A verteron node was an amalgamation of verterons within the Bajoran wormhole.
In 2370, Jadzia Dax and Arjin piloted the USS Rio Grande around verteron nodes while moving a proto-universe to the Gamma Quadrant. (DS9 episode: "Playing God")
When the wormhole was temporarily disrupted by the Cardassians, the verteron nodes in the wormhole became distended and a threat to ships passing through. (TNG - DS9 comic: "Prophets and Losses")