On Sat, 14 Jun 2008 16:05:09 -0700 (PDT), Bill
<connelly.bill from gmail.com> wrote:
>On Jun 15, 12:35 am, usene... from out-of-phase.de (Christian Wilms) wrote:
>> Entertained by my own EIMC <de... from mindyaown.biz> wrote:
>>>> > Yes, when "hours" is meant to imply "a lifetime" it takes just a second
>> > for someone like me to misinterpret the minutiae of this meaning.
>>>> I would be willing to bet against "a lifetime" when it comes to classic
>> LTP/LTD. I think long-term "storage" will prove to be mediated by a
>> different mechanism.
>>>> Best, Chris
>>Well there is LTP and there is LTP like mechanisms. Nothing in the
>brain is done by LTP (100Hz for 1 sec 3 times). However strong
>depolarisation leading to NMDA receptor dependent enhancement of
>synaptic strength, I would be willing to bet that memory formation,
>and maintainance is deeply dependent on this kind of mechanisms. (Re:
>How long does LTP last, at least a year in an Adult Rat Perforant path-
>DG (Abraham WC. How long will long-term potentiation last? Philos
>Trans R Soc Lond B Biol Sci. 2003 358(1432):735-44)
Once you start a second messenger cell signaling pathway, what you
call a "different" mechanism becomes much a matter of philosophy. If
you temporarily upregulate a synaptic receptor pathway so that the
effect lasts hours or days until protein turnover restores it to the
old value, is that a different mechanism from one that activates a
different kind of gene switch that can last forever but still uses a
number of the same intermediaries? I would call these different.