Specific Clinical/Research Interest: Molecular mechanisms of long-term memory
Current Students: MD/PhD: Dillon Chen; PhD: Dhananjay Bambah-mukku, Sarah Stern
Postdoctoral Fellows: Carmen Inda, Akinobu Suzuki
Research Personnel: Gabriella Pollonini
Summary of Research Studies:
A fascinating aspect of learning and memory is its biological basis. In order to occur, long-term memory requires an initial and relatively brief temporal phase during which gene expression is essential (consolidation phase). This is a universal feature of long-term memory processes, which is found in several different forms of memory and conserved throughout evolution. We are interested in the identification and functional characterization of the gene cascade activated during memory consolidation. In addition, our studies aim at determining where in the brain and when following learning this gene cascade is activated.
Our current approach is focused on differential gene expression screenings in specific brain areas of control, naive animals vs. animals that underwent learning. The identification of memory gene candidates is followed by molecular and functional studies aimed at defining the role of each identified component. We are also interested in understanding the molecular mechanisms that accompany memory reorganization after recall. Old and stored memories can become vulnerable if they are recalled (reactivated). These findings led to the hypothesis that when an old memory is reactivated it again becomes labile, and it does so in order to incorporate new information. This process of returning to a labile state after recall can be useful to develop therapeutic approaches for treating traumatic memories (traumatic stress disorders). We are working to understand which brain regions and molecular mechanisms underlie memory destabilization and re-stabilization after recall.
A clinically relevant model in which we apply these studies is addiction.. When drug addicts are exposed to cues that remind them of the rewarding state of the drug, they experience a strong craving response. This compulsive response seems to use mechanisms similar to those involved in memory formation. We are working on the identification and characterization of the molecular changes that occur in the brain when an addictive response is formed. Using rat models of conditioning to a drug of abuse (morphine), we aim at identifying which gene and protein are essential for making a brain addicted and which strategy we can use to disrupt this response. Areas of interest include: Learning and memory responses in vivo (behavior); Analysis of patterns of gene expression (gene arrays); temporally and anatomically restricted gene manipulation; memory reactivation, amnesia, addiction.
