Background:Besides seizures,a myriad of overlapping neuropsychiatric and cognitive comorbidities occur in patients with epilepsy,which further debilitates their quality of life.This study provides an in-depth characte...Background:Besides seizures,a myriad of overlapping neuropsychiatric and cognitive comorbidities occur in patients with epilepsy,which further debilitates their quality of life.This study provides an in-depth characterization of the impact of brivaracetam and rufinamide individually and in combination at 10 and 20 mg/kg doses,respec-tively,on corneal kindling-induced generalized seizures and behavioral alterations.Furthermore,observed convulsive frequency and behavioral changes were corre-lated to post-kindling-induced changes in the activity of markers of oxidative stress.Methods:Adult C57BL/6 mice were kindled via twice-daily transcorneal 50-Hz elec-trical stimulations(3 mA)for 3 s for 12 days until animals reached a fully kindled state.After the kindling procedure,animals were tested using a set of behavioral tests,and neurochemical alterations were assessed.Results:Corneal-kindled animals exhibited intense generalized convulsions,altered behavioral phenotypes typified by positive symptoms(hyperlocomotion),negative symptoms(anxiety and anhedonia),and deficits in semantic and working memory.BRV 10+RFM 20 dual regime increased convulsive threshold and propensity toward the start of stage 4–5 seizures and improved phenotypical deficits,that is,anxiety,depression,and memory impairments.Moreover,this combination therapy mitigated kindling-induced redox impairments as evidenced by reduced malondialdehyde and acetylcholinesterase levels and increased glutathione antioxidant activity in the brain of animals subjected to repetitive brain insult.Conclusion:Based on our outcomes,this dual therapy provides supporting evidence in alleviating epilepsy-induced neurobehavioral comorbidities and changes in redox homeostasis.展开更多
Background:Scientific evidence to guide clinicians on the use of different antiseizure drugs in combination therapy is either very limited or lacking.In this study,the impact of lacosamide and perampanel alone and in ...Background:Scientific evidence to guide clinicians on the use of different antiseizure drugs in combination therapy is either very limited or lacking.In this study,the impact of lacosamide and perampanel alone and in combination was tested in corneal kindling model in mice,which is a cost-effective mechanism for screening of antiseizure drugs.Methods:The impact of lacosamide(5 mg/kg)and perampanel(0.125 mg/kg)alone and their combination was tested in corneal kindling process(3-mA current for 3 s applied twice daily for consecutive 12 days)in male BALB/c mice.Post-kindling,mice were subjected to a battery of behavioral tests assessing anxiety,memory,and depression-like behaviors.Brain tissues were then harvested for analysis of oxidative stress biomarkers.Results:Our results showed that the combination therapy of lacosamide and perampanel was more effective in reducing seizure progression than monotherapy of these drugs.Animals treated with combination therapy showed significant behavioral improvements,as reduced anxiety and depression were noticed,and their cognitive abilities were notably better compared to animals of all other groups.Moreover,biochemical assays of isolated brains from combination-treated group revealed lesser amount of oxidative stress.In addition,outcomes of dual regime were comparable to the phenytoin in seizure control but showed superior benefits in mitigation of kindling-prompted behavioral dysfunction and oxidative stress.Conclusions:This study suggests that the lacosamide and perampanel combination therapy worked noticeably better in halting the corneal kindling process in mice and improved the epilepsy-associated psychiatric disorders that might be due to antioxidant effects of both drugs.展开更多
BACKGROUND：Studies have demonstrated that brain-derived neurotrophic factor （BDNF） has a dual effect on epilepsy. However, the relationship between epilepsy-induced brain injury and BDNF remains poorly understood.O...BACKGROUND：Studies have demonstrated that brain-derived neurotrophic factor （BDNF） has a dual effect on epilepsy. However, the relationship between epilepsy-induced brain injury and BDNF remains poorly understood.OBJECTIVE：According to ultrastructural and molecular parameters, to detect the degree of neuronal injury and BDNF expression changes at different brain regions and different kindling times to determine the effects of BDNF on epilepsy-induced brain injury.DESIGN, TIME AND SETTING：A randomized, controlled, animal experiment based on neuropathology and molecular biology was performed at the Department of Physiology and Department of Pathology, Basic Medical College of Jilin University in 2003.MATERIALS：UltraSensitiveTM SP kit for immunohistochemistry （Fuzhou Maxim Biotechnology, China）, BDNF antibody （concentrated type, Wuhan Boster Biological Technology, China）, JEM-1000SX transmission electron microscopy （JEOL, Japan）, and BH-2 light microscope （Olympus, Japan） were used in the present study.METHODS：Wistar rats were