Acute nicotine decreases, and chronic nicotine increases the expression of brain-derived neurotrophic factor mRNA in rat hippocampus.
Acute nicotine administration (0.5 mg/kg i.p.) significantly decreased BDNF mRNA levels in dentate gyrus, CA3 and CA1 subfields of the rat hippocampus 2 h and 24 h after administration. However, with 7 days nicotine treatment, tolerance developed to the inhibitory effect of nicotine on BDNF mRNA expression and there was a significant increase in BDNF expression 2 h after the final injection in the CA1 region. These data suggests that changes in expression of hippocampal BDNF may be involved in the behavioural effects of nicotine observed after acute and chronic treatment.