Related Experiment Video
Updated: Aug 16, 2026

A Preterm Rat Model for Pain Studies
Published on: February 9, 2024
Development of a new model to investigate the fetal nociceptive pathways
Véronique Houfflin Debarge1, Sophie Bresson, Sophie Jaillard
1Department of Obstetrics, Centre Hospitalier Régional Universitaire de Lille, Lille, France. v-houfflin-debarge@chru-lille.fr
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.
Conclusion:
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.
Related Concept Videos
Nociception
Analgesia and Pain Management

