Objective To study the effects of lead exposure on expression of nerve growth factor(NGF)gene in the rat hippocampus,and explore the molecular toxicological mechanism of the learning and damage induced by lead exposure. Methods Using the reverse transcription-polymerase chain reaction(RT-PCR)and in situ hybridization,NGF mRNA levels in the hippocampus of normal and lead exposure rats were investigated. Results NGF mRNA presented in the normal hippocampus of rats.NGF mRNA levels in the hippocampus were signi...