VTA-IC dopaminergic inputs enhances the salience to consolidate aversive but not appetitive taste recognition memory via D1 receptors

Taste memory involves storing information through plasticity changes in the neural network of taste, including the insular cortex (IC) and ventral tegmental area (VTA), a critical provider of dopamine. Although a VTA-IC dopaminergic pathway has been demonstrated, its role to consolidate taste recognition memory remains poorly understood. We found that photostimulation of dopaminergic neurons in the VTA or VTA-IC dopaminergic terminals of TH-Cre mice increases the salience to facilitate consolidation of a novel taste stimulus regardless of its hedonic value, without altering their taste palatability. Importantly, the inhibition of the D1-like receptor into the IC impairs the salience to facilitate consolidation of an aversive taste recognition memory. Finally, our results showed that VTA photostimulation improves the salience to facilitate consolidation of a conditioned taste aversion memory through the D1-like receptor into the IC. It is concluded that the dopamine activity from the VTA into IC is required to increase the salience to facilitate consolidation of a taste recognition memory. Notably, the D1-like receptor activity into the IC is required to consolidate both innate and learned aversive taste memories but not appetitive taste memory.

Holistic Solutions to Schizophrenia Management in Geriatric Populations

Schizophrenia is a psychiatric condition characterized by dysfunction in thoughts, behavior, and emotions. The illness is typically diagnosed in late adolescence to early adulthood, and generally lasts throughout a patient’s lifetime. This debilitating condition affects approximately 25% of adults aged 55 years old and older. With numbers of elderly adults afflicted by psychiatric illnesses increasing in the future, special precautions need to be taken to address this underserved population. This increase in schizophrenia frequency among elderly populations also has repercussions not just for future healthcare, but health costs as well, with schizophrenia expenses being costly in comparison to other psychiatric ailments. A major theory explaining the genetic and physiological basis of schizophrenia is the dopamine hypothesis, which describes a disruption in the normal transmission of the dopaminergic pathway as well as the mesolimbic system. Current treatments of schizophrenia often involve pharmacological interventions that create heightened side effects in the elderly. There is a need for more research into efficient and effective treatments for the future, especially treatments that can be safe for elderly use such as brain stimulating interventions. Destigmatizing mental health issues and advocating for safer and more efficient therapies are the key to improving outcomes of geriatric schizophrenic patients

Association of COMT Polymorphism and Academic Achievement among Female Undergraduate Students

Academic achievement may be influenced by catechol-O-methyltransferase (COMT) polymorphism. A common functional polymorphism of COMT, the rs4680 is consistently being involved in the modulation of dopaminergic pathway and prefrontal cortex function which may predominantly affect cognitive functions. A total of 197 female participants were recruited in this study. The score of student’s grade point average (GPA) from the latest previous semester was used as the measurement of academic achievement. The COMT polymorphism was genotyped using tetra primer allele specific polymerase chain reaction. The findings indicated that there were 8 (4.1 %), 72 (36.5 %), and 117 (59.4 %) participants harbouring Met/Met, Met/Val, and Val/Val genotype for COMT polymorphism respectively. All the genotype distributions of COMT polymorphism were consistent with Hardy-Weinberg equilibrium (χ2 = 0.495, p > 0.05). The one-way analysis of variance (ANOVA) result demonstrated that participants bearing Met/Met genotype had a better achievement in GPA as compared to the other COMT genotypes (p = 0.001). These findings support evidence that the affective role of COMT polymorphism might overwhelm cognitive abilities in measures of academic achievement like GPA.

Dopaminergic Projections From the Ventral Tegmental Area to the Nucleus Accumbens Modulate Sevoflurane Anesthesia in Mice

The role of the dopaminergic pathway in general anesthesia and its potential mechanisms are still unknown. In this study, we usedc-Fos staining combined with calcium fiber photometry recording to explore the activity of ventral tegmental area (VTA) dopaminergic neurons(VTA-DA) and nucleus accumbens (NAc) neurons during sevoflurane anesthesia. A genetically encoded dopamine (DA) sensor was used to investigate thefunction of the NAc in sevoflurane anesthesia. Chemogenetics and optogenetics were used to explore the role of the VTA-DA in sevofluraneanesthesia. Electroencephalogram (EEG) spectra, time of loss of righting reflex (LORR) and recovery of righting reflex (RORR) were recorded asassessment indicators. We found that VTA-DA and NAc neurons were inhibited during the induction period and were activated during the recoveryperiod of sevoflurane anesthesia. The fluorescence signals of dopamine decreased in the induction of and increased in the emergence from sevoflurane anesthesia.Activation of VTA-DA and the VTADA-NAc pathway delayed the induction and facilitated the emergence accompanying with thereduction of delta band and the augmentation of the gamma band. These data demonstrate that VTA-DA neurons play a critical role in modulating sevofluraneanesthesia via the VTADA-NAc pathway.

