title: New neostigmine-based behavioral mouse model of abdominal pain.
abstract: BACKGROUND
  Animal models of visceral pain have gained much attention as an important tool to elucidate the possible mechanisms underlying functional gastrointestinal (GI) disorders. Here we report the development of a new, minimally invasive behavioral model of abdominal pain induced by ip administration of neostigmine in mice.
  
  
  METHODS
  Spontaneous behavioral responses evoked by ip injection of neostigmine were compared to pain-related behaviors induced by acetic acid solution (ip), mustard oil (MO) and capsaicin (both ic). Pain behaviors were quantified by assessment of defined postures (licking of the abdomen, stretching, squashing of the abdomen and abdominal contractions). Neuronal activation of spinal cord was measured by determining the number of c-Fos-positive cells.
  
  
  RESULTS
  Neostigmine (2.5 μg/kg, ip), acetic acid solution (ip), MO and capsaicin (both ic) induced spontaneous behavioral responses in mice, which were blocked by morphine (3 mg/kg, ip), suggesting the involvement of pain signaling pathways. Injection of neostigmine enhanced c-Fos expression in spinal cord neurons.
  
  
  CONCLUSIONS
  The neostigmine model represents a new minimally invasive mouse model to study visceral pain. Based on the neuronal activation pattern in the spinal cord we suggest that this model may be used to study abdominal pain signaling pathways in the GI tract.
authors.affiliation: Snyder Institute for Chronic Diseases, Division of Gastroenterology, Department of Medicine, University of Calgary, Calgary, AB, Canada.
authors.forename: Jakub
authors.initials: J
authors.lastname: Fichna
authors.forename: Tamia
authors.initials: T
authors.lastname: Lapointe
authors.forename: Kevin
authors.initials: K
authors.lastname: Chapman
authors.forename: Anna
authors.initials: A
authors.lastname: Janecka
authors.forename: Nathalie
authors.initials: N
authors.lastname: Vergnolle
authors.forename: Christophe
authors.initials: C
authors.lastname: Altier
authors.forename: Martin A
authors.initials: MA
authors.lastname: Storr
mesh_terms: D015746:Abdominal Pain / Q000188:drug therapy / Q000209:etiology* / Q000523:psychology; D000818:Animals; D004195:Disease Models, Animal; D008297:Male; D051379:Mice; D009020:Morphine / Q000627:therapeutic use; D009388:Neostigmine / Q000494:pharmacology*; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis; D015398:Signal Transduction
chemical_list: D016760:Proto-Oncogene Proteins c-fos; D009388:Neostigmine; D009020:Morphine