There is a 1953 movie, Donovan's Brain, based on a 1942 story by Curt Siodmak. It's a bit reversed from what you would think about implant technology. There are only a couple of wires, a few tubes, that connect to an old fish tank the naked brain is residing in. The communication is accomplished by wireless telepathy. The naked brain of the dead millionaire never loses it's greedy business ethics but it does change the personalities of the people around it that it seeks to control.
The Brain-In-A-Jar was the plot point of an Outer Limits episode, "The Brain of Colonel Barham." (I always remembered the name as Barros).