Learning from LTP: a comment on recent attempts to identify cellular and molecular mechanisms of memory.

In recent years disappointing evidence has emerged regarding all main lines of evidence supporting connections between long-term potentiation (LTP) and memory. The history of this research, including studies focusing on synaptic alterations following learning experience, on saturation of LTP, and on pharmacological and genetic manipulations of LTP, are discussed briefly and interpreted in light of their observed and inherent limitations. Other approaches, aimed at showing a continuity of plasticity from molecular to synaptic to circuit and systems levels of analysis, are highlighted as potentially more compelling future directions for this research.