title: Role of nitric oxide in altered nociception and memory following chronic stress.
abstract: BACKGROUND
  Chronic stress alters sensory and cognitive function of mankind and animals. Sub-chronic swim stress is known to induce a prolonged hyperalgesia which is mediated through the NMDA and opioid systems. Nitric oxide is a soluble gas which acts as a retrograde messenger that modulates the release of the mentioned neurotransmitters. It is also involved in nociception and memory. The objective of the current study was to evaluate the role of NO pathway in nociception and memory impairments induced by sub-chronic swim stress.
  
  
  METHODS
  A three session forced swimming stress protocol was administered to the rats. Pretreatment with l-NAME (10mg/kg, i.p.), l-Arginine (10mg/kg, i.p.) or saline was made before each swimming session. Anxiety-like behavior, nociception and passive avoidance (PA) learning were evaluated 24h after the last swim stress session.
  
  
  RESULTS
  Swim stress altered locomotion and anxiety-like behaviors in the open field test. Reduced thermal threshold was observed in the nociceptive measurement after swim stress. Pretreatment with l-NAME could reverse the reduced threshold. A decreased step through latency was observed in the PA paradigm after swim stress, which could be inhibited by pretreatment with l-NAME.
  
  
  CONCLUSIONS
  The results of this study indicate that sub-chronic swim stress impairs nociception and PA learning. NO pathway seems to have a modulatory role in these alterations. Further studies are suggested to examine the protective effect of NOS inhibitors on stress-induced impairments in sensory and cognitive function.
authors.affiliation: Oral and Dental Diseases Research Center, Kerman University of Medical Sciences, Kerman, Iran.
authors.forename: Masoud
authors.initials: M
authors.lastname: Nazeri
authors.affiliation: Physiology Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, Iran.
authors.forename: Moazamehosadat
authors.initials: M
authors.lastname: Razavinasab
authors.affiliation: Physiology Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Abareghi
authors.affiliation: Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, Iran. Electronic address: shabanimoh@yahoo.com.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Shabani
mesh_terms: D000818:Animals; D001007:Anxiety / Q000188:drug therapy / Q000209:etiology / Q000378:metabolism; D001120:Arginine / Q000494:pharmacology; D001362:Avoidance Learning / Q000187:drug effects / Q000502:physiology*; D002908:Chronic Disease; D004597:Electroshock; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005106:Exploratory Behavior / Q000187:drug effects / Q000502:physiology; D006358:Hot Temperature; D006930:Hyperalgesia / Q000188:drug therapy / Q000209:etiology / Q000378:metabolism*; D007859:Learning Disabilities / Q000188:drug therapy / Q000209:etiology / Q000378:metabolism*; D008297:Male; D008568:Memory / Q000187:drug effects / Q000502:physiology; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D059225:Nociception / Q000187:drug effects / Q000502:physiology*; D017207:Rats, Sprague-Dawley; D013315:Stress, Psychological / Q000150:complications* / Q000188:drug therapy / Q000378:metabolism; D013550:Swimming
chemical_list: D004791:Enzyme Inhibitors; D009569:Nitric Oxide; D001120:Arginine; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester
keywords: Nitric oxide; Passive avoidance learning; Stress-induced hyperalgesia