Objective Focal cortical dysplasia (FCD) is a common cause of medically intractable epilepsy in pediatric patients.It has indicated that the abnormal cells within the cortical lesions of FCD, which are closely correlated with the severity of seizure, are derived in part from the neural precursor cells (NPCs) of subventricular zone (SVZ).Therefore, to observe the migration, differentiation and the electrophysiological features of the SVZ-derived cells within the cortical dysplastic lesions of FCD will help us better understand the epileptogenicity of FCD.Methods We created an FCD rat model by focal contact of a frozen metal probe on the scalp immediately after birth, in which the SVZ-derived NPCs were labeled with DiI through intracerebroventricular injection.The neurobiological features of DiI+ cells within the freezing-induced cortical lesions were studied by morphological and electrophysiological methods.Results The DiI+ cells, which form a migratory stream from SVZ to cortical lesions, could be continuously observed from Pl0 to P90.The immunofluorescence results showed that the majority of SVZ-derived NPCs in the cortical lesions differentiated into glial ceils and neurons, and to format synaptic connections with the surround cells, suggesting the possibility of these cells to influence the local neural circuit.Electrophysiological studies indicated that the SVZ-NPCs-derived neurons showed high excitability and received more excitatory input, while the feedback suppression to the presynaptic cells reduced.Discussion These data suggested that the high excitability of SVZ-NPCs-derived neurons would result in the hyperexcitability of the local neural circuit, and consequently trigger the kindling of the epileptiform discharge.