SeyyedJavad Mirnajafizadeh; Yaghob Fattollahi; Amir Shojaee; Azam Asgari; Fatemeh Rostami
Volume 21, Issue 5 , September and October 2014, , Pages 951-959
Abstract
Background and purpose: Nowadays repeated transcranial magnetic stimulation (rTMS) is being used as a treatment for some neurological disorders, but its effect on neuronal activity and synaptic plasticity has not been completely determined. The purpose of this study was to evaluate the effect of chronic ...
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Background and purpose: Nowadays repeated transcranial magnetic stimulation (rTMS) is being used as a treatment for some neurological disorders, but its effect on neuronal activity and synaptic plasticity has not been completely determined. The purpose of this study was to evaluate the effect of chronic rTMS on the ability of synaptic plasticity.
Materials and Methods: rTMS was applied to the hippocampal region for 14 days. One week following termination of rTMS, the amount of synaptic long-term potentiation (LTP) in animals was investigated and compared with control group. High-frequency stimulation (HFS) was applied to the perforant path for LTP induction, andfield potentials were recorded from granular layer of the dentate gyrus. Baseline field potential was recorded 10 minutes before HFS. An increase of at least 20% in population spike amplitude was measured as an index of synaptic potentiation.To compare the effects of rTMS on measured parameters, we used t-test and two way ANOVA followed by Benferroni test (Prism 8 software).
Results: Obtained data showed that, following 14 days of rTMS application causeda reduction in population spike amplitude compared to the control group (P
Amir Shojaee; Vahid Sheybani; Khadijeh Esmaeel pour; Yaser Masoumi; Seyyed Javad Mirnajafizadeh
Volume 20, Issue 4 , January and February 2014, , Pages 496-504
Abstract
Background: Low frequency stimulation (LFS) has been recently suggested as an antiepileptic method in treating the drug-resistant epileptic syndromes such as temporal lobe epilepsy. So far, in the most clinical and experimental studies, LFS has been applied to the seizure focus itself. Considering the ...
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Background: Low frequency stimulation (LFS) has been recently suggested as an antiepileptic method in treating the drug-resistant epileptic syndromes such as temporal lobe epilepsy. So far, in the most clinical and experimental studies, LFS has been applied to the seizure focus itself. Considering the role of dentate gyrus in spreading of the limbic seizures, in the present study the effect of LFS of dentate gyrus on amygdala kindling-induced seizures was investigated.
Materials and methods: To kindle the animals, using stereotaxic instrument, a tripolar electrode was inserted into right basolateral area of amygdala and a bipolar electrode was ipsilaterally placed in dentate gyrus of male Wistar rats. After a 10 days recovery period, animals divided into two groups. The animals of kindled group were received daily electrical stimulations. In kindled+LFS group, LFS was delivered to dentate gyrus 1 min after cessation of amygdala kindling stimulation. The maximum seizure stage and duration of afterdischarges were evaluated after kindling stimulation. The effect of LFS on behavioral seizure stages and afterdischarges was compared using Kruskall Wallis and repeated measures 2-way AVOVA. A P value less than 0.05 was considered as significant level.
Results: The required time to achieve a stage 5 seizure was 12 days in kindled group animals. However, animals of kindled+LFS group did not show more than stage 2 seizure following 12 days of stimulation. LFS of dentate gyrus significantly prevented the increment of behavioral seizure stages and afterdischarge duration in kindled-LFS group compared with kindled group.
Conclusion: The results of this study demonstrated that application of LFS in the dentate gyrus can be an effective therapeutic method for controlling the amygdala kindling-induced seizures. Furthermore, this study provide further evidences showing LFS of brain areas involved in spreading the seizures, other than seizure focus can have anticonvulsant affect.