neuroscience - Long-term-potentiation and memory. Where do we stand?

I was reading the answers to the question: How and where, in the human brain, are memories stored? and, as expected, LTP and LTD came out.

Every time I read about LTP/LTD there is always something that bugs me a lot.

When I read papers about LTP/LTD (OK, I should really say "when I browse", as I'm not exactly in that area of neurosciences, and that is probably the reason why I am confused by this) I always see these very neat experiments where stimulating a neuron in a certain way increases/decreases its further responses. Then, I look at the time axes on the graphs, or read the Methods, and I see that the LTP was induced and analysed few minutes after the stimulus.

So my questions are:

1. Is there clear evidence that LTP is involved in long-term memory (not counting 1 hour as long-term...)?


2. Has LTP/LTD been shown in vivo after long period of time (e.g. months).


3. For those who work in the field, is there a strong belief that LTP/LTD are the only phenomena underlying memory?

Answer

Is there clear evidence that LTP is involved in long-term memory (not counting 1 hour as long-term...)? Has LTP/LTD been shown in vivo after long period of time (e.g. months).

This Journal of Neuroscience paper shows LTP in vivo measured out to one year: Abraham WC, Logan B, Greenwood JM, Dragunow M. 2002. Induction and experience-dependent consolidation of stable long-term potentiation lasting months in the hippocampus. The Journal of neuroscience : the official journal of the Society for Neuroscience 22: 9626–34.