A few years ago, scientists discovered a protein with an affinity for oxygen expressed most abundantly in neurons. In reference to its resemblance to hemoglobin, the key transporter of oxygen in blood, they named it neuroglobin. Its function, however, was unclear. Now findings published today in the Proceedings of the National Academy of Sciences suggest that the protein helps protect brain cells from damage during a stroke.

David Greenberg and his colleagues at the Buck Institute for Age Research in Novato, Calif., investigated the role of neuroglobin (Ngb) in brain cell cultures and in the brains of mice. When the researchers deprived the brain cells of oxygenmimicking the conditions of a strokeneuroglobin levels increased. They then simulated stroke-like conditions in mice by blocking blood flow to the brain and again observed increased levels of the protein. Moreover, the stroke-induced cell damage was mediated by the quantity of neuroglobin present: reducing Ngb expression worsened brain injury, whereas increasing Ngb expression lessened it.

According to the report, the research results suggest that neuroglobin plays a role in sensing or responding to oxygen deprivation in the brain. "Understanding how Ngb and other hypoxia-inducible proteins confer neuronal protection," the authors conclude, "may help in the development of improved treatment for ischemic disorders such as stroke."