Differential effect of chronic mild stress on anxiety and depressive-like behaviors in three strains of male and female laboratory mice.

Major depressive disorder is the most common psychiatric disorder worldwide. To understand mechanisms and search for new approaches to treating depression, animal models are crucial. Chronic mild stress (CMS) is the most used animal model of depression. Although CMS is considered a robust model of depression, conflicting results have been reported for emotion-related behaviors, which the intrinsic characteristics of each rodent strain could explain. To further shed light on the impact of genetic background on the relevant parameters commonly addressed in depression, we examined the effect of 4-weeks CMS on anxiety and depression-related behaviors and body weight gain in three strain mice (BALB/c, C57BL/6, and CD1) of both sexes. CMS reduced body weight gain in C57BL/6NCrl and CD1 male mice. C57BL/6 animals exhibited a more pronounced anxious-like behavior than CD1 and BALB/c mice in the light-dark box (LDB) and the elevated plus maze (EPM) tests, whereas BALB/c animals exhibited the more robust depressive-like phenotype in the splash test (ST), tail suspension test (TST) and forced-swimming test (FST). Under CMS, exposure did not affect anxiety-related behaviors in any strain but induced depression-like behaviors strain-dependently. CMS C57BL/6 and CD1 mice of both sexes showed depression-like behaviors, and CMS BALB/c male mice exhibited reduced depressive behaviors in the FST. These results suggest a differential effect of stress, with the C57BL/6 strain being more vulnerable to stress than the CD1 and BALB/c strain mice. Furthermore, our findings emphasize the need for researchers to consider mouse strains and behavioral tests in their CMS experimental designs.

Resilience Dysregulation in Major Depressive Disorder: Focus on Glutamatergic Imbalance and Microglial Activation.

BACKGROUND: Many studies have been shown an important role of glutamatergic system as well microglial activation in the pathophysiology of major depressive disorder (MDD). In humans most resistant to the development of psychiatric disorders, including MDD, are observed a greater degree of resilience resulting from stress. Less resilience is associated with neuroendocrine and neuroinflammatory markers, as well as with glutamatergic system dysregulation. Thus, this review we highlighted findings from literature identifying the function of glutamatergic system, microglial activation and inflammation in resilience. METHODS: We conducted a review of computerized databases from 1970 to 2017. RESULTS: There is an association between microglial activation and glutamatergic system activation with stress vulnerability and resilience. CONCLUSIONS: Glutamate neurotransmission, including neurotransmitter synthesis, signalling, and glutamate receptor functions and expression all seem to be involved with both stress vulnerability and resilience. Moreover, inflammation and microglial activation mediate individual differences in resilience and the risk of stress-induced MDD.

Epigenética, cuidados maternais e vulnerabilidade ao estresse: conceitos básicos e aplicabilidade / Epigenetics, maternal care and stress vulnerability: basic concepts and applicability

Cuidados maternais são experiências do início da vida que têm sido consistentemente relacionados com alterações na expressão gênica por meio de mecanismos epigenéticos como a metilação do DNA ou a modificação de suas histonas. O objetivo deste trabalho é apresentar uma investigação teórica sobre cuidados maternais enquanto evento ambiental que pode produzir alterações epigenéticas atuantes na composição da vulnerabilidade ao estresse. A investigação teve por base estudos empíricos e de revisão de literatura com animais não humanos sobre Epigenética, estresse e cuidados maternais. Apresenta também alguns estudos com humanos que mostram tais efeitos, destacando-se aqueles que influenciam ou são influenciados pelo comportamento operante. A partir da investigação realizada encontrou-se que cuidados maternais pós-parto são uma condição ambiental que produz efeitos no eixo hipotálamo-pituitária-adrenal (HPA), participando da composição da vulnerabilidade ao estresse. Seus possíveis efeitos fisiológicos no condicionamento operante sinalizam alternativas para intervenções baseadas na plasticidade da formação do epigenoma. Este conhecimento, além de promover a aproximação entre a Epigenética e a Análise do Comportamento em nível básico por meio de estudos com animais não humanos, poderá contribuir em nível aplicado para um melhor entendimento do neurodesenvolvimento infantil e adequado planejamento de intervenções efetivas com mães e filhos. (AU)

Maternal care is an early life experience that has been consistently related to alterations in the genetic expression through epigenetic mechanisms such as DNA methylation or DNA histone modification. The present study aims to present a theoretical investigation about maternal care as an environmental event that may produce epigenetic alterations related to the biological bases of stress vulnerability. The research was based on empirical studies as well as literature review on non-human animals concerning epigenetics, stress and maternal care. It also presents some studies on humans that show such effects, particularly the ones that influence or are influenced by the operant behavior. Post-natal maternal care is found to cause effects on the hypothalamic-pituitary-adrenal (HPA) axis activity participating in the building of stress vulnerability. Its possible physiological effects on the operant conditioning point out to alternatives to intervention based on the plasticity of the epigenome formation. This knowledge enhances the proximity between Epigenetics and Behavior Analysis at a basic level through studies with non-human animals and at an applied level through a better understanding of child neurodevelopment and proper planning of effective intervention with mothers and children. (AU)

Vulnerabilidade ao estresse no trabalho e percepção de suporte familiar em porteiros: um estudo correlacional / Vulnerability to the stress at work and perception of family support in doormen: a correlational study

