Influência da atividade mastigatória sobre a morfometria de astrócitos do giro denteado em modelo murino

Abstract

The decrease in masticatory activity is a process that has been proven to influence several aspects of cognition, especially those related to hippocampal functions. Based on this, the present study evaluated the influence of masticatory activity on the morphology of astrocytes in the outer third of the molecular layer of the dentate gyrus by means of three-dimensional reconstruction. With this objective, 15 animals were grouped in different ways according to the isolated or combined supply of diets in different consistencies, called pellet (solid feed) and bran feed. Thus, the HD control group (Hard diet), the group with reduced HD/SD masticatory activity (Hard diet/Soft diet) and the group with HD/SD/HD (Hard Diet/Soft diet/Hard diet) masticatory rehabilitation were formed. At six months of age, brain sections were obtained submitted to immunohistochemical processing for labeling glial fibrillary acidic protein (GFAP), present mainly in astrocytes. The variable chosen for comparison between the experimental groups was astrocyte complexity, as this was a common multimodal variable in all experimental groups. As a result, we detected, in all groups, the composition of two subfamilies of astrocytes: one of greater complexity and the other of less complexity, so-called Type I and Type II, respectively. When comparing each subtype between the diets, the HD group showed greater complexity compared to the groups of masticatory activity alteration (one-way ANOVA, post hoc T test, p< 0.05), both for type I and II. while its reduction negatively impacts the complexity and number of branches, which could affect the function of these cells.