Dopaminergic pathway and athletic mind

Purpose: we reviewed that the mental fatigue is influenced by dopamine depletion, and we assume that increasing DA level can increase athletic stamina and promote athletic performance after prolong exercise. Methods: The search strategy was according to key words contain, Mental fatigue , Decision making , Dopamine, Stroboscope training through the Google scholar, PubMed, and Elsevier. Among the literatures, 100 papers include review and original articles were studied. Finally, we decided to select 49 papers based on similarity and recent studies so more than 50 percent of papers were excluded, because of they were out of date or irrelevant to key words. Results: Based on many studies, it was found dopamine has an essential role on athletic performance and his stamina. Conclusion: The stroboscope vision training in sports could enhance the dopaminergic neurons and associated visuo-motor skills

Parkinson’s disease: Is there a role for dietary and herbal supplements?

: Parkinson’s disease (PD) is characterised by degeneration of the neurons of the nigrostriatal dopaminergic pathway of the brain. The pharmacological cornerstone of PD management is mainly the use of dopamine precursors, dopamine receptor agonists, and agents that inhibit biochemical degradation of dopamine. While these drugs initially relief symptoms and improve the quality of life of patients, progression of the underlying pathological processes such as oxidative stress and neuroinflammation (which have been strongly associated with PD and other neurodegenerative disorders) eventually reduces their benefits; making further benefits now only achievable at high doses which amplify the magnitude and frequency of side-effects. Also, while it is becoming obvious that mainstream pharmacological agents may not always provide the much-needed answer, the question remains what succour can nature provide through dietary supplements, nutraceuticals and herbal remedies? This narrative review examines current literature for evidence of the possible roles (if any) of nutraceuticals, dietary supplements and herbal remedies in the prevention or management of PD, by examining how these compounds could modulate key factors and pathways that are crucial to the pathogenesis and/or progression of PD. The likely limitations of this approach and its possible future roles in PD prevention and management are also considered.

Quetiapine-Induced Place Preference in Mice: Possible Dopaminergic Pathway

Quetiapine, an atypical antipsychotic, is effective in the management of schizophrenia, depression, and anxiety. Although quetiapine overdosage and misuse have been reported, its abuse potential has not been investigated in animals. In this study, the abuse potential of quetiapine was assessed based on the conditioned place preference (CPP) paradigm of drug addiction in a mouse model. First, mice received intraperitoneal injections of quetiapine (40, 80, or 120 mg/kg) every other day during the conditioning phase. In the second experiment, mice were pretreated with 0.03 mg/kg SKF-35866, a D1 receptor antagonist, before receiving saline or quetiapine (120 mg/kg) during the conditioning phase. No significant changes in time spent in the quetiapine-paired chamber were observed compared with time spent in the saline-paired chamber in mice treated with 40 or 80 mg/kg. In contrast, the preference to the quetiapine-paired chamber was significantly increased in mice treated with 120 mg/kg quetiapine, and this effect was blocked by SKF-35866 pretreatment. These results demonstrated, for the first time, the abuse potential of quetiapine in an animal model of drug addiction. Interestingly, this CPP-inducing effect was likely mediated by activating D1 receptors.

Effort-Based Decision-Making for Exercise in People with Parkinson’s Disease

Background: People with Parkinson’s disease (PwPD) are less active than their age-matched peers. Non-motor symptoms, specifically, deficient motivation, may influence decision-making for exercise due to the impaired mesolimbic dopaminergic pathway. Objective: The purpose of this study was to determine if effort-based decision-making for physical effort was different in PwPD compared to healthy controls. We sought to determine the relationship between effort-based decision making for exercise and a discrete motor task as well as the impact of components of motivation on decision-making for physical effort in PwPD. Methods: An effort-based decision-making paradigm using a discrete motor task (button pressing) and a continuous exercise task (cycling) was implemented in 32 PwPD and 23 healthy controls. Components of motivation were measured using the Apathy Scale and the Temporal Experience of Pleasure Scale- Anticipatory Pleasure scale. Results: The presence of Parkinson’s disease (PD) did not moderate decisions for either physical effort task. There was a moderate correlation between decisions for both tasks, within each group. The anticipation of pleasure and apathy were predictors of decisions for both physical effort tasks in PwPD, but not in healthy controls. Conclusion: PwPD responded similarly to effort and reward valuations compared to those without PD. Individuals were consistent in their decisions, regardless of the physical effort task. The anticipation of pleasure and apathy were significant predictors of decisions for exercise in PwPD only. Increased anticipation of pleasure, reduction of apathy, and the use of rewards may enhance engagement in high effort exercise among PwPD.