Previous behavioural studies shows that excessive exposure of fluoride caused diminished intelligent quotient in children compared to the normal children (Wang et al., 2004) and sodium fluoride intoxicated rat exerted loss of memory and learning disability (Yaning et al., 2005). In the present study postnatal rats aged day 21 and day 30 demonstrated loss of memory, learning inability and there was a considerable increase in the goal achieve latency period in NaF treated group when compared to the control pups. The concomitant administration of NaF and quercetin received pups showed better memory, learning ability and there was a significant decrease in the goal achieve latency period compared to the sodium fluoride treated rat pups.
The present study indicates the evidence on mitigation of NaF induced oxidative damage, behavioural and learning impairment, and alternations in levels of pro and antioxidants neurotransmitters and histological changes on concomitant administration of quercetin in developing rat brain. Quercetin restored the levels of antioxidants enzymes (SOD, catalase and Glutathione), monoamines (epinephrine and norepinephrine) levels, as well as ameliorated behavioural and histopathological alterations when compared to the sodium fluoride treated rat pups. The administration of quercetin ameliorated the neuron morphology, nucleus shrinkage and neuronal degeneration in the cerebral cortex of developing rat brain.