Caenorhabditis elegans: a new model system for the study of learning and memory.

The extensive information on the neuroanatomy, development and genetics of Caenorhabditis (C.) elegans make it an ideal candidate model system for the analysis of the mechanisms underlying learning and memory. A first step in this analysis is the demonstration of the capacity of C. elegans to learn. In these experiments non-associative learning in C. elegans was investigated by observing changes in reversal reflex response amplitude to a mechanical vibratory stimulus. The results from these studies of non-associative learning show that C. elegans is capable of short-term habituation, dishabituation and sensitization, as well as long-term retention of habituation training lasting for at least 24 h. These findings set the stage for detailed developmental, genetic and physiological analyses of learning and memory.