The inhibitory effects of fluoride on male f1 rats for body weight gain and cognitive function

Fluoride (F) is ubiquitously present worldwide. F has an important impact on oral and general health. It has recently been reported that there is an association between F exposure to pregnant women by drinking water and the cognitive function of their children. Therefore, we conducted a two-generation exposure experiment using rats exposed to F via drinking water to elucidate the neurotoxic effects of F on F1 rats. The F1 rats were exposed to F via the placenta, their dam's milk, and/or their drinking water at 150 ppm F. We classified the control F1 rats as the CC group, the F1 rats exposed to F from fetus until weaning as the FC group, and those exposed to F from fetus until 9 weeks as the FF group. We evaluated neurotoxicity by behavioral tests including the prepulse inhibition test (PPI) and the determinations of neurochemicals including dopamine (DA) in the seven brain regions. The male F1 rats decreased their body weight via exposure of F after weaning. The significantly lower startle responses which showed impaired cognitive function, were observed in the male FC and FF groups compared with the CC group in the PPI test. The mean DA in the midbrain was significantly lower in the FC and FF groups compared with the control. F exposure via the placenta and dam's milk impaired cognitive function which may be related to DA in the midbrain. The effects of F appear to be focused mainly on males. F exposure from the fetal period may affect body weight gain and cognitive functions.