randomly assigned to control （n = 6）, sham-surgery （n = 6）, and model （n = 60） groups. The control group rats were not treated; an electrode was embedded into the amygdala in rats from the sham-surgery and model groups; an amygdala kindling epilepsy model was established in the model group.MAIN OUTCOME MEASURES：Pathological changes in the temporal lobe and hippocampus were observed by light and electron microscopy at 1, 3, 7, 14, and 21 days following kindling, and BDNF expression in the various brain regions was determined by immunohistochemistry.RESULTS：In the model group, temporal lobe cortical and hippocampal neurons were swollen and the nuclei were laterally deviated. There were also some apoptotic neurons 3 days after kindling. The nucleoli disappeared and the nuclei appeared broken or lysed, as well as slight microglia hyperplasia, at 7 days. Electron microscopic observation displayed chromatin aggregation in the nuclei and slight mitochondrion swelling 3 days after kindling. Injury changes were aggravated at 7 days, characterized by broken cytoplasmic membrane and pyknosis. With the development of seizure, the number of BDNF-positive neurons in the hippocampus and temporal lobe increased and peaked at 7 days. Moreover, hippocampal and cortical temporal lobe injury continued. Following termination of electrical stimulation after 7 days of kindling, BDNF expression decreased, but continued to be expressed, up to 21 days of kindling. In addition, the number of temporal and hippocampal BDNF-positive neurons was greater than the control group.CONCLUSION：Brain injury and BDNF expression peaked at 7 days after kindling, and hippocampal changes were significant.展开更多
Objective Understanding the molecular and cellular mechanisms underlying epileptogenesis yields new in- sights into potential therapies that may ultimately prevent epilepsy. Gap junctions （GJs） create direct interce...Objective Understanding the molecular and cellular mechanisms underlying epileptogenesis yields new in- sights into potential therapies that may ultimately prevent epilepsy. Gap junctions （GJs） create direct intercellular conduits between adjacent cells and are formed by hexameric protein subunits called connexins （Cxs）. Changes in the expression of Cxs affect GJ communication and thereby could modulate the dissemination of electrical discharges. The hippocampus is one of the main regions involved in epileptogenesis and has a wide network of GJs between different cell types where Cx30 is expressed in astrocytes and Cx32 exists in neurons and oligodendrocytes. In the present study, we evaluated the changes of Cx30 and Cx32 expression in rat hippocampus during kindling epileptogenesis. Methods Rats were stereotaxically implanted with stimulating and recording electrodes in the basolateral amygdala, which was electrically stimulated once daily at afterdischarge threshold. Expression of Cx30 and Cx32, at both the mRNA and protein levels, was measured in the hippocampus at the beginning, in the middle （after acquisition of focal seizures）, and at the end （after establishment of generalized seizures） of the kindling process, by real-time PCR and Western blot. Results Cx30 mRNA expression was upregulated at the beginning of kindling and after acquisition of focal seizures. Then it was downregulated when the animals acquired generalized seizures. Overexpression of Cx30 mRNA at the start of kindling was consistent with the respective initial protein increase. Thereafter, no change was found in protein abundance during kindling. Regarding Cx32, mRNA expression decreased after acquisition of generalized seizures and no other significant change was detected in mRNA and protein abundance during kindling. Conclusion We speculate that Cx32 GJ communication in the hip- pocampus does not contribute to kindling epileptogenesis. The Cx30 astrocytic network localized to perivascular regions in the hippocampus is, however, overexpressed at the initiation of kindling to clear excitotoxic molecules from the milieu.展开更多
BACKGROUND： Electrical stimulation kindling model, having epilepsy-inducing and spontaneous seizure and other advantages, is a very ideal experimental animal model. But the kindling effect might be different at diffe...BACKGROUND： Electrical stimulation kindling model, having epilepsy-inducing and spontaneous seizure and other advantages, is a very ideal experimental animal model. But the kindling effect might be different at different sites. OBJECTIVE： To compare the features of animal models of complex partial epilepsy established through unilateral, bilateral and alternate-side kindling at hippocampus and successful rate of modeling among these 3 different ways. DESIGN： A randomized and controlled animal experiment SETTING： Department of Neurology, Qilu Hospital, Shandong University MATERIALS： Totally 60 healthy adult Wistar rats, weighing 200 to 300 g, of either gender, were used in this experiment. BL-410 biological functional experimental system （Taimeng Science and Technology Co. Ltd, Chengdu） and SE-7102 type electronic stimulator （Guangdian Company, Japan） were used in the experiment. METHODS： This experiment was carried out in