Like heart transplantation is there brain transplantation?

No, because like the other poster said, they haven't figured out how to reconnect severed nerves and have them still be functional. The other practical problems would be things like location...the brain basically floats in a layer of fluid, and there is so much vasculature (and so many nerves) attached to it that it would be really impractical to remove and replace it...and the ethical problems it would pose would be virtually insurmountable, because the brain is the seat of everything we are and do. Would the recipient be taking on the characteristics of the donor, making them a completely different person than they were before the transplant? Thorny questions like that would tie up medical ethics committees in hopeless knots even if brain transplantation was physically feasible. I don't see it happening any time soon.

No. But there are brain surgeries! Brains cant be transplanted. The whole nueral network might fail leading to death of a person. But u can get expert answers from others.

No. Doctors haven't figured out how to join nerves that have been severed. For example, whenever the doctors learn how to repair a person's spinal cord that has been severed, then that's half the battle. If they could do that, then people like Christopher Reeve wouldn't have needed all that 24 hour care, and he would have been up and around after his surgery. Understand now? Have a good day.