en Experimental research article Experimental research article <span style="FONT-SIZE: 12pt FONT-FAMILY: "Palatino Linotype" mso-fareast-font-family: 'Times New Roman' mso-bidi-font-family: 'Times New Roman' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA">In the present study, the effects of different doses of nicotine on immobility time in mice were tested. Intraperitioneal administration of low doses of nicotine (0.025 mg/kg) decreased, but higher doses (0.8 and 1 mg/kg) increased immobility time. The anti-immobility response induced by low doses of nicotine was inhibited by high doses of the D₂ receptor antagonist sulpiride, the central nicotinic receptor antagonist mecamylamine, reserpine and propranolol. The D₁ receptor antagonist SCH 23390, the peripheral D₂ receptor antagonist domperidone, hexamethonium, phenoxybenzamine and atropine did not alter nicotine effect. It can be concluded that the anti-immobility effect induced by low doses of nicotine is mediated by D₂dopamine receptor mechanism and possibly through a central nicotinic receptor stimulation. </span> Nicotine; Immobility time; Sulpride; Mecamylamine; Reserpine; Propranolol 24 31 http://ppj.phypha.ir/browse.php?a_code=A-10-73-1&slc_lang=en&sid=1 Mohammad Reza Zarrindast 320031947532846001650 320031947532846001650 Yes Abolghasemi 320031947532846001651 320031947532846001651 No Masoumeh Sabetkasai 320031947532846001652 320031947532846001652 No