On Sat, 29 May 1999 19:29:11 -0400, Sarge <dsargent at ix.netcom.com>
wrote:
>> At 5:35 PM +0000 5/21/99, Simon Marsh wrote:
>> >Some neuroscientests estimate that during an average lifespan, a person uses
>> >only 1/100 of 1% (.0001) of his potentional brain capacity. - Why do we
>> >have a brain with so much capacity that we hardly test a fraction of it in a
>> >normal life time?
>>Why, indeed!!? Look at the cells which comprise the human body. I think that
>ALL (~100%) of the cells are replaced by 'new' cells roughly, every 4 months.
>There is something I have heard about concerning the reason WHY this process
>doesn't continue indefinitely (I'll get back to your question very shortly. I
>just think this is somewhat related and if not, it's interesting). I've heard
>that the ends of chromosomes (called 'trellacurs', or something, I think?)
>apparently are SHORTER with age. This is a hot topic in the breakthrough field
>of cloning technology. The question is whether the cloned organism will have a
>shortened life expectancy because the chromosomes that are the base cell
>(conception) have this shorter characteristic. -
Neurones don't replicate. Neither do macroglia cells. For the most
part the brain has little replication other than those by the
embryonic stem cells (which is believed to be the cause of
neurogenesis in adults)