Investigating synaptic plasticity and chronobiology underlying memory consolidation

Memory consolidation, the process by which novel experiences are gradually transformed into stable memories, is a fundamental neurobiological phenomenon.

Current models suggest that interactions between where the memories are initially encoded (hippocampus) and subsequently stored for long-term (neocortex) are crucial.

During an experience, inputs from the hippocampal region are thought to “tag” groups of neurons in the neocortex, which allows their reactivation during sleep or rest subsequently changing the neocortical circuit architecture.

We hypothesize that this initial tagging of neocortical neurons is a result of structural changes in the very connection points, synapses, between the hippocampus and its target neurons in the neocortex.

To test our hypothesis, we will implement state-of-the-art molecular-genetic methods to mark synapses of hippocampal neurons in the neocortex and investigate whether these have undergone learning associated structural changes and whether these are dependent on hippocampal output.

A further angle of our study will be to test if the changes in synapse structure we discovered are affected by disturbances in circadian rhythms which is highly influential on effective learning and remembering.

These studies will help to identify the neural substrates for long-term memories and to explain how disparate cortical areas generate coherent cognitive states.