Effect of Low-Frequency Stimulation on Adenosine A1 and A2A Receptors Gene Expression in Dentate Gyrus of Perforant Path Kindled Rats

Received: 19/Dec/2007, Accepted: 15/Mar/2008 Objective: It has been suggested that low frequency stimulation (LFS) exerts its inhibitory effect on epileptogenesis through adenosine receptors activation. In the present study, effect of different LFS frequencies on A1 and A2A receptors gene expression was investigated in perforant path kindled seizures. Materials and Methods: Animals were kindled by perforant path stimulation. Afterdischarges were recorded from the dentate gyrus. LFS (0.5, 1 and 5 Hz) was applied at the end of each kindling stimulation. On the 7th day, A1 and A2A receptors gene expression were evaluated in the dentate gyrus. Results: Application of different LFS frequencies retarded the kindling acquisition. Also, it decreased the afterdischarge durations and behavioural seizure stages 4 and 5 significantly. LFS application prevented the kindling induced decrease in the A1 receptor gene expression. On the other hand, LFS attenuated the level of A2A receptor gene expression in the dentate gyrus. LFS had the most effect at the frequency of 5 Hz. Conclusion: It may be suggested that antiepileptogenic effects of LFS is mediated somehow through changes in the gene expression of adenosine A1 (which has inhibitory effects) and A2A (which has excitatory effects) receptors. These effects might be somehow frequency dependent.