About the Cover
Shown are excitatory pyramidal neurons and inhibitory parvalbumin-expressing interneurons in the hippocampus (area CA2). These neuron populations both express perineuronal nets (PNNs), here visualized via a staining for aggrecan (orange), but it is unclear whether PNN expression on either cell type differentially impacts behavior. To study the function of PNN on pyramidal neurons and parvalbumin-expressing interneurons in isolation, Georgia Alexander and colleagues generated conditional knockout mouse strains for aggrecan. This enabled PNN deletion from either neuron population so the researchers could observe resulting behavioral differences. See the article by Alexander et al. for more information on the roles of PNNs in hippocampal-dependent behavior that depend on cell type expression. Cover image: Georgia Alexander