biostudies-literature00630Briones BANational Institute of Neurological Disorders and StrokeIntramural NIH HHSNIMH NIH HHSNational Institute of Mental HealthNINDS NIH HHSDivision of Graduate Education375-388https://www.ebi.ac.uk/biostudies/studies/S-EPMC8020456biostudies-literatureUnknown31(4)Adult-born granule cells (abGCs) integrate into the hippocampus and form connections with dentate gyrus parvalbumin-positive (PV+) interneurons, a circuit important for modulating plasticity. Many of these interneurons are surrounded by perineuronal nets (PNNs), extracellular matrix structures known to participate in plasticity. We compared abGC projections to PV+ interneurons with negative-to-low intensity PNNs to those with high intensity PNNs using retroviral and 3R-Tau labeling in adult mice, and found that abGC mossy fibers and boutons are more frequently located near PV+ interneurons with high intensity PNNs. These results suggest that axons of new neurons preferentially stabilize near target cells with intense PNNs. Next, we asked whether the number of abGCs influences PNN formation around PV+ interneurons, and found that near complete ablation of abGCs produced a decrease in the intensity and number of PV+ neurons with PNNs, suggesting that new neuron innervation may enhance PNN formation. Experience-driven changes in adult neurogenesis did not produce consistent effects, perhaps due to widespread effects on plasticity. Our study identifies abGC projections to PV+ interneurons with PNNs, with more presumed abGC mossy fiber boutons found near the cell body of PV+ interneurons with strong PNNs.HippocampusAdult-born granule cell mossy fibers preferentially target parvalbumin-positive interneurons surrounded by perineuronal nets.PMC8020456R01 MH117459MH117459‐01ZIA MH002784ZIAMH002784F32 MH127772DGE‐1656466MH118631‐01R01 MH118631F31 NS089303Haye AEPitcher MNEngel EABriones BACameron HAGould EPisano TJDiethorn EJ63falseAdult-born granule cell mossy fibers preferentially target parvalbumin-positive interneurons surrounded by perineuronal nets.Adult-born granule cells (abGCs) integrate into the hippocampus and form connections with dentate gyrus parvalbumin-positive (PV+) interneurons, a circuit important for modulating plasticity. Many of these interneurons are surrounded by perineuronal nets (PNNs), extracellular matrix structures known to participate in plasticity. We compared abGC projections to PV+ interneurons with negative-to-low intensity PNNs to those with high intensity PNNs using retroviral and 3R-Tau labeling in adult mice, and found that abGC mossy fibers and boutons are more frequently located near PV+ interneurons with high intensity PNNs. These results suggest that axons of new neurons preferentially stabilize near target cells with intense PNNs. Next, we asked whether the number of abGCs influences PNN formation around PV+ interneurons, and found that near complete ablation of abGCs produced a decrease in the intensity and number of PV+ neurons with PNNs, suggesting that new neuron innervation may enhance PNN formation. Experience-driven changes in adult neurogenesis did not produce consistent effects, perhaps due to widespread effects on plasticity. Our study identifies abGC projections to PV+ interneurons with PNNs, with more presumed abGC mossy fiber boutons found near the cell body of PV+ interneurons with strong PNNs.2021-01-01T00:00:00Z2021 Apr2024-02-15T03:21:18.919Z2022-02-09T14:17:02.695ZS-EPMC80204563343272110.1002/hipo.23296