The Effect Of BDNF Hyper-expression In Periaqueductal Gray On Epilepsy

Object: Observe the effects of neuroprotection on the ventrolateral Periaqueductal Gray,v PAG via the sustained high expression of local neurotrophic factor on seizures.Methods: Eighty healthy male Sprague-Dawley rats aged 8 to10 weeks were randomly divided into 3 groups:Viral group carrying BDNF gene(32),Virus group without BDNF gene(24),Normal saline group(24).Three groups of the rats were respectively injected with the adeno-associated virus vector carrying BDNF and GFP gene,homologous adeno-associated virus vector without BDNF gene,normal saline.GFP labeled the adeno-associated virus vector was used to detect the accuracy of injection site.Eight brain tissue of v PAG with 2 days after the stereotactic injection was taken as the frozen sections and was photographed under the fluorescent microscope.On the 3rd,6th,10 th and 15 th day after the injection,six v PAG tissues were collected from each group and each different time points,and the expression of BDNF was detected by the western blot at the protein level at each time node.Another 120 healthy male SD rats were divided into 3 groups:Viral group carrying BDNF gene(40),Without carrying the BDNF genome(40),Normal saline group(40).The adeno-associated virus vector carrying BDNF gene,homologous adenoassociated virus vector without BDNF gene,normal saline and normal saline were injected into the v PAG region of 3 groups of the rats by the stereotactic injection technique.After 7 days,20 rats in each group were given pilocarpine to induce the acute epileptic seizures.To observe the effect of BDNF gene transfection into v PAG on the seizure by behavioural recording after the seizure in rats.After 3 days,20 rats in each group were given the Lithium-pilocarpine intraperitoneal injection to induce the Status Epilepticus(SE).To observe the effect of BDNF gene transfection into v PAG on the spontaneous seizure after the epileptic status in rats by video recording.(10th~50th days after the status of epilepsy).Results: GFP emitted green fluorescence in vPAG region under microfluoroscopy.On the 3rd,6th,10 th and 15 th day after the stereotactic injection,the expression of v PAG in western blot was significantly higher than that in the group without BDNF gene virus and normal saline group,and there was the significant difference in the expression of BDNF in western blot.(all P < 0.05).The expression of BDNF in the viral group carrying BDNF gene increased gradually on the third day,the sixth day and the tenth day,and there was no significant difference between the 15 th day and the 10 th day.There were significant differences in the duration and the severity of acute epileptic seizures in rats with gene-carrying virus,normal saline and blank control groups.(all P<0.05).There were significant differences in the frequency,duration and the severity after Status Epilepticus in rats with gene-carrying virus,normal saline and blank control groups on the 10 th ~50th day after the status epilepticus.(all P<0.05).Conclusion: Sustained local over expression of BDNF in v PAG can alleviate the acute seizure attacks and the chronic development of chronic spontaneous seizure attacks.