the Experimental Animal Center of Shandong University from April to June 2004. After rats were anesthetized, electrode was implanted into the hippocampus. From the first day of measurement of afterdischarge threshold value, rats were given two-square-wave suprathreshold stimulation once per day with 400 μA intensity, 1ms wave length, 60 Hz frequency for 1 s duration. Left hippocampus was stimulated in unilateral kindling group, bilateral hippocampi were stimulated in bilateral kindling group, and left and right hippocampi were stimulated alternately every day in the alternate-side kindling group. Seizure intensity was scored： grade 0： normal, 1： wet dog-like shivering, facial spasm, such as, winking, touching the beard, rhythmic chewing and so on; 2： rhythmic nodding; 3： forelimb spasm;4： standing accompanied by bilateral forelimb spasm;5： tumbling, losing balance, four limbs spasm. Modeling was successful when seizure intensity reached grade 5. t test was used for the comparison of mean value between two samples. MAIN OUTCOME MEASURES： Comparison of the successful rate of modeling, the times of stimulation to reach intensity of grade 5, the lasting time of seizure of grade 3 of rats in each group. RESULTS： Four rats of alternate-side kindling group dropped out due to infection-induced electrode loss, and 56 rats were involved in the result analysis. The successful rate of unilateral kindling group, bilateral kin- dling group and alternate-side kindling group was 55%（11/20）,100%（16/16）and 100%（20/20）, respective- ly. The stimuli to reach the grade 5 spasm were significantly more in the bilateral kindling group than in the unilateral kindling group [（30.63±3.48）, （19.36±3.47）times, t=8.268, P 〈 0.01], and those were significantly fewer in the alternate-side kindling group than in the unilateral kindling group [（ 10.85±1.98）times, t=-8.744, P 〈 0.01]. The duration of grade 3 spasm was significantly longer in the bilateral kindling group than in the unilateral kindling group [（9.75±2.59）, （3.21 ±1.58）days,t=-8.183,P 〈 0.01], Among 20 successful rats of al- ternate-side kindling group, grade 5 spasm was found in the left hippocampi of 11 rats, but grade 3 spasm in their right hippocampi; Grade 5 spasm was found in the right hippocampi of the other 9 rats, grade 4 spasm in the left hippocampus of 1 rat and grade 3 of 8 rats. CONCLUSION ： The speed of establishing epilepsy seizure model by alternate-side kindling is faster than that by unilateral kindling, while that by bilateral kindling is slower than that by unilateral kindling. The successful rate is very high to establish complex partial epilepsy with alternate-side or bilateral kindling. Epilepsy seizure established by alternate-side kindling has antagonistic effect of kindling and the seizure duration of grade 3 spasm is prolonged.展开更多
Since the last decade deep brain stimulation has been proposed as an alternative treatment for patients who do not become seizure-free with the current pharmacological treatments and cannot undergo resective surgical ...Since the last decade deep brain stimulation has been proposed as an alternative treatment for patients who do not become seizure-free with the current pharmacological treatments and cannot undergo resective surgical procedure. However, the optimal stimulation parameters remain undetermined and active research in humans and animals is necessary. The present study was designed to investigate the effect of unilateral Low Frequency Stimulation (LFS) of hippocampus on seizure development by using the hippocampal rapid kindling method (hRK) in rats. We used male Wistar rats implanted with electrodes in the ventral hippocampus. All rats underwent hRK (biphasic square wave pulses, 20 Hz for 10 seconds) during three consecutive days (twelve stimulations per day). The control group (hRK;n = 6) received only RK stimulus, while the treated group (LFS-hRK;n = 8) received also LFS (biphasic square wave pulses, 1 Hz for 30 seconds) immediately before the RK stimulus, during three consecutive days. At the end of behavioral testing on day 3, 62% (P < 0.05) of the animals receiving LFS treatment were still not fully kindled staying in stages 0-III (P < 0.01). The number of stimulations needed to achieve generalized seizures (stage IV-V of Racine scale) was significantly higher (P < 0.05) in the LFS group with respect to control group. No significant differences in the cumulative daily afterdischarge duration were observed between both groups. These findings suggest that preemptive LFS can significantly decrease the incidence of hippocampus-kindled seizures and delay the progression and secondary generalization of focal seizures.展开更多
