Encyclopedia of Pain

2013 Edition
| Editors: Gerald F. Gebhart, Robert F. Schmidt

Sex Differences in Descending Pain Modulatory Pathways

Reference work entry
DOI: https://doi.org/10.1007/978-3-642-28753-4_3967
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Synonyms

 Endogenous descending pain modulatory pathways;  Descending inhibition;  Descending inhibitory pathway;  Periaqueductal gray – rostral ventromedial medulla (PAG-RVM) pathway;  Periaqueductal gray – nucleus raphe magnus (PAG-NRM) pathway

Definition

The midbrain periaqueductal gray (PAG) and its descending projections to the rostral ventromedial medulla (RVM) have long been recognized as the key neural circuit mediating opioid-based analgesia. It is well established that administration of the opioid morphine produces greater analgesia in males compared to females, and recent studies indicate that this PAG-RVM pathway contributes to the sexually dimorphic actions of morphine. Many anatomical and physiological studies since the 1960s have characterized this descending pathway. However, the majority of these studies were conducted exclusively in males with the implicit assumption that the anatomy and physiology of this circuit was the same in females, and this now is known not to...

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Notes

Acknowledgments

This work was supported by NIH grant DA16272.

References

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© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  1. 1.US Army Institute of Surgical ResearchFort Sam HoustonUSA
  2. 2.Neuroscience InstituteGeorgia State UniversityAtlantaUSA