gocentral
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Below there is a comment to my email by Doug:
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)
Thoughts from anyone else?
Below there is a comment by Nicholas:
I think our problems here are coming from the notions of long and short, that are 1) subjective 2) applied differently according to the level we consider. Long term potentiation and depression effectively belong to long term synaptic adaptation but to the short term neuron adaptation.
So we have (funny characters chosen to avoid semantic relations):
- short-term neuroadaptation ==>short term synaptic plasticity e.g. receptor desenzitisation or potentiation ==>long term synaptic plasticity e.g. LTP and LTD
- mid-term neuroadaptation e.g. synapse creation/suppression
- long-term neroadaptation e.g. dendritic remodelling, axonal reorganisation
"long term synaptic plasticity" would actually overlap "mid-term neuroadaptation"
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.
If "plasticity" was viewed as a property, I would agree. It would characterize the possibility to adapt. An increase of plasticity would render LTP or LTD easier to induce. But this is not the usual sense as far as I am aware. Extract from one of the latest review of Graham Collingridge (PMID: 15550950):
"Long-term potentiation and long-term depression are processes that have been widely studied to understand the molecular basis of information storage in the brain. Glutamate receptors are required for the induction and expression of these forms of plasticity"
That's an is_a relationship to me.
Or, if you don't like Graham, one from Calabresi (PMID: 15582223) "Long- and short-term changes in the efficacy of synaptic transmission are known as synaptic plasticity. Phenomena such as long-term depression (LTD) and long-term potentiation (LTP) are two classical forms of synaptic plasticity"
Doug wrote: 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'm thinking aloud here: I often read that LTP and LTD were regulation of "synaptic efficacy" or "synaptic strength". Could-we find a subtle difference between synaptic efficacy and synaptic transmission? Would synaptic efficacy be a potential while synaptic transmission would be the revelation of that synaptic efficacy when a signal is received? In that sense, LTP and LTD would characterise different synaptic transmissions caused by be modified efficacies. Now a gene that we would annotate would be involved in the change of efficacy, not transmission.
erika wrote: 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. 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.
That is OK.
erika wrote: Long-term neuronal synaptic plasticity generally involves increase or decrease in actual synapse numbers.
That is not. At least not "generally".
erika wrote: Short-term neuronal synaptic plasticity generally involves increasing or decreasing synaptic sensitivity.
That is not. Cf comment of Doug.
Original comment by: arike
Dear all, last week I have sent an email to Neurobiology Group for asking suggestions about possible new terms. I would like to insert terms for describing Long-term potentiation (LTP) and Long-term depression. Below you can find the email I have sent to the group. Erika
>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
Reported by: arike
Original Ticket: "geneontology/ontology-requests/3271":https://sourceforge.net/p/geneontology/ontology-requests/3271