Abstracts

The cellular mechanisms underlying epileptogenesis in the setting of cortical dysplasia are still poorly understood. In this study, the changes in the blood-brain barrier (BBB) integrity after pentylenetetrazole (PTZ)-kindling were investigated in rats with cortical dysplasia. To show the changes in the expression of occludin, immunohistochemical and Western blot methods as well as electron microscopy were used., In this study, 38 young adult Sprague-Dawley rats were used for NaFlu staining method and 108 animals were used for other parameters in parallel groups. Study groups consist of a control (8), cortical dysplasia (10), kindling (10) and cortical dysplasia in addition to kindling and PTZ groups (10). The day of insemination was taken as the embryonic (E) day 0. The pregnant rats which have been given sodium pentobarbital anesthesia with the dose of 30 mg/kg, were administered gamma irradiation of 145 cGy from the uterus on day E 17. The baby rats were given 30 mg/kg PTZ three times per week intraperitoneally to induce kindling model starting from the 2^nd week after birth to the 8^th week. The changes in the expression of occludin, which is a tight junction protein in BBB, were shown by using immunohistochemical and Western blot methods in addition to electron microscopy., While the arterial blood pressure remained at the control blood pressure values in the rats of cortical dysplasia and cortical dysplasia in addition to kindling groups, application of acute PTZ increased the blood pressure level significantly. The amount of NaFlu dye did not convey a remarkable increase in these rats. However, after seizures induced by PTZ application in the rats of cortical dysplasia and cortical dysplasia in addition to kindling groups, BBB permeability increased siginificantly., In the groups of rats with cortical displasia and PTZ kindled rats with cortical displasia no BBB permeability alterations were observed. However, in the dysplasia+kindling group of rats with acutely induced seizures after being given PTZ, a significant alteration of BBB permeability was seen. This shows that displasia with kindling model is more responsive to acute seizures at least in terms of BBB permeability.,