Topic: assembly drift

In a standard model, associative memories are represented by assemblies of strongly interconnected neurons. It has recently been proposed that these assemblies are not static but drift freely in neural circuits. This explains experimental findings of changing memory representations. On the level of single neurons, assembly drift is reflected by characteristic dynamics: relatively long times of stable assembly membership interspersed with fast transitions. How can we mechanistically understand these dynamics? Here we answer this question by proposing simplified, reduced models. We first constru

Sleep-associated hippocampal reactivations are thougt to be central to the processing of memories and in particular to their consolidation. Nevertheless, it is unclear whether reactivated assemblies are static or whether they reorganize gradually over prolonged sleep. In this study, we tracked the neural activity of principal hippocampal cells in CA1 from the acquisition of a spatial memory, through an extended rest period (~20 hours) to its recall. We applied multiple decoding strategies to track the evolution of memory related activity over several hours of sleep.We observed that while durin