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Sample records for pilocarpine-induced rat epileptiform

  1. Cyclooxygenase-2 inhibitor inhibits hippocampal synaptic reorganization in pilocarpine-induced status epilepticus rats

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    Hai-ju ZHANG; Ruo-peng SUN; Ge-fei LEI; Lu YANG; Chun-xi LIU

    2008-01-01

    Objective: To examine modulations caused by cyclooxygenase-2 (COX-2) inhibitors on altered microenvironments and overbalanced neurotransmitters in pilocarpine-induced epileptic status rats and to investigate possible mechanisms. Methods:Celecoxib (a COX-2 inhibitor) was administered 45 min prior to pilocarpine administration. The effects of COX-2 inhibitors on mIPSCs (miniature GABAergic inhibitory postsynaptic currents) of CA3 pyramidal cells in the hippocampus were recorded. Expressions of COX-2, c-Fos, newly generated neurons, and activated microgliosis wore analyzed by immunohistochemistry, and expressions of α-subunit of γ-amino butyric acid (GABAA) receptors and mitogen-activated protein kinase/extracellular sig-nal-regulated protein kinase (MAPK/ERK) activity were detected by Western blotting. Results: Pretreatment with celecoxib showed protection against pilocarpine-induced seizures. Celecoxib prevented microglia activation in the hilus and inhibited the abnormal neurogenesis and astrogliosis in the hippocampus by inhibiting MAPK/ERK activity and c-Fos transcription. Celecoxib also up-regulated the expression of GABAA receptors. NS-398 (N-2-cyclohexyloxy-4-nitrophenyl-methanesuifonamide), another COX-2 inhibitor, enhanced the frequency and decay time of mIPSCs. Conclusion: The COX-2 inhibitor celecoxib decreased neuronal excitability and prevented epileptogenesis in pilocarpine-induced status epilepticus rats. Celecoxib regulates synaptic reorganization by inhibiting astrogliosis and ectopic neurogenesis by attenuating MAPK/ERK signal activity, mediated by a GABAergic mechanism.

  2. Does pilocarpine-induced epilepsy in adult rats require status epilepticus?

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    Graciela Navarro Mora

    Full Text Available Pilocarpine-induced seizures in rats provide a widely animal model of temporal lobe epilepsy. Some evidences reported in the literature suggest that at least 1 h of status epilepticus (SE is required to produce subsequent chronic phase, due to the SE-related acute neuronal damage. However, recent data seems to indicate that neuro-inflammation plays a crucial role in epileptogenesis, modulating secondarily a neuronal insult. For this reason, we decided to test the following hypotheses: a whether pilocarpine-injected rats that did not develop SE can exhibit long-term chronic spontaneous recurrent seizures (SRS and b whether acute neurodegeneration is mandatory to obtain chronic epilepsy. Therefore, we compared animals injected with the same dose of pilocarpine that developed or did not SE, and saline treated rats. We used telemetric acquisition of EEG as long-term monitoring system to evaluate the occurrence of seizures in non-SE pilocarpineinjected animals. Furthermore, histology and MRI analysis were applied in order to detect neuronal injury and neuropathological signs. Our observations indicate that non-SE rats exhibit SRS almost 8 (+/22 months after pilocarpine-injection, independently to the absence of initial acute neuronal injury. This is the first time reported that pilocarpine injected rats without developing SE, can experience SRS after a long latency period resembling human pathology. Thus, we strongly emphasize the important meaning of including these animals to model human epileptogenesis in pilocarpine induced epilepsy.

  3. Does Pilocarpine-Induced Epilepsy in Adult Rats Require Status epilepticus?

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    Navarro Mora, Graciela; Bramanti, Placido; Osculati, Francesco; Chakir, Asmaa; Nicolato, Elena; Marzola, Pasquina; Sbarbati, Andrea; Fabene, Paolo Francesco

    2009-01-01

    Pilocarpine-induced seizures in rats provide a widely animal model of temporal lobe epilepsy. Some evidences reported in the literature suggest that at least 1 h of status epilepticus (SE) is required to produce subsequent chronic phase, due to the SE-related acute neuronal damage. However, recent data seems to indicate that neuro-inflammation plays a crucial role in epileptogenesis, modulating secondarily a neuronal insult. For this reason, we decided to test the following hypotheses: a) whether pilocarpine-injected rats that did not develop SE can exhibit long-term chronic spontaneous recurrent seizures (SRS) and b) whether acute neurodegeneration is mandatory to obtain chronic epilepsy. Therefore, we compared animals injected with the same dose of pilocarpine that developed or did not SE, and saline treated rats. We used telemetric acquisition of EEG as long-term monitoring system to evaluate the occurrence of seizures in non-SE pilocarpineinjected animals. Furthermore, histology and MRI analysis were applied in order to detect neuronal injury and neuropathological signs. Our observations indicate that non-SE rats exhibit SRS almost 8 (+/22) months after pilocarpine-injection, independently to the absence of initial acute neuronal injury. This is the first time reported that pilocarpine injected rats without developing SE, can experience SRS after a long latency period resembling human pathology. Thus, we strongly emphasize the important meaning of including these animals to model human epileptogenesis in pilocarpine induced epilepsy. PMID:19503612

  4. Lipoic acid effects on glutamate and taurine concentrations in rat hippocampus after pilocarpine-induced seizures

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    P S Santos

    2011-01-01

    Full Text Available Pilocarpine-induced seizures can be mediated by increases in oxidative stress and by cerebral amino acid changes. The present research suggests that antioxidant compounds may afford some level of neuroprotection against the neurotoxicity of seizures in cellular level. The objective of the present study was to evaluate the lipoic acid (LA effects in glutamate and taurine contents in rat hippocampus after pilocarpine-induced seizures. Wistar rats were treated intraperitoneally (i.p. with 0.9% saline (Control, pilocarpine (400 mg/kg, Pilocarpine, LA (10 mg/kg, LA, and the association of LA (10 mg/kg plus pilocarpine (400 mg/kg, that was injected 30 min before of administration of LA (LA plus pilocarpine. Animals were observed during 24 h. The amino acid concentrations were measured using high-performance liquid chromatograph (HPLC. In pilocarpine group, it was observed a significant increase in glutamate content (37% and a decrease in taurine level (18% in rat hippocampus, when compared to control group. Antioxidant pretreatment significantly reduced the glutamate level (28% and augmented taurine content (32% in rat hippocampus, when compared to pilocarpine group. Our findings strongly support amino acid changes in hippocampus during seizures induced by pilocarpine, and suggest that glutamate-induced brain damage plays a crucial role in pathogenic consequences of seizures, and imply that strong protective effect could be achieved using lipoic acid through the release or decrease in metabolization rate of taurine amino acid during seizures.

  5. Effect of duration of pilocarpine-induced status epilepticus on subsequent cognitive function in rats.

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    Balakrishnan, S; Nidhi, G; Pandhi, P

    2001-03-01

    The aim of this study was to determine the effect of the duration of pilocarpine-induced status epilepticus (SE) on subsequent cognitive function in rats. SE was induced by pilocarpine (320 mg/kg i.p.) and was terminated by injection of 1 mg/kg diazepam at 30, 60 and 90 min in 3 groups of 10 rats each. Cognitive function was tested by a passive avoidance task and was assessed at the baseline and on days 1, 7, 14 and 21 (post SE). It was found that cognitive function was disrupted on days 7, 14 and 21 post SE in rats who had SE for 60 and 90 min, whereas it was not affected in rats that had 30 min of SE. Hence, the duration of SE may affect future cognitive performance and mandates emergency treatment.

  6. Expression and significance of GIT1 in hippocampus of lithium-pilocarpine-induced epileptic rats

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    Li-hua ZHENG

    2015-07-01

    Full Text Available Objective  To investigate the expression changes of G-protein-coupled receptor kinase-interacting protein 1 (GIT1 in lithium-pilocarpine-induced epileptic rat model and explore its role in the genesis and development of epilepsy.  Methods  The lithium-pilocarpine-induced model of status epilepticus (SE was established in 42 specific pathogen free (SPF male adult Wistar rats, and those rats were randomly divided into control group and 6 epilepsy groups (1, 3, 7, 14, 30, 60 d after SE. The expression of GIT1 mRNA was detected by fluroescent quantitative polymerase chain reaction (PCR, while the expression of GIT1 protein was examined by Western blotting and immunohistochemistry was applied to test the expression of CA1 region, dentate gyrus and parahippocampal cortex in rat hippocampus at different time points.  Results  GIT1 mRNA level rised in acute phase on 1st and 3rd day after SE (P = 0.012, 0.002, then increased continously in latency on 7th and 14th day (P = 0.003, 0.001, and reached the peak in chronic phase on 30th and 60th day (P = 0.000, for all. GIT1 protein expression rised in acute phase and increased continously in chronic phase, but there was no significant difference compared with control group (P > 0.05, for all. Then, it reached the peak in chronic phase (P = 0.000, for all. Until the 30th day, the GIT1 expression of CA1 region, dentate gyrus and parahippocampal cortex in the hippocampus of rats in 6 epilepsy groups was significantly higher than that of control group (P = 0.000, for all.  Conclusions  The up-regulated expression of GIT1 in the hippocampus of epileptic rat was probably involved in the formation process of chronic epilepsy by regulating cytoskeleton dynamic regrouping to influence excitatory neural networks. DOI: 10.3969/j.issn.1672-6731.2015.06.011

  7. Anticonvulsive and antioxidant effects of curcumin on pilocarpine-induced seizures in rats

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    DU Peng; TANG Hai-yan; LI Xin; LIN Hao-jie; PENG Wei-feng; MA Yu; FAN Wei; WANG Xin

    2012-01-01

    Background Curcumin,an active ingredient of turmeric with antioxidant and anti-inflammatory properties has recently been reported to have anticonvulsant effects in several animal models of epilepsy.This study aimed to investigate the effects of curcumin on the pilocarpine rat model of status epilepticus.Methods The effect of intraperitoneal administration of curcumin (30,100,and 300 mg/kg) on pilocarpine-induced seizures in rats was tested.The correlation between seizure activity and hippocampal levels of nitric oxide synthase and free radicals was quantified.Whether curcumin treatment modulated these parameters was also investigated.Results Curcumin significantly increased seizure threshold at doses of 100 and 300 mg/kg.Rats with pilocarpineinduced seizures showed significantly elevated levels of malonaldehyde,nitric oxide synthase,and lactate dehydrogenase,but decreased levels of superoxide dismutase and glutathione compared with normal control rats.At doses of 100 and 300 mg/kg,curcumin reversed the effects of pilocarpine-indUced seizures on nitric oxide synthase,lactate dehydrogenase,glutathione,and superoxide dismutase.However,curcumin did not restore the elevated malonaldehyde levels.Conclusion Curcumin has anticonvulsant activity in the pilocarpine rat model of seizures,and that modulation of free radicals and nitric oxide synthase may be involved in this effect.

  8. Exposure to Mozart music reduces cognitive impairment in pilocarpine-induced status epilepticus rats.

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    Xing, Yingshou; Qin, Yi; Jing, Wei; Zhang, Yunxiang; Wang, Yanran; Guo, Daqing; Xia, Yang; Yao, Dezhong

    2016-02-01

    Patients with temporal lobe epilepsy (TLE) often display cognitive deficits. However, current epilepsy therapeutic interventions mainly aim at how to reduce the frequency and degree of epileptic seizures. Recovery of cognitive impairment is not attended enough, resulting in the lack of effective approaches in this respect. In the pilocarpine-induced temporal lobe epilepsy rat model, memory impairment has been classically reported. Here we evaluated spatial cognition changes at different epileptogenesis stages in rats of this model and explored the effects of long-term Mozart music exposure on the recovery of cognitive ability. Our results showed that pilocarpine rats suffered persisting cognitive impairment during epileptogenesis. Interestingly, we found that Mozart music exposure can significantly enhance cognitive ability in epileptic rats, and music intervention may be more effective for improving cognitive function during the early stages after Status epilepticus. These findings strongly suggest that Mozart music may help to promote the recovery of cognitive damage due to seizure activities, which provides a novel intervention strategy to diminish cognitive deficits in TLE patients.

