ABSTRACT
Neuroscientists have been working for many years to comprehend the mechanisms by which the nervous system stores and retrieves information. Although considerable progress has been made in some areas, many fundamental questions remain unsolved. One reason for the general lack of progress is that relatively few experimental response systems have been developed in adequate detail. The few model biological systems that have been proposed to study the neuronal correlates of learning have generated exciting new findings. But even these systems have been either fairly restrictive in the questions they can ask or are still in an early stage of development.
