Cellular and network mechanisms of hippocampal-prefrontal coordincation during memory consolidation

After learning, labile memories are initially consolidated into permanent representations. This process involves the interplay between the hippocampus, where memory traces are originally formed, and the prefrontal cortex, where they are stored long term. The synchronisation of both structures during sleep has been causally related to memory consolidation. But how is the activity of neuronal populations across distant structures coordinated?

To answer this question I will train rats in a spatial memory task and record the neuronal activity in the hippocampus and cortex during sleep before and after learning. This approach will reveal which neuronal populations are implicated in the sleep reactivation of learning-related activity. Diverse anatomical pathways can mediate the transfer of information from the hippocampus to the cortex but the impossibility of recording all of them simultaneously has prevented the elucidation of these mechanisms. I will perform functional magnetic resonance imaging in sleeping rats to assess brain-wide activation at times of hippocampal-prefrontal synchrony during memory consolidation after learning. I will also causally verify the synaptic mechanisms pointed out in the previous stages by silencing those specific neuronal populations at times of inter-areal synchronisation and checking the effect of these manipulations on memory consolidation.