Glutamate transporters are thought to have a role for preventing the glutamate excitotoxicity in the epilepsy. We previously demonstrated that glutamate transporter subtypes exhibited dynamic changes in the kainate-induced rat epilepsy (SFN 31st Annual Meeting abstract 815.5, 2001). In the present study, we examined the expressions of glial glutamate transporters, EAAT1 and EAAT2, as well as neuronal glutamate transporter EAAT3 in the human epileptic tissue, focal cortical dysplasia (FCD) which belongs to migration disorders of human cerebral cortex. The surgically resected tissue from the nine cases with FCD (age 2 to 65 years, Palmini grade 2 to 3) were used for immunohistochemistry. Diffuse neuropil staining of EAAT2 was retained or increased in the dysplastic cortex except one case. A majority of subcortical reactive astrocytes were immunoreactive for EAAT2, but negative for EAAT1. Thus, EAAT2 is responsible to uptake the extracellular glutamate in the dysplastic cortex. Dysplastic neurons showed inten...