  9. Effects of ketogenic diets on the occurrence of pilocarpine-induced status epilepticus of rats.

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    Gama, Iclea Rocha; Trindade-Filho, Euclides Marinho; Oliveira, Suzana Lima; Bueno, Nassib Bezerra; Melo, Isabelle Tenório; Cabral-Junior, Cyro Rego; Barros, Elenita M; Galvão, Jaqueline A; Pereira, Wanessa S; Ferreira, Raphaela C; Domingos, Bruna R; da Rocha Ataide, Terezinha

    2015-02-01

    Two sources of medium-chain triglycerides--triheptanoin with anaplerotic properties and coconut oil with antioxidant features--have emerged as promising therapeutic options for the management of pharmacoresistant epilepsy. We investigated the effects of ketogenic diets (KDs) containing coconut oil, triheptanoin, or soybean oil on pilocarpine-induced status epilepticus (SE) in rats. Twenty-four adult male Wistar rats were divided into 4 groups and fed a control diet (7% lipids) or a KD containing soybean oil, coconut oil, or triheptanoin (69.8% lipids). The ketogenic and control diets had a lipid:carbohydrate + protein ratio of 1:11.8 and 3.5:1, respectively. SE was induced in all rats 20 days after initiation of the dietary treatment, through the administration of pilocarpine (340 mg/kg; i.p.). The latency, frequency, duration, and severity of seizures before and during SE were observed with a camcorder. SE was aborted after 3 h with the application of diazepam (5 mg/kg; i.p.). The rats in the triheptanoin-based KD group needed to undergo a higher number of seizures to develop SE, as compared to the control group (P < 0.05). Total weight gain, intake, energy intake, and feed efficiency coefficient, prior to induction of SE, differed between groups (P < 0.05), where the triheptanoin-based KD group showed less weight gain than all other groups, less energy intake than the Control group and intermediate values of feed efficiency coefficient between Control and other KDs groups. Triheptanoin-based KD may have a neuroprotective effect on the establishment of SE in Wistar rats.

  10. The expression of somatostatin receptors in the hippocampus of pilocarpine-induced rat epilepsy model.

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    Kwak, Sung-Eun; Kim, Ji-Eun; Choi, Hui-Chul; Song, Hong-Ki; Kim, Yeong-In; Jo, Seung-Mook; Kang, Tae-Cheon

    2008-01-01

    During the course of this study, we sought examine whether the expression of somatostatin receptors (SSTRs) is altered in the hippocampus following pilocarpine-induced status epilepticus (SE) in order to understand the role/function of SSTRs in the hippocampus after epileptogenic insults. SSTR1 and SSTR4 immunoreactivities were increased in the hippocampus at 1 week after SE. At 4 weeks after SE, SRIF1-family (SSTR 2A, SSTR2B, and SSTR5) immunoreactivity was increased only in neuropil. Both SSTR2A and 2B immunoreactivities were increased in CA2-3 pyramidal cells. However, SSTR3 and SSTR4 immunoreactivities were reduced in the CA1 pyramidal cells of epileptic rat due to neuronal loss. In addition, SSTR5 immunoreactivity was reduced in CA2 pyramidal cells and various interneurons. Both SSTR2B and SSTR4 immunoreactivities were increased within microglia following SE. Our findings suggest that increases in neuron-glial SSTR expressions may be closely related to the enhanced inhibition of the dentate gyrus and regulation of reactive microgliosis in the hippocampus of a pilocarpine model of temporal lobe epilepsy.

  11. Dendritic morphology, synaptic transmission, and activity of mature granule cells born following pilocarpine-induced status epilepticus in the rat

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    Fei eGao

    2015-10-01

    Full Text Available To understand the potential role of enhanced hippocampal neurogenesis after pilocarpine-induced status epilepticus (SE in the development of epilepsy, we quantitatively analyzed the geometry of apical dendrites, synaptic transmission, and activation levels of normotopically distributed mature newborn granule cells in the rat.SE in male Sprague-Dawley rats lasting for more than 2 hours was induced by an intraperitoneal injection of pilocarpine. The complexity, spine density, miniature post-synaptic currents, and activity-regulated cytoskeleton-associated protein (Arc expression of granule cells born five days after SE were studied at least 10 weeks after CAG-GFP retroviral vector-mediated labeling.Mature granule cells born after SE had dendritic complexity similar to that of granule cells born naturally, but with denser mushroom-like spines in dendritic segments located in the outer molecular layer. Miniature inhibitory post-synaptic currents (mIPSCs were similar between the controls and rats subjected to SE; however, smaller miniature excitatory post-synaptic current (mEPSC amplitude with a trend toward less frequent was found in mature granule cells born after SE. After maturation, granule cells born after SE did not show denser Arc expression in the resting condition or after being activated by transient seizure activity than vicinal GFP-unlabeled granule cells.Thus our results suggest that normotopic granule cells born after pilocarpine-induced SE are no more active when mature than age-matched, naturally born granule cells.

  12. Glutamate binding is altered in hippocampus and cortex of Wistar rats after pilocarpine-induced Status Epilepticus.

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    Cunha, Alexandra Olimpio Siqueira; Mortari, Márcia Renata; Carolino, Ruither Oliveira Gomes; Coutinho-Netto, Joaquim; Dos Santos, Wagner Ferreira

    2007-08-31

    Several evidences have pointed to biochemical alterations in some brain structures after experimental Status Epilepticus (SE). Thus, the effects of pilocarpine-induced SE on the glutamate binding in the hippocampus and cortex of Wistar rats were evaluated. Groups of animals were submitted to a 3h SE induced by intrahippocampal microinjection of pilocarpine, which was interrupted by the administration of sodium thiopental. Two weeks later the animals were sacrificed and had their cerebral cortices and hippocampi removed in order to perform the binding experiments. The results show that the pilocarpine-induced SE provoked an increase in 2.5-fold in the B(max) values for glutamate binding in the cortex, but not in the hippocampus. Moreover, we observed a 4-fold increase for the Kd values in the hippocampus and a 2-fold increase in the cortex. These findings might indicate that the epileptogenesis involves alterations in the glutamate receptors that are not restricted to the limbic system. Moreover, changes in these receptors are not exclusively of number, but rather involve the affinity for their ligands.

  13. Mitochondrial and nuclear changes in hippocampal neurons in a lithium-pilocarpine-induced status epilepticus rat model

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    Shuhai Tang; Li Zhang; Jianying Sun; Xiaojun Pan

    2009-01-01

    BACKGROUND: Mitochondrial damage plays a key role in neuronal damage.OBJECTIVE: To observe ultrastructural damage to mitochondria and nuclei, as well as caspase-3 expression, in hippocampal CA3 neurons of lithium-pilocarpine-induced status epilepticus rats.DESIGN, TIME AND SETTING: The neuropathological, randomized, controlled study was performed at the Animal Experimental Center, Shandong University, China in May 2008.MATERIALS: A total of 75 healthy, adult, male, Wistar rats were randomly assigned into model (n = 45) and control (n = 30) groups. Lithium-pilocarpine (Sigma, USA) was used in this study.METHODS: Rats in the model group were intraperitoneally injected with lithium chloride (3 mEq/kg),and 24 hours later with pilocarpine (45 mg/kg), to induce seizures for 2 hours. Rats in the control group were intraperitoneally infused with the same volume of saline. Rat hippocampal CA3 tissue was obtained at 3, 12, and 24 hours following status epilepticus.MAIN OUTCOME MEASURES: Neuronal changes were observed under an optical microscope. Ultrastructural changes in mitochondria and nuclei were observed using an electron microscope.caspase-3 mRNA levels were quantified by semiquantitative RT-PCR.RESULTS: After 3 hours of status epilepticus, mitochondria with swollen cristae and ruptured membranes were observed by electron microscopy. Nuclei with marginated chromatin were observed after 24 hours status epilepticus. RT-PCR results demonstrated increased caspase-3 expression at 12 hours, and significantly increased expression at 24 hours following termination of status epilepticus. This was in accordance with acidophilia occurrence, as indicated by hematoxylin-eosin staining, and time of ultrastructural damage to nuclei.CONCLUSION: In lithium-pilocarpine-induced status epilepticus rat models, ultrastructural damage to mitochondria in hippocampal neurons occurred during early stages, followed by increased caspase-3 expression and nuclear changes. These results suggested

  14. Indomethacin can downregulate the levels of inflammatory mediators in the hippocampus of rats submitted to pilocarpine-induced status epilepticus

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    Michele Juliane Vieira

    2014-09-01

    Full Text Available OBJECTIVE: Refractory status epilepticus is one of the most life-threatening neurological emergencies and is characterized by high morbidity and mortality. Additionally, the use of anti-inflammatory drugs during this period is very controversial. Thus, this study has been designed to analyze the effect of a low dose of indomethacin (a COX inhibitor on the expression of inflammatory molecules. METHOD: The hippocampus of rats submitted to pilocarpine-induced long-lasting status epilepticus was analyzed to determine the expression of inflammatory molecules with RT-PCR and immunohistochemistry. RESULTS: Compared with controls, reduced levels of the kinin B2 receptors IL1β and TNFα were found in the hippocampus of rats submitted to long-lasting status epilepticus and treated with indomethacin. CONCLUSIONS: These data show that low doses of indomethacin could be employed to minimize inflammation during long-lasting status epilepticus.

  15. Pilocarpine-induced epilepsy alters the expression and daily variation of the nuclear receptor RORα in the hippocampus of rats.

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    Rocha, Anna Karynna Alves de Alencar; de Lima, Eliangela; do Amaral, Fernanda Gaspar; Peres, Rafael; Cipolla-Neto, José; Amado, Débora

    2016-02-01

    It is widely known that there is an increase in the inflammatory responses and oxidative stress in temporal lobe epilepsy (TLE). Further, the seizures follow a circadian rhythmicity. Retinoic acid receptor-related orphan receptor alpha (RORα) is related to anti-inflammatory and antioxidant enzyme expression and is part of the machinery of the biological clock and circadian rhythms. However, the participation of RORα in this neurological disorder has not been studied. The aim of this study was to evaluate the RORα mRNA and protein content profiles in the hippocampus of rats submitted to a pilocarpine-induced epilepsy model at different time points throughout the 24-h light-dark cycle analyzing the influence of the circadian rhythm in the expression pattern during the acute, silent, and chronic phases of the experimental model. Real-time PCR and immunohistochemistry results showed that RORα mRNA and protein expressions were globally reduced in both acute and silent phases of the pilocarpine model. However, 60days after the pilocarpine-induced status epilepticus (chronic phase), the mRNA expression was similar to the control except for the time point 3h after the lights were turned off, and no differences were found in immunohistochemistry. Our results indicate that the status epilepticus induced by pilocarpine is able to change the expression and daily variation of RORα in the rat hippocampal area during the acute and silent phases. These findings enhance our understanding of the circadian pattern present in seizures as well as facilitate strategies for the treatment of seizures.

