Lateralized spontaneous exploratory behavior in maturing rats induced by new geometrically differentiated environments after administration with trace elements

Abstract

Functional laterality is known as an intrinsic property of the brain. Since several studies have shown the presence of laterality in many species other than humans, it has been suggested that this is an adaptive mechanism to aid survival. Previous studies have shown that lateralized behavior observed during exposure to different environmental stimuli is not constant in normal animals, depending on the geometrical form of the exploratory field. In these exploratory fields, animals showed right- or left-biased exploratory behavior, according to the nature of the geometrical properties of the environment. Previously, it was found that tellurium (Te) was able to block spontaneous left-biased exploration in one defined geometrical environment. In the present work, the influence of Te and selenium (Se) in animals exposed to novel geometrically different environments were studied. Three geometrically different testing fields (square, rectangle, and T-shaped) were presented to Se- and Te-treated groups of rats. The results show that in the square field, only the Se treatment was able to block spontaneous right-biased exploratory responses; in the rectangular field, both Se and Te treatments blocked right-biased exploratory responses, and in the T-shaped field, only Te was able to block spontaneous left-biased exploratory responses. Data suggest that trace elements modify lateralized behavioral responses independently of the form of the novel exploratory field, suggesting the presence of a specific action in the brain.