Reactive oxygen species (ROS) are generally associated with pathological conditions such as seizures, stroke and neurodegeneration. In a study published in Nature Chemical Biology, researchers found a benefit from ROS production in brain stem cells of the adult hippocampus.

Christopher Chang and colleagues used a new fluorescent indicator to show that the ROS hydrogen peroxide (H2O2) is generated in the brain stem cells through the action of the enzyme Nox2. The H2O2 regulates the signalling protein Akt which is involved in promoting normal cell proliferation.

Individuals lacking the Nox enzymes that generate ROS exhibit cognitive defects, as would be expected if ROS were deleterious. This study challenges the view that abundant brain ROS are exclusively deleterious.