Fig. 2

Schematic summary of the cell types that participate in the CNS immunoregulation and impact on memory functions by modulating hippocampal neurogenesis in the DG during neuroinflammation. As presented in this figure, under pathological conditions, the differentiation of microglia, astrocytes, and other neuroglia into reactive phenotypes modulates the CNS neuroinflammation and affects the DG neurogenesis. Brain-resident leukocytes in the meninges have been reported to influence the DG neurogenesis and memory functions. In addition, more blood immune cells bypass the BBB and infiltrate into the CNS. The intercommunication between these cell types, as well as neurons, greatly relies on various cytokines and neurotrophins