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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
Endogenous morphine modulates acute thermonociception in mice
M Guarna1, E Bianchi, A Bartolini
1Neuroscience Research Institute, State University of New York, USA.
Journal of Neurochemistry
|March 21, 2002
Summary
The study found that depleting endogenous morphine in mice reduced pain sensitivity and weakened the pain-relieving effects of a specific opioid agonist. This suggests endogenous morphine plays a role in modulating pain perception.
Area of Science:
- Neuroscience
- Pharmacology
- Pain Research
Background:
- Endogenous morphine synthesis is present across diverse animal nervous systems.
- Endogenous morphine acts as a neurotransmitter or neurohormone.
- Exogenous morphine modulates pain perception.
Purpose of the Study:
- To investigate the role of endogenous morphine in pain modulation.
- To examine the effects of endogenous morphine depletion on nociceptive transmission.
Main Methods:
- Immunoneutralization of endogenous morphine via intracerebroventricular injection of anti-morphine IgG in mice.
- Assessment of nociceptive transmission using the hot plate test.
- Evaluation of the effects on the mu-selective agonist DAMGO.
Main Results:
- Depletion of endogenous morphine decreased thermal response latency in mice.
- Immunoneutralization attenuated the anti-nociceptive effect of DAMGO.
- Evidence suggests endogenous morphine is involved in pain modulation.
Conclusions:
- Endogenous morphine plays a significant role in the modulation of pain perception.
- The findings support the involvement of endogenous opioid systems in pain regulation.
