Proliferation and Apoptosis of Adult Neural Stem Cell after Status Convulsion in the Adult Rat Hippocampus

Abstract: The objective of this research is to explore the proliferation and apoptosis of adult neural stem cell after status convulsion (SC) in the adult rat hippocampus. Seizures were induced in adult Wistar rats injected with lithium and pilocarpine intraperitoneally and controlled 30 minutes later. Rats were sacrificed at 6 time points (1， 3， 7， 14， 28， 56 days) after SC. Each rat was injected with bromodeoxyuridine (BrdU) intraperitoneally 1 day before killed. The expression of BrdU and neuroepthelial stem cell protein (nestin) were determined by immunohistochemistry to mark the proliferation of adult neural stem cell. Double-label immunofluorescence of nestin and in situ terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) were used to assess the survival of newly generated progenitor cells. In the normal hippocampus formation， only a small amount of BrdU+ and nestin+ cells were found in dentate gyrus， not CA1 and CA3 region. One day after SC ， the amount of BrdU positive cells began to increase in the CA1 region and dentate gyrus， the former peaked 7 days ， began to decrease 14 days after ， and reached normal 28 days after， while the latter increased up to 20-fold 14 days after and reached normal at 56 days after SC. A large amount of BrdU positive cells were observed in CA3 region at 7 days following SC. The number of BrdU and nestin positive cells of the same region at the same time point had no statistical significance. TUNEL-positive nuclei were observed in almost all of the nestin positive cells in CA1 region within the first 3 days after SC， but didn't exist in dentate gyrus during the whole experiment process. Taken together， we can purpose that SC stimulates the proliferation of inherent neural stem cells within a certain time window， and part of the newly generated cells appear to migrate from proliferation area into the in juried area.

CSTR: 32200.14.cjcb.2007.03.0029