Inflammation is detrimental for neurogenesis in adult brain

TLDR

New hippocampal neurons are continuously generated in the adult brain. Lipopolysaccharide‑induced microglial activation in the hippocampus strongly impairs both basal and injury‑stimulated neurogenesis, but systemic minocycline restores it, indicating that microglia‑mediated suppression of neurogenesis may underlie cognitive deficits in aging, dementia, epilepsy, and other inflammatory brain disorders.

Abstract

New hippocampal neurons are continuously generated in the adult brain. Here, we demonstrate that lipopolysaccharide-induced inflammation, which gives rise to microglia activation in the area where the new neurons are born, strongly impairs basal hippocampal neurogenesis in rats. The increased neurogenesis triggered by a brain insult is also attenuated if it is associated with microglia activation caused by tissue damage or lipopolysaccharide infusion. The impaired neurogenesis in inflammation is restored by systemic administration of minocycline, which inhibits microglia activation. Our data raise the possibility that suppression of hippocampal neurogenesis by activated microglia contributes to cognitive dysfunction in aging, dementia, epilepsy, and other conditions leading to brain inflammation.