Abstract

The synaptic mechanism of learning-memory injury induced by chronic fluorosis in brain was investigated. 192 Sprague-Dawley (SD) male rats, one-month-old, were randomly divided into four groups and given 15, 30, 60 mg / L NaF solution and tap water respectively for 18 months. Behavior of rats was evaluated by open field and Morris Water Maze test every 3 months. The hippocampal synaptic membrane fluidity was detected by electron spin resonance, the expression level of post synaptic density 95 (PSD -95) in hippocampal CA3 region was detected by immunohistochemistry. Results showed that in rats with chronic fluorosis compared with the controls, locomotor activity and exploratory behavior were significantly or very significantly suppressed, spatial learning and memory ability were significantly declined;. synaptic membrane fluidity and the protein level of PSD-95 of hippocampus were greatly decreased. The data indicated that the changes of synaptosome membrane fluidity and PSD-95 expression level in hippocampus might be the one synaptic mechanism of learning-memory injury induced by chronic fluorosis in brain.