Verterons are subatomic particles that are present in wormholes. Verterons can interfere with sensor scans and only exist when artificially created. (TNG: "The Pegasus"; DS9: "In the Hands of the Prophets";) Verterons also allow the extrapolation of a wormhole's subspace bearing by detecting their exit vector, allowing one to pinpoint the terminus spacial coordinate for any wormhole. (VOY: "Eye of the Needle")
The Bajoran wormhole was formed by self-sustaining verterons. (DS9: "In the Hands of the Prophets", "Playing God")
As of the mid-2150s, a verteron-emission array was installed on Mars to redirect comets for terraforming purposes. The verteron array was briefly hijacked by Terra Prime supremacists seeking to rid Earth of aliens, but their plot was foiled by Captain Jonathan Archer of Enterprise. (ENT: "Terra Prime")
A pulse of verterons is capable of disabling a starship. The USS Enterprise-D was disabled by a Hekaran probe in 2370 when the probe emitted a verteron pulse, immediately disabling the Enterprise's warp and impulse drives as well as the ship's shields. (TNG: "Force of Nature")
In late 2369, Keiko O'Brien looked at verterons in one of her school lessons. (DS9: "In the Hands of the Prophets")
In 2373, the USS Voyager bombarded a subspace instability near the Takarian planet with verterons to induce the Barzan wormhole to re-open at that location. (VOY: "False Profits")
Apocrypha
In the Star Trek/X-men crossover novel Planet X, it was revealed that verteron particles are present in subspace. The novel also revealed that Nightcrawler, an X-man with the power of teleportation, reappears in normal space covered in verteron particles, suggesting that the dimension he travels through when he teleports is related to subspace.