periaqueductal gray

== English == === Alternative forms === periaqueductal grey === Etymology === Shortening of periaqueductal gray matter. === Noun === periaqueductal gray (plural not attested) (neuroanatomy) The region surrounding the cerebral aqueduct in the midbrain, playing an important role in analgesia. [From 20th c.] Synonyms: central gray, PAG === References === Bear et al. Neuroscience, Exploring the Brain Co. 2001, Lippincot Williams and Wilkins