Long-term potentiation (LTP), a relatively long-lived increase in syna
ptic strength, remains the most popular model for the cellular process
that may underlie information storage within neural systems. The stro
ngest arguments for a role of LTP in memory are theoretical and involv
e Hebb's Postulate, Marr's theory of hippocampal function, and neural
network theory. Considering LTP research as a whole, few studies have
addressed the essential question: Is LTP a process involved in learnin
g and memory? The present manuscript reviews research that attempts to
link LTP with learning and memory, focusing on studies utilizing elec
trophysiological, pharmacological, and molecular biological methodolog
ies. Most evidence firmly supports a role for LTP in learning memory.
However, an unequivocal experimental demonstration of a contribution o
f LTP to memory is hampered by our lack of knowledge of the biological
basis of memory and of the ways in which memories are represented in
ensembles of neurons, the existence of a variety of cellular forms of
LTP, and the likely resistance of distributed memory stores to degrada
tion by treatments that incompletely disrupt LTP.