The role of 5-hydroxytryptamine (5-HT) receptor subtypes and plasticity in the 5-HT systems in the regulation of nociceptive sensitivity.

Abstract

This review shows that the role of 5-hydroxytryptamine (5-HT) in the regulation of nociception depends on the 5-HT receptor subtypes involved and on long-term functional changes in the 5-HT receptors. Stimulation of the 5-HT1 receptors, as well as of the 5-HT2 and 5-HT3 receptors, may reduce nociceptive sensitivity. In addition, activation of 5-HT2 and 5-HT3 receptors may also enhance nociceptive sensitivity. Up- or down-regulation of the 5-HT receptors may result in long-lasting changes, plasticity, in the 5-HT systems. Lesioning of 5-HT neurons induces denervation supersensitivity to 5-HT, and prolonged stimulation of 5-HT receptors may produce subsensitivity to 5-HT. In the spinal cord denervation supersensitivity to 5-HT may depend on reduced release of substance P (SP). An increase in the release of SP, on the other hand, may reduce the effects of 5-HT receptor activation. Long-term treatment with antidepressants which are used in clinical pain therapy appears to up-regulate the 5-HT1 receptors and to down-regulate the 5-HT2 receptors.

• Authors: P K Eide, K Hole
• Journal: Cephalalgia : an international journal of headache (Cephalalgia) Vol. 13 Issue 2 Pg. 75-85 (Apr 1993) ISSN: 0333-1024 [Print] England
• PMID: 7684323 (Publication Type: Journal Article, Review)

Chemical References

• Receptors, Serotonin
• Substance P

Topics

• Animals
• Denervation
• Humans
• Nociceptors (physiology)
• Receptors, Serotonin (classification, physiology)
• Stimulation, Chemical
• Substance P (physiology)