ABSTRACT
O diabetes é um distúrbio complexo e heterogêneo caracterizado por hiperglicemia resultante de defeitos na secreção e ação da insulina. Tem sido reconhecido que, além do comprometimento de órgãos como rins, olhos, fígado e coração, o sistema nervoso central é suscetível aos efeitos deletérios da hiperglicemia em longo prazo. A encefalopatia diabética representa uma das complicações do diabetes, na qual os danos são caracterizados por alterações do funcionamento cognitivo, modificações estruturais e neurofisiológicas no cérebro. Existe uma associação bem reconhecida entre a depressão e o diabetes, uma vez que a prevalência de depressão é maior na população diabética comparada com a população geral. Porém, os mecanismos atribuídos a essa relação ainda estão em fase de investigação. O estresse oxidativo desempenha um papel importante nas complicações do diabetes e pode ser um mecanismo biológico envolvido na relação entre a depressão e o diabetes, relacionado à encefalopatia diabética. Neste artigo de revisão, apresentamos uma visão geral dos principais conceitos relacionados ao assunto, bem como dos dados clínicos e experimentais que suportam a relação entre o dano oxidativo no cérebro e a depressão relacionada com encefalopatia diabética...
Diabetes is a complex and heterogeneous disorder characterized by hyperglycemia resulting from defects in the secretion and action of insulin. It has been recognized that, in addition to the involvement of organs such as kidney, eye, liver, and heart, the central nervous system is susceptible to the deleterious effects of hyperglycemia in the long term. Diabetic encephalopathy is one of the complications of diabetes, in which the damage is characterized by changes in cognitive functioning, structural and neurophysiologic changes in the brain. There is a well-known association between depression and diabetes, since the prevalence of depression is higher in the diabetic population compared to the general population. However, the mechanisms assigned to this relationship are still under investigation. Oxidative stress plays an important role in the complications of diabetes and can be a biological mechanism involved in the relation between depression and diabetes related to diabetic encephalopathy. This review article is an overview of key concepts related to the subject, as well as of the clinical and experimental data supporting the relationship between oxidative damage in the brain and depression related to diabetic encephalopathy...
Subject(s)
Humans , Brain Diseases , Depressive Disorder , Diabetes Complications , Oxidative StressABSTRACT
Females are often less aggressive than males, but they exhibit high levels of agonistic behavior against an intruder in the area of the nest during lactation. This behavior is referred to as maternal aggression. In rats, maternal aggressive behavior occurs more often from postpartum day 3 (PPD 3) to PPD 12. Social instigation is an experimental protocol used to increase the levels of aggression that are typical of the species. In the present study we used social instigation to analyze the expression of a marker of neuronal activity, c-fos. Lactating rats on PPD 5, in the presence of their pups, were divided into four groups: (1) no social instigation and no aggressive behavior, (2) social instigation and no aggressive behavior, (3) no social instigation and aggressive behavior, and (4) social instigation and aggressive behavior. Sixty minutes after the aggression test we used immunohistochemistry to detect Fos in two brain regions, the ventral-orbital region of the prefrontal cortex (VO PFC) and dorsal raphe nucleus (DRN). Our results showed that rats with aggressive behavior that were provoked exhibited an increase in Fos expression in the VO PFC compared with the control group (i.e., no social instigation and no aggressive behavior). No change in Fos expression was found in the DRN. These results complement previous findings with microinjection of serotonin 5-hydroxytryptamine-1B receptor agonists into the same region, demonstrating that the VO PFC is an important region in the modulation of maternal aggressive behavior.