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RATIONALE: The accumulation of beta-amyloid peptide (Aß) in the forebrain leads to cognitive dysfunction and neurodegeneration in Alzheimer's disease. Studies have shown that individuals with a consistently cognitively active lifestyle are less vulnerable to Aß toxicity. Recent research has demonstrated that intrahippocampal Aß can impact catecholaminergic release and spatial memory. Interestingly, exposure to novelty stimuli has been found to stimulate the release of catecholamines in the hippocampus. However, it remains uncertain whether repeated enhancing catecholamine activity can effectively alleviate cognitive impairment in individuals with Alzheimer's disease. OBJECTIVES: Our primary aim was to investigate whether repeated exposure to novelty could enable cognitive resilience against Aß. This protection could be achieved by modulating catecholaminergic activity within the hippocampus. METHODS: To investigate this hypothesis, we subjected mice to three different conditions-standard housing (SH), repeated novelty (Nov), or daily social interaction (Soc) for one month. We then infused saline solution (SS) or Aß (Aß1-42) oligomers intrahippocampally and measured spatial memory retrieval in a Morris Water Maze (MWM). Stereological analysis and extracellular baseline dopamine levels using in vivo microdialysis were assessed in independent groups of mice. RESULTS: The mice that received Aß1-42 intrahippocampal infusions and remained in SH or Soc conditions showed impaired spatial memory retrieval. In contrast, animals subjected to the Nov protocol demonstrated remarkable resilience, showing strong spatial memory expression even after Aß1-42 intrahippocampal infusion. The stereological analysis indicated that the Aß1-42 infusion reduced the tyrosine hydroxylase axonal length in SH or Soc mice compared to the Nov group. Accordingly, the hippocampal extracellular dopamine levels increased significantly in the Nov groups. CONCLUSIONS: These compelling results demonstrate the potential for repeated novelty exposure to strengthen the dopaminergic system and mitigate the toxic effects of Aß1-42. They also highlight new and promising therapeutic avenues for treating and preventing AD, especially in its early stages.

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OBJECTIVES: Investigate whether the coexistence of pain and depressive symptoms is a risk factor for cognitive decline in individuals aged 50 or older. METHOD: Longitudinal trajectory study involving 4,718 participants from the English Longitudinal Study of Ageing (ELSA). Joint pain was self-reported, and intensity was classified as mild, moderate/intense. Depressive symptoms were investigated using the Centre for Epidemiologic Studies Depression Scale (CES-D-8 ≥ 4). The sample was divided into six groups: no pain and no depression (NP/NDe), mild pain and no depression (MP/NDe), moderate/intense pain and no depression (M-IP/NDe), no pain and depression (NP/De), mild pain and depression (MP/De), and moderate/intense pain and depression (M-IP/De). The outcome of interest was performance in memory, executive function, and global cognition. Generalised linear mixed models were used to analyse performance in the cognitive domains and global cognition score as a function of pain and depressive symptoms during 12 years of follow-up. RESULTS: Over time, individuals with M-IP/De had a greater memory decline (-0.038 SD/year, 95%CI: -0.068 to -0.007) and the global cognition score (-0.033 SD/year, 95%CI: -0.063 to -0.002) than those with NP/NDe. CONCLUSION: The coexistence of moderate/intense pain and depressive symptoms is a risk factor for the decline of global cognition and memory.

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Humans are exposed every day to innumerable external stimuli, both environmental and microbial. Immunological memory recalls each specific stimulus and mounts a secondary response that is faster and of a larger magnitude than the primary response; this process constitutes the basis for vaccine development. The COVID-19 pandemic offers a unique opportunity to study the development of immune memory against an emergent microorganism. Memory T cells have an important role in the resolution of COVID-19, and they are key pillars of immunological memory. In this review, we summarize the main findings regarding anti-SARS-CoV-2 memory T cells after infection, after vaccination, and after the combination of these two events ("hybrid immunity"), and analyze how these cells can contribute to long-term protection against the infection with SARS-CoV-2 variants.

Los humanos se exponen cada día a innumerables estímulos externos, tanto ambientales como microbianos. La memoria inmunológica registra de manera específica un estímulo y articula una respuesta secundaria más rápida y de mayor magnitud que la respuesta primaria; este proceso constituye la base del desarrollo de vacunas. La pandemia de COVID-19 ofreció la oportunidad de estudiar el desarrollo de la memoria inmunológica contra un microorganismo emergente. Las células T de memoria tienen un papel importante en la resolución de COVID-19 y son pilares importantes de la memoria inmunológica. En esta revisión se resumen los principales hallazgos de la respuesta de las células T de memoria contra la infección por SARS-CoV-2, a la vacunación o a la combinación de ambos procesos ("inmunidad híbrida"), y se discute cómo estas células pueden contribuir a la protección a largo plazo contra distintas variantes del virus.

