A limitação na construção do ninho reduziu o comportamento materno e induziu parâmetros tipo-depressivos maternos acompanhados por astrogliose no córtex pré-frontal

Abstract

Stress is a condition of physiological and/or psychological disorder that alters the quality of life, generating immediate and/or delayed responses. In the postnatal period, stressful events contribute to the appearance of vulnerabilities and psychopathologies. Among postpartum psychiatric disorders, postpartum depression is a serious psychiatric disorder with devastating consequences not only for the mother but also for the offspring. Nest Building Limitation (LCN) is an animal stress model that mimics the behaviors resulting from perinatal stress, mainly characterized by reduced maternal care. Therefore, the objective of this work was to study the effects of NCL on the development of maternal depressive-like parameters and their influence on maternal behavior and the initial development of the offspring. For this, between Postpartum Days (PND) 2 to 9, the mothers of the LCN group were kept in boxes with reduced shavings (1000 ml) and the Control group of mothers were kept in boxes with an abundance of shavings (4500 ml). The rats underwent evaluation of maternal behavior and weight gain (PND 2 to 9), locomotor activity in the open field (PND 5) and forced swimming test (PND 8 and 9). Subsequently, the rats were decapitated to remove the brain structures, hippocampus and cortex for quantification of GFAP protein expression by Western Blotting. The puppies were submitted to analysis of physical and reflexological development and monitoring of weight gain (PND 2 to 9). It was observed that LCN decreased the maternal parameter of licking the pup, increased the latency for the rat to catch the first pup and take it to the nest, increased the nest building time and increased the time of non-maternal sefl grooming compared to the group control. In the forced swimming test, the LCN mothers showed a higher frequency of immobility and a longer time of immobility compared to the Control. There was no change in exploratory locomotor activity in the open field test. There was also an increase in GFAP protein expression in the prefrontal cortex of LCN mothers when compared to the control group. There was a reduction in weight gain in male LCN pups (PND 7 to 9) when compared to the Control group. It was verified that the offspring of the LCN group presented a delay in presenting the negative geotaxis reflex in the male offspring and a delay in the day of presenting the posture straightening in the female offspring when compared to the control group. It is concluded, therefore, that the limitation in nest building (LCN) was able to induce effects on the development of maternal depressive-like parameters and in the reduction in maternal care, accompanied by astrogliosis in the prefrontal cortex, as well as impacts on the development initial reflexology of the offspring.