Este estudo objetivou avaliar e correlacionar os níveis de vulnerabilidade ao estresse no trabalho e percepção de suporte familiar em trabalhadores porteiros. Participaram 100 porteiros de uma empresa prestadora de serviços de médio porte. Utilizou-se o questionário de caracterização, a Escala de Vulnerabilidade ao Estresse no Trabalho (EVENT) e o Inventário de Percepção de Suporte Familiar (IPSF). A idade média dos participantes foi de 37,8 anos; trabalhavam na empresa, em torno de quatro anos e como porteiros, em média, há cinco anos. Os resultados mostraram uma pontuação média na medida de estresse geral da EVENT, sugerindo indicação de poucos estressores nesse grupo de porteiros. O IPSF também apresentou pontuação média, indicando que grande parte dos participantes possui percepção de bom suporte familiar. As análises mostraram correlações negativas fracas, porém estatisticamente significantes, entre a dimensão adaptação familiar do ipsf e as dimensões clima e funcionamento organizacional, pressão no trabalho e total da EVENT.

This study had the objective of evaluating and correlating the levels of work stress vulnerability and family support perception in doormen workers. 100 doormen of a medium sized, service provider company took part. A characterization questionnaire, the Scale of Vulnerability to the Stress at Work (EVENT), and the Inventory of Perception of Family Support (IPSF) were used. The age average of the participants was 37,8 years old, who worked in the company around four years, and as doormen, an average of five years. The results showed an average score that was obtained in measuring general stress of EVENT, suggesting that few stress factors were indicated on this doormen group. The IPSF also presented an average score, indicating that most of the participants have the perception of good family support. The analysis showed negative correlations between work stress vulnerability and family support, but statistically significant.

Vulnerabilidade ao estresse no trabalho e percepção de suporte familiar em porteiros: um estudo correlacional / Vulnerability to the stress at work and perception of family support in doormen: a correlational study

Este estudo objetivou avaliar e correlacionar os níveis de vulnerabilidade ao estresse no trabalho e percepção de suporte familiar em trabalhadores porteiros. Participaram 100 porteiros de uma empresa prestadora de serviços de médio porte. Utilizou-se o questionário de caracterização, a Escala de Vulnerabilidade ao Estresse no Trabalho (EVENT) e o Inventário de Percepção de Suporte Familiar (IPSF). A idade média dos participantes foi de 37,8 anos; trabalhavam na empresa, em torno de quatro anos e como porteiros, em média, há cinco anos. Os resultados mostraram uma pontuação média na medida de estresse geral da EVENT, sugerindo indicação de poucos estressores nesse grupo de porteiros. O IPSF também apresentou pontuação média, indicando que grande parte dos participantes possui percepção de bom suporte familiar. As análises mostraram correlações negativas fracas, porém estatisticamente significantes, entre a dimensão adaptação familiar do ipsf e as dimensões clima e funcionamento organizacional, pressão no trabalho e total da EVENT.(AU)

This study had the objective of evaluating and correlating the levels of work stress vulnerability and family support perception in doormen workers. 100 doormen of a medium sized, service provider company took part. A characterization questionnaire, the Scale of Vulnerability to the Stress at Work (EVENT), and the Inventory of Perception of Family Support (IPSF) were used. The age average of the participants was 37,8 years old, who worked in the company around four years, and as doormen, an average of five years. The results showed an average score that was obtained in measuring general stress of EVENT, suggesting that few stress factors were indicated on this doormen group. The IPSF also presented an average score, indicating that most of the participants have the perception of good family support. The analysis showed negative correlations between work stress vulnerability and family support, but statistically significant.(AU)

Construcción y validación del cuestionario vulnerabilidad estrés / Making and validation of the stress vulnerability questionnaire

Se realizó la construcción y validación de un test psicométrico para la determinación de vulnerabilidad al estrés. El test, denominado cuestionario vulnerabilidad estrés, fue realizado básicamente a partir de la batería psicométrico del método de enfoque sistémico de evaluación del estrés. Se confeccionó un cuestionario inicial de 63 ítems y 3 subescalas con el que se realizó un estudio piloto; al depurarlo, la forma definitiva fue redactada con 39 ítems y sometida a un estudio para determinar fiabilidad y validez. Se determinó una estructura trifactorial coincidente con el diseño previo. La consistencia interna fue de 0,92 según el alfa de Cronbach y de 0,90 con el coeficiente de Spearman-Brown. Se encontró una correlación test-retest de 0,97 y se correlacionó además, de forma significativa con criterios externos de vulnerabilidad-escala de neuroticismo del test de Eysenck, ansiedad como rasgo de Spielberger y el criterio clínico. Se concluyó que el cuestionario vulnerabilidad estrés constituye un instrumento válido y fiable para medir vulnerabilidad al estrés sobre la base del método de enfoque sistémico.

A psychometric test was constructed and validated to determine stress. The test denominated stress vulnerability questionnaire was basically based on the psychometric battery of the systemic approach method for evaluating stress. An initial questionnaire composed of 63 items and 3 subscales was made to conduct a pilot study. On depurating the questionnaire, the final form contained 39 items and it was subjected to a study to find out reliability and validity. A trifactorial structure coinciding with the previous design was determined. The internal consistency was 0.92 according to Cronbach's alpha and 0.90 according to Spearman-Brown's coefficient.. A test-retest correlation of 0.97 was attained and it was also significantly correlated to the external criteria of vulnerability-neuroticism scale of Eysenck's test, Spielberg's anxiety trait and the clinical criterion. It was concluded that the stress vulnerability questionnaire is a valid and reliable instrument to measure vulnerability to stress based on the systemic approach method.