Several models of induction seizure and epilepsy in experimental animals

Background & Aims:  Animal models provide crucial tools to study epilepsy which is one of the most common   neurological disorder. Experimental models are valid and essential to discover new antiepileptic drugs as well as to elucidate circuitry dysfunction of disease. Therefore, in this review, we summarize the prominent used methods for induction experimental seizures and epilepsy induced by electrical, chemoconvulsants, traumatic brain injury, acoustic stimulation as well as hyperthermia and hypoxia condition. Material and Methods: In this review data were collected through searching electronic databases of PubMed and Google Scholar for several methods of induction seizure and epilepsy in experimental animals. Results: The maximal electroshock (MES), pentylentetrazole (PTZ), and 6-Hz seizure models are three simple seizure models for inducing acute seizure in intact animal. The pilocarpine, kainic acid, antibiotics, metals and organophosphorus compounds have epileptogenic potency for inducing motor seizures. The most common type of chronic models of epilepsy are electrical kindling, PTZ-induced kindling and transgenic models. Pharmacoresistance models include the phenytoin- or lamotrigine-pretreated kindled rats model, the 6-Hz mouse model, pentylentetrazole induced seizures in rats pre-exposed to pilocarpine and intrauterine exposure of rats to methylazoxymethanol. Lastly, Posttraumatic epilepsy, audiogenic seizures, hyperthermia and neonatal hypoxia model as well as in vitro models are used to induce and study seizures. Conclusion: Epilepsy and seizure in experimental animals can be modeled by several factors include acute and chronic stimulation, mechanical insults and changing environmental conditions in both forms in vivo and vitro

Basic and clinical role of vitamins in epilepsy

Background & Aims: Epilepsy is a brain disorder which affects about 50 million people worldwide. Good diet is an essential measure to controlling seizure attacks. Since some combination therapy can reduce epileptogenesis, therefore this review summarizes the available evidences about the application of vitamins in animal models and humans for understanding what specific combinations of antiepileptic drugs and vitamins are likely to be effective for epilepsy therapy. Material and methods: In this review, electronic databases including PubMed and Google Scholar were searched for monotherapy and polytherapy by vitamins. Results: Administration of vit A inhibits development of seizures and lethality in animal models. Also vitamins B1, B6 and B12 pre-treatment might lead to a protective effect against degenerative cellular in mice. In addition use of low dose of sodium valproate with vitamins C or E increase the anticonvulsant activity of the drug in mice. Moreover, Vitamin D enhances antiepileptic effects of lamotrigine, phenytoin and valproate in animal's models. Vitamin E has an anticonvulsant effect in ferrous chloride seizures, hyperbaric oxygen seizures as well as penicillin-induced seizures in contrast kindling, maximal electroshock and kainite models. Some researches demonstrated that vitamins D and B as adjunctive therapy in epileptic patient can relieve seizures. A clinical data have shown beneficial effects of vitamin E in raising total antioxidant capacity, catalase, and glutathione in patients with uncontrolled epilepsy. Only few clinical studies exist to support the efficacy of the vitamin A and K in epilepsy. Conclusion: However vitamin therapy is not a substitute for antiepileptic drugs but add on therapy by them may relieve drugs- induced deficiencies as well as more researches are needed to evaluate the effectiveness of vitamins in epileptic humans

Investigating the Effects of Subchronic Sesame and Flaxseed Oils Consumption against Seizure and Depression in Adult Male Mice: Effects of Sesame and Flaxseed oils against seizure and depression

Epilepsy is a highly debilitating disorder by unpredictable seizures associated with emotional disturbance.One potential treatment for seizure and depression is dietary therapy. So, this study evaluated effects of daily oral administration of sesame and flaxseed oils in depression and seizure. Twenty-one adult male mice were divided into the following groups: control (normal saline recipient, 1ml/kg( , sesame and flaxseed oils groups (8ml/kg bodyweight, for 21 days). At the 22nd day, locomotor activity and depressive - like behavior were assessed by open field and tail suspension tests. Also in 23rd day, animals received a subcutaneous injection of strychnine for induction of seizure. The seizure latency and death time were recorded through observation of animal behavior immediately after injection of strychnine. There were no significant differences in locomotor activity among control, sesame and flaxeed groups. But it has been shown a significant increase in latency to immobility (p=0.027) and decrease in total immobility (p=0.001) in flaxseed oil group compared to control group. Also sesame oil group showed a significant reduction in the duration of total immobility (p=0.027) and its latency to immobility wasn’t significant. There were no significant differences in latency to seizure and death time in flaxseed oil groups compared to the control group. The subchronic consumption of sesame oil significantly increased the death time than the control group (p=0.04) but the latency to seizure was not significant. The results reveal that sesame and flaxseed may be considered as a food adjuvant for attenuating emotional problems in epilepsy

