White matter injury

Ischemic stroke can cause secondary demyelination. Whether phagocytic astrocytes can contribute to such demyelination is unclear. Here, the authors show that lipocalin-2 (LCN-2) expression increased in astrocytes upon injury. LCN-2 expressing astrocytes acquire a phagocytic phenotype and contribute to secondary demyelination in a mouse model of ischemic stroke.

Tzong-Shiue Yu et al. assess the impact of astrocytic ApoE on hippocampal neurogenesis and behavior after traumatic brain injury (TBI) in mice. Their results suggest that postnatal ablation of astrocytic APOE reduces dendritic complexity in newborn dentate gyrus neurons and cognitive ability, providing further insight into a role for APOE in injury-induced neurogenesis following TBI.

Prolonged hypoxia, which can be due to stroke or ascent to high altitude, can lead to cerebral edema. Here, the authors used a combination of sodium and proton MRI and experimentally induced hypoxic conditions to identify the cause for brain swelling: Ionic edema, an intermediate between cytotoxic and vasogenic edema defined by sodium ion accumulation in extracellular space and an intact endothelium.

Hikaru Takeuchi et al. report that lead exposure in healthy controls might have an impact on brain activity and brain anatomy, particularly the dopaminergic system.