Epilepsy is one of the most common serious neurological disorders. Pharmacoresistant epilepsy patients are poorly controlled or their seizures are refractory to drug treatment. Resective surgery is frequently a promis...Epilepsy is one of the most common serious neurological disorders. Pharmacoresistant epilepsy patients are poorly controlled or their seizures are refractory to drug treatment. Resective surgery is frequently a promising therapy in this population, however, not all the patients meet the eligibility criteria for the surgical treatment. Deep brain stimulation has been investigated in clinical studies and animal studies as an alternative treatment, but the optimal stimulation parameters remain an issue. The present study was designed to investigate the effect of unilateral high-frequency stimulation (HFS) of hippocampus on seizure development by using the hippocampal rapid kindling method (hRK) in rats, and compared the results with those of low-frequency stimulation previously published by our group. We used male Wistar rats implanted with electrodes in the ventral hippocampus. All rats underwent hRK (biphasic square wave pulses, 20 Hz for 10 seconds) during three consecutive days (twelve stimulations per day). The control group (hRK;n = 7) received only RK stimulus, while the treated group (HFS-hRK;n = 9) received also HFS (biphasic square wave pulses, 130 Hz for 30 seconds) immediately before the RK stimulus, during three consecutive days. At the end of behavioral testing 78% (p 0.01) of the animals receiving HFS treatment were still not fully kindled staying in stages 0 -III (p 0.01). HFS group needed a higher number of stimulations to achieve stage III (p 0.05) with respect to control group. However, no significant differences in the cumulative daily afterdischarge duration were observed. HFS did not present significant differences compared with LFS in any of studied parameters. The findings suggest that unilateral HFS applied on hippocampus effectively inhibited the epileptogenic process induced by hippocampal rapid kindling. According to the comparative results about hippocampal rapid kindled animals stimulated with HFS and LFS (5 Hz), we found no conclusive information on which treatment is most efficient.展开更多
Objective To test the hypothesis that neuronal cdc2 like kinase (Cdk5/p35 nck5a ) plays an important role in neuronal maturation and sprouting Methods Changes kinase activity, expression levels and subcellular...Objective To test the hypothesis that neuronal cdc2 like kinase (Cdk5/p35 nck5a ) plays an important role in neuronal maturation and sprouting Methods Changes kinase activity, expression levels and subcellular localizations of Cdk5 and p35 nck5a in the rat hippocampus were studied during kindling progression by Western blot analysis, immunohistochemitry, immunoprecipitation and kinase assay Results Kinase activity in kindling rats was significantly higher than that in normal adult rats The kinase activity at stage 3 was most prominent among all stages of kindling progression The changes in kinase activity coincided with those of p35 nck5a expression in kindling rats In contrast, the expression of Cdk5 was constant throughout the progression of kindling stages However, subcellular localization of Cdk5 dramatically changed in the hippocampal neurons of kindling rats Cdk5 was translocated from axon to soma when kinase activity was high p35 nck5a was always localized in the soma throughout kindling progression Conclusions Neuronal cdc2 like kinase plays an important role in synaptic reorganization, and the translocation of Cdk5 to the soma from the axon may be a novel regulatory mechanism to control kinase activity展开更多
The antiepileptic effect of pinellia total alkaloids（PTA） on penicillin（PNC） chronically kindled rats was investigated. We investigated the effects of PTA on Glu,Asp,Gly andγ-aminobutyric acid（GABA） concentrati...The antiepileptic effect of pinellia total alkaloids（PTA） on penicillin（PNC） chronically kindled rats was investigated. We investigated the effects of PTA on Glu,Asp,Gly andγ-aminobutyric acid（GABA） concentrations and the expression level of cerebral GABA_A receptor in hippocampus.The influence of PTA on epilepsy seizure latency and degree in PNC chronically kindled rats were observed.High performance liquid chromatography（HPLC） was adopted to measure the concentrations of Glu, Asp,Gly and GABA in hippocampus. Reverse transcriptase-polymerase chain reaction （RT-PCR） was used to determine the expression of cerebral GABAA receptor mRNA. Compared with normal rats, the levels of GABA and Gly decreased obviously while the level of Glu and Asp increased significantly in model rats. The cerebral GABAA receptor mRNA level was also decreased at the same time. The difference was statistically different compared to the control group. PTA could prolong the latent period of the penicillin induced seizure and weaken the extent of seizure, compared with the model group without PTA treatment. Moreover, PTA increased the level of GABA and the expression level of GABAA receptor, while decreased the level of Glu significantly. However, it had no obvious effect on the level of Gly and Asp. Pre-treatment of PTA can also increase the GABAA receptor mRNA level. In conclusion, PTA could alleviate the PNC chronically kindled rat seizure. It increased the GABA level and the expression of GABAA receptor, and it decreased the Glu concentration.展开更多
基金The authors extend their appreciation to the Distinguished Scientist Fellowship program at King Saud University,Riyadh,Saudi Arabia,for funding this work through Research Supporting Project Number RSP2024R131.
