BDNF and nicotine dependence: These previously reported findings showedthat BDNF might regulate the responsiveness of dopamine in such a vital way that mayrelevant to the etiology or treatment of several conditions implicating dopamine.Earlier studies [29] have documentedthat chronic nicotine could increase BDNFexpression in the rat hippocampus, whereas acute nicotine prominently decreases thegene expression of BDNF. Genome-wide linkageinvestigations have suggested that the chromosome 11p13 region is likely to harborgenes conferring susceptibility to nicotine dependence [30].