Estresse precoce e comportamentos do tipo ansiedade na vida adulta : o papel do sistema corticotrofinérgico no núcleo leito da estria terminal

Abstract

Introduction: Decreased maternal care during early life period can lead to biological and behavioral disfunctions. It is believed that the corticotrophin-releasing factor (CRF) plays an important role in maternal behavior regulation. However, the mechanisms that underlie this relation are not fully understand. Objectives: To investigate the effects of CRF infusion in the BNST in maternal care and anxiety-like behavior in the offspring. Methods: The litters of BALB/cJ mice were randomly assigned to SAL or CRF group. The dams were exposed to 5 infusions of CRF or saline in the first and second week after birth, on the same days of the infusion, the maternal behavior of both groups was observed. The offspring of both groups was testes in three anxiety-like behavior protocols. Results: The CRF infusion in the dams, during the first weeks of life of the offspring, decreased the frequency of arched-back nursing and increased the number of exits from the nest. This decrease in maternal care provoked increased anxiety-like behavior in female offspring from CRF dams and decreased in male. Moreover, CRF offspring, independently of sex, increased the locomotor activity. Conclusion: The findings increase the evidence of the importance and role of CRF and BNST in maternal care and contribute to the hypothesis that decreased maternal care results in anxiety-like phenotypes in early adulthood.