  16. Differential patterns of synaptotagmin7 mRNA expression in rats with kainate- and pilocarpine-induced seizures.

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    Gordana Glavan

    Full Text Available Previous studies in rat models of neurodegenerative disorders have shown disregulation of striatal synaptotagmin7 mRNA. Here we explored the expression of synaptotagmin7 mRNA in the brains of rats with seizures triggered by the glutamatergic agonist kainate (10 mg/kg or by the muscarinic agonist pilocarpine (30 mg/kg in LiCl (3 mEq/kg pre-treated (24 h rats, in a time-course experiment (30 min-1 day. After kainate-induced seizures, synaptotagmin7 mRNA levels were transiently and uniformly increased throughout the dorsal and ventral striatum (accumbens at 8 and 12 h, but not at 24 h, followed at 24 h by somewhat variable upregulation within different parts of the cerebral cortex, amigdala and thalamic nuclei, the hippocampus and the lateral septum. By contrast, after LiCl/pilocarpine-induced seizures, there was a more prolonged increase of striatal Synaptotagmin7 mRNA levels (at 8, 12 and 24 h, but only in the ventromedial striatum, while in some other of the aforementioned brain regions there was a decline to below the basal levels. After systemic post-treatment with muscarinic antagonist scopolamine in a dose of 2 mg/kg the seizures were either extinguished or attenuated. In scopolamine post-treated animals with extinguished seizures the striatal synaptotagmin7 mRNA levels (at 12 h after the onset of seizures were not different from the levels in control animals without seizures, while in rats with attenuated seizures, the upregulation closely resembled kainate seizures-like pattern of striatal upregulation. In the dose of 1 mg/kg, scopolamine did not significantly affect the progression of pilocarpine-induced seizures or pilocarpine seizures-like pattern of striatal upregulation of synaptotagmin7 mRNA. In control experiments, equivalent doses of scopolamine per se did not affect the expression of synaptotagmin7 mRNA. We conclude that here described differential time course and pattern of synaptotagmin7 mRNA expression imply regional

  17. Subthalamic and Cortical Local Field Potentials Associated with Pilocarpine-Induced Oral Tremor in the Rat.

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    Long, Lauren L; Podurgiel, Samantha J; Haque, Aileen F; Errante, Emily L; Chrobak, James J; Salamone, John D

    2016-01-01

    Tremulous jaw movements (TJMs) are rapid vertical deflections of the lower jaw that resemble chewing but are not directed at any particular stimulus. In rodents, TJMs are induced by neurochemical conditions that parallel those seen in human Parkinsonism, including neurotoxic or pharmacological depletion of striatal dopamine (DA), DA antagonism, and cholinomimetic administration. Moreover, TJMs in rodents can be attenuated by antiparkinsonian agents, including levodopa (L-DOPA), DA agonists, muscarinic antagonists, and adenosine A2A antagonists. In human Parkinsonian patients, exaggerated physiological synchrony is seen in the beta frequency band in various parts of the cortical/basal ganglia/thalamic circuitry, and activity in the tremor frequency range (3-7 Hz) also has been recorded. The present studies were undertaken to determine if tremor-related local field potential (LFP) activity could be recorded from motor cortex (M1) or subthalamic nucleus (STN) during the TJMs induced by the muscarinic agonist pilocarpine, which is a well-known tremorogenic agent. Pilocarpine induced a robust TJM response that was marked by rhythmic electromyographic (EMG) activity in the temporalis muscle. Compared to periods with no tremor activity, TJM epochs were characterized by increased LFP activity in the tremor frequency range in both neocortex and STN. Tremor activity was not associated with increased synchrony in the beta frequency band. These studies identified tremor-related LFP activity in parts of the cortical/basal ganglia circuitry that are involved in the pathophysiology of Parkinsonism. This research may ultimately lead to identification of the oscillatory neural mechanisms involved in the generation of tremulous activity, and promote development of novel treatments for tremor disorders.

  18. Role of the Mitochondrial Calcium Uniporter in Rat Hippocampal Neuronal Death After Pilocarpine-Induced Status Epilepticus.

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    Wang, Cui; Xie, Nanchang; Wang, Yunlong; Li, Yulin; Ge, Xinjie; Wang, Menglu

    2015-08-01

    The mitochondrial calcium uniporter (MCU) is reportedly involved in oxidative stress, apoptosis, and many neurological diseases. However, the role of the MCU in epilepsy remains unknown. In this study, we found that the MCU inhibitor Ru360 significantly attenuated neuronal death and exerted an anti-apoptotic effect on rat hippocampal neurons after pilocarpine-induced status epilepticus (SE), while the MCU activator spermine increased seizure-induced neuronal death and apoptosis. In addition, Ru360 decreased the level of seizure-induced reactive oxygen species (ROS) in mitochondria isolated from rat hippocampi. Moreover, Ru360 restored the altered mitochondrial membrane potential and cytochrome c (CytC) release in epileptic hippocampi. However, spermine treatment exerted an opposite effect on seizure-induced ROS production and mitochondrial membrane potential alteration and CytC release compared with Ru360 treatment. Altogether, the findings of this study suggest that MCU inhibition exerts a neuroprotective effect on seizure-induced brain injury possibly through the mitochondria/ROS/CytC pathway.

  19. Lovastatin decreases the synthesis of inflammatory mediators during epileptogenesis in the hippocampus of rats submitted to pilocarpine-induced epilepsy.

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    Gouveia, T L F; Scorza, F A; Iha, H A; Frangiotti, M I B; Perosa, S R; Cavalheiro, E A; Silva, J A; Feliciano, R S; de Almeida, A C; Naffah-Mazzacoratti, M G

    2014-07-01

    Statins may act on inflammatory responses, decreasing oxidative stress and also reducing brain inflammation in several brain disorders. Epileptogenesis is a process in which a healthy brain becomes abnormal and predisposed to generating spontaneous seizures. We previously reported that lovastatin could prevent neuroinflammation in pilocarpine-induced status epilepticus (SE). In this context, this study investigated the long-lasting effects of lovastatin on mRNA expression of proinflammatory cytokines (interleukin-1β, tumor necrosis factor α, interleukin-6) and the antiinflammatory cytokine IL-10 in the hippocampus during epileptogenesis by immunohistochemistry and real time polymerase chain reaction (RT-PCR) during the latent and chronic phases in the epilepsy model induced by pilocarpine in rats. For these purposes, four groups of rats were employed: saline (CONTROL), lovastatin (LOVA), pilocarpine (PILO), and pilocarpine plus lovastatin (PILO+LOVA). After pilocarpine injection (350mg/kg, i.p.), the rats were treated with 20mg/kg of lovastatin via an esophagic probe 2h after SE onset. All surviving rats were continuously treated during 15days, twice/day. The pilocarpine plus lovastatin group showed a significant decrease in the levels of IL-1β, TNF-α, and IL-6 during the latent phase and a decreased expression of IL-1β and TNF-α in the chronic phase when compared with the PILO group. Moreover, lovastatin treatment also induced an increased expression of the antiinflammatory cytokine, IL-10, in the PILO+LOVA group when compared with the PILO group in the chronic phase. Thus, our data suggest that lovastin may reduce excitotoxicity during epileptogenesis induced by pilocarpine by increasing the synthesis of IL-10 and decreasing proinflammatory cytokines in the hippocampus.

  20. In vivo imaging of mGluR5 changes during epileptogenesis using [11C]ABP688 PET in pilocarpine-induced epilepsy rat model.

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    Hongyoon Choi

    Full Text Available INTRODUCTION: Metabotropic glutamate receptor 5 (mGluR5 that regulates glutamatergic neurotransmission contributes to pathophysiology of epilepsy. In this study, we monitored the changes of mGluR5 in vivo using [11C]ABP688 PET during the epileptogenesis in a pilocarpine-induced epilepsy rat model. METHODS: In vivo mGluR5 images were acquired using [11C]ABP688 microPET/CT in pilocarpine-induced chronic epilepsy rat models and controls. We also acquired microPET/CT at acute, subacute as well as chronic periods after status epilepticus. Non-displaceable binding potential (BPND of [11C]ABP688 was calculated using simplified reference tissue model in a voxel-based manner. mGluR5 BPND of the rat brains of epilepsy models and controls were compared. RESULTS: Status epilepticus developed after pilocarpine administration and was followed by recurrent spontaneous seizures for more than 3 weeks. In chronic epilepsy rat model, BPND in hippocampus and amygdala was reduced on a voxel-based analysis. Temporal changes of mGluR5 BPND was also found. In acute period after status epilepticus, mGluR5 BPND was reduced in the whole brain. BPND of caudate-putamen was restored in subacute period, while BPND of the rest of the brain was still lower. In chronic period, global BPND was normalized except in hippocampus and amygdala. CONCLUSIONS: In vivo imaging of mGluR5 using [11C]ABP688 microPET/CT could successfully reveal the regional changes of mGluR5 binding potential of the rat brain in a pilocarpine-induced epilepsy model. The temporal and spatial changes in mGluR5 availability suggest [11C]ABP688 PET imaging in epilepsy provide abnormal glutamatergic network during epileptogenesis.

  1. Glycyrrhizin ameliorates oxidative stress and inflammation in hippocampus and olfactory bulb in lithium/pilocarpine-induced status epilepticus in rats.

    Science.gov (United States)

    González-Reyes, Susana; Santillán-Cigales, Juan Jair; Jiménez-Osorio, Angélica Saraí; Pedraza-Chaverri, José; Guevara-Guzmán, Rosalinda

    2016-10-01

    Glycyrrhizin (GL) is a triterpene present in the roots and rhizomes of Glycyrrhiza glabra that has anti-inflammatory, hepatoprotective and neuroprotective effects. Recently, it was demonstrated that GL produced neuroprotective effects on the postischemic brain as well as on the kainic acid injury model in rats. In addition to this, GL also prevented excitotoxic effects on primary cultures. The aims of the present study were to evaluate GL scavenging properties and to investigate GL's effect on oxidative stress and inflammation in the lithium/pilocarpine-induced seizure model in two cerebral regions, hippocampus and olfactory bulb, at acute time intervals (3 or 24h) after status epilepticus (SE). Fluorometric methods showed that GL scavenged three reactive oxygen species: hydrogen peroxide, peroxyl radicals and superoxide anions. In contrast, GL was unable to scavenge peroxynitrite, hydroxyl radicals, singlet oxygen and 2,2-diphenil-1-picrylhydrazyl (DPPH) radicals suggesting that GL is a weak scavenger. Additionally, administration of GL (50mg/kg, i.p.) 30min before pilocarpine administration significantly suppressed oxidative stress. Moreover, malondialdehyde levels were diminished and glutathione levels were maintained at control values in both cerebral regions at 3 and 24 after SE. At 24h after SE, glutathione S-transferase and superoxide dismutase activity increased in the hippocampus, while both glutathione reductase and glutathione peroxidase activity were unchanged in the olfactory bulb at that time. In addition, GL suppressed the induction of the proinflammatory cytokines interleukin-1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) in both cerebral regions evaluated. These results suggest that GL confers protection against pilocarpine damage via antioxidant and anti-inflammatory effects.

  2. Increased excitability and metabolism in pilocarpine induced epileptic rats: effect of Bacopa monnieri.

    Science.gov (United States)

    Mathew, Jobin; Paul, Jes; Nandhu, M S; Paulose, C S

    2010-09-01

    We have evaluated the acetylcholine esterase and malate dehydrogenase activity in the muscle, epinephrine, norepinephrine, insulin and T3 content in the serum of epileptic rats. Acetylcholine esterase and malate dehydrogenase activity increased in the muscle and decreased in the heart of the epileptic rats compared to control. Insulin and T3 content were increased significantly in the serum of the epileptic rats. Our results suggest that repetitive seizures resulted in increased metabolism and excitability in epileptic rats. Bacopa monnieri and Bacoside-A treatment prevents the occurrence of seizures there by reducing the impairment on peripheral nervous system.

  3. Exposure to Mozart music reduces cognitive impairment in pilocarpine-induced status epilepticus rats

    National Research Council Canada - National Science Library

    Xing, Yingshou; Qin, Yi; Jing, Wei; Zhang, Yunxiang; Wang, Yanran; Guo, Daqing; Xia, Yang; Yao, Dezhong

    2016-01-01

    .... Here we evaluated spatial cognition changes at different epileptogenesis stages in rats of this model and explored the effects of long-term Mozart music exposure on the recovery of cognitive ability...

  4. Altered MT1 and MT2 melatonin receptors expression in the hippocampus of pilocarpine-induced epileptic rats.

    Science.gov (United States)

    Rocha, Anna Karynna Alves de Alencar; de Lima, Eliangela; Amaral, Fernanda; Peres, Rafael; Cipolla-Neto, José; Amado, Débora

    2017-06-01

    Clinical and experimental findings show that melatonin may be used as an adjuvant to the treatment of epilepsy-related complications by alleviates sleep disturbances, circadian alterations and attenuates seizures alone or in combination with AEDs. In addition, it has been observed that there is a circadian component on seizures, which cause changes in circadian system and in melatonin production. Nevertheless, the dynamic changes of the melatoninergic system, especially with regard to its membrane receptors (MT1 and MT2) in the natural course of TLE remain largely unknown. The aim of this study was to evaluate the 24-hour profile of MT1 and MT2 mRNA and protein expression in the hippocampus of rats submitted to the pilocarpine-induced epilepsy model analyzing the influence of the circadian rhythm in the expression pattern during the acute, silent, and chronic phases. Melatonin receptor MT1 and MT2 mRNA expression levels were increased in the hippocampus of rats few hours after SE, with MT1 returning to normal levels and MT2 reducing during the silent phase. During the chronic phase, mRNA expression levels of both receptors return to levels close to control, however, presenting a different daily profile, showing that there is a circadian change during the chronic phase. Also, during the acute and silent phase it was possible to verify MT1 label only in CA2 hippocampal region with an increased expression only in the dark period of the acute phase. The MT2 receptor was present in all hippocampal regions, however, it was reduced in the acute phase and it was found in astrocytes. In chronic animals, there is a reduction in the presence of both receptors especially in regions where there is a typical damage derived from epilepsy. Therefore, we conclude that SE induced by pilocarpine is able to change melatonin receptor MT1 and MT2 protein and mRNA expression levels in the hippocampus of rats few hours after SE as well as in silent and chronic phases. Copyright © 2017

  5. Spatial memory deficits in juvenile rats with pilocarpine induced temporal lobe epilepsy

    Directory of Open Access Journals (Sweden)

    Orbán-Kis K

    2014-10-01

    Full Text Available One of the most frequent forms of epilepsy in humans is temporal lobe epilepsy. Characteristic to this form of the disease is the frequent pharmacoresistance and the association with behavioural disorders and cognitive impairment. The objective of our study was to establish the degree of cognitive impairment in a rat model of temporal lobe epilepsy after an initial epileptogenic exposure but before of the onset of the effect of long-duration epilepsy.

