To investigate early effects of gamma knife on synaptophysin(SYN) expression and mossy fiber sprouting(MFS) in pilocarpine-induced model of temporal lobe epilepsy and explore the mechanisms of Gamma Knife radiosurgery for temporal lobe epilepsy, and so as to provide a theoretical basis for clinical practice.

      All Wistar rats were divided randomly into three groups: blank control group, treatment group and non-treatment group.

     Developed temporal lobe epilepsy model induced by lithium-pilocarpine. Treatment group rats were treated by Leksell Gamma Knife on 2w after status epilepticus. Irradiation target was the left hippocampus; the central dose was 40Gy at the isodose line 70%.Immunohistochemistry and Timm staining were used to observe the expression of SYN and MFS in the inner molecular layer (IML).

     As compared with the non-treatment group ,treated rats showed reductions in the number of spontaneous seizures in the latter of the study (Weeks 6-8). The expression of SYN in IML was increased compared with blank control group. As compared with the non-treatment group, treatment group SYN particles had different degrees of reduction in the left dentate gyrus IML. No significant difference between the two groups on 2h, (P>0.05); 2w-8w later difference between the two groups was statistically significant (P<0.05);treatment group the Timm staining score in the left dentate gyrus IML have different degrees of reduction, no significant difference between the two groups from 2h to 4w(P>0.05);8w later, it became significantly different(P<0.05). 

     This is a retrospective study.

     Gamma Knife irradiation can inhibit the expression of SYN and reduce the MFS in IML in early stages. 

     Such a change may be one of the important mechanisms of Gamma Knife treatment of temporal lobe epilepsy.