title: Forced swim stress but not exogenous corticosterone could induce the reinstatement of extinguished morphine conditioned place preference in rats: involvement of glucocorticoid receptors in the basolateral amygdala.
abstract: Addiction is a common psychiatric disease and stress has an important role in the drug seeking and relapse behaviors. The involvement of basolateral amygdala (BLA) in the effects of stress on reward pathway is discussed in several studies. In this study, we tried to find out the involvement of glucocorticoid receptors (GRs) in the BLA in stress-induced reinstatement of extinguished morphine-induced conditioned place preference (CPP) in rats. The CPP paradigm was done in adult male Wistar rats weighing 220-320 g, and conditioning score and locomotor activity were recorded by Ethovision software. Animals received effective dose of morphine (5mg/kg) daily, during the 3-day conditioning phase. In extinction phase, rats were put in the CPP box for 30 min a day for 8 days. After extinction, animals were injected by corticosterone (10 m/kg) or exposed to forced swim stress (FSS) 10 min before subcutaneous administration of ineffective dose of morphine (0.5mg/kg) in order to reinstate the extinguished morphine-CPP. To block the glucocorticoid receptors in the BLA, after stereotaxic surgery and placing two cannulae in this area bilaterally, animals received GR antagonist mifepristone (RU38486; 0.3, 3 and 30 ng/0.3 μl DMSO per side) prior to exposure to FSS then each animal received ineffective dose of morphine (0.5mg/kg) as drug-induced reinstatement. The results revealed that physical stress (FSS) but not exogenous corticosterone can significantly induce reinstatement of extinguished morphine-CPP, and intra-BLA mifepristone prevents the stress-induced reinstatement. It can be proposed that stress partially exerts its effect on the reward pathway via glucocorticoid receptors in the BLA.
authors: Molecular Medicine Research Centre, Hormozgan University of Medical Sciences, Bandar Abbas, Iran.
authors: Sara
authors: S
authors: Karimi
authors: Molecular Medicine Research Centre, Hormozgan University of Medical Sciences, Bandar Abbas, Iran.
authors: Ghassem
authors: G
authors: Attarzadeh-Yazdi
authors: Neuroscience Research Center, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, P.O. Box 19615-1178, Tehran, Iran.
authors: Saeid
authors: S
authors: Yazdi-Ravandi
authors: Neuroscience Research Center, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, P.O. Box 19615-1178, Tehran, Iran.
authors: Soghra
authors: S
authors: Hesam
authors: Neuroscience Research Center, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, P.O. Box 19615-1178, Tehran, Iran.
authors: Pegah
authors: P
authors: Azizi
authors: Neurobiology Research Center, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Yasaman
authors: Y
authors: Razavi
authors: Neuroscience Research Center, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, P.O. Box 19615-1178, Tehran, Iran; Neurobiology Research Center, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Electronic address: Haghparast@yahoo.com.
authors: Abbas
authors: A
authors: Haghparast
mesh_terms: D000679:Amygdala / Q000187:drug effects / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects / Q000502:physiology*; D003345:Corticosterone / Q000494:pharmacology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005108:Extinction, Psychological / Q000187:drug effects / Q000502:physiology*; D006727:Hormone Antagonists / Q000494:pharmacology; D008297:Male; D015735:Mifepristone / Q000494:pharmacology; D009020:Morphine / Q000008:administration & dosage*; D009294:Narcotics / Q000008:administration & dosage*; D051381:Rats; D017208:Rats, Wistar; D011965:Receptors, Glucocorticoid / Q000378:metabolism*; D013315:Stress, Psychological / Q000209:etiology / Q000523:psychology*; D013550:Swimming / Q000523:psychology*
chemical_list: D006727:Hormone Antagonists; D009294:Narcotics; D011965:Receptors, Glucocorticoid; D015735:Mifepristone; D009020:Morphine; D003345:Corticosterone
keywords: Basolateral amygdala; Conditioned place preference; Corticosterone; Glucocorticoid receptor; Physical stress; Reinstatement