In search of anticipated synchronization in the dentate gyrus

Abstract

[eng] The Dentate Gyrus (DG), a neural circuit of the hippocampus, is known to play a key part in the memory formation and consolidation process which takes place in the brain. The Granule Cells (GC) of the DG with their sparse firing in particular, are hypothesized to perform pattern separation by relaying an orthogonal version of the Entorhinal Cortex (EC) input in deeper structures of the hippocampus. In this study, we adapted a biologically plausible model focusing on the point of view of a single GC in order to analyze its synchronization behaviour with respect to the EC input. We report that under Long Term Potentiation of the Perforant Path, the GC is able to follow the EC in time, a behaviour known as Delayed Synchronization. However, we could not find a regime where the GC temporally follows the EC, a very interesting phenomenon coined Anticipated Synchronization (AS). Since AS is expected to have a great impact in Spike Timing Dependent Plasticity, we analyze the principles of the phenomenon and explain why the DG does not exhibit this peculiar behaviour.