DIY brain repair

The adult brain can generate new neurons in the subventricular zone and dentate gyrus, but it is has been unclear if these cells can migrate to replace those lost following ischaemic damage or disease. In August 5 Nature Medicine, Andreas Arvidsson and colleagues from Lund University Hospital, Lund, Sweden, show that in rats the adult brain has the capacity of recruiting endogenous neuronal precursors and self-repair after insults causing extensive neuronal death (Nat Med 2002, doi:10.1038/nm747).

Arvidsson et al. caused experimental strokes in rats by the transient occlusion of the middle cerebral artery. They observed that following this procedure newly generated neurons, together with neuroblasts (probably already formed before the insult) migrated into the severely damaged area of the striatum, where they expressed markers characteristic of mature, striatal medium-sized spiny neurons.

These results suggest that "stroke induces differentiation of new neurons into the phenotype of most of the neurons destroyed ...