Re: NEURO: Head Transplants"

Robert J. Bradbury (
Mon, 30 Aug 1999 00:42:45 -0700 (PDT)

On Sun, 29 Aug 1999, Brian Manning Delaney wrote:

> Hi Greg. I've followed White's research a bit, and I believe
> this is indeed an accurate report on the state of his research.

I think White gave a presentation at A4M a couple of years ago.

> Stem cell research will soon obviate any need for whole
> part/organ replacement, I'm guessing -- at least in many cases.

I'm of the opinion that one of the major problems is the cell division rate. How long does it take you to grow a 5 kg (?) liver from a single cell with a 24 hour doubling time? {I could compute this since I'm pretty sure the information is in NM, but I'm being lazy tonight.}

The question comes down to how much you can "push" mammalian growth (e.g. with hyperoxygenation/glucose levels, hormones, etc.). What is the fastest growing mammal? And would this result in an organ that was "prematurely" aged? [Pushing division rates=pushing mutations, pushing oxygen levels=pushing free radical damage, pushing glucose= pushing protein glycosylation, etc.]

> It's in the case of the
> brain, above all, that I think stem cell infusion could be
> extremely beneficial. The newer cells could just take up the
> connections currently maintained by older cells (which taking up
> might require, though, "rehearsing the thought" that the old
> cells are maintaining).

I've thought about this as well. I think there are going to be three very interesting avenues; (a) hormones to promote axonal hypergrowth; (b) hormones to promote stem cell multiplication and (c) stem cell injections, perhaps followed by (a) or (b).

I think (a) gets you back to the childhood state of hyperlearning, perhaps sacrificing some of your "known" knowledge. I agree that rehearsing would repattern old memories on new cells, I suspect however that without such rehearsing (and I'm sure you can't rehearse "everything"), that much of the old information will fade away.

I am "Robert Bradbury++++", my mind has been painted over four times, I can no longer remember my childhood, etc. I think Heinlein discussed that Lazarus Long had undergone some mental compression to make room for more information as the years had gone by. [I guess thats what happens without nanotech!]

> In fact, it seems that we pretty much have the science for this
> to take place -- certainly in many organs -- just not, for the
> most part, the technology (though even that we partly have, in a
> not thoroughly tested form).

People will die and be lost forever while we wait for the tests...