  6. Variations in elemental compositions of rat hippocampal formation between acute and latent phases of pilocarpine-induced epilepsy: an X-ray fluorescence microscopy study.

    Science.gov (United States)

    Chwiej, J; Dulinska, J; Janeczko, K; Appel, K; Setkowicz, Z

    2012-06-01

    There is growing experimental evidence that tracing the elements involved in brain hyperexcitability, excitotoxicity, and/or subsequent neurodegeneration could be a valuable source of data on the molecular mechanisms triggering or promoting further development of epilepsy. The most frequently used experimental model of the temporal lobe epilepsy observed in clinical practice is the one based on pilocarpine-induced seizures. In the frame of this study, the elemental anomalies occurring for the rat hippocampal tissue in acute and silent periods after injection of pilocarpine in rats were compared. X-ray fluorescence microscopy was applied for the topographic and quantitative elemental analysis. The differences in the levels of elements such as P, S, K, Ca, Fe, Cu, and Zn between the rats 3 days (SE72) and 6 h (SE6) after pilocarpine injection as well as naive controls were examined. Comparison of SE72 and control groups showed, for specific areas of the hippocampal formation, lower levels of P, K, Cu, and Zn, and an increase in Ca accumulation. These results as well as further analysis of the differences between the SE72 and SE6 groups confirmed that seizure-induced excitotoxicity as well as mossy fiber sprouting are the mechanisms involved in the neurodegenerative processes which may finally lead to spontaneous seizures in the chronic period of the pilocarpine model. Moreover, in the light of the results obtained, Cu seems to play a very important role in the pathogenesis of epilepsy in this animal model. For all areas analyzed, the levels of this element recorded in the latent period were not only lower than those for controls but were even lower than the levels found in the acute period. The decreased hippocampal accumulation of Cu in the phase of behavior and EEG stabilization, a possible inhibitory effect of this element on excitatory amino acid receptors, and enhanced seizure susceptibility in Menkes disease (an inherited Cu transport disorder leading to Cu

  7. Reciprocal regulation of epileptiform neuronal oscillations and electrical synapses in the rat hippocampus.

    Science.gov (United States)

    Kinjo, Erika R; Higa, Guilherme S V; Morya, Edgard; Valle, Angela C; Kihara, Alexandre H; Britto, Luiz R G

    2014-01-01

    Gap junction (GJ) channels have been recognized as an important mechanism for synchronizing neuronal networks. Herein, we investigated the participation of GJ channels in the pilocarpine-induced status epilepticus (SE) by analyzing electrophysiological activity following the blockade of connexins (Cx)-mediated communication. In addition, we examined the regulation of gene expression, protein levels, phosphorylation profile and distribution of neuronal Cx36, Cx45 and glial Cx43 in the rat hippocampus during the acute and latent periods. Electrophysiological recordings revealed that the GJ blockade anticipates the occurrence of low voltage oscillations and promotes a marked reduction of power in all analyzed frequencies.Cx36 gene expression and protein levels remained stable in acute and latent periods, whereas upregulation of Cx45 gene expression and protein redistribution were detected in the latent period. We also observed upregulation of Cx43 mRNA levels followed by changes in the phosphorylation profile and protein accumulation. Taken together, our results indisputably revealed that GJ communication participates in the epileptiform activity induced by pilocarpine. Moreover, considering that specific Cxs undergo alterations through acute and latent periods, this study indicates that the control of GJ communication may represent a focus in reliable anti-epileptogenic strategies.

  8. Coenzyme Q10 enhances the anticonvulsant effect of phenytoin in pilocarpine-induced seizures in rats and ameliorates phenytoin-induced cognitive impairment and oxidative stress.

    Science.gov (United States)

    Tawfik, Mona K

    2011-12-01

    Conventional antiepileptic drugs fail to adequately control seizures and predispose to cognitive impairment and oxidative stress with chronic usage in a significant proportion of patients with epilepsy. Coenzyme Q10 (CoQ10), an antioxidant compound, exhibits a wide range of therapeutic effects that are attributed to its potent antioxidant capacity. To evaluate the neuroprotective effects of CoQ10 in rats against the observed oxidative stress during seizures induced by pilocarpine, and to study its interactions with the conventional antiepileptic drug phenytoin, two experiments were performed. Experiment 1 was conducted to test the effect of phenytoin, CoQ10, or both on seizure severity and oxidative markers in the pilocarpine model of epilepsy. Experiment 2 was conducted to test the effect of 2 weeks of chronic treatment with phenytoin, CoQ10, or both on oxidative markers and behavioral tests in rats. Overall, CoQ10 reduced the severity of pilocarpine-induced seizures and the severity of oxidative stress. Moreover, it potentiated the antiepileptic effects afforded by phenytoin treatment, with the potential safety and efficacy in ameliorating oxidative stress and cognitive impairment caused by chronic phenytoin therapy. Our findings strongly suggest that CoQ10 can be considered a safe and effective adjuvant to phenytoin therapy in epilepsy both to ameliorate seizure severity and to protect against seizure-induced oxidative damage by reducing the cognitive impairment and oxidative stress associated with chronic use of phenytoin.

  9. Cannabidiol Post-Treatment Alleviates Rat Epileptic-Related Behaviors and Activates Hippocampal Cell Autophagy Pathway Along with Antioxidant Defense in Chronic Phase of Pilocarpine-Induced Seizure.

    Science.gov (United States)

    Hosseinzadeh, Mahshid; Nikseresht, Sara; Khodagholi, Fariba; Naderi, Nima; Maghsoudi, Nader

    2016-04-01

    Abnormal and sometimes severe behavioral and molecular symptoms are usually observed in epileptic humans and animals. To address this issue, we examined the behavioral and molecular aspects of seizure evoked by pilocarpine. Autophagy can promote both cell survival and death, but there are controversial reports about the neuroprotective or neurodegenerative effects of autophagy in seizure. Cannabidiol has anticonvulsant properties in some animal models when used as a pretreatment. In this study, we investigated alteration of seizure scores, autophagy pathway proteins, and antioxidant status in hippocampal cells during the chronic phase of pilocarpine-induced epilepsy after treatment with cannabidiol. Cannabidiol (100 ng, intracerebroventricular injection) delayed the chronic phase of epilepsy. Single administration of cannabidiol during the chronic phase of seizure significantly diminished seizure scores such as mouth clonus, head nodding, monolateral and bilateral forelimb clonus and increased the activity of catalase enzyme and reduced glutathione content. Such a protective effect in the behavioral scores of epileptic rats was also observed after repeated administrations of cannabidiol at the onset of the silent phase. Moreover, the amount of Atg7, conjugation of Atg5/12, Atg12, and LC3II/LC3I ratio increased significantly in epileptic rats treated with repeated injections of cannabidiol. In short, our results suggest that post-treatment of Cannabidiol could enhance the induction of autophagy pathway and antioxidant defense in the chronic phase of epilepsy, which could be considered as the protective mechanisms of cannabidiol in a temporal lobe epilepsy model.

  10. The spiny rat Proechimys guyannensis as model of resistance to epilepsy: chemical characterization of hippocampal cell populations and pilocarpine-induced changes.

    Science.gov (United States)

    Fabene, P F; Correia, L; Carvalho, R A; Cavalheiro, E A; Bentivoglio, M

    2001-01-01

    At variance with pilocarpine-induced epilepsy in the laboratory rat, pilocarpine administration to the tropical rodent Proechimys guyannensis (casiragua) elicited an acute seizure that did not develop in long-lasting status epilepticus and was not followed by spontaneous seizures up to 30 days, when the hippocampus was investigated in treated and control animals. Nissl staining revealed in Proechimys a highly developed hippocampus, with thick hippocampal commissures and continuity of the rostral dentate gyri at the midline. Immunohistochemistry was used to study calbindin, parvalbumin, calretinin, GABA, glutamic acid decarboxylase, and nitric oxide synthase expression. The latter was also investigated with NADPH-diaphorase histochemistry. Cell counts and densitometric evaluation with image analysis were performed. Differences, such as low calbindin immunoreactivity confined to some pyramidal cells, were found in the normal Proechimys hippocampus compared to the laboratory rat. In pilocarpine-treated casiraguas, stereological cell counts in Nissl-stained sections did not reveal significant neuronal loss in hippocampal subfields, where the examined markers exhibited instead striking changes. Calbindin was induced in pyramidal and granule cells and interneuron subsets. The number of parvalbumin- or nitric oxide synthase-containing interneurons and their staining intensity were significantly increased. Glutamic acid decarboxylase(67)-immunoreactive interneurons increased markedly in the hilus and decreased in the CA1 pyramidal layer. The number and staining intensity of calretinin-immunoreactive pyramidal cells and interneurons were significantly reduced. These findings provide the first description of the Proechimys hippocampus and reveal marked long-term variations in protein expression after an epileptic insult, which could reflect adaptive changes in functional hippocampal circuits implicated in resistance to limbic epilepsy.

  11. Regulation of epileptiform discharges in rat neocortex by HCN channels.

    Science.gov (United States)

    Albertson, Asher J; Williams, Sidney B; Hablitz, John J

    2013-10-01

    Hyperpolarization-activated, cyclic nucleotide-gated, nonspecific cation (HCN) channels have a well-characterized role in regulation of cellular excitability and network activity. The role of these channels in control of epileptiform discharges is less thoroughly understood. This is especially pertinent given the altered HCN channel expression in epilepsy. We hypothesized that inhibition of HCN channels would enhance bicuculline-induced epileptiform discharges. Whole cell recordings were obtained from layer (L)2/3 and L5 pyramidal neurons and L1 and L5 GABAergic interneurons. In the presence of bicuculline (10 μM), HCN channel inhibition with ZD 7288 (20 μM) significantly increased the magnitude (defined as area) of evoked epileptiform events in both L2/3 and L5 neurons. We recorded activity associated with epileptiform discharges in L1 and L5 interneurons to test the hypothesis that HCN channels regulate excitatory synaptic inputs differently in interneurons versus pyramidal neurons. HCN channel inhibition increased the magnitude of epileptiform events in both L1 and L5 interneurons. The increased magnitude of epileptiform events in both pyramidal cells and interneurons was due to an increase in network activity, since holding cells at depolarized potentials under voltage-clamp conditions to minimize HCN channel opening did not prevent enhancement in the presence of ZD 7288. In neurons recorded with ZD 7288-containing pipettes, bath application of the noninactivating inward cationic current (Ih) antagonist still produced increases in epileptiform responses. These results show that epileptiform discharges in disinhibited rat neocortex are modulated by HCN channels.

  12. Differential paired-pulse responses between the CA1 region and the dentate gyrus are related to altered CLC-2 immunoreactivity in the pilocarpine-induced rat epilepsy model.

