Intrinsic functional connectivity of the periaqueductal gray, a resting fMRI study

Behav Brain Res. 2010 Aug 25;211(2):215-9. doi: 10.1016/j.bbr.2010.03.042. Epub 2010 Mar 27.


The periaqueductal gray (PAG) is known to play a crucial role in pain modulation and has shown a strong interaction with anterior cingulate cortex in previous functional imaging studies. We investigated the intrinsic functional connectivity of PAG using resting fMRI data from 100 subjects. The results showed that PAG is functionally connected to ACC (rostral and pregenual ACC) and also rostral ventromedial medulla (RVM), forming a core ACC-PAG-RVM network for pain modulation even no pain stimulus is applied. The comparison between genders showed that for the contrast of female minus male, significant difference was observed at mid-cingulate cortex; for the contrast of male minus female, significant differences were observed at left medial orbital prefrontal cortex, and uncus; right insula/operculum and prefrontal cortex. We believe eluciation of this intrinsic PAG network during the resting state will enhance our physiological and pathological understandings of the development and maintenance of chronic pain states.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Arousal / physiology*
  • Brain Mapping*
  • Cerebral Cortex / physiology*
  • Female
  • Gyrus Cinguli / physiology
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Neural Pathways / physiology*
  • Periaqueductal Gray / physiology*
  • Reference Values
  • Rest / physiology*
  • Sex Factors
  • Young Adult