Spatiotemporal dynamics of PDGFRβ expression in pericytes and glial scar formation in penetrating brain injuries in adults

Aims Understanding the spatiotemporal dynamics of reactive cell types following brain injury is important for future therapeutic interventions. We have previously used penetrating cortical injuries following intracranial recordings as a brain repair model to study scar‐forming nestin‐expressing cells. We now explore the relationship between nestin‐expressing cells, PDGFRβ+ pericytes and Olig2+ glia, including their proliferation and functional maturation. Methods In 32 cases, ranging from 3 to 461 days post injury (dpi), immunohistochemistry for PDGFRβ, nestin, GFAP, Olig2, MCM2, Aquaporin 4 (Aq4), Glutamine Synthetase (GS) and Connexin 43 (Cx43) was quantified for cell densities, labelling index (LI) and cellular co‐expression at the injury site compared to control regions. Results PDGFRβ labelling highlighted both pericytes and multipolar parenchymal cells. PDGFRβ LI and PDGFRβ+/MCM2+ cells significantly increased in injury Zones at 10–13 dpi with migration of pericytes away from vessels with increased co‐localization of PDGRFβ with nestin compared to control regions (P