    Science.gov (United States)

    Kwak, Sung-Eun; Kim, Ji-Eun; Kim, Duk-Soo; Won, Moo Ho; Lee, Hong Jin; Choi, Soo-Young; Kwon, Oh-Shin; Kim, Jin-Sang; Kang, Tae-Cheon

    2006-10-18

    The epileptic hippocampus shows differential paired-pulse responses between the dentate gyrus and the CA1 region. However, little data are available to explain this phenomenon. In the present study, we identified the relationship between regional differences of paired-pulse response and voltage gated Cl(-) channel 2 (CLC-2)/vesicular GABA transport (VGAT) expression in a pilocarpine-induced rat model. During epileptogenic periods, paired-pulse inhibitions in the dentate gyrus and the CA1 region were markedly reduced. After recurrent seizure onset, paired-pulse inhibition in the dentate gyrus was markedly enhanced, while that in the CA1 region more reduced. Unlike VGAT, CLC-2 immunoreactivity was markedly reduced in the hippocampus during epileptogenic periods and was re-enhanced only in the dentate gyrus after recurrent seizure onset. Linear regression analysis showed an inverse proportional relationship between alterations in CLC-2 immunoreactivity and changes in normalized population spike amplitude ratio within the CA1 region and the dentate gyrus. Therefore, our findings suggest that the regionally specific alterations in CLC-2 immunoreactivity after SE may determine the properties of paired-pulse responses in the hippocampus of the pilocarpine-induced rat epilepsy model.

  13. Pilocarpine-induced seizures trigger differential regulation of microRNA-stability related genes in rat hippocampal neurons

    Science.gov (United States)

    Kinjo, Erika R.; Higa, Guilherme S. V.; Santos, Bianca A.; de Sousa, Erica; Damico, Marcio V.; Walter, Lais T.; Morya, Edgard; Valle, Angela C.; Britto, Luiz R. G.; Kihara, Alexandre H.

    2016-01-01

    Epileptogenesis in the temporal lobe elicits regulation of gene expression and protein translation, leading to reorganization of neuronal networks. In this process, miRNAs were described as being regulated in a cell-specific manner, although mechanistics of miRNAs activity are poorly understood. The specificity of miRNAs on their target genes depends on their intracellular concentration, reflecting the balance of biosynthesis and degradation. Herein, we confirmed that pilocarpine application promptly (<30 min) induces status epilepticus (SE) as revealed by changes in rat electrocorticogram particularly in fast-beta range (21–30 Hz). SE simultaneously upregulated XRN2 and downregulated PAPD4 gene expression in the hippocampus, two genes related to miRNA degradation and stability, respectively. Moreover, SE decreased the number of XRN2-positive cells in the hilus, while reduced the number of PAPD4-positive cells in CA1. XRN2 and PAPD4 levels did not change in calretinin- and CamKII-positive cells, although it was possible to determine that PAPD4, but not XRN2, was upregulated in parvalbumin-positive cells, revealing that SE induction unbalances the accumulation of these functional-opposed proteins in inhibitory interneurons that directly innervate distinct domains of pyramidal cells. Therefore, we were able to disclose a possible mechanism underlying the differential regulation of miRNAs in specific neurons during epileptogenesis. PMID:26869208

  14. Transcranial focal electrical stimulation reduces the convulsive expression and amino acid release in the hippocampus during pilocarpine-induced status epilepticus in rats.

    Science.gov (United States)

    Santana-Gómez, César E; Alcántara-González, David; Luna-Munguía, Hiram; Bañuelos-Cabrera, Ivette; Magdaleno-Madrigal, Víctor; Fernández-Mas, Rodrigo; Besio, Walter; Rocha, Luisa

    2015-08-01

    The aim of the present study was to evaluate the effects of transcranial focal electrical stimulation (TFS) on γ-aminobutyric acid (GABA) and glutamate release in the hippocampus under basal conditions and during pilocarpine-induced status epilepticus (SE). Animals were previously implanted with a guide cannula attached to a bipolar electrode into the right ventral hippocampus and a concentric ring electrode placed on the skull surface. The first microdialysis experiment was designed to determine, under basal conditions, the effects of TFS (300 Hz, 200 μs biphasic square pulses, for 30 min) on afterdischarge threshold (ADT) and the release of GABA and glutamate in the hippocampus. The results obtained indicate that at low current intensities (Status Epilepticus".

  15. Berberine exerts an anticonvulsant effect and ameliorates memory impairment and oxidative stress in a pilocarpine-induced epilepsy model in the rat.

    Science.gov (United States)

    Gao, Fei; Gao, Ying; Liu, Yang-Feng; Wang, Li; Li, Ya-Jun

    2014-01-01

    Though new antiepileptic drugs are emerging, approximately a third of epileptic patients still suffer from recurrent convulsions and cognitive dysfunction. Therefore, we tested whether berberine (Ber), a vegetable drug, has an anticonvulsant property and attenuates memory impairment in a pilocarpine (Pilo)-induced epilepsy model in rats. The rats were injected with 400 mg/kg Pilo to induce convulsions, and Ber 25, 50, and 100 mg/kg were administrated by the intragastric route once daily 7 days before Pilo injection until the experiment was over. Convulsions were observed after Pilo injection. For the rats that developed status epilepticus (SE), malondialdehyde, glutathione levels, superoxide dismutase, and catalase activity in the hippocampus were measured 24 hours after SE. The rats received the Morris water-maze test 2 weeks after SE, and then were killed for fluoro-jade B staining to detect the degenerating neurons. We found Ber delayed latency to the first seizure and the time to develop SE in a dose-dependent manner. Malondialdehyde levels were decreased, while glutathione and catalase activity were strengthened in Ber-injected SE rats. In the Morris water-maze test, Ber decreased escape latency compared to saline-treated SE rats. Additionally, Ber reduced the number of fluoro-jade B-positive cells in the hippocampal CA1 region. Our data suggest that Ber exerts anticonvulsant and neuroprotective effects on Pilo-induced epilepsy in rats. Simultaneously, Ber attenuates memory impairment. The beneficial effect may be partly due to mitigation of the oxidative stress burden.

  16. Berberine exerts an anticonvulsant effect and ameliorates memory impairment and oxidative stress in a pilocarpine-induced epilepsy model in the rat

    Directory of Open Access Journals (Sweden)

    Gao F

    2014-11-01

    Full Text Available Fei Gao,1,* Ying Gao,2,* Yang-feng Liu,3 Li Wang,4 Ya-jun Li1 1Department of Neurology, First Affiliated Hospital of Xi’an Medical University, Xi’an, People’s Republic of China; 2Department of Radiotherapy Oncology, First Affiliated Hospital of Medical College of Xi’an Jiaotong University, Xi’an, People’s Republic of China; 3Department of Neurology, People’s Liberation Army No. 451 Hospital, Xi’an, People’s Republic of China; 4Department of Scientific Research, First Affiliated Hospital of Xi’an Medical University, Xi’an, People’s Republic of China *These authors contributed equally to this work Abstract: Though new antiepileptic drugs are emerging, approximately a third of epileptic patients still suffer from recurrent convulsions and cognitive dysfunction. Therefore, we tested whether berberine (Ber, a vegetable drug, has an anticonvulsant property and attenuates memory impairment in a pilocarpine (Pilo-induced epilepsy model in rats. The rats were injected with 400 mg/kg Pilo to induce convulsions, and Ber 25, 50, and 100 mg/kg were administrated by the intragastric route once daily 7 days before Pilo injection until the experiment was over. Convulsions were observed after Pilo injection. For the rats that developed status epilepticus (SE, malondialdehyde, glutathione levels, superoxide dismutase, and catalase activity in the hippocampus were measured 24 hours after SE. The rats received the Morris water-maze test 2 weeks after SE, and then were killed for fluoro-jade B staining to detect the degenerating neurons. We found Ber delayed latency to the first seizure and the time to develop SE in a dose-dependent manner. Malondialdehyde levels were decreased, while glutathione and catalase activity were strengthened in Ber-injected SE rats. In the Morris water-maze test, Ber decreased escape latency compared to saline-treated SE rats. Additionally, Ber reduced the number of fluoro-jade B-positive cells in the

  17. Synchrotron radiation Fourier-transform infrared and Raman microspectroscopy study showing an increased frequency of creatine inclusions in the rat hippocampal formation following pilocarpine-induced seizures

    OpenAIRE

    Dulinska, J.; Setkowicz, Z.; Janeczko, K.; C. SANDT; Dumas, P.; Uram, L.; Gzielo-Jurek, K.; Chwiej, J.

    2011-01-01

    In the present work, synchrotron radiation Fourier-transform infrared (SRFTIR) and Raman microspectroscopies were used to evaluate a possible role of creatine in the pathogenesis and progress of pilocarpine-evoked seizures and seizure-induced neurodegenerative changes in the rat hippocampal tissue. The main goal of this study was to identify creatine deposits within the examined brain area, to analyze their frequency in epileptic animals and naive controls and to examine correlations between ...

  18. Growth-associated phosphoprotein expression is increased in the supragranular regions of the dentate gyrus following pilocarpine-induced seizures in rats.

    Science.gov (United States)

    Naffah-Mazzacoratti, M G; Funke, M G; Sanabria, E R; Cavalheiro, E A

    1999-01-01

    Neuroplasticity has been investigated considering the neuronal growth-associated phosphoprotein as a marker of neuronal adaptive capabilities. In the present work, studying the hippocampal reorganization observed in the epilepsy model induced by pilocarpine, we carried out quantitative western blotting associated with immunohistochemistry to determine the distribution of growth-associated phosphoprotein in the hippocampus of rats in acute, silent and chronic periods of this epilepsy model. The fibers and punctate elements from the inner molecular layer of the dentate gyrus were strongly immunostained in animals killed 5 h after status epilepticus, compared with the same region in control animals. Rats presenting partial seizures showed no alterations in the immunostaining pattern compared with saline-treated animals. The hippocampal dentate gyrus of animals during the seizure-free period and presenting spontaneous recurrent seizures was also characterized by strong growth-associated phosphoprotein immunostaining of fibers and punctate elements in the inner molecular layer, contrasting with the control group. As determined by western blotting analysis, growth-associated phosphoprotein levels increased following status epilepticus and remained elevated at the later time-points, both during the silent period and during the period of chronic recurring seizures. Pilocarpine-treated animals, which did not develop status epilepticus, showed no change in growth-associated phosphoprotein levels, indicating that status epilepticus is important to induce growth-associated phosphoprotein overexpression. The measurement of this overexpression could represent one of the early signals of hippocampal reorganization due to status epilepticus-induced damage.

  19. Pyrrolidine dithiocarbamate (PDTC) inhibits the overexpression of MCP-1 and attenuates microglial activation in the hippocampus of a pilocarpine-induced status epilepticus rat model.

    Science.gov (United States)

    Lv, Rilang; Xu, Xiaoyun; Luo, Zheng; Shen, Nan; Wang, Feng; Zhao, Yongbo

    2014-01-01

    The aim of this study was to investigate the effects of pyrrolidine dithiocarbamate (PDTC) on MCP-1 expression and microglial activation in the hippocampus of a rat model of pilocarpine (PILO)-induced status epilepticus (SE). Moreover, seizure susceptibility, frequency and severity as well as brain damage were analyzed and changes in behavior were recorded. Chemokine MCP-1 expression and microglial activation were detected by immunohistochemistry (IHC). Fluoro-Jade C (FJC) and NeuN staining were used for the evaluation of tissue damage. Our results showed that although SE resulted in the upregulation of MCP-1 and microglial activation in the rat hippocampus 24 h after seizure onset, pretreatment with PDTC significantly inhibited the MCP-1 overexpression and attenuated the microglial activation. These effects were accompanied by neurodegenerative amelioration. To the best of our knowledge, these findings indicated for the first time that the activation of the nuclear factor-κB (NF-κB) pathway may contribute to MCP-1 upregulation and microglial activation in the context of epilepsy. PDTC was also shown to exert anticonvulsant activity and to have a neuroprotective effect on the hippocampal CA1 and CA3 regions, potentially through attenuating microglial activation.

