Gene Expression & Memory Persistence

Experience changes the strength and number of synaptic connections in the brain. This process, known as synaptic plasticity, provides a cellular mechanism for memory storage. While short-term forms of plasticity involve localized, transient changes in synaptic efficacy, persistent forms of synaptic plasticity, such as those underlying long-term memory, have been shown to require new RNA and protein synthesis. This means that signals are transported from the synapse, where they are generated, to the nucleus, where they alter gene expression. The newly synthesized gene products must then be transported from the cell soma to the synapse to produce enduring changes in synaptic strength. Our lab is interested in both aspects of communication between the synapse and the nucleus during synaptic plasticity in neurons, focusing on 1) signaling from synapse to nucleus and 2) mRNA localization and regulated translation. We study these questions in cultured Aplysia sensory-motor neurons and in cultured rodent hippocampal neurons using cell biological, molecular biological and electrophysiological techniques. We are beginning to develop tools to study these processes in more complex circuits in living animals.