Nicotine withdrawal upregulates nitrergic and galaninergic activity in the rat dorsal raphe nucleus and locus coeruleus

► Nicotine withdrawal increased NOS and galanin staining in DRN subregions and locus coeruleus. ► Nicotine affected more NOS in caudal dorsomedial and lateral wing DRN subregions. ► Nicotine increased both NOS and galanin in specific neurons of rostral ventromedial DRN. ► Nicotine withdrawal stimulates LC-DRN galaninergic neurons. ► NO and galanin synthesized locally in the DRN and LC may mediate the effect of nicotine exposure.