title: The influence of electrical stimulation on dorsal raphe nucleus with different current intensities on morphine-induced conditioned place preference in male rats.
abstract: BACKGROUND
  The dorsal raphe nucleus (DRN) influences a wide range of behavioral and physiological processes. The purpose of the present study was to test the effects of electrical stimulation of the DRN with different current intensities on morphine-induced conditioned place preference (CPP).
  
  
  METHODS
  Male Wistar rats were divided for experimental groups (n=7). Stimulating electrodes were stereotaxically implanted into the DRN in anesthetized rats. We investigated the influences of electrical stimulation of the DRN with different current intensities with ineffective and effective dose of morphine (0.5 and 2.5mg/kg, respectively) on morphine-induced CPP.
  
  
  RESULTS
  Subcutaneous administration of morphine 2.5mg/kg produced significant CPP in comparison with saline group. The stimulation of the DRN with different current intensities (10, 25, 50 and 100μA) in combination with an effective dose of morphine did not show significant differences on acquisition phases, whereas there were significant decreases on expression phases versus to the morphine group on CPP only in current intensity 100μA. The stimulation of the DRN with different current intensities in combination with an ineffective dose of morphine showed significant increases in current intensities (50 and 100μA) on acquisition phases of CPP, but did not show significant differences on expression phases versus to the morphine group on CPP.
  
  
  CONCLUSIONS
  It is possible that electrical stimulation of the DRN with changes in concentration of serotonin or involving other transmitters such as glutamate and GABA would be involved with these changes of CPP.
authors.affiliation: Department of Physiology, Faculty of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Gholam Reza
authors.initials: GR
authors.lastname: Ghavipanjeh
authors.affiliation: Department of Physiology, Faculty of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. Electronic address: poursha@med.mui.ac.ir.
authors.forename: Ali Asghar
authors.initials: AA
authors.lastname: Pourshanazari
authors.affiliation: Department of Physiology, Faculty of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Hojjatllah
authors.initials: H
authors.lastname: Alaei
authors.affiliation: Department of Physiology, Faculty of Sciences, Payam Noor Isfahan University, Isfahan, Iran.
authors.forename: Sara
authors.initials: S
authors.lastname: Karimi
mesh_terms: D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects*; D065847:Dorsal Raphe Nucleus / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D007279:Injections, Subcutaneous; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects; D009294:Narcotics / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013238:Stereotaxic Techniques
chemical_list: D009294:Narcotics; D009020:Morphine
keywords: Conditioned place preference; DRN; Electrical stimulation; Morphine; Rat