LTP induction and AMPA

Neuroscience FAQ, Q&A — Tags: , — 8:10 am

 

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QUESTION 1: When you say ‘LTP induction’, does it mean increasing number of AMPA receptors?
Sujin
ANSWER 1:Hi Sujin,Long-term potentiation (LTP) is considered a neuronal analog of memory so I do not think that “increasing number of AMPA receptors” fully describes the process. The trafficking of AMPA receptors to synapses is thought to be one of mechanisms. During LTP induction, there is an increased delivery of AMPA receptors to synaptically active regions without changes in receptor affinity (1), by exocytosis to stimulated spines (2). This delivery precedes the full expression of LTP (3).

I suggest that you read the latest review article “AMPA receptor regulation during synaptic plasticity in hippocampus and neocortex” in Seminars in Cell & Developmental Biology doi:10.1016/j.semcdb.2011.06.007.

Sources

1. J Physiol, 2004, 559, 543-554

2. PNAS, 2010 vol. 107, 36, 15951-15956

3. PNAS, 2008 vol. 105, 32, 11388-11393

QUESTION 2 : First of all, thank you very much.

But I am curious about this… you mean AMPA receptors were already made, stored in somewhere and when it is needed, go to synaptically active regions?

If I am right, where were they stored in?

p.s I can’t speak English very well. I hope you understand.

ANSWER 2: I perfectly understand you, don’t worry.

Most of AMPA receptors are located within neuronal cytoplasm. As to their expression, there’s, for example, a special protein (NSF) involved in neurotransmitter release from the presynaptic terminal that binds to the GluR2 subunit of AMPA and regulates surface expression of AMPA receptors. It can get too complicated to give you more details and I am not sure about the level of your basic knowledge so please don’t hesitate telling me more about your interest.

 

Tanya Zilberter


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