en The Fruit Essential oil of <i>Cuminum cyminum</i> L. Reduced the Acquisition but not Expression of Ineffective dose of Morphine-Induced Conditioned Place Preference in Morphine- Sensitized Mice فارماكولوژی و سم شناسی Pharmacology & Toxicology پژوهشی Research <div dir="ltr" style="text-align: justify;"><strong>Background:</strong> <em>Cuminum cyminum</em> fruit essential oil (FEO) dose-dependently can attenuate the expression of morphine tolerance and dependence in morphine-dependent mice. <strong>Objective: </strong>In this study, the effects of <em>Cuminum cyminum</em> FEO on acquisition and expression of morphine-induced conditioned place preference (CPP) in morphine-sensitized mice were studied. <strong>Methods:</strong> Repeated subcutaneous (s.c.) administration of morphine (5 mg/kg), once daily for three and 5 days free of the opioid (sensitization period), increased conditioning response induced by ineffective doses of morphine (0.25, 0.5 and 0.75 mg/kg). <strong>Results:</strong> The results showed that intra-peritoneal (i.p.) injection of Cumin FEO (0.001, 0.01, 0.1, 0.5, 1 and 2% 5 ml/kg) or Tween-80 (0.5% 5 ml/kg), 60 min before administration of morphine or saline during sensitization period (acquisition), decreased the conditioning response induced by ineffective dose of morphine (0.5 mg/kg s.c.) at the doses of 1% (P<0.05) and 2% (P<0.001) while Cumin FEO (0.001-2% i.p.), just 60 min before the test on post-conditioning phase (expression experiments), did not alter the conditioning scores in morphine- and non-sensitized mice. <strong>Conclusion:</strong> Our findings showed that the <em>Cuminum cyminum</em> fruit essential oil reduces the acquisition but not expression of morphine-induced conditioned place preference in morphine-sensitized mice.</div> <div dir="ltr" style="text-align: justify;"><strong>Background:</strong> <em>Cuminum cyminum</em> fruit essential oil (FEO) dose-dependently can attenuate the expression of morphine tolerance and dependence in morphine-dependent mice. <strong>Objective: </strong>In this study, the effects of <em>Cuminum cyminum</em> FEO on acquisition and expression of morphine-induced conditioned place preference (CPP) in morphine-sensitized mice were studied. <strong>Methods:</strong> Repeated subcutaneous (s.c.) administration of morphine (5 mg/kg), once daily for three and 5 days free of the opioid (sensitization period), increased conditioning response induced by ineffective doses of morphine (0.25, 0.5 and 0.75 mg/kg). <strong>Results:</strong> The results showed that intra-peritoneal (i.p.) injection of Cumin FEO (0.001, 0.01, 0.1, 0.5, 1 and 2% 5 ml/kg) or Tween-80 (0.5% 5 ml/kg), 60 min before administration of morphine or saline during sensitization period (acquisition), decreased the conditioning response induced by ineffective dose of morphine (0.5 mg/kg s.c.) at the doses of 1% (P<0.05) and 2% (P<0.001) while Cumin FEO (0.001-2% i.p.), just 60 min before the test on post-conditioning phase (expression experiments), did not alter the conditioning scores in morphine- and non-sensitized mice. <strong>Conclusion:</strong> Our findings showed that the <em>Cuminum cyminum</em> fruit essential oil reduces the acquisition but not expression of morphine-induced conditioned place preference in morphine-sensitized mice.</div> <,i>,Cuminum cyminum<,/i>,, Morphine, Conditioned place preference, Sensitization, Mice <,i>,Cuminum cyminum<,/i>,, Morphine, Conditioned place preference, Sensitization, Mice 64 74 http://jmp.ir/browse.php?a_code=A-10-237-1&slc_lang=en&sid=1 A Haghparast A Haghparast Haghparast@yahoo.com 100319475328460038278 100319475328460038278 Yes Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran J Zarringhalam J Zarringhalam 100319475328460038279 100319475328460038279 No Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran A Khatibi A Khatibi 100319475328460038280 100319475328460038280 No Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran E Dianati E Dianati 100319475328460038281 100319475328460038281 No Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran J Shams J Shams 100319475328460038282 100319475328460038282 No Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran