Ischemic vulnerability of primary murine microglial cultures.

Microglia are known to secrete neurotoxic substances and have been implicated in potentiating injury in a variety of neuropathological settings including stroke. However, little is known about the susceptibility of microglia to ischemia. Here we characterize microglial vulnerabilities to ischemia-like insults. Microglia were remarkably resistant to hypoxia, but a majority of cells were killed after 30 h of aglycemia and 24 h continuous exposure to combined oxygen and glucose deprivation. Serum deprivation also resulted in significant cell death after 24 h. Interestingly, microglia activated by lipopolysaccharide were protected against death by serum deprivation, but not aglycemia. We conclude that microglia display susceptibility to ischemia-like insults that most resembles astrocytes, and that activation in some settings renders them capable of generating factors that enhance their own survival.