文摘Background:Besides seizures,a myriad of overlapping neuropsychiatric and cognitive comorbidities occur in patients with epilepsy,which further debilitates their quality of life.This study provides an in-depth characterization of the impact of brivaracetam and rufinamide individually and in combination at 10 and 20 mg/kg doses,respec-tively,on corneal kindling-induced generalized seizures and behavioral alterations.Furthermore,observed convulsive frequency and behavioral changes were corre-lated to post-kindling-induced changes in the activity of markers of oxidative stress.Methods:Adult C57BL/6 mice were kindled via twice-daily transcorneal 50-Hz elec-trical stimulations(3 mA)for 3 s for 12 days until animals reached a fully kindled state.After the kindling procedure,animals were tested using a set of behavioral tests,and neurochemical alterations were assessed.Results:Corneal-kindled animals exhibited intense generalized convulsions,altered behavioral phenotypes typified by positive symptoms(hyperlocomotion),negative symptoms(anxiety and anhedonia),and deficits in semantic and working memory.BRV 10+RFM 20 dual regime increased convulsive threshold and propensity toward the start of stage 4–5 seizures and improved phenotypical deficits,that is,anxiety,depression,and memory impairments.Moreover,this combination therapy mitigated kindling-induced redox impairments as evidenced by reduced malondialdehyde and acetylcholinesterase levels and increased glutathione antioxidant activity in the brain of animals subjected to repetitive brain insult.Conclusion:Based on our outcomes,this dual therapy provides supporting evidence in alleviating epilepsy-induced neurobehavioral comorbidities and changes in redox homeostasis.
基金The authors extended their appreciation to Distinguished Scientist Fellowship program at King Saud University,Riyadh,Saudi Arabia,for funding this work through research supporting project number(RSP2024R131).
文摘Background:Scientific evidence to guide clinicians on the use of different antiseizure drugs in combination therapy is either very limited or lacking.In this study,the impact of lacosamide and perampanel alone and in combination was tested in corneal kindling model in mice,which is a cost-effective mechanism for screening of antiseizure drugs.Methods:The impact of lacosamide(5 mg/kg)and perampanel(0.125 mg/kg)alone and their combination was tested in corneal kindling process(3-mA current for 3 s applied twice daily for consecutive 12 days)in male BALB/c mice.Post-kindling,mice were subjected to a battery of behavioral tests assessing anxiety,memory,and depression-like behaviors.Brain tissues were then harvested for analysis of oxidative stress biomarkers.Results:Our results showed that the combination therapy of lacosamide and perampanel was more effective in reducing seizure progression than monotherapy of these drugs.Animals treated with combination therapy showed significant behavioral improvements,as reduced anxiety and depression were noticed,and their cognitive abilities were notably better compared to animals of all other groups.Moreover,biochemical assays of isolated brains from combination-treated group revealed lesser amount of oxidative stress.In addition,outcomes of dual regime were comparable to the phenytoin in seizure control but showed superior benefits in mitigation of kindling-prompted behavioral dysfunction and oxidative stress.Conclusions:This study suggests that the lacosamide and perampanel combination therapy worked noticeably better in halting the corneal kindling process in mice and improved the epilepsy-associated psychiatric disorders that might be due to antioxidant effects of both drugs.
