Effects of acute restraint and unpredictable chronic mild stress on brain corticotrophin releasing factor mRNA in the elevated T-maze.

Corticotrophin releasing factor (CRF) modulates stress/anxiety-related responses. Previous studies showed that exposure to acute restraint and unpredictable chronic mild stress (UCMS) facilitates elevated T-maze (ETM) avoidance responses, an anxiogenic-like effect. This study verified the role of CRF in the modulation of ETM avoidance and escape reactions, in unstressed rats and in animals exposed to acute restraint or to UCMS, by quantifying CRF mRNA concentrations in stress/anxiety-related brain regions, through semiquantitative in situ hybridization. Results showed that stress exposure altered CRF mRNA in regions related to the modulation of stress/anxiety: the cingulate cortex, the hippocampus, the paraventricular and dorsomedial hypothalamus, the medial and central amygdalas, the dorsal region of the dorsal raphe (dDR) and the ventrolateral periaqueductal gray. A regression analysis showed that the anxiogenic-like effects observed in acute restraint animals were particularly associated to increases in CRF mRNA in the paraventricular hypothalamus, medial and central amygdalas and dDR. On the other hand, anxiogenic-like effects observed after UCMS exposure are associated to increases in CRF mRNA in the medial and central amygdalas, in the BNST and in the ventrolateral periaqueductal grey. This observation suggests important differences in the neurocircuitry that mediates responses to acute and chronic stress exposure. CRF mRNA in regions traditionally related to the modulation of panic reactions (the dorsal periaqueductal grey and the lateral wings of the dorsal raphe) were not observed, what might explain the absence of panicogenic-like effects of stress exposure. These results contribute to a better understanding of the role played by CRF in stress/anxiety-related responses.

Fatores associados à rotatividade de diretores no município do rio de janeiro / Contextual factors related to schoool principal's turnover in the city of rio de janeiro

RESUMO: Este estudo investiga a rotatividade de diretores no município do Rio de Janeiro, no período de 2006 a 2012, período que compreende o momento antes e depois da implementação de políticas de responsabilização escolar pela Secretaria Municipal de Educação. O objetivo do estudo foi investigar os fatores associados às taxas de rotatividade de diretores em escolas de ensino fundamental da rede municipal, frente ao aumento das pressões sobre o cargo de diretor, decorrentes da mudança nas regras de provimento de cargo e da adoção de políticas de responsabilização escolar. Os resultados sugerem que a experiência do diretor, a porcentagem de alunos com distorção idade-série nas escolas e o desempenho dos estudantes estão associados à probabilidade dos diretores permanecerem no cargo, em especial nos mandatos que se iniciaram no período após a adoção de políticas de responsabilização escolar.

ABSTRACT: This study investigates school principal's turnover in the city of Rio de Janeiro from 2006 to 2012, a period that includes the years before and after the implementation of school accountability policies by the Municipal Education Department. The goal of the study was to investigate the contextual factors related to school principal's turnover rates at public primary schools, due to a growth of pressures over school principal's position, because of changes in the requirements to become a principal and the implementation of school accountability policies. The results suggest that the principal's experience, the percentage of pupils with age/grade gap in schools, and student performance are associated with the likelihood of principals' re-elections, especially at mandates that began in the period after the implementation of school accountability policies.