  20. Propofol effectively inhibits lithium-pilocarpine-induced status epilepticus in rats via downregulation of N-methyl-D-aspartate receptor 2B subunit expression

    Institute of Scientific and Technical Information of China (English)

    Henglin Wang; Zhuoqiang Wang; Weidong Mi; Cong Zhao; Yanqin Liu; Yongan Wang; Haipeng Sun

    2012-01-01

    Status epilepticus was induced via intraperitoneal injection of lithium-pilocarpine. The inhibitory ef-fects of propofol on status epilepticus in rats were judged based on observation of behavior, elec-troencephalography and 24-hour survival rate. Propofol (12.5-100 mg/kg) improved status epilep-ticus in a dose-dependent manner, and significantly reduced the number of deaths within 24 hours of lithium-pilocarpine injection. Western blot results showed that, 24 hours after induction of status epilepticus, the levels of N-methyl-D-aspartate receptor 2A and 2B subunits were significantly in-creased in rat cerebral cortex and hippocampus. Propofol at 50 mg/kg significantly suppressed the increase in N-methyl-D-aspartate receptor 2B subunit levels, but not the increase in N-methyl-D-aspartate receptor 2A subunit levels. The results suggest that propofol can effectively inhibit status epilepticus induced by lithium-pilocarpine. This effect may be associated with down-regulation of N-methyl-D-aspartate receptor 2B subunit expression after seizures.

  1. Hippocampal distribution of IL-1β and IL-1RI following lithium-pilocarpine-induced status epilepticus in the developing rat

    Directory of Open Access Journals (Sweden)

    Dulce-Mariely Álvarez-Croda

    2016-01-01

    Full Text Available The contribution of Interleukin-1β (IL-1β to neuronal injury induced by status epilepticus (SE in the immature brain remains unclear. The goal of this study was to determine the hippocampal expression of IL-1β and its type 1 receptor (IL-1RI following SE induced by the lithium-pilocarpine model in fourteen-days-old rat pups; control animals were given an equal volume of saline instead of the convulsant. IL-1β and IL-1RI mRNA hippocampal levels were assessed by qRT-PCR 6 and 24 h after SE or control conditions. IL-1β and IL-1RI expression was detected in the dorsal hippocampus by immunohistochemical procedures; Fluoro-Jade B staining was carried out in parallel sections in order to detect neuronal cell death. IL-1β mRNA expression was increased 6 h following SE, but not at 24 h; however IL-1RI mRNA expression was unaffected when comparing with the control group. IL-1β and IL-1RI immunoreactivity was not detected in control animals. IL-1β and IL-1RI were expressed in the CA1 pyramidal layer, the dentate gyrus granular layer and the hilus 6 h after SE, whereas injured cells were detected 24 h following seizures. Early expression of IL-1β and IL-1RI in the hippocampus could be associated with SE-induced neuronal cell death mechanisms in the developing rat.

  2. Central muscarinic receptor subtypes involved in pilocarpine-induced salivation, hypertension and water intake.

    Science.gov (United States)

    Borella, T L; De Luca, L A; Colombari, D S A; Menani, J V

    2008-12-01

    Recent evidence has suggested that pilocarpine (ACh receptor agonist) injected peripherally may act centrally producing salivation and hypertension. In this study, we investigated the effects of specific M(1) (pirenzepine), M(2)/M(4) (methoctramine), M(1)/M(3) (4-DAMP) and M(4) (tropicamide) muscarinic receptor subtype antagonists injected into the lateral cerebral ventricle (LV) on salivation, water intake and pressor responses to peripheral pilocarpine. Male Holtzman rats with stainless steel cannulae implanted in the LV were used. Salivation was measured in rats anaesthetized with ketamine (100 mg per kg body weight) and arterial pressure was recorded in unanaesthetized rats. Salivation induced by i.p. pilocarpine (4 micromol per kg body weight) was reduced only by 4-DAMP (25-250 nmol) injected into the LV, not by pirenzepine, methoctramine or tropicamide at the dose of 500 nmol. Pirenzepine (0.1 and 1 nmol) and 4-DAMP (5 and 10 nmol) injected into the LV reduced i.p. pilocarpine-induced water intake, whereas metoctramine (50 nmol) produced nonspecific effects on ingestive behaviours. Injection of pirenzepine (100 nmol) or 4-DAMP (25 and 50 nmol) into the LV reduced i.v. pilocarpine-induced pressor responses. Tropicamide (500 nmol) injected into the LV had no effect on pilocarpine-induced salivation, pressor responses or water intake. The results suggest that central M(3) receptors are involved in peripheral pilocarpine-induced salivation and M(1) receptors in water intake and pressor responses. The involvement of M(3) receptors in water intake and pressor responses is not clear because 4-DAMP blocks both M(1) and M(3) receptors.

  3. Enhanced pyridoxal 5'-phosphate synthetic enzyme immunoreactivities do not contribute to GABAergic inhibition in the rat hippocampus following pilocarpine-induced status epilepticus.

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    Kwak, S-E; Kim, J-E; Kim, D-W; Kwon, O-S; Choi, S-Y; Kang, T-C

    2009-03-31

    To comprehend the role of pyridoxal 5'-phosphate (PLP) in epilepsy or seizure, we investigated whether the expressions of two PLP synthetic enzymes (pyridoxal kinase, PLK; pyridoxine-5'-phosphate oxidase, PNPO) are altered in the hippocampus and whether changes in paired-pulse responses in the hippocampus are associated with altered PLP synthetic enzyme expressions following status epilepticus (SE). PLK and PNPO immunoreactivities were significantly increased in the rat hippocampus accompanied by reductions in paired-pulse inhibition at 1 day and 1 week after SE. Four weeks after SE, PLK and PNPO immunoreactivities in dentate granule cells were similar to those in control animals, while their immunoreactivities were markedly reduced in Cornu Ammonis 1 (CA1) pyramidal cells due to neuronal loss. Linear regression analysis identified a direct proportional relationship between PLK/PNPO immunoreactivity and normalized population spike amplitude ratio in the dentate gyrus and the CA1 region as excluded the data obtained from 4 weeks after SE. These findings indicate that the upregulation of PLK and PNPO immunoreactivities in principal neurons may not be involved in gamma-aminobutyric acid (GABA)ergic inhibition, but rather in enhanced excitability during epileptogenic periods.

  4. Vigabatrina aumenta atividade da superóxido dismutase no corpo estriado de ratos após crises convulsivas induzidas pela pilocarpina Vigabratine increases superoxide dismutase activity in striatum of rat after pilocarpine-induced seizures

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    Rivelilson Mendes de Freitas

    2010-01-01

    ES: Os resultados do presente estudo indicam que durante as crises convulsivas ocorrem alterações comportamentais, entretanto, não foram verificadas mudanças na atividade da SOD durante a fase aguda dessas crises. Esses dados sugerem que os efeitos anticonvulsivantes da vigabatrina podem ser decorrentes da neuromodulação da SOD. No entanto, serão realizados novos estudos neurofarmacológicos para o esclarecimento do mecanismo de ação da vigabatrina no modelo de epilepsia induzido pela pilocarpina.BACKGROUND: Pilocarpine-induced seizures have been suggested to be mediated by increases in oxidative stress. Current studies have suggested that antioxidant compounds may afford some level of neuroprotection against the neurotoxicity of seizures. OBJECTIVES: This study investigated the pharmacological actions of vigabatrin on behavioral changes and superoxide dismutase (SOD activity in striatum of adult rats. METHODS: Adult rats (2 months old were used in the experiments and divided into four groups. The first was treated with 0.9% saline (control group. The second group was treated with pilocarpine (400 mg/kg, i.p., P400 group. The third group received vigabatrin alone (500 mg/kg, i.p., VGB group and the fourth group was treated with vigabatrin (500 mg/kg, i.p. and 30 minutes later received pilocarpine (400 mg/kg, i.p., VGB + P400 group. The animals which had seizures and status epilepticus (SE and did not die within 24 hours of observation were sacrificed to perform the neurochemical studies. RESULTS: Behavioral studies showed that the administration of pilocarpine produces peripheral cholinergic signs, tremors and stereotyped movements in all animals. An amount of 75% of those rats developed to seizures and SE. In turn, the pre-treatment with vigabatrin produced a 50% reduction in the rate of seizures and SE. Regarding the neurochemical studies, there were no changes in the striatal SOD activity in P400 group as compared to the control group. However, in the VGB + P

  5. 莲心碱对氯化锂-匹鲁卡品致癫模型急性期皮层脑电图的影响%Effect of liensinine on electrocorticogram in lithium-pilocarpine induced acute epilepsy rats

    Institute of Scientific and Technical Information of China (English)

    吴靖; 周宏斌; 潘松青

    2016-01-01

    目的:探讨莲心碱对氯化锂—匹鲁卡品致癫大鼠模型急性期皮层脑电图的影响。方法32只 SD 大鼠随机分为生理盐水对照组(A 组,10μg)、低剂量莲心碱组(B 组,莲心碱2.5 g·L -1,25μg)、高剂量莲心碱组(C 组,莲心碱5 g·L -1,50μg)、左乙拉西坦组(D 组,100 g·L -1,1 mg),建立氯化锂—匹鲁卡品癫痫大鼠模型后侧脑室注射药物,记录各组大鼠脑电图的改变。结果莲心碱组及左乙拉西坦组与对照组相比大鼠的痫性放电频率减低,快波(β波)比率减少,慢波(δ波)比率增加;高剂量莲心碱组和左乙拉西坦组相比无统计学差异。结论莲心碱在氯化锂—匹鲁卡品癫痫大鼠模型急性期具有抗癫痫作用。%Objective To explore the effect of liensinine on electrocorticogram in lithium -pilocarpine induced acute epilepsy rats. Methods Thirty -two SD rats were randomized into four groups (8 rats in each group):epilepsy model group(group A,10 μg),low dose of liensinine group(group B,2.5 g·L -1 ,25 μg),high dose of liensinine group(group C,5 g·L -1 ,50 μg),levetiracetam group (group D,100 g·L -1 ,1 mg).Electrocorticogram of rats was recorded after lithium -pilocarpine model was induced and the drug was intra -cerebroventricular injected.Results Compared with group A,the epileptic discharge was significantly decreased in groups B,C and D (P <0.05).The proportion of δslow wave was enhanced,meanwhile βfast wave was decreased in groups B,C and D.And there was no significant difference between high dose of liensinine group and levetiracetam group.Conclusions Liensinine has the role of anti -epilepsy in acute model of epileptic rats induced by lithium -pilocarpine.

  6. Ações neuroprotetoras da vitamina C no corpo estriado de ratos após convulsões induzidas pela pilocarpina Neuroprotective actions of vitamin C in rat striatum after pilocarpine-induced seizures

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    Rivelilson Mendes de Freitas

    2010-01-01

    especially in limbic structures. OBJECTIVES: This study aimed to evaluate the neuroprotective effects of vitamin C in the histopathological changes observed in rat striatum after seizures. MATERIAL AND METHODS: Healthy Wistar rats were divided into four groups. The first group was treated with 0.9% saline (control group and the second one with pilocarpine (400 mg/kg, P400 group. Third and fourth groups were treated with vitamin C (250 mg/kg, 30 minutes before receiving P400 (P400 + VIT C group or 0.9% saline (VIT C group, respectively. After the treatments, all groups were observed for 24 hours, sacrificed and dissected out to remove their brains for histopathological analysis. RESULTS: The group P400 presented seizures that progressed to status epilepticus in 75% of the animals. Pretreatment with vitamin C produced a 35% reduction in this index. P400 and P400 + VIT C groups revealed 80% and 20% of animals with brain injury, respectively. In P400 group, lesion severity of the striatum was 50%. In turn, in striatal region of animals treated with P400 + VIT C group, we detected a reduction of 40% in the severity degree. DISCUSSION: Pilocarpine-induced seizures are installed by the cholinergic system and propagated by free radicals and by glutamatergic system, leading to brain damage. The antioxidant drugs may have therapeutic potential for epileptic patients to protect against brain injure through removing free radicals produced, suggesting that vitamin C may influence epileptogenesis and promote neuroprotective actions during seizures.

