The neurons in the brain and body will inevitably learn connectivity patterns to best take advantage of neural signals from the other. Which is kind of an interesting wrinkle to the mind body problem: the brain likely has more capability to remap circuits than the body. So, if you implant a brain into a body... The implanted brain changes more to match the implanted body than vice versa.

It would be interesting to see from a scientific and humanities viewpoint.

If you take a smoker and transplant their brain into a healthy non-smoker body, would that decrease their likelihood of continuing to smoke?

What about an obese person into a slender body? Or a man/woman into the opposite sex's body, assuming the rejection issue was dealt with? How much will change about a person based on what body they are in, and how much can you change without changing the person, and how much about a person can you change just by changing the body they find themselves in?