Remapping of hippocampal place cells in an unrewarded contextual memory task

AZUL SILVA; PEDRO BEKINSCHTEIN; MARIANO BELLUSCIO

Congreso; XXXV Congress of the Argentine Society for Research in Neuroscience 2020; 2020

In order to retrieve an episodic memory our brain needs to integrate thecontextual information available. But usually, the information isincomplete, so which memory is retrieved in a particular situation?Pattern completion allows us to generalize and retrieve memoriesalthough information is partial. On the other side, when we need toencode a new memory without interfering with a pre-existing one,pattern separation is involved. The hippocampus has a key role inthese memory processes.Som ehippocampal neurons, place cells (PC), are tuned to spatial locationand generally change their tuning when sensory inputs change(remapping). But sometimes, although the context changes, PC doesn?tremap. Accumulating evidence has suggested that the hippocampalability of storing and distinguishing between different situationsand contexts, can be related with place cell?s remapping.Theaim of this project is to understand how the remapping observed inCA1 and CA3, two hippocampal regions, correlates with the evocationof contextual memories. To tackle this question we use a behavioraltask that allows us to discriminate if an animal recognizes a contextas new (pattern separation), or as one it already knows (patterncompletion). We carried out electrophysiological recordings in CA3and CA1 while the animal was performing the task. Preliminary resultsshows that there is a correlation between the amount of remapping andthe memory that the animal is recalling.