Participação da ontogênese calosa no estabelecimento de especializações cerebrais: um estudo das correlações entre assimetria motora e sensório-motora em camundongos com agenesia calosa por irradiação X pré-natal

Abstract

Previous studies showed that callosal agenesis by exposition to prenatal ionizing irradiation leads to changes in the cerebral lateralized behavior. Other studies suggest genetic factors as involved in the establisment of cerebral lateralization. The intention this work was to study, in mice, the correlations between the establisment of the cerebral lateralization on the paw preference test, that objectives the study of motor laterality, and on the open-field test, that objetives the study of sensoriomotor lateralization on the periphery. In the open-field test the animals were subdivided in subgroups: that were exposed a stressing continuous sound factor of 105 dB and 3000 Hz and that weren’t exposed. It were tested 49 nonirradiated males, 51 nonirradiated females, 34 irradiated males, 39 irradiated females. The statistical tool used were the regression analysis with the Pearson Coefficient and the ANOVA. The results showed significance in correlations of directional laterality of the paw preference x directional laterality of the open-field, and in directional laterality of the paw preference x lateralisation index of the open-field. This was expressed in the nonirradiated males without sound and nonirradiated females with sound. The changes on the laterality index in the irradiated mice on the respective groups suggest the role of the callosal ontogenesis on the establisment of laterality as a dual expression. On the other hand, the presence of significance index on the above cited nonirradiated grouos suggest the role of genetic and/or epigenetic factors on the laterality establishment as a dual expression.