Highly polysialylated neural cell adhesion molecule positive cells increased and changed localization in rat hippocampus with exposure to repeated kindled seizures

Highly polysialylated neural cell adhesion molecule (PSA-NCAM) is involved in migration of neural stem cells as well as neural plasticity. Immunoreactive PSA-NCAM expression was examined in rat with repeated exposure to amygdaloid kindled generalized seizures (GS). The number of PSA-NCAM-positive cells in bilateral dentate gyrus (DG) increased significantly at GS. Although total positive cell number was not significantly different between 3 times GS (3 GS) and 30 times GS (30 GS) groups, a greater number of positive cells were located in the outer granule cell layer (GCL), and the immunopositive dendrite greatly extended to the molecular layer in the 30 GS group. These observations indicate that increased migration of newly generated cells as well as plastic change of originally existed neural cells may occur in response to the recurrent GS, which may contribute to abnormal reconstruction of synaptic network in hippocampus and epileptogenisity in kindling.