title: Role of dopamine D1-like receptor within the nucleus accumbens in acute food deprivation- and drug priming-induced reinstatement of morphine seeking in rats.
abstract: Dopamine is a predominant neurotransmitter in the nervous system, which plays an important role in both drug priming- and cue-induced reinstatement of cocaine and heroin seeking. Therefore, in the present study, the conditioned place preference (CPP) paradigm was used to evaluate the effects of intra-accumbal administration of SCH23390 as a dopamine D1-like receptor antagonist on food deprivation (FD) and drug priming-induced reinstatement. Sixty-eight adult male albino Wistar rats weighing 200-280 g were bilaterally implanted by cannulae into the nucleus accumbens (NAc). For induction of the CPP, subcutaneous (sc) administration of morphine (5mg/kg) was used daily during a three-day conditioning phase. The conditioning score and locomotor activity were recorded by using the Ethovision software. Under extinction conditions, rats were given an 'off' period and were tested for FD-induced reinstatement following the 24-h or 48-h FD condition, and for drug priming-induced reinstatement under the sated condition following an injection of 0.5 and 1mg/kg (sc) morphine. In the next experiments, animals received different doses of intra-accumbal SCH23390 (0.25, 1 and 4 μg/0.5 μl saline) bilaterally and were subsequently tested for FD- and morphine priming-induced reinstatement. Our findings indicated that only a dose of 1mg/kg and not 0.5mg/kg of morphine induced the reinstatement of morphine. 24-h FD similar to 48-h FD induced the reinstatement of seeking behaviors facilitated by an ineffective dose of morphine (0.5mg/kg). Furthermore, the D1-like receptor antagonist attenuated FD- and drug priming-induced reinstatement dose-dependently. It is concluded that FD- and drug priming-induced reinstatement may be mediated, at least in some way, by activation of dopamine D1-like receptors in the NAc.
authors.affiliation: Department of Basic Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Sadeghzadeh
authors.affiliation: Department of Basic Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
authors.forename: Vahab
authors.initials: V
authors.lastname: Babapour
authors.affiliation: Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Electronic address: Haghparast@yahoo.com.
authors.forename: Abbas
authors.initials: A
authors.lastname: Haghparast
mesh_terms: D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D003213:Conditioning, Psychological / Q000187:drug effects / Q000502:physiology; D018492:Dopamine Antagonists / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D058999:Drug-Seeking Behavior / Q000187:drug effects / Q000502:physiology*; D005508:Food Deprivation / Q000502:physiology*; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D009294:Narcotics / Q000494:pharmacology*; D009714:Nucleus Accumbens / Q000187:drug effects* / Q000378:metabolism; D011897:Random Allocation; D017208:Rats, Wistar; D017447:Receptors, Dopamine D1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013037:Spatial Behavior / Q000187:drug effects / Q000502:physiology; D013312:Stress, Physiological / Q000187:drug effects / Q000502:physiology; D013315:Stress, Psychological / Q000503:physiopathology
chemical_list: D001552:Benzazepines; D018492:Dopamine Antagonists; D009294:Narcotics; D017447:Receptors, Dopamine D1; C534628:SCH 23390; D009020:Morphine
keywords: Conditioned place preference; D1-like receptor; Drug priming-induced reinstatement; Food deprivation-induced reinstatement; Nucleus accumbens; Reward