We thank the reviewers for their constructive comments. We have now made their recommended modifications, and we feel the article is much stronger and more suitable for Scholarpedia.
We have now added the additional references and a summary/concluding paragraph to highlight the importance of metaplasticity, as requested by reviewer #1.
As requested by reviewer #2, we have now improved the heirarchichal ordering of the topics, and have provided a better context for the material. We have also clarified the distinction between metaplasticity and neuromodulation, and have pointed out that in some cases it may be difficult to distinguish between the two. We now believe the article has a much better slow and is easier to follow.
We appreciate the constructive criticisms of the reviewers, and we hope that they now find the article suitable for online publication in Scholarpedia.
My majot concern is that it reads like a laundy list. There is no clear motivation for why? And little heirarchy in how the different topics are ordered. True much of Biology is like this, but it will be better here to give it more context and order, even at the cost of omitting some examples. For example the first two sections are NMDA receptor activated metaplasticity and mGluR dependent metaplasticity. This is about mechanism (mostly) the next one is heterosynaptic - does this mean it does not depend on NMDAR?, another section is about visual cortex, does this again mean it is not NMDAR? In short, I think some order and heirarchy are in place.
The destinction between neuromodulation of plasticity and metaplasticity is important - but needs to be further clarfied. Does neuromodulation mean that the applied chemical needs to be present at time of plasticity? What if the mechanism of metaplasticity involved an endogeneous and prolonges release of some modulator? Can the difference be prefectly deliniated?
The examples themselves are very comprehensive, and complete. I would like to see more order and context even at the cost of less detail.