On Tue, 23 Oct 2001 03:21:23 +1000, Michael Jameson
<m.jameson at hunterlink.net.au> wrote:
>Bob wrote:
>
>> >> >The paper that is the main focus of the article is "DNA recombination as
>> >> >a possible mechanism in declarative memory" by Sandra Pena de Ortiz and
>> >> >Yuri Arshavsky, Journal of Neuroscience Research, vol 63, p 72 (2001).
>> >>
>> >> Ok, I have looked at that paper. It is rather vague, but intriguing.
>> >> Those who want to consider the questions the poster raised should read
>> >> it.
>> >>
>> >> The basic idea they suggest is that memory storage may involve somatic
>> >> recombination, as with immunoglobulin genes. They provide evidence,
>> >> both from the known literature and from their new work, that somatic
>> >> recombination is "possible" or even "likely" in the nervous system.
>> >>
>> >> The proposal does lead to some predictions that are presumably open to
>> >> testing, so it does seem like a constructive proposal. One could
>> >> rephrase the proposal... what is the role of enzymes of somatic
>> >> recombination in the nervous system?
>>From this I take it that enzymes of somatic recombination are known to exist,
>but what role (if any) they play in the nervous system is unknown?
yes, on all counts
The term somatic recombination might have multiple meanings. Their
specific precedent is the type of rearrangement/recombination event
that goes on in the development of immune system cells. The enzymes
for those events are generally well known, and there is evidence for
(some of) them in the nervous system. The JNR paper reviews this.
>>>> Their key point is the proposed role for somatic recombination (of the
>> general type used for immunoglobulin gene rearrangements). The hints
>> for this relate to findings that some of the required gene products
>> are found in the nervous system, and that knockout mice for these
>> genes show specific neuro defects.
>>These are the two main substantiating points?
yes. So it would seem that such DNA enzymes have some special
relevance to the nervous system. That in itself is intriguing. Any
relationship to memory is speculative, and I don't think they really
propose how it works (which is why some of the criticisms expressed in
this thread doesn't hold, because the proposal is too vague to
criticize.)
>>> That leaves a big gap between what is known and their proposal that
>> DNA, via somatic recomb, may "store memories". But it does open up
>> some questions for experimental study. Example... Turn off one of
>> these enzymes (using your favorite turn-off-gene technology, such as
>> RNA(i)). Does that affect memory acquisition, or any other
>> identifiable process?
>>>> Their "big idea" is certainly speculative. But it does have something
>> behind it, and leads to expts. So it may be a useful idea, even if the
>> answer isn't exactly what they suggested. There are tantalizing hints
>> that somatic recomb is doing _something_ in neuro system.
>>Okay, that's interesting in itself. Even if it isn't about memory it might be
>doing something else.
yes; a proposal which open up some good work is useful, regardless of
the detail of the original model.
regards,
bob