en Behavioral Neuroscience Behavioral Neuroscience Original Original <b> Introduction:</b> The hippocampus (HIP), the primary brain structure related to learning and memory, receives sparse but comprehensive dopamine innervations and contains dopamine D1/D2-like receptors. It is demonstrated that dopamine receptors in dentate gyrus (DG) region of HIP have a remarkable function in spatial reward processing. Much less is known about the involvement of HIP and its D1/D2 dopamine receptors in drug-seeking behaviors, more particularly, in the morphine extinguished conditioned place preference (CPP). <div><b>Methods: </b>To find out the role of D1/D2-like receptors within the DG in morphine-seeking behaviors, forty adult male albino Wistar rats weighing 220-280g were unilaterally implanted by a cannula into the DG. The CPP paradigm was done conditioning score and locomotors activity were recorded by Ethovision software. All drugs/vehicles were microinjected one day after extinction (just before the CPP test) into the DG as reinstatement day. </div><div><b>Results: </b>The results showed that intra-DG administration of different dose of SCH23390 (0.25, 1 and 4μg/0.5μl saline), as a selective D1-like receptor antagonist and sulpiride (0.25, 1 and 4μg/0.5μl DMSO), as a selective D2-like receptor antagonist dose-dependently attenuated the morphine-extinguished CPP reinstated by priming injection of morphine (1 mg/kg, sc). </div><div><b>Discussion:</b> It can be concluded that D1/D2-like receptors within this region have an important role in morphine-seeking behaviors in extinguished rats. </div> Reward, D1-like receptor, D2-like receptor, Dentate gyrus, Reinstatement, ‎Morphine 73 82 http://bcn.iums.ac.ir/browse.php?a_code=A-10-744-1&slc_lang=en&sid=1 Behrooz Khakpour-Taleghani khakpour_b@yahoo.com 1370031947532846005276 1370031947532846005276 No Cellular & Molecular Research Center and Department of Physiology, School of ‎Medicine, Guilan University of Medical Sciences, Rasht, Iran Zahra Reisi zahraraisi62@gmail.com 1370031947532846005277 1370031947532846005277 No Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, ‎P.O.Box 19615-1178, Tehran, Iran Abbas Haghparast Haghparast@yahoo.com 1370031947532846005278 1370031947532846005278 Yes Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, ‎P.O.Box 19615-1178, Tehran, Iran