Objective To study effects of lanthanum (La) on cAMP response element binding protein (CREB) phosphorylation and brain derived neurotrophic factor (BDNF) expression in cerebral cortex of rats after weaning.
Methods Forty female rats were divided randomly into four groups:control,low-,medium-,and high-dose La-administrated groups.Pregnant rats in La-administrated groups were administrated with 0.25%,0.5% and 1.0% LaCl3 in drinking water after delivery,respectively.The offspring of the La-administrated groups were given to LaCl3 by respective parental lactation before weaning,and then were administrated with 0.25%,0.5% and 1.0% LaCl3 in drinking water for one month respectively.Learning and memory of the pups were measured by water maze test.La contents,CREB phosphorylation,BDNF mRNA and protein expression in the cerebral cortex of offspring were also detected.
Results In the water maze test,the error counts and the latency of the low-and medium-dose La-administrated groups were significantly higher than those of the control group,and the pattern was also observed in the high-dose La-administrated group as compared with the control and the low-dose La-administrated groups.The exposure level of La correlated with the La contents in the cerebral cortex positively (r=0.954) but with BDNF mRNA expression and BDNF protein expression negatively (r=-0.976,r=-0.952,respectively).
Conclusion La may induce impairments of learning and memory in rats after weaning,which is possibly related to lower levels of CREB phosphorylation,BDNF gene transcription and protein expression caused by La exposure.
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