rbg@cbosgd.UUCP (Richard Goldschmidt) (11/13/84)
References: <290@pecosdg.UUCP> <5579@brl-tgr.ARPA> <420@utcsrgv.UUCP> >But now that medical science has crossed this barrier, where >will it stop? Where should it stop? >Consider: X is severely injured in a car accident, and is completely >paralysed from the neck down. He is offered the choice of life in >a wheelchair, with only his facial muscles to control things, or >the transplant of a baboon's body. He chooses the baboon, and we >have a human head on a baboon's body. Is it human? Does the brain >alone make it human? Should a doctor perform this kind of operation, >if it's what X wants? >utcsrgv!dave The example chosen may not really answer the question. The problem with neurological injuries is that they don't "heal". If it was possible to get a FUNCTIONAL cross-species "body transplant", then the person could also be effectively treated, and recover function after spinal cord transection. However, there is a great deal of (animal) research into how to stimulate functional recovery after neurological injury. The most promising method could be crudely termed a "brain transplant", and involves implantation of a clump of embryonic brain cells, which induce neuronal growth in the adult nervous system which never occurs normally. It is a bit more complicated, with issues of transmitter specificity in induction, and the lack of spatial mapping in regenerated connections, but some functional recovery is possible. The ethical issue here is the source of fetal brain tissue needed for treatment (until the specific factors are identified and purified). There are lots of aborted fetuses getting thrown away, but my guess is that they are out of bounds for most researchers in this country. The first attempts at using some variation of this method in humans have taken place in Sweden, but involve using cells from the patients own adrenal gland for Parkinson's treatment. Look for the first transplant using brain tissue from either human or animal fetuses to occur there too. Rich Goldschmidt {ucbvax,ihnp4,decvax,allegra} ! cbosgd!rbg ARPA: cbosgd!rbg@berkeley.arpa