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Rapid Determination of the Thermal Nociceptive Threshold in Diabetic Rats
Published on: May 17, 2012
Threshold and rate sensitivity of low-threshold thermal nociception
1The John B. Pierce Laboratory, New Haven, CT 06519, USA. green@jbpierce.org
The European Journal of Neuroscience
|June 8, 2010
Summary
Low-threshold thermal nociception (LTN) involves skin sensations from mild temperature changes. This study found that adaptation temperature and rate of change influence LTN, suggesting low-threshold thermoreceptors mediate these sensations.
Area of Science:
- Neuroscience
- Sensory Physiology
- Thermoreception
Background:
- Low-threshold thermal nociception (LTN) describes burning or pricking sensations from innocuous skin temperature changes.
- LTN suggests that primary afferent fibers, typically associated with warm and cold sensations, relay signals to the nociceptive system.
Purpose of the Study:
- To investigate how different adaptation temperatures (ATs) and rates of temperature change affect thermal sensations and LTN in humans.
- To determine if LTN is mediated by low-threshold thermoreceptors.
Main Methods:
- Experiment 1: Subjects rated warmth, cold, and nociceptive sensations during incremental temperature changes from various ATs.
- Experiment 2: The rate of temperature change was increased to assess its impact on thermal and nociceptive sensations.
Main Results:
- Thresholds for nociceptive and thermal sensations shifted similarly with AT during cooling.
- During heating, AT significantly affected the nociceptive threshold only between 32°C and 34°C.
- Increased rate of temperature change amplified thermal and nociceptive sensations, particularly for heating-induced nociception.
Conclusions:
- Results support the mediation of LTN by low-threshold thermoreceptors.
- Heating-induced LTN might involve a subset of transient receptor potential (TRP) channels distinct from those mediating mild warmth sensations.
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