Learning, remembering something, and recalling memories is supported by multiple separate groups of neurons connected inside and across key regions in the brain. If these neural assemblies fail to sync together at the right time, the memories are lost, a new study led by the universities of Bristol and Heidelberg has found. 

"Neural assemblies" – groups of neurons that join forces to process information – were first proposed over 70 years ago, but have proved difficult to pinpoint.

Using brain recordings in rats, the research team has shown that memory encoding, storage and recall is supported by dynamic interactions incorporating multiple neural assemblies formed within and between the hippocampus and prefrontal cortex.  When the coordination of these assemblies fails, the animals made mistakes. 

The next steps for the research would be to modulate neural assembly interactions, either using drugs or via brain stimulation, which Dr Kucewicz is currently doing in human patients, to test whether disrupting or augmenting them would impair or enhance remembering.  The research team presumes the same mechanisms would work in human patients to restore memory functions impaired in a particular brain disorder. 

Read the University of Bristol’s news item

'Distinct hippocampal-prefrontal neural assemblies coordinate memory encoding, maintenance, and recall' by Aleks Domanski, Michal T. Kucewicz, Emma S.J. Robinson, Matt W. Jones et al. in Current Biology