Resilience and Vulnerability to Trauma: Early Life Interventions Modulate Aversive Memory Reconsolidation in the Dorsal Hippocampus.

Early life experiences program lifelong responses to stress. In agreement, resilience and vulnerability to psychopathologies, such as posttraumatic stress disorder (PTSD), have been suggested to depend on the early background. New therapies have targeted memory reconsolidation as a strategy to modify the emotional valence of traumatic memories. Here, we used animal models to study the molecular mechanism through which early experiences may later affect aversive memory reconsolidation. Handling (H)-separation of pups from dams for 10 min-or maternal separation (MS) - 3-h separation-were performed from PDN1-10, using non-handled (NH) litters as controls. Adult males were trained in a contextual fear conditioning (CFC) task; 24 h later, a short reactivation session was conducted in the conditioned or in a novel context, followed by administration of midazolam 3 mg/kg i.p. (mdz), known to disturb reconsolidation, or vehicle; a test session was performed 24 h after. The immunocontent of relevant proteins was studied 15 and 60 min after memory reactivation in the dorsal hippocampus (dHc) and basolateral amygdala complex (BLA). Mdz-treated controls (NH) showed decreased freezing to the conditioned context, consistent with reconsolidation impairment, but H and MS were resistant to labilization. Additionally, MS males showed increased freezing to the novel context, suggesting fear generalization; H rats showed lower freezing than the other groups, in accordance with previous suggestions of reduced emotionality facing adversities. Increased levels of Zif268, GluN2B, ß-actin and polyubiquitination found in the BLA of all groups suggest that memory reconsolidation was triggered. In the dHc, only NH showed increased Zif268 levels after memory retrieval; also, a delay in ERK1/2 activation was found in H and MS animals. We showed here that reconsolidation of a contextual fear memory is insensitive to interference by a GABAergic drug in adult male rats exposed to different neonatal experiences; surprisingly, we found no differences in the reconsolidation process in the BLA, but the dHc appears to suffer temporal desynchronization in the engagement of reconsolidation. Our results support a hippocampal-dependent mechanism for reconsolidation resistance in models of early experiences, which aligns with current hypotheses for the etiology of PTSD.

Determinação do limite mínimo de detecção da técnica de Nested-PCR para os poliomavírus JC e BK / Assessment of minimum detection limit of Nested-PCR for JC and BK polyomaviruses

Introduction: Polyomaviruses (BKV and JCV) cause infection mainly in immunocompromised adults. A sensitive and specific diagnosis tool is fundamental to demonstrate the BKV and JCV infections. Nowadays many laboratories are using a PCR technique for detecting polyomaviruses genome in clinical samples. In this context, the purpose of this study is to determine the threshold of detection of the nested-PCR for polyomaviruses JC and BK. Methods: Serial dilutions of the samples of BKV and JCV of known concentration (100 copies/mL, 50 copies/mL, 25 copies/mL, 10 copies/mL, 5 copies/mL, and 1 copy/ml) were subjected to the technique of nested-PCR. All dilutions were tested 11 times to determine the minimum detection limit. Results: The minimum detection limit of the nested-PCR for JC and BK viruses was 25 copies/mL. This dilution (25 copies/mL) showed 100% PCR positive reaction. Furthermore, we found that weak positive results were obtained at dilutions of 1,5 and 10 copies/mL in some repetitions. Dilutions of 25, 50, and 100 copies/mL always had very positive results. Conclusions: These values are similar to those reported in other studies, contributing to the indication of this PCR for potential diagnostic purposes.

Introdução: Os poliomavírus (JCV e BKV) causam infecções principalmente em adultos imunocomprometidos. Um diagnóstico sensível e específico é de fundamental importância para os pacientes portadores de JCV e BKV. Atualmente alguns laboratórios têm utilizado a técnica de PCR para a detecção do material genético destes vírus em amostras clínicas. Assim, o objetivo deste estudo é determinar o limite mínimo de detecção da técnica de nested-PCR para os poliomavírus JC e BK. Métodos: Diluições seriadas (100 cópias/mL; 50 cópias/mL; 25 cópias/mL; 10 cópias/mL; 5 cópias/mL e 1 cópia/mL) de controles positivos comerciais de JCV e BKV com concentrações conhecidas foram submetidas à técnica de nested-PCR semi-duplex. Todas as diluições foram testadas 11 vezes para determinação do limite mínimo de detecção. Resultados: O limite mínimo de detecção da reação de nested-PCR para os vírus JC e BK foi de 25 cópias/mL para ambos, com 100% de positividade das diluições testadas na reação de PCR. Ainda, pudemos observar que resultados positivos fracos foram obtidos nas diluições de 1, 5 e 10 cópias/mL em algumas das repetições realizadas. As diluições de 25, 50 e 100 cópias/mL sempre obtiveram resultado rancamente positivo. Conclusões: Estes valores são semelhantes aos relatados em outros estudos, contribuindo para a indicação desta reação de PCR para potenciais fins diagnósticos.

Processo de envelhecimento: percepcoes de docentes da rede basica de educacao do municipio de Uruguaiana-RS / Aging process: perceptions of elementary school teachers of the municipal education in Uruguaiana-RS, Brazil

OBJETIVO: Verificar a percepção do processo de envelhecimento humano pelos docentes da rede pública de educação básica de Uruguaiana-RS. MÉTODOS: Trata-se de estudo descritivo, cuja amostra foi composta por 13 educadores que responderam a um questionário, previamente validado por pesquisadores da área, contendo oito perguntas. As respostas foram posteriormente lidas, analisadas e categorizadas por meio da técnica de análise de conteúdo. RESULTADOS: Encontraram-se aspectos positivos e negativos na investigação, de acordo com os valores socioculturais de cada docente. Os educadores encaram o envelhecimento como uma etapa de transferência e partilha de experiências e conhecimentos e, apesar das adversidades e problemas de saúde que supostamente enfrentarão, têm uma visão otimista desse processo. CONCLUSÕES: Os relatos afirmaram que a qualidade de vida futura é reflexo da atual. Assim, a autopercepção pode levar à mudança de comportamento de uma comunidade, proporcionando uma ótica diferente desse ciclo biológico. Ressalta-se a importância de se investir em estudos de conscientização para eliminar preconceitos e estereótipos comuns às pessoas em relação a essa etapa da vida, especialmente junto a esse público que é formador de opinião. .

OBJECTIVE: To assess the perception about the human aging process of teachers from public elementary schools in the city of Uruguaiana, state of Rio Grande do Sul, Brazil. METHODS: This is a descriptive study, with sample composed by 13 teachers who responded to a questionnaire previously validated by researchers, containing eight questions, which was subsequently read, analyzed and categorized through the content analysis technique. RESULTS: There were positives and negatives in that investigation, in accordance with the sociocultural values of each teacher. Educators see aging as a step for the transfer and sharing of experiences and knowledge, and in spite of adversity and health problems that supposedly will face, they have an optimistic view of this process. CONCLUSIONS: The reports stated that the future quality of life is a reflection of the current, so self-perception can change the behavior of a community by providing different perspectives of this biological cycle. We emphasize the importance of investing in studies to suppress prejudices and stereotypes common to people concerning this stage of life, especially with this audience that is an opinion maker. .