The Behavioural Responses Displayed by Litter Rats After Chronic Administration of Non-Toxic Concentrations of ZnTe to Parent Rats are Mediated Primarily by Te

Abstract

Trace elements are an omnipresent group of chemical elements that are found practically in all types of environments sustaining life. Since its principal characteristic is the very low concentration in ground and water, it was thought that its importance to metabolic processes to the living cell was minimal. However, in the past 15 years knowledge has been accumulated regarding that these chemical elements have important influences on the cell dynamic homeostatic mechanisms. Previous evidence from our laboratory has shown that chronic administration of ZnTe to pregnancy, delivery and subsequent juvenile stages in rats affected several of its behavioural parameters related to motivated, lateralized exploration, and defensive behaviour. In the second part of this study, Zn and Te were examined to discern which of both elements could be responsible of the behavioural changes observed previously. ZnTe and ZnCl2 were used in chronic administration. All groups of rats were examined under 4 different experimental approaches: (1) general motor activity and motivated exploration; (2) lateralized exploratory activity; (3) defensive behaviour, and (4) social behaviour. Results shown that Te specifically increased motivated behaviour; blocked the spontaneous left-biased exploration, escape and social responses related to territorial challenges. On the other hand, Zn increased the ambulatory activity, rearing and focalized motivated behaviour, and modified differently some behavioural parameters associated to exploration. Present data are in agreement with previous results, and support the concept that trace elements can modulate behaviour by brain mechanisms that appear to be selective.