Induction of nestin synthesis in rat brain cells by ischemic damage.

Nestin, an intermediate filament protein, is known to be expressed in proliferating and provisional cells in the forming mammalian brain, disappearing on differentiation. The aim of the present work was to identify the morphological types and locations of cells regaining the ability to synthesize nestin after transient total brain ischemia in rats. Transient ischemia was found to be followed by the induction of nestin synthesis in astrocytes in the damaged area; these cells acquired structural features not characteristic of the adult brain, and these persisted in the long term. Nestin synthesis was also induced in proliferation-capable undifferentiated cells in the subventricular zone. The acquisition by astrocytes of some of the phenotypic features of immature glial cells, however, does not provide grounds for the notion that they were transformed into neural stem cells.