A fundamental problem in psychology and neuroscience is to understand how the transient memory of an experience becomes stabilized and available as long-term memory. A general theory of memory is that sleep is important to make the memory of an experience stable and resistant to interference. One specific theory has proposed that there are two systems at work during learning, a fast acting system that encodes temporary memories into a brain area called the hippocampus and a slower system that transfer these memories during sleep into a more permanent form in higher-level cortical regions. This process depends on a communicative interaction between the hippocampus and cortex. The present research is the first to directly test the hypothesis of the interleaved interaction between brain regions in the formation of stable more permanent memories from experience. Evidence of this interaction between fast-acting and long-term representations has implications for understanding a number of neurological problems involving memory, for explaining changes in memory with aging, and for the development of new robust computer memory systems. The project provides training opportunities for postdoctoral fellows and data and tools dissemination.
Simultaneous electrical and optical recordings from the hippocampus and neocortex will be made as rodents acquire new memories and consolidate these memories into a stable more permanent form of long-term memory. The project examines patterns of activity in these different brain regions to test the hypothesis that interleaved activity patterns during resting state reflects an interplay of recent and long-term memories. Further, a comparison of brain activity in resting states and task-dependent states will examine the question of whether stable long-term memories are regularized by consolidation to be less detailed and more general. The research will measure patterns in collections of spiking neurons along with global patterns of brain electrical activity to test these hypotheses about the process of memory consolidation.