Impaired human hippocampal neurogenesis after treatment for central nervous system malignancies.

The effects of cancer treatments such as cranial radiation and chemotherapy on human hippocampal neurogenesis remain unknown. In this study, we examine neuropathological markers of neurogenesis and inflammation in the human hippocampus after treatment for acute myelogenous leukemia or medulloblastoma. We demonstrate a persistent radiation-induced microglial inflammation that is accompanied by nearly complete inhibition of neurogenesis after cancer treatment. These findings are consistent with preclinical animal studies and suggest potential therapeutic strategies.