基金Supported by a Grant from the Health Department of Jilin Province,No. 2000029
文摘BACKGROUND：Studies have demonstrated that brain-derived neurotrophic factor （BDNF） has a dual effect on epilepsy. However, the relationship between epilepsy-induced brain injury and BDNF remains poorly understood.OBJECTIVE：According to ultrastructural and molecular parameters, to detect the degree of neuronal injury and BDNF expression changes at different brain regions and different kindling times to determine the effects of BDNF on epilepsy-induced brain injury.DESIGN, TIME AND SETTING：A randomized, controlled, animal experiment based on neuropathology and molecular biology was performed at the Department of Physiology and Department of Pathology, Basic Medical College of Jilin University in 2003.MATERIALS：UltraSensitiveTM SP kit for immunohistochemistry （Fuzhou Maxim Biotechnology, China）, BDNF antibody （concentrated type, Wuhan Boster Biological Technology, China）, JEM-1000SX transmission electron microscopy （JEOL, Japan）, and BH-2 light microscope （Olympus, Japan） were used in the present study.METHODS：Wistar rats were randomly assigned to control （n = 6）, sham-surgery （n = 6）, and model （n = 60） groups. The control group rats were not treated; an electrode was embedded into the amygdala in rats from the sham-surgery and model groups; an amygdala kindling epilepsy model was established in the model group.MAIN OUTCOME MEASURES：Pathological changes in the temporal lobe and hippocampus were observed by light and electron microscopy at 1, 3, 7, 14, and 21 days following kindling, and BDNF expression in the various brain regions was determined by immunohistochemistry.RESULTS：In the model group, temporal lobe cortical and hippocampal neurons were swollen and the nuclei were laterally deviated. There were also some apoptotic neurons 3 days after kindling. The nucleoli disappeared and the nuclei appeared broken or lysed, as well as slight microglia hyperplasia, at 7 days. Electron microscopic observation displayed chromatin aggregation in the nuclei and slight mitochondrion swelling 3 days after kindling. Injury changes were aggravated at 7 days, characterized by broken cytoplasmic membrane and pyknosis. With the development of seizure, the number of BDNF-positive neurons in the hippocampus and temporal lobe increased and peaked at 7 days. Moreover, hippocampal and cortical temporal lobe injury continued. Following termination of electrical stimulation after 7 days of kindling, BDNF expression decreased, but continued to be expressed, up to 21 days of kindling. In addition, the number of temporal and hippocampal BDNF-positive neurons was greater than the control group.CONCLUSION：Brain injury and BDNF expression peaked at 7 days after kindling, and hippocampal changes were significant.
文摘Objective Understanding the molecular and cellular mechanisms underlying epileptogenesis yields new in- sights into potential therapies that may ultimately prevent epilepsy. Gap junctions （GJs） create direct intercellular conduits between adjacent cells and are formed by hexameric protein subunits called connexins （Cxs）. Changes in the expression of Cxs affect GJ communication and thereby could modulate the dissemination of electrical discharges. The hippocampus is one of the main regions involved in epileptogenesis and has a wide network of GJs between different cell types where Cx30 is expressed in astrocytes and Cx32 exists in neurons and oligodendrocytes. In the present study, we evaluated the changes of Cx30 and Cx32 expression in rat hippocampus during kindling epileptogenesis. Methods Rats were stereotaxically implanted with stimulating and recording electrodes in the basolateral amygdala, which was electrically stimulated once daily at afterdischarge threshold. Expression of Cx30 and Cx32, at both the mRNA and protein levels, was measured in the hippocampus at the beginning, in the middle （after acquisition of focal seizures）, and at the end （after establishment of generalized seizures） of the kindling process, by real-time PCR and Western blot. Results Cx30 mRNA expression was upregulated at the beginning of kindling and after acquisition of focal seizures. Then it was downregulated when the animals acquired generalized seizures. Overexpression of Cx30 mRNA at the start of kindling was consistent with the respective initial protein increase. Thereafter, no change was found in protein abundance during kindling. Regarding Cx32, mRNA expression decreased after acquisition of generalized seizures and no other significant change was detected in mRNA and protein abundance during kindling. Conclusion We speculate that Cx32 GJ communication in the hip- pocampus does not contribute to kindling epileptogenesis. The Cx30 astrocytic network localized to perivascular regions in the hippocampus is, however, overexpressed at the initiation of kindling to clear excitotoxic molecules from the milieu.
