A neuro-depolarizing device was a suicide device used by covert operatives in Section 31 in the 24th century to prevent others from extracting information from their mind. The neuro-depolarizer was implanted into the operatives brain and could be activated by thought while the operative was restrained in a force field. While the device killed the operative immediately, higher brain function remained for up to an hour, though the memory pathways had been scrambled. The device prevented the use of Romulan mind probes, requiring someone to go into the mind of the operative to find information.
In 2375, Luther Sloan of Section 31 activated a neuro-depolarizing device in an attempt to prevent Doctor Julian Bashir from obtaining a cure for the morphogenic virus designed by Section 31. (DS9: "Extreme Measures")