The Effect of Acute and Chronic Sesame Oil Consumption on the Strychnine Induced Seizure in Adult Rats

Background & objectives: Diet plays an important role in control of seizure in epileptic patients. Therefore in this research, the effect of acute and chronic sesame oil consumption on the seizure induced by strychnine in adult rats was investigated. Methods: In this experimental study, forty -two rats were divided into six groups: control (saline recipient, 1 ml/kg (, acute recipients of sodium valproate as positive control group (100 or 200 mg/kg, ip.), acute recipients of sesame oil (0.75 or 1.5 ml/kg, ip.) and chronic recipient of sesame oil (1.5 ml/kg/day, orally, 21 days). To induce seizure, strychnine was injected intraperitoneally 30 minutes after receiving saline, valproate or oil. Then seizure onset time and death time were recorded within 30 minutes. Results: Acute injection of sesame oil increased seizure onset time and death time compared to control group but it was no significantly different. The chronic consumption of sesame oil significantly increased seizure onset time (p=0.029) in compared to control group, but there was no effect on the death time. Also, there were no significant differences in seizure onset time and death time between acute and chronic groups. Conclusion: It seems that chronic consumption of sesame oil delayed the onset of seizure and reduced the kindled seizure acquisition

Interaction of Sodium Valproate With Low-Frequency Electrical Stimulation During Kindlingn

Introduction: The interaction between antiepileptic drugs and brain electrical stimulation is a potential therapy to control seizures in patients with pharmacoresistance to drugs. So, the present study aimed to design to determine the effect of a subeffective dose of sodium valproate combined with low-frequency electrical stimulation during kindling. Methods: One tripolar electrode was implanted stereotactically in the CA1 hippocampus of male Wistar rats. One week after surgery, the rats were kindled by electrical stimulation of hippocampus in a rapid manner (12 stimulations/day) for 6 days with sodium valproate alone or combined with low-frequency electrical stimulation (four packages contained 200 monophasic square wave pulses of 0.1-ms duration at 1 Hz, immediately after kindling stimulations). The duration of afterdischarge, maximum latency to stages 4 and 5, and the maximum duration of these stages were recorded by electromadule during kindling. Results: Application of sodium valproate with low-frequency electrical stimulation caused a reduction in cumulative afterdischarge duration. The maximum latency to the onset of stage 5 seizure increased after sodium valproate application alone, without having a significant effect on the fourth stage. Our findings showed reductions in the seizures duration and increasing in the latency times of both stages after the application of sodium valproate with low-frequency electrical stimulation. Conclusion: It seems that usage of sodium valproate with low-frequency electrical stimulation during kindling was more effective to suppress the epileptic activity than its administration alone and may have a critical role on the antiepileptic effects of sodium valproate

Evaluation the Efficacy of Sodium Valproate and Low Frequency Stimulation During CA1 Hippocampal Kindling on Anxiety-Like Behavior in Adult Male Rat

Background and Aim: Emotional disorders are prevalent in many epileptic patients. So, in this research, we have studied the efficacy of two treatment methods of seizure on anxiety-like behavior during kindling in adult male rat. Materials and Methods: 42 male rats were randomly divided into 6 groups: Control, Sham operation, saline-kindled and drug-kindled groups which have received saline or drug 15 minutes before kindling stimulations, and saline-kindled-LFS or drug-kindled-LFS group which have received saline or drug 15 minutes before kindling stimulations and LFS applied after termination of kindling stimulations. Anxiety-like behavior was assessed on the 6th day by using elevated plus maze and open field apparatus. Findings: kindling significantly increased open arms (OAs) entries percentage, OAs exploration percentage, increasing jumping from elevated plus maze (p<0.001) and rearing frequency in open field apparatus (p<0.05) compared to the sham group. Sodium valproate increased OAs entries percentage and OAs exploration percentage in drug-kindled group compared to sham group (p<0.001). But, there wasn’t any significant difference in jumping from elevated plus maze and rearing in open field compared to sham group. Also, there was no significant change in these parameters in Saline-kindled-LFS, drug-kindled and drug–kindled-LFS groups. Conclusion: Sodium valproate and LFS, as two therapies controlling epilepsy, decrease anxiety induced by kindling stimulation