文摘BACKGROUND： Electrical stimulation kindling model, having epilepsy-inducing and spontaneous seizure and other advantages, is a very ideal experimental animal model. But the kindling effect might be different at different sites. OBJECTIVE： To compare the features of animal models of complex partial epilepsy established through unilateral, bilateral and alternate-side kindling at hippocampus and successful rate of modeling among these 3 different ways. DESIGN： A randomized and controlled animal experiment SETTING： Department of Neurology, Qilu Hospital, Shandong University MATERIALS： Totally 60 healthy adult Wistar rats, weighing 200 to 300 g, of either gender, were used in this experiment. BL-410 biological functional experimental system （Taimeng Science and Technology Co. Ltd, Chengdu） and SE-7102 type electronic stimulator （Guangdian Company, Japan） were used in the experiment. METHODS： This experiment was carried out in the Experimental Animal Center of Shandong University from April to June 2004. After rats were anesthetized, electrode was implanted into the hippocampus. From the first day of measurement of afterdischarge threshold value, rats were given two-square-wave suprathreshold stimulation once per day with 400 μA intensity, 1ms wave length, 60 Hz frequency for 1 s duration. Left hippocampus was stimulated in unilateral kindling group, bilateral hippocampi were stimulated in bilateral kindling group, and left and right hippocampi were stimulated alternately every day in the alternate-side kindling group. Seizure intensity was scored： grade 0： normal, 1： wet dog-like shivering, facial spasm, such as, winking, touching the beard, rhythmic chewing and so on; 2： rhythmic nodding; 3： forelimb spasm;4： standing accompanied by bilateral forelimb spasm;5： tumbling, losing balance, four limbs spasm. Modeling was successful when seizure intensity reached grade 5. t test was used for the comparison of mean value between two samples. MAIN OUTCOME MEASURES： Comparison of the successful rate of modeling, the times of stimulation to reach intensity of grade 5, the lasting time of seizure of grade 3 of rats in each group. RESULTS： Four rats of alternate-side kindling group dropped out due to infection-induced electrode loss, and 56 rats were involved in the result analysis. The successful rate of unilateral kindling group, bilateral kin- dling group and alternate-side kindling group was 55%（11/20）,100%（16/16）and 100%（20/20）, respective- ly. The stimuli to reach the grade 5 spasm were significantly more in the bilateral kindling group than in the unilateral kindling group [（30.63±3.48）, （19.36±3.47）times, t=8.268, P 〈 0.01], and those were significantly fewer in the alternate-side kindling group than in the unilateral kindling group [（ 10.85±1.98）times, t=-8.744, P 〈 0.01]. The duration of grade 3 spasm was significantly longer in the bilateral kindling group than in the unilateral kindling group [（9.75±2.59）, （3.21 ±1.58）days,t=-8.183,P 〈 0.01], Among 20 successful rats of al- ternate-side kindling group, grade 5 spasm was found in the left hippocampi of 11 rats, but grade 3 spasm in their right hippocampi; Grade 5 spasm was found in the right hippocampi of the other 9 rats, grade 4 spasm in the left hippocampus of 1 rat and grade 3 of 8 rats. CONCLUSION ： The speed of establishing epilepsy seizure model by alternate-side kindling is faster than that by unilateral kindling, while that by bilateral kindling is slower than that by unilateral kindling. The successful rate is very high to establish complex partial epilepsy with alternate-side or bilateral kindling. Epilepsy seizure established by alternate-side kindling has antagonistic effect of kindling and the seizure duration of grade 3 spasm is prolonged.
文摘Since the last decade deep brain stimulation has been proposed as an alternative treatment for patients who do not become seizure-free with the current pharmacological treatments and cannot undergo resective surgical procedure. However, the optimal stimulation parameters remain undetermined and active research in humans and animals is necessary. The present study was designed to investigate the effect of unilateral Low Frequency Stimulation (LFS) of hippocampus on seizure development by using the hippocampal rapid kindling method (hRK) in rats. We used male Wistar rats implanted with electrodes in the ventral hippocampus. All rats underwent hRK (biphasic square wave pulses, 20 Hz for 10 seconds) during three consecutive days (twelve stimulations per day). The control group (hRK;n = 6) received only RK stimulus, while the treated group (LFS-hRK;n = 8) received also LFS (biphasic square wave pulses, 1 Hz for 30 seconds) immediately before the RK stimulus, during three consecutive days. At the end of behavioral testing on day 3, 62% (P < 0.05) of the animals receiving LFS treatment were still not fully kindled staying in stages 0-III (P < 0.01). The number of stimulations needed to achieve generalized seizures (stage IV-V of Racine scale) was significantly higher (P < 0.05) in the LFS group with respect to control group. No significant differences in the cumulative daily afterdischarge duration were observed between both groups. These findings suggest that preemptive LFS can significantly decrease the incidence of hippocampus-kindled seizures and delay the progression and secondary generalization of focal seizures.
