Shredder and the Neuro Scrambler
The Neuro Scrambler was a device invented by Shredder sometime before the events of Splinter No More in the 1987-1996 animated series.
Concerned about being followed by the Turtles in the sewers, Shredder requested that Krang transport the Neuro Scrambler to his location, so that he could leave it in waiting for his enemies. It initially had the desired effect, causing the Turtles to physically attack each other until April reminded them of Splinter. She located the device, and the Turtles destroyed it, negating the effect.
The effects of the Neuro Scrambler include severe headaches, loss of equilibrium and eventual homicidal aggressiveness. The effects can be shaken off for a brief time by extreme force of will.