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Obesity is a significant health concern that is correlated with various adverse health outcomes. Diet-induced obesity (DIO) is associated with impaired cognitive function. Pharmacological treatments for obesity are limited and may have serious adverse effects. Zingiber officinale (ZO) has anti-inflammatory and antioxidant effects, in addition to metabolic effects. This study aimed to assess the effects of Zingiber officinale supplementation on cognitive function, anxiety levels, neurotrophin levels, and the inflammatory and oxidative status in the cortex following DIO in mice. Two-month-old male Swiss mice were fed DIO or standard chow for 4 months and subsequently subdivided into the following groups (n = 10 mice/group): (i) control - vehicle (CNT + vehicle); (ii) CNT supplemented with ZO (CNT + ZO); (iii) obese mice (DIO + vehicle); and (iv) obese mice supplemented with ZO (DIO + ZO) (n = 10). Zingiber officinale extract (400 mg/kg/day) was administered for 35 days via oral gavage. The DIO + vehicle group exhibited impaired recognition memory. The CNT + ZO group presented a greater number of crossings in the open field. No difference between the groups was observed in the plus maze test. DIO + vehicle increased the DCFH and carbonylation levels in the cortex. The DIO + vehicle group presented a reduction in catalase activity. The expression of inflammatory or neurotrophin markers in the cerebral cortex was not different. In conclusion, our findings indicate that supplementation with ZO reverses the cognitive impairment in DIO mice and enhances the antioxidant status of the cerebral cortex.

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SMA actuators are a group of lightweight actuators that offer advantages over conventional technology and allow for simple and compact solutions to the increasing demand for electrical actuation. In particular, an increasing number of SMA torsional actuator applications have been published recently due to their ability to supply rotational motion under load, resulting in advantages such as module simplification and the reduction of overall product weight. This paper presents the conceptual design, operating principle, experimental characterization and working performance of torsional actuators applicable in active rudder in aeronautics. The proposed application comprises a pair of SMA torsion springs, which bi-directionally actuate the actuator by Joule heating and natural cooling. The experimental results confirm the functionality of the torsion springs actuated device and show the rotation angle of the developed active rudder was about 30° at a heating current of 5 A. After the design and experiment, one of their chief drawbacks is their relatively slow operating speed in rudder positioning, but this can be improved by control strategy and small modifications to the actuator mechanism described in this work.

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Here, we performed single-cell RNA sequencing of S1 and receptor binding domain protein-specific B cells from convalescent COVID-19 patients with different clinical manifestations. This study aimed to evaluate the role and developmental pathway of atypical memory B cells (MBCs) in response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The results revealed a proinflammatory signature across B cell subsets associated with disease severity, as evidenced by the upregulation of genes such as GADD45B, MAP3K8, and NFKBIA in critical and severe individuals. Furthermore, the analysis of atypical MBCs suggested a developmental pathway similar to that of conventional MBCs through germinal centers, as indicated by the expression of several genes involved in germinal center processes, including CXCR4, CXCR5, BCL2, and MYC. Additionally, the upregulation of genes characteristic of the immune response in COVID-19, such as ZFP36 and DUSP1, suggested that the differentiation and activation of atypical MBCs may be influenced by exposure to SARS-CoV-2 and that these genes may contribute to the immune response for COVID-19 recovery. Our study contributes to a better understanding of atypical MBCs in COVID-19 and the role of other B cell subsets across different clinical manifestations.

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Benzodiazepines are commonly used drugs to treat anxiety in crime witnesses. These increase GABA inhibitory effects, which impairs aversive memory encoding and consolidation. Eyewitness memory is essential in justice. However, memory is malleable leading to false memories that could cause a selection of an innocent in a lineup. Here, we studied whether a low dose of Clonazepam impairs memory encoding as well as consolidation of faces and narrative of the event. We performed two experiments using a double-blind and between subject design (N = 216). Day 1: subjects watched a crime video and received Clonazepam 0.25 mg (CLZ group) or placebo (PLC group) before (Exp. 1) or after the video (Exp. 2) to assess the effect on encoding and consolidation. One week later, the memory was assessed using a present and absent target lineup and asking for a free recall. Regarding encoding, we found that in the CLZ group memory was impaired in the free recall task, while no differences were found for recognition memory. Regarding consolidation, we did not observe memory measures that were affected by this dose of benzodiazepines. The results suggest that while some aspects of eyewitness memory could be modulated even with low doses of benzodiazepine, others could not be affected. More studies should be performed with higher doses of CLZ similar to those administered in real life. These results are relevant in the judicial field to assess the reliability of the eyewitness elections under the effects of this drug.

