Abstract
Abstract only Neurogenesis persists throughout adult human life in the dentate gyrus and subventricular zone. Recent evidence points to increased neurogenesis in the hippocampus of epileptic animal models. The abnormal migration of new neurons to ectopic locations in the dentate gyrus, in conjunction with aberrant integration of new neurons into the granule cell layer, has been hypothesized to contribute to increased seizure activity. Many studies have also shown an increase in neurogenesis secondary to CNS insults such as stroke and trauma. We therefore hypothesized that we would see increased expression of SOX2, a neural stem cell marker, in hippocampal sclerosis. Using immunohistochemical analysis, we examined the hippocampus from nine patients for SOX2 expression. Seven were from patients with a known history of temporal lobe epilepsy and histologically confirmed Ammon's horn sclerosis and two were from normal autopsy controls. We found many immunoreactive cells throughout the hippocampous, including the subventricular zone, in all seven seizure cases, and no expression of sox2 in the autopsy controls. These results provide further evidence in support of active neurogenesis in epilepsy and suggest that SOX2 plays a role in neurogenesis in hippocampal sclerosis. This research was funded and supported by Barrow Neurological Institute.