Rat developmental fluoride exposure affects retention memory, leads to a depressive-like behavior, and induces biochemical changes in offspring rat brains

Abstract

Water is the principal source of human exposure to fluoride (F). The high permeability of the placenta and blood-brain barrier to F during the intrauterine life up to the end of lactation may be crucial to neurological fetus development. Therefore, this study explores the effects of 5 and 10 mg/l F exposure during entire gestation and lactation periods, through neurobehavioral and biochemical tests performed on 90-day-old male offspring rats. The present study shows that pre and peri-natal exposure to F doses that are in the range of those found in groundwater sources in Argentina affects long-term memory and leads to a depressive-like behavior in 90-day-old male pup. Furthermore, the purpose of the investigation was to find out the possible biochemical changes through which the pre and peri-natal F-administration could generate such behavioral variations. We found alterations in transaminases, acetylcholinesterase, and alkaline phosphatase enzymes activity in specific brain areas (the prefrontal cortex, the striatum, and the hippocampus), together with findings regarding misbalanced oxidative stress. In conclusion, F exposure during the early stages of rat development alters brain-oxidative stress markers as well as the activity of enzymes implicated in cholinergic and glutamatergic systems. These molecular changes could contribute to the neurobehavioral alterations described in the present investigation.

Keywords: Fluoride; Long-term memory; Neurotoxicity; Offspring; Oxidative stress.