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Measuring Changes in Tactile Sensitivity in the Hind Paw of Mice Using an Electronic von Frey Apparatus
Published on: December 19, 2013
An improved method for assessing mechanical allodynia in the rat
1Department of Oral and Craniofacial Biological Sciences, University of Maryland Dental School, Baltimore 21201-1586, USA. knr001@dental.umaryland.edu
Physiology & Behavior
|December 22, 1999
Summary
A new method assesses mechanical pain sensitivity and allodynia in rats without weight-bearing interference. This technique reliably measures pain thresholds in both hind paws and orofacial regions, aiding pain research.
Area of Science:
- Neuroscience
- Pain Research
- Animal Models
Background:
- Assessing mechanical nociceptive threshold and allodynia in rats is crucial for understanding pain mechanisms.
- Existing methods may be confounded by factors like weight-bearing.
- A reliable and objective method is needed, particularly for the orofacial region.
Purpose of the Study:
- To develop and validate a novel method for assessing mechanical nociceptive threshold and allodynia in rats.
- To evaluate the method's applicability in both hind paw and orofacial regions.
- To investigate the induction and persistence of allodynia following inflammation.
Main Methods:
- Rats were habituated to stand on hind paws, leaning against an experimenter's hand, remaining unrestrained.
- Semmes-Weinstein monofilaments were used to probe mechanical sensitivity on hind paw and orofacial skin.
- Inflammatory agent (complete Freund's adjuvant) was injected into hind paw, peritemporomandibular joint tissue (PTMJ), or perioral (PO) skin.
Main Results:
- Baseline median withdrawal thresholds were established for hind paws (62.9 g), PTMJ (62.9 g), and PO skin (25.6 g).
- Inflammation induced significant mechanical allodynia, reducing thresholds to 0.09 g (hind paw), 5.60 g (PTMJ), and 3.24 g (PO skin).
- Allodynia persisted for at least two weeks post-inflammation.
Conclusions:
- The developed method provides a simple, objective, and reliable assessment of mechanical sensitivity in rats, free from weight-bearing confounds.
- This technique is effective for both hind paw and orofacial regions, facilitating studies on persistent orofacial pain.
- The method is valuable for investigating the central mechanisms of mechanical allodynia and related pain conditions.
