Cellular and molecular aspects of short-term and long-term memory from molluscan systems

Abstract

Cellular and molecular mechanisms of short-term memory and long-term memory are reviewed based on observations of molluscan models of Aplysia californica, Lymnaea stagnalis, and Hermissenda crassicornis. It is generally accepted that short-term memory results from changes in the synaptic strength of preexisting neuronal connections that involve covalent modifications of preexisting proteins by various kinases. On the other hand, the synaptic plasticity underlying long-term memory is believed to involve protein synthesis and modulation of gene expression to induce new mRNA, protein synthesis, and morphologic modifications. These processes and mechanisms are compared in three molluscan model systems and likely have commonalities with those of mammals.