors for alcohol consumption (Drd1, Drd2, Cnr1, Oprm) as well as immune-related proteins (Il-6, Il-1β, Tlr4) and the brain-derived neurotrophic factor (Bdnf). Our results confirmed that when administered contingently, systemic OEA administration reduced alcohol SA and attenuated cue-induced reinstatement. Interestingly, we also observed that OEA treatment reduced the number of sessions needed for the extinction of alcohol seeking. Biochemical analyses showed that OEA induced gene expression changes in dopamine and cannabinoid receptors in the striatum and hippocampus. In addition, OEA treatment modulated the long-term immune response and increased Bdnf expression. These results suggest that boosting OEA levels may be an effective strategy for reducing alcohol SA and preventing relapse. Full article

In recent years, enterprises have increasingly recognized the pivotal role of external users in driving product innovation. Open innovation platforms (OIPs), which facilitate interactions between companies and external innovators, have emerged as critical conduits in this regard. However, OIP managers face the challenge of motivating innovators to sustain their contributions. While some OIPs have implemented material incentives, the impact of such rewards on users’ ongoing innovation efforts remains uncertain. This study utilized a large-scale dataset from an OIP to examine how performance-contingent material rewards influence the subsequent behaviors of online innovators. Employing a quasi-experimental design involving propensity score matching (PSM) and difference-in-differences (DID) analysis, we found that receiving performance-contingent material rewards led to a decrease in the quantity of subsequent ideas generated by innovators. However, these rewarded innovators produced ideas of higher quality. Interestingly, the novelty of ideas submitted by innovators declined following their receiving of rewards. Moreover, newly enlisted innovators exhibited a more positive response to these incentives. Our findings provide valuable insights for platform managers seeking to optimize incentive mechanisms. We suggest adopting diversified incentive approaches and refining incentive strategies to effectively motivate continuous innovation among users on OIPs. Full article

The human reward network consists of interconnected brain regions that process stimuli associated with satisfaction and modulate pleasure-seeking behaviors. Impairments in reward processing have been implicated in several medical and psychiatric conditions, and there is a growing interest in disentangling the underlying pathophysiological mechanisms. The brain–gut axis plays a regulatory role in several higher-order neurophysiological pathways, including reward processing. In this context, the aim of the current review was to critically appraise research findings on the contribution of the brain–gut axis to the human reward system. Enteric neuropeptides, which are implicated in the regulation of hunger and satiety, such as ghrelin, PYY_3–36, and glucagon-like peptide 1 (GLP-1), have been associated with the processing of food-related, alcohol-related, and other non-food-related rewards, maintaining a delicate balance between the body’s homeostatic and hedonic needs. Furthermore, intestinal microbiota and their metabolites have been linked to differences in the architecture and activation of brain reward areas in obese patients and patients with attention deficit and hyperactivity disorder. Likewise, bariatric surgery reduces hedonic eating by altering the composition of gut microbiota. Although existing findings need further corroboration, they provide valuable information on the pathophysiology of reward-processing impairments and delineate a novel framework for potential therapeutic interventions. Full article