title: Development of a new model to investigate the fetal nociceptive pathways.
abstract: OBJECTIVE
  The aim of the study was to develop an experimental model to investigate the fetal nociceptive pathways and fetal analgesia.
  
  
  METHODS
  We tested the electromyographic (EMG) response from the biceps femoris to electrical stimulation of the sural nerve in chronically-prepared fetal lambs with and without sufentanil.
  
  
  RESULTS
  An EMG response could be recorded 140 ms after the electrical stimulation above a threshold of current's intensity. The response presents the characteristics of a nociceptive flexion reflex. The reflex magnitude increased with the stimulus intensity. Sufentanil decreased the response. Bradycardia was noted 10 s after the stimulation and was not observed after sufentanilinfusion. Catecholamine concentrations were not altered by the stimulation.
  
  
  CONCLUSIONS
  Our study shows that a nociceptive flexion reflex can be recorded in the ovine fetus. We suggest that this reflex can be used as a new tool to study the ontogenesis of the nociceptive pathways and the effects of analgesic drugs during fetal life.
authors.affiliation: Department of Obstetrics, Centre Hospitalier Régional Universitaire de Lille, Lille, France. v-houfflin-debarge@chru-lille.fr
authors.forename: Véronique
authors.initials: V
authors.lastname: Houfflin Debarge
authors.forename: Sophie
authors.initials: S
authors.lastname: Bresson
authors.forename: Sophie
authors.initials: S
authors.lastname: Jaillard
authors.forename: Frédéric
authors.initials: F
authors.lastname: Elbaz
authors.forename: Yvon
authors.initials: Y
authors.lastname: Riou
authors.forename: Serge
authors.initials: S
authors.lastname: Dalmas
authors.forename: Philippe
authors.initials: P
authors.lastname: Deruelle
authors.forename: Anne Sophie
authors.initials: AS
authors.lastname: Ducloy
authors.forename: Francis
authors.initials: F
authors.lastname: Puech
authors.forename: Laurent
authors.initials: L
authors.lastname: Storme
mesh_terms: D000698:Analgesia; D000701:Analgesics, Opioid / Q000494:pharmacology; D000818:Animals; D004576:Electromyography; D005260:Female; D005333:Fetus / Q000502:physiology*; D006340:Heart Rate, Fetal; D023421:Models, Animal; D009619:Nociceptors / Q000502:physiology*; D017288:Pain Threshold / Q000187:drug effects / Q000502:physiology*; D011247:Pregnancy; D012018:Reflex / Q000187:drug effects / Q000502:physiology; D012756:Sheep; D017409:Sufentanil / Q000494:pharmacology
chemical_list: D000701:Analgesics, Opioid; D017409:Sufentanil