Neuroprotection: the role of neuroglia.

Astrocytes protect neurons against: 1. Glutamate excitotoxicity through exchange of glutamine for glutamate. 2. Reactive oxygen and nitrogen (peroxynitrite) species. 3. Toxins of endo- and exogenous origin e.g. cyanide. Astrocytes and microglia also protect neurons by storing excess iron and by brushing away from the brain tissue damaged cell constituents such as aged mitochondria, peroxidized cytomembranes and nitrated proteins.