  7. PROPAGATION OF EPILEPTIFORM ACTIVITY DURING DEVELOPMENT OF AMYGDALA KINDLING IN RATS - LINEAR AND NONLINEAR ASSOCIATION BETWEEN IPSILATERAL AND CONTRALATERAL SITES

    NARCIS (Netherlands)

    BELDHUIS, HJA; SUZUKI, T; PIJN, JPM; TEISMAN, A; DASILVA, FHL; BOHUS, B

    1993-01-01

    The relationship between ipsi- and contralateral epileptiform electroencephalographic (EEG) activity was investigated in rats that were kindled daily in the amygdala. Two types of relationship-linear and non-linear associations-were studied and used to estimate time delays of EEG activity between ho

  8. Expressional analysis of the astrocytic Kir4.1 channel in a pilocarpine-induced temporal lobe epilepsy model.

    Science.gov (United States)

    Nagao, Yuki; Harada, Yuya; Mukai, Takahiro; Shimizu, Saki; Okuda, Aoi; Fujimoto, Megumi; Ono, Asuka; Sakagami, Yoshihisa; Ohno, Yukihiro

    2013-01-01

    The inwardly rectifying potassium (Kir) channel Kir4.1 in brain astrocytes mediates spatial K(+) buffering and regulates neural activities. Recent studies have shown that loss-of-function mutations in the human gene KCNJ10 encoding Kir4.1 cause epileptic seizures, suggesting a close relationship between the Kir4.1 channel function and epileptogenesis. Here, we performed expressional analysis of Kir4.1 in a pilocarpine-induced rat model of temporal lobe epilepsy (TLE) to explore the role of Kir4.1 channels in modifying TLE epileptogenesis. Treatment of rats with pilocarpine (350 mg/kg, i.p.) induced acute status epilepticus, which subsequently caused spontaneous seizures 7-8 weeks after the pilocarpine treatment. Western blot analysis revealed that TLE rats (interictal condition) showed significantly higher levels of Kir4.1 than the control animals in the cerebral cortex, striatum, and hypothalamus. However, the expression of other Kir subunits, Kir5.1 and Kir2.1, remained unaltered. Immunohistochemical analysis illustrated that Kir4.1-immunoreactivity-positive astrocytes in the pilocarpine-induced TLE model were markedly increased in most of the brain regions examined, concomitant with an increase in the number of glial fibrillary acidic protein (GFAP)-positive astrocytes. In addition, Kir4.1 expression ratios relative to the number of astrocytes (Kir4.1-positive cells/GFAP-positive cells) were region-specifically elevated in the amygdala (i.e., medial and cortical amygdaloid nuclei) and sensory cortex. The present study demonstrated for the first time that the expression of astrocytic Kir4.1 channels was elevated in a pilocarpine-induced TLE model, especially in the amygdala, suggesting that astrocytic Kir4.1 channels play a role in modifying TLE epileptogenesis, possibly by acting as an inhibitory compensatory mechanism.

  9. Expressional analysis of the astrocytic Kir4.1 channel in a pilocarpine-induced temporal lobe epilepsy model

    Directory of Open Access Journals (Sweden)

    Yuki eNagao

    2013-07-01

    Full Text Available The inwardly-rectifying potassium (Kir channel Kir4.1 in brain astrocytes mediates spatial K+ buffering and regulates neural activities. Recent studies have shown that loss-of-function mutations in the human gene KCNJ10 encoding Kir4.1 cause epileptic seizures, suggesting a close relationship between the Kir4.1 channel function and epileptogenesis. Here, we performed expressional analysis of Kir4.1 in a pilocarpine-induced rat model of temporal lobe epilepsy (TLE to explore the role of Kir4.1 channels in modifying TLE epileptogenesis. Treatment of rats with pilocarpine (350 mg/kg, i.p. induced acute status epilepticus, which subsequently caused spontaneous seizures 7–8 weeks after the pilocarpine treatment. Western blot analysis revealed that TLE rats (interictal condition showed significantly higher levels of Kir4.1 than the control animals in the cerebral cortex, striatum and hypothalamus. However, the expression of other Kir subunits, Kir5.1 and Kir2.1, remained unaltered. Immunohistochemical analysis illustrated that Kir4.1-immunoreactivity-positive astrocytes in the pilocarpine-induced TLE model were markedly increased in most of the brain regions examined, concomitant with an increase in the number of glial fibrillary acidic protein (GFAP-positive astrocytes. In addition, Kir4.1 expression ratios relative to the number of astrocytes (Kir4.1-positive cells/GFAP-positive cells were region-specifically elevated in the amygdala (i.e., medial and cortical amygdaloid nuclei and sensory cortex. The present study demonstrated for the first time that the expression of astrocytic Kir4.1 channels was elevated in a pilocarpine-induced TLE model, especially in the amygdala, suggesting that astrocytic Kir4.1 channels play a role in modifying TLE epileptogenesis, possibly by acting as an inhibitory compensatory mechanism.

  10. Voluntary Control of Epileptiform Spike-Wave Discharges in Awake Rats.

    Science.gov (United States)

    Taylor, Jeremy A; Rodgers, Krista M; Bercum, Florencia M; Booth, Carmen J; Dudek, F Edward; Barth, Daniel S

    2017-06-14

    Genetically inherited absence epilepsy in humans is typically characterized by brief (seconds) spontaneous seizures, which involve spike-wave discharges (SWDs) in the EEG and interruption of consciousness and ongoing behavior. Genetic (inbred) models of this disorder in rats have been used to examine mechanisms, comorbidities, and antiabsence drugs. SWDs have also been proposed as models of complex partial seizures (CPSs) following traumatic brain injury (post-traumatic epilepsy). However, the ictal characteristics of these rat models, including SWDs and associated immobility, are also prevalent in healthy outbred laboratory rats. We therefore hypothesized that SWDs are not always associated with classically defined absence seizures or CPSs. To test this hypothesis, we used operant conditioning in male rats to determine whether outbred strains, Sprague Dawley and Long-Evans, and/or the inbred WAG/Rij strain (a rat model of heritable human absence epilepsy) could exercise voluntary control over these epileptiform events. We discovered that both inbred and outbred rats could shorten the duration of SWDs to obtain a reward. These results indicate that SWD and associated immobility in rats may not reflect the obvious cognitive/behavioral interruption classically associated with absence seizures or CPSs in humans. One interpretation of these results is that human absence seizures and perhaps CPSs could permit a far greater degree of cognitive capacity than often assumed and might be brought under voluntary control in some cases. However, these results also suggest that SWDs and associated immobility may be nonepileptic in healthy outbred rats and reflect instead voluntary rodent behavior unrelated to genetic manipulation or to brain trauma.SIGNIFICANCE STATEMENT Our evidence that inbred and outbred rats learn to control the duration of spike-wave discharges (SWDs) suggests a voluntary behavior with maintenance of consciousness. If SWDs model mild absence seizures and

  11. Manipulating epileptiform bursting in the rat hippocampus using chaos control and adaptive techniques.

    Science.gov (United States)

    Slutzky, Marc W; Cvitanovic, Predrag; Mogul, David J

    2003-05-01

    Epilepsy is a relatively common disease, afflicting 1%-2% of the population, yet many epileptic patients are not sufficiently helped by current pharmacological therapies. Recent reports have suggested that chaos control techniques may be useful for electrically manipulating epileptiform bursting behavior in vitro and could possibly lead to an alternative method for preventing seizures. We implemented chaos control of spontaneous bursting in the rat hippocampal slice using robust control techniques: stable manifold placement (SMP) and an adaptive tracking (AT) algorithm designed to overcome nonstationarity. We examined the effect of several factors, including control radius size and synaptic plasticity, on control efficacy. AT improved control efficacy over basic SMP control, but relatively frequent stimulation was still necessary and very tight control was only achieved for brief stretches. A novel technique was developed for validating period-1 orbit detection in noisy systems by forcing the system directly onto the period-1 orbit. This forcing analysis suggested that period-1 orbits were indeed present but that control would be difficult because of high noise levels and nonstationarity. Noise might actually be lower in vivo, where regulatory inputs to the hippocampus are still intact. Thus, it may still be feasible to use chaos control algorithms for preventing epileptic seizures.

  12. Sinusoidal stimulation trains suppress epileptiform spikes induced by 4-AP in the rat hippocampal CA1 region in-vivo.

    Science.gov (United States)

    Zheshan Guo; Zhouyan Feng; Ying Yu; Wenjie Zhou; Zhaoxiang Wang; Xuefeng Wei

    2016-08-01

    Deep brain stimulation (DBS) shows promises in the treatment of refractory epilepsy. Due to the complex causes of epilepsy, the mechanisms of DBS are still unclear. Depolarization block caused by the persistent excitation of neurons may be one of the possible mechanisms. To test the hypothesis, 4-aminopyridine (4-AP) was injected in rat hippocampal CA1 region in-vivo to induce epileptiform activity. Sinusoidal stimulation trains were applied to the afferent pathway (Schaffer collaterals) of CA1 region to suppress the epileptiform spikes. Results show that 2-min long trains of sinusoidal stimulation (50 Hz) decreased the firing rate of population spikes (PS) and decreased the PS amplitudes significantly. In addition, small positive sharp waves replaced PS activity during the periods of stimulation. A lower frequency sinusoidal stimulation (10 Hz) failed to decrease the firing rate of PS, but decreased the PS amplitudes significantly. These results suggest that stimulation trains of sinusoidal waves could suppress epileptiform spikes. Presumably, the stimulation with a high enough frequency might excite the downstream neurons persistently and elevate the membrane potentials continuously, thereby cause depolarization blocks in the neurons. The findings of the study provide insights in revealing the mechanisms of DBS, and have important implications to the clinical treatment of epilepsy.

  13. Modulation of pilocarpine-induced seizures by cannabinoid receptor 1.

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    Rebecca L Kow

    Full Text Available Administration of the muscarinic agonist pilocarpine is commonly used to induce seizures in rodents for the study of epilepsy. Activation of muscarinic receptors has been previously shown to increase the production of endocannabinoids in the brain. Endocannabinoids act at the cannabinoid CB1 receptors to reduce neurotransmitter release and the severity of seizures in several models of epilepsy. In this study, we determined the effect of CB1 receptor activity on the induction in mice of seizures by pilocarpine. We found that decreased activation of the CB1 receptor, either through genetic deletion of the receptor or treatment with a CB1 antagonist, increased pilocarpine seizure severity without modifying seizure-induced cell proliferation and cell death. These results indicate that endocannabinoids act at the CB1 receptor to modulate the severity of pilocarpine-induced seizures. Administration of a CB1 agonist produced characteristic CB1-dependent behavioral responses, but did not affect pilocarpine seizure severity. A possible explanation for the lack of effect of CB1 agonist administration on pilocarpine seizures, despite the effects of CB1 antagonist administration and CB1 gene deletion, is that muscarinic receptor-stimulated endocannabinoid production is acting maximally at CB1 receptors to modulate sensitivity to pilocarpine seizures.

  14. Effect of Ghrelin on nuclear factor-κB and tumor necrosis factor-α in the cerebral cortex of immature rats with pilocarpine-induced epilepsy%Ghrelin对匹罗卡品诱导癫(癎)大鼠大脑皮层核因子-κB和肿瘤坏死因子-α表达的影响

    Institute of Scientific and Technical Information of China (English)

    张瑞云; 王清义; 李培国; 隋风轩; 王华

    2010-01-01

    目的 探讨Ghrelin治疗匹罗卡品诱导的癫(癎)大鼠大脑皮层核因子(NF)-κB和肿瘤坏死因子(TNF)-α基因和蛋白表达水平的变化.方法 建立匹罗卡品诱导的癫(癎)大鼠模型,将模型分为模型组、生理盐水组和Ghrelin治疗组,同时设正常对照组,比较各组大鼠大脑皮层NF-κB和TNF-α蛋白和基因表达水平.结果 模型组大鼠脑组织NF-κB和TNF-α蛋白和基因表达均增多,正常对照组两者表达较少;Ghrelin治疗组大鼠脑组织NF-κB和TNF-α蛋白和基因表达水平均比模型组和生理盐水组明显降低,差异有显著性(P<0.05).结论 Ghrelin可能通过降低癫(癎)大鼠大脑皮层NF-κB和TNF-α蛋白和基因表达水平,减轻皮层神经细胞的炎症反应,达到对神经细胞的保护作用.%Objective To explore the changes of gene and protein expressions of nuclear factor-κB(NF-κB) and tumor necrosis factor-α (TNF-α) in immature rats with pilocarpine-induced epilepsy treated with ghrelin. Methods The pllocarpine-induced epilepsy model in immatured rats were built, then the rats were divided into three groups: Ghrelin-treated group, saline-treated group and model group, meanwhile the normal control group was set. The NF-κB and TNF-α levels of gene and protein in the cerebral cortex of immature rats were detected. Results The expression levels of gene and protein of NF-κB and TNF-α were increased in model group,but decreased in the normal control group;NF-κB and TNF-α levels in Ghrelin treated group were obviously lower than those of saline-treated group and model group(P < 0. 05). Conclusion The protective mechanism of Ghrelin for nerve cell is cutting down the expressions of NF-κB and TNF-α in the cerebral cortex of immature rats with epilepsy and lessening inflammatory reaction in neurocytes.

