Effects of fluoride on synapse morphology and myelin damage in mouse hippocampus.
Level 5 - mechanism / opinion, no new human data
Animal experimental research
PubMed 29241138 · doi:10.1016/j.chemosphere.2017.12.027
What was done
Healthy adult mice were exposed to sodium fluoride (NaF) at doses of 25, 50, and 100 mg NaF/L in drinking water for 60 days. The researchers evaluated mouse hippocampal tissue for synaptic ultrastructure morphology, myelin damage markers (proteolipid protein [PLP] mRNA and myelin-associated glycoprotein [MAG] levels), and expression of cAMP response element-binding protein (CREB), brain-derived neurotrophic factor (BDNF), and neural cell adhesion molecule (NCAM).
What was found
The abstract reports directional findings without specific numerical values or effect sizes: - Medium (50 mg/L) and high (100 mg/L) fluoride groups showed ultrastructural alterations in neuron synapses, including indistinct and short synaptic clefts and thickened postsynaptic densities. - PLP mRNA expression was significantly reduced in medium and high fluoride groups. - MAG levels were significantly increased in the high fluoride group compared to the medium group. - High fluoride exposure reduced both mRNA and protein levels of CREB, BDNF, and NCAM.
Why it matters
This study provides an animal model mechanism suggesting that subchronic high fluoride intake may induce hippocampal synaptic restructuring and myelin injury through downregulation of neurotrophic and cell-adhesion pathways.
Limits
The findings derive entirely from an animal model with no human clinical correlation. The abstract omits the total sample size (n), precise numerical values, variance, and effect sizes. Functional or behavioral cognitive outcomes were not assessed.
Cited by
- supports Fluoride damages the myelin sheath of neurons and impairs mitochondrial integrity in the brain.