Obesidade precoce induz comportamentos tipo-depressivos e altera a expressão de GFAP no córtex pré-frontal

Abstract

Childhood obesity and mental disorders, including depression, are growing rapidly, bringing numerous consequences to the individual. The objective of the work was to evaluate the influence of early obesity induced by small littles on the development of depression-like symptoms in addition to the expression of glial fibrillary acidic protein (GFAP). Small littles was used, with a reduced litter (NR) containing 4 puppies (2 males and 2 females) and a normal litter (NN) containing 12 puppies (6 males and 6 females). The mothers' maternal behavior was evaluated between postpartum days 2 and 5. In behavioral tests with the offspring, the open field test, social play behavior test and forced swimming test were carried out. Weighing of the retroperitoneal and dangeronadal tissues and quantification of GFAP expression in the hippocampus and prefrontal cortex was performed by Western Blotting. The work was approved by the ethics committee for animal use under number 036/2021. The results were evaluated using GraphPad software version 8.0. Maternal behavior was assessed using the Student's t test. For weight, 2-way RM ANOVA was used followed by the Newman- Keuls test, using litter (NN and NR) and repeated days (1 to 36). For the behavior, fat and western blotting tests, two-way ANOVA was used followed by the Newman-Keuls multiple comparison test considering the litter factors (NN or NR) and sex (male or female) as factors and for the correlation the Pearson test. Small little increased the maternal parameter of licking the chick and decreased the non-maternal parameter of staying outside the nest without exploring. There was a more pronounced weight gain in NR animals, both males and females, from PND25 onwards, which was maintained until PND36. A greater weight of retroperitoneal fat was observed in NR animals, both in males and females, and a greater amount of dangeronadal fat in females. There was no change in locomotor activity in the open field test. In the social play behavior test, there was a reduction in interaction time in NR animals, both in males and females. In the forced swimming test, male NR animals showed longer immobility time. An increase in GFAP protein expression was also observed in the prefrontal cortex of male NR animals. A correlation was found between weight and adipose tissue and GFAP expression and between GFAP expression and immobility time in forced swimming. It is concluded that litter reduction increased maternal behavior and decreased non-maternal behavior in addition to inducing excess weight in the pre- pubertal period. Finding marked depressive-like symptoms in males, possibly because they present astrogliosis, characterized by greater expression of GFAP in the prefrontal cortex.