Astrocytes re-express nestin in deafferented target territories of the adult rat hippocampus.

Up-regulation of the intermediate filament protein, nestin, is a sensitive indicator for the extent of astrocytic activation in regions of CNS close to the point of injury. However, it remains unclear whether activated astrocytes in distant, deafferented CNS territories are also capable of nestin re-expression. Here, we demonstrate that traumatic injury to the dentate gyrus is followed by the rapid but transient expression of nestin in astrocytes located in the stratum lucidum of field CA3. Up-regulation of nestin was first detected at 1 day, was still visible at 14 days, and returned to close to control levels by 28 days post-injury. The present investigation clearly demonstrates the sensitivity of nestin expression as a indicator of astroglial activation in hippocampal target territories undergoing deafferentation-related changes.