Unilateral lesion of the nigrostriatal pathway decreases the response of GABA interneurons in the dorsal raphe nucleus to 5-HT1A receptor stimulation in the rat

► The SNc and mPFC regulate the firing activity of GABA interneurons in the DRN. ► 8-OH-DPAT (i.v.) produced in three types of effects in the interneurons of rats with sham lesions of the SNc. ► 8-OH-DPAT (i.v.) inhibited all interneurons in rats with lesions of the SNc, mPFC and the paired lesions. ► mPFC lesion increased response of the interneurons to 8-OH-DPAT, whereas the SNc lesion decreased it. ► SNc lesion decreased the percentage of PV-5-HT1A co-expressing neurons in the DRVL.