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Assessment of Morphine-induced Hyperalgesia and Analgesic Tolerance in Mice Using Thermal and Mechanical Nociceptive Modalities
Published on: July 29, 2014
Habituation to painful stimulation involves the antinociceptive system
U Bingel1, E Schoell, W Herken
1Department of Neurology, University of Hamburg (UKE), Germany. bingel@uke.uni-hamburg.de
Pain
|January 30, 2007
Summary
Repeated painful stimuli decrease pain perception and associated brain activity in key pain processing areas. However, activity in the subgenual anterior cingulate cortex (sgACC), involved in pain control, increases, suggesting enhanced antinociception.
Area of Science:
- Neuroscience
- Pain Research
- Neuroimaging
Background:
- Pain perception involves complex interactions between nociceptive (pain-signaling) and antinociceptive (pain-inhibiting) mechanisms.
- Understanding the neural basis of these interactions is crucial for developing effective pain management strategies.
Purpose of the Study:
- To investigate how the healthy human brain processes, perceives, and modulates pain following repeated daily painful stimulation over eight consecutive days.
- To identify changes in brain activity associated with pain habituation.
Main Methods:
- Functional magnetic resonance imaging (fMRI) was used to monitor brain activity in 20 healthy subjects.
- Subjects underwent a daily 20-minute pain paradigm for 8 days, with fMRI scans on days 1, 8, and 22.
Main Results:
- Subjects reported significantly decreased pain ratings after repeated stimulation.
- fMRI data revealed decreased blood-oxygen-level-dependent (BOLD) responses in classical pain processing areas (thalamus, insula, SII, putamen).
- A significant increase in pain-related BOLD responses was observed in the subgenual anterior cingulate cortex (sgACC).
Conclusions:
- Habituation to pain is characterized by reduced pain perception and decreased neural activity in pain processing regions.
- The observed increase in sgACC activity suggests a role for enhanced endogenous antinociceptive mechanisms in pain habituation.
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