"Michael Jameson" <m.jameson at hunterlink.net.au> skrev i melding
news:3BCBFEBE.63C3114A at hunterlink.net.au...
> Brian wrote:
> > "Michael Jameson" <m.jameson at hunterlink.net.au> skrev i melding
> > news:3BC9B655.E545C259 at hunterlink.net.au...> [...]
> > > Journal of Theoretical Biology 2001 Jan 21;208(2):145-9
> > > "Memory and DNA."
> > > Dietrich A, Been W.
> > > Institute of Human Genetics, University of Amsterdam, Academic Medical
> > > Centre, Meibergdreef 15, NL 1105 AZ Amsterdam, The Netherlands.
> > > a.dietrich at amc.uva.nl> > >
> > > A model is presented for the storage of long-term memory. In our model
> > > consolidation takes place by specific DNA sequences. These DNA
sequences
> > > are obtained by the recombination of DNA in a similar way to that
during
> > > meiosis and the production of immunological antibodies. DNA has the
> > > potential of the production of large numbers of specific DNA
sequences.
> > > These sequences can be attached to images of neural networks.The
> > > following considerations lead to the theory: (1)Most of the DNA is not
> > > used: approximately 3% of our DNA is used. (2)There are no cell
> > > divisions in the brain after adulthood is reached. Structural DNA
> > > arrangements will not be altered nor disrupted as a consequence of
cell
> > > division and mitosis. (3)Chromosomal pairing is demonstrated in the
> > > brain, which could indicate the exchange of DNA. In addition, in our
> > > first survey experiments we found a positive reaction of components of
> > > the synaptonemal complex (SC) in the nuclei of brain cells. The SC is
> > > highly meiosis specific and plays a major role in genetic
recombination.
> > >
> > > Copyright 2001 Academic Press.
> > >
> > > Mick.
> > > --
> > > "You are the music while the music lasts" - Antonio Damasio (after TS
> > > Eliot).
> >
> > So, you're basically saying that the gene-transcriptions are reversed ?
>> I don't have a clue what it means. My interest is from the direction of
> memory function and I am less than ill-informed about genetics.
Then grab a book, and start reading.
> > Only a retro-virus like the HIV are capable of that, unless you have
some
> > data that indicate otherwise.
>> The New Scientist article indicated that the general hypothesis has 'only
> circumstantial evidence so far' - 'DNA certainly has the capacity to act
as a
> stable blueprint... Once neurons are fully grown they don't divide again,
so
> there's no danger of disrupting the DNA during cell division, and no
problem
> if you disrupt genes that are needed to make new cells. In any case,
there's
> plenty of DNA to spare for archiving our memories. As much as 97 per cent
of
> our DNA has no obvious function'.
No, DNA is as you said the _stable_ blue-print.
The major differences we call _mutations_, in the sequence.
There _are_ sections of the DNA that we call junk-genes, but that is simply
because 'we' (not me) don't really know what it is for (I see it as
spacefill were
new mutations might occur, and create new functions out of previously unused
ones).
Sometimes they're positive changes, orther times they're neutral or negative
which means that the organism doesn't change (obviously) or dies
respectively.
I would suspect that far more than 3% is used to develope an organism, and
the 3%
figure seems to be the _genetic differences_ between certain _species_.
The developement of the brain needs (according to what I've read/heard)
around
50.000 genes.
And no, the neuron doesn't divide (except in certain cases), but it doesn't
mean the
DNA is unused.
RNA-sequencing occur in neurons as in other cells (transcription from
DNA->RNA).
> > And no, more that 3% of the data are used.
> > That would say that only 3% of the DNA were used to create a human
during
> > developement.
> > It seems more data are required
>> I don't understand. The abstract said that 'approximately 3% of our DNA is
> used'. How are 'DNA' and 'data' interchangeable? Do you believe that 3%
> figure to be incorrect?
Data means exactly that, DNA is biological data.
Unless they can provide a REASON that reverse gene-transcription occurs, I
won't take it at face-value.
It sounds like Lysenkoism to me.
Last, I'm currently reading "Memory" by Kandel et al, and they have never
mentioned any reverse transcription so far, and so far I've dealt through
the
book with conditioned, habituationed and sensitizationed responses (which is
what is called undeclared memory, short term).
I've just begun with declared memory, and so far there's nothing about
storing
long term memory data onto the DNA-string by reverse transcription.
I know it might sound terrific to have such huge quantities of data on DNA,
but
the facts is that it isn't so, memory is stored at the synapses.
I made the mistake of overlooking this fact, and searched (in a wild
goose-chase)
after something I termed a 'neo-dendrite' which would have something to do
with
long term memory.
Don't do the same mistake, please.
Brian
> Mick.
> --
> "You are the music while the music lasts" - Antonio Damasio (after TS
Eliot).