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Long term potentiation and long term depression
Marc Gillespie
gillespm at cshl.edu
Fri Mar 24 13:40:57 PST 2006
Hi All,
See comments below.
On Mar 23, 2006, at 1:02 PM, Doug howe wrote:
> Erika,
> You are correct that LTP (Long Term Potentiation) and LTD (Long
> Term Depression) both reflect changes in synaptic activity (at the
> level of individual synapses) over the long term (at least
> hours...ranging up to weeks or more). So a GO term like GO:0048172
> (regulation of short-term neuronal synaptic plasticity) will not be
> useful for LTD or LTP. Further, LTP and LTD are the results of
> synaptic plasticity...they are not the plasticity itself, so terms
> like "positive regulation of synaptic plasticity" will not be
> useful either I don't think.
>
> It looks to me like new terms would be needed to represent LTP and
> LTD specifically.
>
> I propose the following...open for discussion...
>
> positive regulation of synaptic transmission (GO:0050806)
> ---[i]long term potentiation (GO:new)
>
> negative regulation of synaptic transmission (GO:0050805)
> ---[i]long term depression (GO:new)
I am not sure I understand. Are these terms describing:
1) a specific type of regulation encompassed by (children of) "GO:
0048169 regulation of long-term neuronal synaptic plasticity"
or
2) are they meant to describe something other than plasticity?
I am ok with 1, but disagree with 2. I would not want to classify LTP
and LTD without implying plasticity. Seems like plasticity is to
amorphous a term, though I did like "neuroadaptation". Though I
probably like it not because it is any-less amorphous, but rather it
carries less historical baggage.
Marc
Marc Gillespie
Cold Spring Harbor Laboratory
Stein Lab
1 Bungtown Road
Cold Spring Harbor, NY 11724
email: gillespm at cshl.edu
telephone: (718) 990-5249
http://www.reactome.org
>
>
>
> Thoughts from anyone else?
>
> -Doug
>
>
> erika wrote:
>> Dear all,
>> I am annotating ionotropic gluatamate receptor and I would like to
>> insert terms about long term potentiation (LTP) and long term
>> depression (LTD).
>> I know that there are these two terms that described two form of
>> synaptic plasticity.
>> GO:0048169 regulation of long-term neuronal synaptic plasticity:
>> A process that modulates long-term neuronal synaptic plasticity,
>> the ability of neuronal synapses to change long-term as
>> circumstances require. Long-term neuronal synaptic plasticity
>> generally involves increase or decrease in actual synapse numbers.
>>
>> GO:0048172 regulation of short-term neuronal synaptic plasticity:
>> A process that modulates short-term neuronal synaptic plasticity,
>> the ability of neuronal synapses to change in the short-term as
>> circumstances require. Short-term neuronal synaptic plasticity
>> generally involves increasing or decreasing synaptic sensitivity.
>>
>> So I can not understand if we should add new terms about LTP and
>> LTD or we could use GO:0048172 (regulation of short-term neuronal
>> synaptic plasticity) and GO:0048169 (regulation of long-term
>> neuronal synaptic plasticity) for LTP and for LTD
>> This is a new topic for me so any help will be appreciated.
>> I have read that LTD is a weakening of a synapse that lasts from
>> hours to days. So I am not sure that short term plasticity could
>> be the correct term for LTD because GO:0048172 (regulation of
>> short-term neuronal synaptic plasticity) describes changes in the
>> short time. LTD results from either strong synaptic stimulation
>> (as occurs in the cerebellum Purkinje cells) to persistent weak
>> synaptic stimulation (as in the hippocampus).
>> In addiction, LTD refers only to a weakening of a synapse and not
>> to an increasing of it.
>> LTD is thought to result from changes in postsynaptic receptor
>> density, although changes in presynaptic release may also play a
>> role. Slow, weak stimulation of CA1 neurons also brings about long-
>> term changes in the synapses, in this case, a reduction in the
>> sensitivity. It involves Glu binding to a different type of NMDA
>> receptor.
>> Instead, long-term potentiation (LTP) is the long-lasting
>> strengthening of the connection between two nerve cells.
>> Experimentally, a series of short, high-frequency electric
>> stimulations to a nerve cell synapse can strengthen, or
>> potentiate, that synapse for minutes to hours. In living cells,
>> LTP occurs naturally and can last from hours to days, months, and
>> years. The biological mechanisms of LTP, largely via the interplay
>> of protein kinases, phosphatases, and gene expression, give rise
>> to synaptic plasticity and provide the foundation for a highly
>> adaptable nervous system.
>> Researches in Geneva, Switzerland have demonstrated that formation
>> of LTP in rat brains coincides with the formation of additional
>> synapses (at least one more) between the presynaptic axon terminal
>> and the dendrite it synapses with. (Report by Toni, N., et al,
>> Nature, 25 Nov 99). Presumably this, too, increases the efficiency
>> of synaptic transmission.
>> I am confused because both LTP and LTD refer to changes in the
>> long term.
>> So are they part of process of regulation of ONLY long term
>> synaptic plasticity regulation GO:0048169?
>> Thanks very much
>> Erika
>> Erika Feltrin, PhD student
>>
>> Bioinformatics Lab-CRIBI
>>
>> Padua University
>>
>> erika at cribi.unipd.it <mailto:erika at cribi.unipd.it>
>>
>>
>> c/o EMBL-European Bioinformatics Institute
>>
>> Wellcome Trust Genome Campus
>>
>> Cambridge CB10 1SD
>>
>> United Kingdom
>>
>>
>> erika at ebi.ac.uk <mailto:erika at ebi.ac.uk>
>>
>> +44 (0) 1223 492600 (work)
>>
>>
>>
>>
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