Research in our laboratory focuses on the study of the formation and maintenance of memories within the hippocampus and neocortex. To study the basis of these processes, we employ a combination of molecular genetic, electrophysiological, pharmacological, behavioral, and computational approaches. In particular, we use a technique that allows us to record simultaneously the activity of ensembles of hundreds of single neurons in freely behaving animals.
These studies have led to the exploration of the nature of sleep and its role in memory. Previous theories have suggested that sleep states may be involved in the process of memory consolidation, in which memories are transferred from short to longer-term stores and possibly reorganized into more efficient forms. Recent findings have identified explicit correlates of dreaming during periods of rapid eye movement (REM) sleep. By reconstructing the content of these states, specific memories can be tracked during the course of the consolidation process.
Simultaneous monitoring of areas in the hippocampus and neocortex has allowed us to study the downstream effects of activation. Recent experiments have demonstrated a relationship between the activity of the hippocampus during awake and sleep states, and activity within the prefrontal cortex, a neocortical region involved in higher cognition, decision-making, and memory. Recent recordings in the entorhinal cortex have revealed responses dependent upon future behavioral trajectory as well as reflecting generalization across tasks and environments.
Combining the measurement of ongoing neuronal activity with manipulation of molecular genetic targets in the hippocampus and neocortex has allowed us to study how specific cellular mechanisms regulate neural function to produce learning and memory at the behavioral level. Taken together, these approaches contribute to the overall research objective: to understand the link from cellular/subcellular mechanisms of plasticity, to neural ensemble representations and interactions, to learning, memory, behavior, and cognition.