EFFECTS OF DRINKING WATER CONTAINING ALUMINUM AND FLUORIDE SALTS ON THE LEARNING BEHAVIOR AND BRAIN NEUROTRANSMITTERS OF MALE RAT OFFSPRING

Abstract

The widely existence of aluminum and fluoride in the environment makes the exposure to these pollutants unavoidable. Few studies reported the toxic impact of these pollutants "separately" on the neurotransmitters involved in the cognitive behavior of rodent offspring. The present study aimed to evaluate the potential impact of these pollutants "together" on the amino acid neurotransmitters of different brain regions (cerebral cortex, hypothalamus and hippocampus) and the learning ability of male rat offspring. The rat offspring were exposed to deionized water containing 0.5 g AlCl3/L, 0.15 g NaF/L, or their combination throughout the prenatal period of brain growth in the uterus (via the placenta) and the postnatal period until 70 days old (via lactation and drinking water). The results indicated that the levels of most excitatory and inhibitory amino acid neurotransmitters were significantly affected in the three brain regions of exposed male offspring to AlCl3 and/or NaF, as compared with the control male offspring. In addition, the learning ability was more affected in the male offspring exposed to AlCl3 plus NaF, a finding that indicates a synergistic effect. The alteration in the learning ability of rat offspring exposed to AlCl3 plus NaF was concomitant with the increase in the cerebral cortical glycine, hypothalamic and hippocampal γ-aminobutyric acid, and hippocampal glutamate. In conclusion, administration of the AlCl3 plus NaF was more neurotoxic than each salt alone.