Learning and memory in invertebrates: Mollusks

Mollusks exhibit several forms of memory that are commonly observed in higher invertebrates and vertebrate species. These animals provide powerful experimental systems for examining the cellular and molecular mechanisms of memory, because observations at the behavioral level can often be linked directly to cellular and molecular changes in the central nervous system (CNS). Here, we focus on three molluskan species that have made significant contributions to our understanding of mechanisms of learning and memory: Aplysia, Hermissenda, and Lymnaea. While each species exhibits diverse forms of memory in different response systems, striking similarities emerge in the molecular mechanisms that are engaged in memory formation. © 2009 Elsevier Ltd All rights reserved