Abstract
Purpose:Continuing neurogenesis in the hippocampal dentate gyrus has been accepted not only from animal experiments but also human samples. We examined neurogenesis and neural maturation in the dentate gyrus in human epileptic hippocampus. Methods: Neurogenesis was confirmed with immunohistohemical staining of NeuroD, PSA-NCAM, and NeuN. Age at surgery, hippocampal sclerosis, seizure duration, and seizure frequency were evaluated using statistical approach to the number of PSA-NCAM positive newborn neurons in the subgranular cell layer and granular cell layer. We compared the staining of NKCC1 and KCC2 to the newborn neurons between the hippocampal sclerosis and non-hippocampal sclerosis groups to examine the neural maturation. Results: The number of new born neurons was statistically low in the hippocampal sclerosis group (p=0.0003). Seventy-four percent of PSA-NCAM positive newborn neurons co-stained with NKCC1 and 36.0% of those were positive with KCC2 in the non-hippocampal sclerosis group. On the other hand, in the hippocampal sclerosis group, percentages of those ion-co-transporters were 67.6%, 6.3%, respectively. The KCC2 expression ratio in the hippocampal sclerosis group was statistically low (p=0.003). Conclusion: Neurogenesis still continues even in human epileptic hippocampus. In sclerotic hippocampus, neurogenesis is reduced and neural maturation is also restricted.