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We investigated whether allowing individuals to exchange verbal information during dyadic practice changed the effect of analogy instructions intended to strengthen explicit motor learning by an implicit means. Forty-three right-handed college students performed golf putting, aiming at a target three meters away. Participants were assigned to one of two groups: Dyadic Practice Analogy Instruction or Individual Practice Analogy Instruction. Participants in the Dyadic Practice group were allowed to communicate with one another about the task during their practice. Before practice, participants performed a working memory capacity test. Both groups performed 180 trials of golf distributed across three days. On each day, there were four blocks of 15 trials. On the third day, participants reported the explicit rules they used to learn the task and they completed the Intrinsic Motivation Inventory. On the fourth day, they took three learning tests: retention, dual-task transfer, and social pressure transfer tests. Results of the retention test indicated that both groups learned the task comparably. Similarly, there were no significant group differences between the participants' number of explicit rules learned and their motivation levels on either of the transfer tests. Finally, only the participants in the Dyadic Practice Analogy Group showed a significant correlation between their performance on the dual-task transfer test and their working memory capacity. Overall, we found that dyadic practice did not interfere with the implicit type of motor learning promoted by analogy instruction (i.e., implicit learning).

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Purpose: The globally increasing older population raises concerns about age-related conditions, including cognitive impairment and depressive symptoms. In Latin America, nearly one-third of the population is affected by either of these conditions. However, data investigating the association between cognitive impairment and depressive symptoms, particularly in Brazil, are limited to small-scale studies that have not carefully examined the critical effects of variables such as education level and socioeconomic status on this relationship. We aimed at exploring this association in a representative population-based cohort. Methods: We used the Brazilian Longitudinal Study of Aging (ELSI-BRAZIL) database to examine the relationship between depressive symptoms and cognitive impairment in Brazilian older adults, adjusted for potential confounders. Direct acyclic graphs and multivariable linear regression were used to build our model. Depressive symptoms were measured using a short version of the Center for Epidemiologic Studies Scale (CES D-8), and combined memory recall test as a surrogate of cognitive impairment. Results: The study included 8280 participants. Only education level was identified as a confounder for the relationship between memory loss and depressive symptoms. After adjusting for age, sex, and education level, there was strong evidence for a negative association between depressive symptoms and memory performance. For every 5-unit increase in the CES D-8 score, there was a reduction in memory capacity, translating to a loss of approximately one word in the combined words recall test (mean - 0.18, 95% CI -0.22; -0.15, P < 0.001). In addition, we found strong evidence for an interaction between socioeconomic status and depressive symptoms. Subjects belonging to medium socioeconomic status (SES) showed more pronounced memory decline, when compared to those with lower SES (mean - 0.28, 95% CI -0.42 to -0.14, P < 0.001). Conclusions: In adults aged over 50, after adjusting for sex, age, and educational level, a 5-unit increase in CES D-8 score is associated with loss of one point in the combined memory recall test. This association seems to be confounded by educational level and significantly modified by socioeconomic status.

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Introduction In clinical practice, patients with the same degree and configuration of hearing loss, or even with normal audiometric thresholds, present substantially different performances in terms of speech perception. This probably happens because other factors, in addition to auditory sensitivity, interfere with speech perception. Thus, studies are needed to investigate the performance of listeners in unfavorable listening conditions to identify the processes that interfere in the speech perception of these subjects. Objective To verify the influence of age, temporal processing, and working memory on speech recognition in noise. Methods Thirty-eight adult and elderly individuals with normal hearing thresholds participated in the study. Participants were divided into two groups: The adult group (G1), composed of 10 individuals aged 21 to 33 years, and the elderly group (G2), with 28 participants aged 60 to 81 years. They underwent audiological assessment with the Portuguese Sentence List Test, Gaps-in-Noise test, Digit Span Memory test, Running Span Task, Corsi Block-Tapping test, and Visual Pattern test. Results The Running Span Task score proved to be a statistically significant predictor of the listening-in-noise variable. This result showed that the difference in performance between groups G1 and G2 in relation to listening in noise is due not only to aging, but also to changes in working memory. Conclusion The study showed that working memory is a predictor of listening performance in noise in individuals with normal hearing, and that this task can provide important information for investigation in individuals who have difficulty hearing in unfavorable environments.