文摘Epilepsy is one of the most common serious neurological disorders. Pharmacoresistant epilepsy patients are poorly controlled or their seizures are refractory to drug treatment. Resective surgery is frequently a promising therapy in this population, however, not all the patients meet the eligibility criteria for the surgical treatment. Deep brain stimulation has been investigated in clinical studies and animal studies as an alternative treatment, but the optimal stimulation parameters remain an issue. The present study was designed to investigate the effect of unilateral high-frequency stimulation (HFS) of hippocampus on seizure development by using the hippocampal rapid kindling method (hRK) in rats, and compared the results with those of low-frequency stimulation previously published by our group. We used male Wistar rats implanted with electrodes in the ventral hippocampus. All rats underwent hRK (biphasic square wave pulses, 20 Hz for 10 seconds) during three consecutive days (twelve stimulations per day). The control group (hRK;n = 7) received only RK stimulus, while the treated group (HFS-hRK;n = 9) received also HFS (biphasic square wave pulses, 130 Hz for 30 seconds) immediately before the RK stimulus, during three consecutive days. At the end of behavioral testing 78% (p 0.01) of the animals receiving HFS treatment were still not fully kindled staying in stages 0 -III (p 0.01). HFS group needed a higher number of stimulations to achieve stage III (p 0.05) with respect to control group. However, no significant differences in the cumulative daily afterdischarge duration were observed. HFS did not present significant differences compared with LFS in any of studied parameters. The findings suggest that unilateral HFS applied on hippocampus effectively inhibited the epileptogenic process induced by hippocampal rapid kindling. According to the comparative results about hippocampal rapid kindled animals stimulated with HFS and LFS (5 Hz), we found no conclusive information on which treatment is most efficient.
文摘Objective To test the hypothesis that neuronal cdc2 like kinase (Cdk5/p35 nck5a ) plays an important role in neuronal maturation and sprouting Methods Changes kinase activity, expression levels and subcellular localizations of Cdk5 and p35 nck5a in the rat hippocampus were studied during kindling progression by Western blot analysis, immunohistochemitry, immunoprecipitation and kinase assay Results Kinase activity in kindling rats was significantly higher than that in normal adult rats The kinase activity at stage 3 was most prominent among all stages of kindling progression The changes in kinase activity coincided with those of p35 nck5a expression in kindling rats In contrast, the expression of Cdk5 was constant throughout the progression of kindling stages However, subcellular localization of Cdk5 dramatically changed in the hippocampal neurons of kindling rats Cdk5 was translocated from axon to soma when kinase activity was high p35 nck5a was always localized in the soma throughout kindling progression Conclusions Neuronal cdc2 like kinase plays an important role in synaptic reorganization, and the translocation of Cdk5 to the soma from the axon may be a novel regulatory mechanism to control kinase activity
基金Natural Science Foundation of Shanxi Province (Grant No.20041109).
文摘The antiepileptic effect of pinellia total alkaloids（PTA） on penicillin（PNC） chronically kindled rats was investigated. We investigated the effects of PTA on Glu,Asp,Gly andγ-aminobutyric acid（GABA） concentrations and the expression level of cerebral GABA_A receptor in hippocampus.The influence of PTA on epilepsy seizure latency and degree in PNC chronically kindled rats were observed.High performance liquid chromatography（HPLC） was adopted to measure the concentrations of Glu, Asp,Gly and GABA in hippocampus. Reverse transcriptase-polymerase chain reaction （RT-PCR） was used to determine the expression of cerebral GABAA receptor mRNA. Compared with normal rats, the levels of GABA and Gly decreased obviously while the level of Glu and Asp increased significantly in model rats. The cerebral GABAA receptor mRNA level was also decreased at the same time. The difference was statistically different compared to the control group. PTA could prolong the latent period of the penicillin induced seizure and weaken the extent of seizure, compared with the model group without PTA treatment. Moreover, PTA increased the level of GABA and the expression level of GABAA receptor, while decreased the level of Glu significantly. However, it had no obvious effect on the level of Gly and Asp. Pre-treatment of PTA can also increase the GABAA receptor mRNA level. In conclusion, PTA could alleviate the PNC chronically kindled rat seizure. It increased the GABA level and the expression of GABAA receptor, and it decreased the Glu concentration.
