Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.07.14.202218v1?rss=1 Authors: Carames, J. M., Perez-Montoyo, E., Garcia-Hernandez, R., Canals, S. Abstract: Distinct forms of memory processing are often causally identified with specific brain regions, but a key facet of memory processing includes linking separated neuronal populations. Using cell-specific manipulations of inhibitory neuronal activity, we discovered a key role of the dentate gyrus (DG) in coordinating dispersed neuronal populations during memory formation. In whole-brain fMRI and electrophysiological experiments, we found that parvalbumin (PV) interneurons in the DG control the functional coupling of the hippocampus within a wider network of neocortical and subcortical structures including the prefrontal cortex (PFC) and the nucleus accumbens (NAc). In a novel object-location task, regulation of PV interneuron activity enhanced or prevented memory encoding and, without effect upon the total number of task activated c-Fos+ cells, revealed a correlation between activated neuronal populations in the hippocampus-PFC-NAc network. These data suggest a critical regulatory role of PV interneurons in the dentate gyrus in brain-wide polysynaptic communication channels and the association of cell assemblies across multiple brain regions. Copy rights belong to original authors. Visit the link for more info