RESUMO
Dopamine release in the nucleus accumbens core (NAcC) is generally considered to be a proxy for phasic firing of the ventral tegmental area dopamine (VTADA) neurons. Thus, dopamine release in NAcC is hypothesized to reflect a unitary role in reward prediction error signaling. However, recent studies reveal more diverse roles of dopamine neurons, which support an emerging idea that dopamine regulates learning differently in distinct circuits. To understand whether the NAcC might regulate a unique component of learning, we recorded dopamine release in NAcC while male rats performed a backward conditioning task where a reward is followed by a neutral cue. We used this task because we can delineate different components of learning, which include sensory-specific inhibitory and general excitatory components. Furthermore, we have shown that VTADA neurons are necessary for both the specific and general components of backward associations. Here, we found that dopamine release in NAcC increased to the reward across learning while reducing to the cue that followed as it became more expected. This mirrors the dopamine prediction error signal seen during forward conditioning and cannot be accounted for temporal-difference reinforcement learning. Subsequent tests allowed us to dissociate these learning components and revealed that dopamine release in NAcC reflects the general excitatory component of backward associations, but not their sensory-specific component. These results emphasize the importance of examining distinct functions of different dopamine projections in reinforcement learning.
Assuntos
Dopamina , Aprendizagem , Núcleo Accumbens , Recompensa , Animais , Núcleo Accumbens/metabolismo , Núcleo Accumbens/fisiologia , Dopamina/metabolismo , Masculino , Ratos , Aprendizagem/fisiologia , Ratos Sprague-Dawley , Sinais (Psicologia) , Área Tegmentar Ventral/fisiologia , Área Tegmentar Ventral/metabolismoRESUMO
Bilingual children experience more variation in their language environment than monolingual children and this impacts their rate of language development with respect to monolinguals. How long it takes for bilingual children learning English as a second language (L2) to display similar abilities to monolingual age-peers has been estimated to be 4-6 years, but conflicting findings suggest that even 6 years in school is not enough. Most studies on long-term L2 development have focused on just one linguistic sub-domain, vocabulary, and have not included multiple individual difference factors. For the present study, Chinese first language-English L2 children were given standardized measures of vocabulary, grammar and global comprehension every year from 4 ½ to 6 ½ years of English in school (ages 8½ to 10½); language environment factors were obtained through an extensive parent questionnaire. Children converged on monolingual norms differentially according to the test, with the majority of children reaching monolingual levels of performance on the majority of tests by 5 ½ years of English exposure. Individual differences in outcomes were predicted by length of English exposure, mother's education, mother's English fluency, child's use of English in the home, richness/quality of the English input outside school and age of arrival in Canada. In sum, the timeframe for bilinguals to catch up to monolinguals depends on linguistic sub-domain, task difficulty and on individual children's language environment, making 4-6 years an approximate estimate only. This study also shows that language environment factors shape not only early-stage but also late-stage bilingual development.
Assuntos
Desenvolvimento da Linguagem , Multilinguismo , Canadá , Criança , Pré-Escolar , Meio Ambiente , Humanos , Individualidade , Fatores de TempoRESUMO
Background: The overall prevalence of dyslipidemia continues to increase, which poses a significant risk for coronary artery disease. Some patients with dyslipidemia do not respond to or benefit from conventional lipid-lowering therapy, which warrants the need for alternative and complementary therapies. Chinese patent medicine (CPM) has shown great potential in the treatment of dyslipidemia, but its clinical value needs to be further explored. This study aims to systematically evaluate the efficacy and safety of CPM in treating dyslipidemia. Methods: This study was registered in INPLASY as INPLASY202330090. The randomized controlled trials included in this study were published in January 2013 to March 2023 and retrieved from the Web of Science, PubMed, Embase, Cochrane Library, SinoMed, China National Knowledge Internet, WanFang, and VIP. The bias risk in the study was independently evaluated by two reviewers using the Cochrane Randomized Trial Bias Risk Tool (RoB 2) Review Manager 5.4 software was used for the overall effect analysis and subgroup analysis of four blood lipids, and the trial sequential analysis (TSA) was conducted to check the results. Results: A total of 69 studies were included, involving 6,993 participants. The methodological quality was in the middle level. Meta-analysis showed that CPM markedly improved the levels of total cholesterol (TC) [mean difference (MD) =-0.54 mmol/L; 95% confidence interval (CI): -0.71 to -0.37; P<0.001], triglyceride (TG) (MD =-0.43 mmol/L; 95% CI: -0.53 to -0.33; P<0.001), low-density lipoprotein cholesterol (LDL-C) (MD =-0.40 mmol/L; 95% CI: -0.50 to -0.30; P<0.001) and increased levels of high-density lipoprotein cholesterol (HDL-C) (MD =0.23 mmol/L; 95% CI: 0.18 to 0.27; P<0.001), in patients with dyslipidemia. Though CPM did not differ significantly from statins when used alone, it could improve lipid profile better in all cases when used in combination with statins and with drugs used for comorbidities or co-morbidities. Subgroup analysis found that the efficacy of pill formulations was superior to other formulations, and CPM showed better lipid-lowering response in the context of comorbidity. The TSA confirmed the robustness of the analysis of the LDL-C level. No significant difference was observed in the incidence of adverse events between the treatment group and the control group [risk ratio (RR) =0.89; 95% CI: 0.69-1.16; P=0.40]. Conclusions: CPM can yield superior therapeutic effects in ameliorating dyslipidemia without exacerbating adverse effects as an alternative and complementary therapy. In addition, the therapeutic effect can be improved by emphasizing pill formulation and strengthening the standardization of syndromes.
RESUMO
BACKGROUND: Depression is a common psychiatric disorder and has become a growing public health issue. Traditional Chinese medicine (TCM) tonic prescriptions have been clinically proven to be an effective treatment for depression. PURPOSE: This study aimed to identify the core prescription to improve depression among the numerous TCM tonic prescriptions. METHODS AND RESULTS: First, we used meta-analysis to clarify the efficacy and safety of tonic prescriptions in depression among 37 studies and identified 16 effective tonic prescriptions. Second, we conducted data mining to analyze the tonic prescriptions and identified important nourishing herbs. Third, based on the data mining results, we constructed a Delphi experiment to investigate the effects of these important nourishing herbs in depression. Combining the results of Delphi expert questionnaires and weight analysis, a core TCM tonic prescription, Jianpi Tongmai formula (JPTMF) for the treatment of depression, was constructed and was composed of invigorating Spleen qi herbs. Fourth, we verified that JPTMF can improve chronic unpredictable mild stress (CUMS) induced depression-like behaviors in mice. Fifth, we predicted that the mechanism of JPTMF in the treatment of depression was mainly associated with chemical synaptic transmission and neuroinflammation through network pharmacology and determined preliminary confirmation through animal experiments. CONCLUSION: This study was undertaken to evaluate the efficacy of TCM tonic prescriptions on depression and construct a core TCM tonic prescription, JPTMF, through a progressive analysis. Network pharmacology and animal experiments verified the reliability of JPTMF. The proposal of JPTMF is of innovative significance, and may provide far-reaching implications for improving depression by using nourishing herbs. Furthermore, the integrated methods applied in this study provide an innovative paradigm for the standardization and scientific basis of TCM research.