Short-term and long-term memory in single cells.

Many approaches have been used to study short- and long-term memory. Bacteria detect chemical gradients using a memory obtained by the combination of a fast excitation process and a slow adaptation process. This model system, which has the advantages of extensive genetic and biochemical information, shows no features of long-term memory. To study long-term memory, neural cell line systems have been developed that exhibit two phenomena associated with learning and memory, habituation and potentiation. The expression of these phenomena in clonal cell lines, devoid of synaptic connections, makes it possible to study the biochemical and molecular mechanisms that contribute to short-term and long-term memory.