Figure 4.

Seizure activity induces neurogenesis and modulates the size of the IMF. A single seizure episode leads to an increase in the number of BrdU-positive cells during the first week after seizure activity but proliferative activity within the dentate area returns to baseline levels after 28 days (A) compared to control animals (B). Newborn cells matured into CR-expressing neurons 14 days after seizures (A) resulting in a significantly bigger size of the IMF (A) compared to controls (B). Twenty-eight days after seizures, the rate of proliferation and the number of early post-mitotic CR-positive neurons had returned to baseline levels whereas the size of the IMF in seizure animals (A) was still significantly enlarged compared to controls (B), suggesting that axonal processes sent from newborn neurons via the IMF remain stable for at least weeks.