atonal chaotic

It's not a brain transplant, it's a body transplant.

javarush

Assuming all technicalities were solved, then I would go along with speculating that a person's identity would be transplanted with the brain. Why? There are physiologic reasons (vascular responses to preserve pressure and timing of tissue death) to believe that after a beheading, the head has enough reserves to enable consciousness to survive for a number of seconds. (Certainly, there are many anectodal urban legends echoing this.) Therefore, a "person" may be preserved for that duration and I suppose it's theoretically possible to extend that time by preserving nutrient flow, oxygenation, and metabolic waste removal.

BUT, whether all technicalities of isolating the brain and then successfully transplanting it can possibly be solved is a whole 'nother matter. At least, it is difficult to have a good discussion of this without some knowledge of the anatomy and physiology of the brain. The layman view often concentrates on the cortex and neglects the essential roles of the midbrain and brainstem, especially the former. Information filtering, awareness, coordinated thought, and emotional reactions are all controlled by structures in the midbrain; more specifically the limbic system. Without this system, no awareness, recall, formation, or coordination of cortical memory -- i.e. "thoughts" -- is believed to be possible. This is at the core of the question of the persistent vegetative state; e.g. the hotly debated cases of Terri Shiavo and Karen Ann Quinlan. This is also a flashpoint for discussions on fetal consciousness. It may be worth researching keywords such as "amygdala", "hippocampus", "thalamus", "limbic system", "reticular activating system" or "RAS".

As for transplantation, I see three obvious hurdles. First is the host's natural immune response to reject transplated tissue. Second is disrupted function due to mechanical damage from the surgery to dissect and then graft. Third is the tissue's rejection of the host; i.e. inability to adapt and integrate function into the host body. This last point especially applies to the critical hormonal roles of the pituitary, hypothalamus, and related structures.

4321lynx

Assuming all above were solved, which is doubtful, it is still doubtful that a young body would somehow rejuvenate an aging brain, not just the physiology of the neurons but their intimate blood supply, ageing blood vessels.

CanoeMan

Damn you and your quick responses. That was my line.

philian

This is not my area of expertise, so excuse my ignorance, but wouldn't the problem of rejuvenating aging cells be solved long before we are able to successfully transplant a brain?

4321lynx

If it were solved & we could rejuvenate cells, & neurons at that, then where is the necessity for a transplant? We presumably would be able to rejuvenate the whole person.

Irascible Doughnut

Maybe the recipients would feel in a way similar to those who say they were born in the wrong body and thus for instance have a sex change operation. So at least give a man's brain to a man and a woman's to a woman <edit>

Irascible Doughnut

But basically it raises the question whether or not what constitutes a person is stored exclusively in their brain or, as some people say, also in each and every cell, or even outside the physical body, like in conscience fields or whatever it was called.

philian

To continue on the previous question: If I had my brain placed in another body, would I still know how to type, or play the piano, etc. I know the technical knowledge would still be there, but would the skill?

Koyaanisqatsi

I would agree that long before we'd have the expertise to successfully transplant a human brain into another body, that we'd have the ability to rejuvenate the existing body. Nano-technology alone is some ten to twenty years away from being able to do this (supposedly, though my figures may be off).

I would also think that instead of transplanting a brain into another dead human body, we would transplant one into a robot or the like, or "download" a brain into a robot.

It seems to me that "brain transplants" are more the stuff of science fiction and that the facts would be radically different. Like when you watch a sci fi movie from the fifties or sixties talking about how we'd all be flying around on jetpacks in the 1990's or the like.

The general idea of it may become a reality, but the actual hows and whats would be as different as thinking jetpack technology is what would be commonplace.