The antiepileptogenic effect of electrical stimulation at different low frequencies is accompanied with change in adenosine receptors gene expression in rats.
OBJECTIVE
Previous studies have shown that the anticonvulsant effects of low-frequency stimulation (LFS) can be affected by activation of adenosine receptors. In the present study, the effect of LFS at different frequencies on kindling rate and adenosine receptors gene expression was investigated.


METHODS
Animals were kindled by perforant path stimulation in a rapid kindling manner. LFS (0.5, 1, and 5 Hz) was applied after termination of each kindling stimulation. Seizure severity was measured according to behavioral and electrophysiologic parameters. At the end of the experiments, adenosine A(1) and A(2A) receptor gene expression were measured.


RESULTS
The inhibitory effect of LFS on kindling acquisition was observed at all frequencies. In addition, the inhibitory action of LFS on enhancement of field excitatory postsynaptic potential slope and population spike amplitude during kindling acquisition was not affected by the LFS frequency. However, the effects of LFS on paired-pulse recordings were greater at frequency of 5 Hz. Application of LFS during kindling acquisition also prevented the kindling induced decrease in the A(1) receptor gene expression and attenuated the level of A(2A) receptor gene expression in the dentate gyrus. These effects were also greater at the frequency of 5 Hz.


CONCLUSIONS
According to these data, it may be suggested that the antiepileptogenic effects of LFS, developed through inhibition of synaptic transmission in the dentate gyrus, is mediated somehow through preventing the decrease of A(1) receptor and through attenuating the A(2A) receptor gene expression. These effects might be dependent on the frequency of LFS.
Jahanshahi
A
A
Department of Physiology, School of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
Mirnajafi-Zadeh
Javad
J
Javan
Mohammad
M
Mohammad-Zadeh
Mohammad
M
Rohani
Razieh
R
D000818:Animals; D018891:Dentate Gyrus / Q000502:physiology*; D004195:Disease Models, Animal; D004558:Electric Stimulation / Q000379:methods*; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D015870:Gene Expression; D007696:Kindling, Neurologic / Q000502:physiology*; D008297:Male; D019580:Perforant Pathway / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D018047:Receptors, Purinergic P1 / Q000235:genetics* / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012640:Seizures / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D009435:Synaptic Transmission / Q000502:physiology
D018047:Receptors, Purinergic P1