title: The role of the cholinergic system in the signal attenuation rat model of obsessive-compulsive disorder.
abstract: BACKGROUND
  In comparison to studies of the involvement of the serotonergic, dopaminergic, and glutamatergic systems in the pathophysiology of obsessive-compulsive disorder (OCD), research on the involvement of the cholinergic system in this disorder has remained sparse.
  
  
  OBJECTIVE
  The aim of this study was to test the role of the cholinergic system in compulsive behavior using the signal attenuation rat model of OCD. In this model, "compulsive" behavior is induced by attenuating a signal indicating that a lever-press response was effective in producing food.
  
  
  METHODS
  The acetylcholinesterase inhibitor physostigmine (0.05, 0.10, and 0.15 mg/kg), the nicotinic agonist nicotine (0.03, 0.06, 0.10, 0.30, 0.60, and 1.00 mg/kg), the nicotinic antagonist mecamylamine (1, 3, 5, and 8 mg/kg), the muscarinic agonist oxotremorine (0.0075, 0.0150, and 0.0300 mg/kg), and the muscarinic antagonist scopolamine (0.15, 0.50, 1.00, and 1.50 mg/kg) were acutely administered to rats just before assessing their lever-press responding following signal attenuation (experiments 1, 3, 5, 7, and 9, respectively). Because the effects of signal attenuation are assessed under extinction conditions, drug doses that were effective in the above experiments were also tested in an extinction session of lever-press responding that was not preceded by signal attenuation (experiments 2, 4, 6, 8, and 10).
  
  
  RESULTS
  Acute systemic administration of the cholinergic agents did not exert a selective anti- or pro-compulsive effect in the signal attenuation model.
  
  
  CONCLUSIONS
  Acetylcholine does not seem to play a role in the signal attenuation rat model of OCD.
authors.forename: Roni
authors.initials: R
authors.lastname: Yankelevitch-Yahav
authors.affiliation: School of Psychological Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel.
authors.forename: Yankelevitch-Yahav
authors.initials: YY
authors.lastname: Roni
authors.forename: Dapha
authors.initials: D
authors.lastname: Joel
authors.forename: Joel
authors.initials: J
authors.lastname: Daphna
mesh_terms: D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology; D003192:Compulsive Behavior / Q000503:physiopathology*; D003216:Conditioning, Operant / Q000187:drug effects / Q000502:physiology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005108:Extinction, Psychological / Q000187:drug effects / Q000502:physiology; D008297:Male; D008464:Mecamylamine / Q000008:administration & dosage / Q000494:pharmacology; D009538:Nicotine / Q000008:administration & dosage / Q000494:pharmacology; D009771:Obsessive-Compulsive Disorder / Q000503:physiopathology*; D010095:Oxotremorine / Q000008:administration & dosage / Q000494:pharmacology; D010830:Physostigmine / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012601:Scopolamine / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D010095:Oxotremorine; D008464:Mecamylamine; D009538:Nicotine; D010830:Physostigmine; D012601:Scopolamine; D000109:Acetylcholine