  15. Neuron to astrocyte communication via cannabinoid receptors is necessary for sustained epileptiform activity in rat hippocampus.

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    Guyllaume Coiret

    Full Text Available Astrocytes are integral functional components of synapses, regulating transmission and plasticity. They have also been implicated in the pathogenesis of epilepsy, although their precise roles have not been comprehensively characterized. Astrocytes integrate activity from neighboring synapses by responding to neuronally released neurotransmitters such as glutamate and ATP. Strong activation of astrocytes mediated by these neurotransmitters can promote seizure-like activity by initiating a positive feedback loop that induces excessive neuronal discharge. Recent work has demonstrated that astrocytes express cannabinoid 1 (CB1 receptors, which are sensitive to endocannabinoids released by nearby pyramidal cells. In this study, we tested whether this mechanism also contributes to epileptiform activity. In a model of 4-aminopyridine induced epileptic-like activity in hippocampal slice cultures, we show that pharmacological blockade of astrocyte CB1 receptors did not modify the initiation, but significantly reduced the maintenance of epileptiform discharge. When communication in astrocytic networks was disrupted by chelating astrocytic calcium, this CB1 receptor-mediated modulation of epileptiform activity was no longer observed. Thus, endocannabinoid signaling from neurons to astrocytes represents an additional significant factor in the maintenance of epileptiform activity in the hippocampus.

  16. Effect of serotonin depletion on seizures learning-memory in pilocarpine-induced epileptic rats%脑内5-羟色胺减少对致痫大鼠癫痫发作及学习记忆的影响

    Institute of Scientific and Technical Information of China (English)

    吕晓钗; 黄华品; 林婉挥; 陈圣根

    2012-01-01

    目的:于中脑正中中缝核局部微量注射5,7-二羟色胺(5,7-DHT),探讨5-羟色胺(5-HT)与癫痫的关系及匹罗卡品(PILO)致痫大鼠学习记忆改变的可能机制.方法:成年SD大鼠随机分为PILO组、PILO+5,7-DHT组、空白对照组三组,然后根据是否出现癫痫持续状态(SE)再将PILO组分成:PILO+ SE组和PILO-SE组两亚组;利用视频脑电图观察大鼠癫痫发作及皮层脑电变化;运用Morris水迷宫测评大鼠空间学习记忆水平;最后运用免疫组化法观察大鼠中缝核5-HT能神经元.结果:大鼠予以5,7-DHT( PILO+ 5,7- DHT组)处理后造模成功率、死亡率及慢性期自发性发作频率均增高;与空白组比较PILO+ SE组中缝核5-HT能神经元数目有所下降(P<0.05),而PILO+5,7-DHT组下降更明显(P<0.01);与空白组比较PILO+ SE组平均逃避潜伏期延长、穿越平台次数减少、原平台象限停留时间缩短(P<0.05),而与PILO+ SE组比较PILO+ 5,7-DHT组变化不明显.结论:脑内5-H水平的降低容易诱发癫痫发作,尚不能认为癫痫大鼠合并认知功能障碍与脑内5-HT水平下降有关.%Objective: To investigate the relationship between serotonin(5-HT)and epilepsy and the mechanism of learning-memory in pi-locaipine(PILO)-induced epileptic rats after5,7-dihydroxytryplamine (5,7-DHT) microinjection in median raphe nucleus. Methods: Adult S D rats were randomly divided into 3 groups: PIL0 group, PTL0 + 5,7-DHT group, vehicle control group; PIL0 group was divided into two groups by status epilepticus(SE): PIL0+ SE group and HL0-SE group. The rats' seizures and cortex electroencephalography(EEG) were observed by vedio EEC. The rats' spatial learning-memory was evaluated by Morris water maze. Finally, serotonergic neuron in raphe nuclei was observed by immunohistochemisty. Results: After treatment of 5,7-DHT (PIL0 + 5,7-DHT group), the success rate, the mortality and the frequency of chronic spontaneous seizures in pilocarpine-induced

  17. 多药转运蛋白对匹罗卡品癫(癎)大鼠模型脑内拉莫三嗪浓度的影响%Impact of multi-drug transporters on regulation of concentration of lamotrigine in hippocampal extracellular fluid in rat after pilocarpine-induced seizures

    Institute of Scientific and Technical Information of China (English)

    马爱梅; 张守文; 刘玉玺; 胡风云

    2009-01-01

    Objective To investigate the impact of multi-drug transporters including P-glycoprotein (PGP) and multi-drug resistance associated protein (MRP) on concentration of lamotrigine in the extracellular fluid in hippocampus of epilepsy rat models induced by pilocarpine, and to deduce the multi-drug resistance mechanisms in refractory epilepsy. Methods The epilepsy rat models were established by repeated administration (by ip) of pilocarpine. A microdialysis probe was placed into the hippocampus of the epileptic rats and dialysate was collected at five time-points from 30--150 minutes after systemic injections of lamotrigine (10 mg/kg). The concentration of lamotrigine in the extracellular fluid in the hippocampus was determined by high-performance liquid chromatography (HPLC). Then PGP inhibitor verapamil and MRP inhibitor probenecid was added individually through microdialysis probe and the concentration of lamotrigine was detected again. Results Compared with control group (0. 41 ± 0. 10 in 60 minutes, 0. 50 ±0.04 in 90 minutes, 0. 39 ±0. 09 in 120 minutes and 0. 30±0.06 in 150 minutes), verapamil significantly increased the concentration of lamotrigine in extracellular fluid of the hippocampus 60--150 minutes (0. 65 ±0. 11, 0. 84 ± 0. 09, 0. 70± 0. 09 and 0. 58 ± 0. 08 respectively) after injection (F value were 5.01, 8.61, 10. 23 and 7.89, all P < 0. 05) and probenecid also enhanced the concentration of lamotrigine 90--150 minutes (0. 75 ± 0. 09, 0. 58±0. 10 and 0. 49±0. 07) after injection (F = 6. 58, 4. 56, 4. 75, all P < 0. 05). Conclusions Penetration of lamotrigine through blood-brain barrier in pilocarpine induced epilepsy rats is restricted by PGP and MRP, resulting in decreased concentration of lamotrigine in the extracellular fluid of the hippocampus. Therefore, increasing expression of PGP and MRP in brains of epilepsy patients might be an important mechanism involved in multi-drug resistance in refractory epilepsy.%目的 观察多药转运蛋

  18. Electroencephalographic characterization of pentylenetetrazole kindling in rats and modulation of epileptiform discharges by nitric oxide.

    Science.gov (United States)

    Bartsch, Victoria; Díaz, Javier; González, Ignacio; Cavada, Gabriel; Ocampo-Garcés, Adrián; Wyneken, Ursula

    2014-02-01

    Epileptogenesis is a progressive process which culminates with spontaneous, recurrent and unpredictable epileptic seizures due to enhanced neuronal excitability. Well-characterized animal models of this process are needed to clarify its underlying molecular mechanisms, in which the role of nitric oxide has been a controversial component. We have used kindling with a sub-convulsive dose of pentylenetetrazole to objectively characterize early electroencephalographic changes during epileptogenesis. We used electroencephalographic recordings both during pentylenetetrazole (20 mg/kg) kindling for 20 days and then, 24 days later to quantify the number, duration and spectral power of epileptic discharges. The levels of nitric oxide were modulated locally in the cerebral cortex by pharmacological agents. The number of epileptiform discharges increased during the kindling protocol as well as 24 days later, revealing the induction of a self-sustaining epileptogenic process. Epileptic discharges were characterized by theta frequencies (4-10 Hz) that were associated with absence-like seizures. However, during kindling, the spectral power of the theta band progressively decreased, while the power of higher frequencies, in the beta band, increased. Nitric oxide in the cerebral cortex inhibited the number and amplitude of epileptic discharges. The electroencephalographic characterization of this kindling protocol provides a valuable tool to detect consequences of therapeutic interventions undertaken at initial phases of epileptogenesis, especially those targeted towards stopping this process. Increases of nitric oxide in the cerebral cortex could be a useful intervention to negatively modulate neuronal excitability, epileptic discharges and the progression of epileptogenesis.

  19. Rebamipide and mosapride enhance pilocarpine-induced salivation

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    Kazuo Hike

    2009-08-01

    Full Text Available Background: During esophageal acid clearance, salivation plays an important role in defending the esophageal mucosa. Mosapride, an agent used in chronic, long-term therapy of gastro-esophageal reflux disease (GERD was regarded as mediating its efficacy through prokinetic properties. Rebamipide is also widely used as an anti-gastritis and anti-ulcer agent in GERD patients with chronic gastritis. The aim of this study is to investigate the effects of rebamipide, mosapride, and risperidone on the salivation induced by pilocarpine. Materials and Methods: The experiments were conducted on 4-week male SD rats (120-150g. The salivation was induced by intraperitoneally administrated pilocarpine and saliva was collected using preweighted small cotton balls inserted into the animal's mouth every 30 min for 180 min. Thirteen minutes before intraperitoneal administration of pilocarpine, rebamipide, mosapride, and risperidone were administered intraduodenally. Control rats were conducted by intraperitoneal administration of saline and intraduodenal administration of 0.5% methylcellulose solution. Rsults: The saliva weight at 0-30 min was significantly (p<0.01 increased after administration of pilocarpine, compared to control rats. An additional administration of mosapride and rebamipide increased the saliva weight at 0-30 min. The total volume of saliva for 150 min after administration of pilocarpine was the highest after preadministration of rebamipide, followed by mosapride, and risperidone. Conclusions: Increase in salivation produced by i.p. pilocarpine was enhanced by preadministration of rebamipide and mosapride.

  20. Anticonvulsant effect of Rhynchophylline involved in the inhibition of persistent sodium current and NMDA receptor current in the pilocarpine rat model of temporal lobe epilepsy.

    Science.gov (United States)

    Shao, Hui; Yang, Yang; Mi, Ze; Zhu, Guang-Xi; Qi, Ai-Ping; Ji, Wei-Gang; Zhu, Zhi-Ru

    2016-11-19

    Rhynchophylline (RIN) is a significant active component isolated from the Chinese herbal medicine Uncaria rhynchophylla. Several studies have demonstrated that RIN has a significant anticonvulsant effect in many types of epilepsy models in vivo. However, the mechanisms of the anticonvulsant effect remain elusive. Using combined methods of behavioral testing, immunofluorescence and electrophysiological recordings, we characterized the anticonvulsant effect of RIN in a pilocarpine-induced status epilepticus (SE) rat model of temporal lobe epilepsy (TLE) and investigated the underlying cellular mechanisms. In one set of experiments, rats received RIN treatment prior to pilocarpine injection. In a second set of experiments, rats received RIN treatment following the onset of stage 3 seizures. Pretreatment and posttreatment with RIN effectively reduced the seizure severity in the acute phase of TLE. Furthermore, RIN protected medial entorhinal cortex (mEC) layer III neurons from neuronal death and terminated spontaneous epileptiform discharge of mEC layer II neurons in SE-experienced rats. Whole-cell voltage-clamp recordings indicated that RIN inhibited neuronal hyperexcitability via inhibition of the persistent sodium current (INaP) and NMDA receptor current. Immunofluorescence experiments also demonstrated that RIN rectified the pilocarpine-induced upregulation of Nav1.6 and NR2B protein expression. In conclusion, our results identified RIN as an anticonvulsant agent that inhibited ictal discharge via INap and NMDA receptor current inhibition.

  1. Effects of EES on apoptotic neurons in rat hippocampus after lithium-pilocarpine induced status epilepticus%全蝎醇提物对Li-Pilo癫痫持续状态大鼠海马神经细胞凋亡的影响

    Institute of Scientific and Technical Information of China (English)

    喻良; 孙红斌; 梁益; 谢彦; 何保明; 许飞

    2009-01-01

    目的 探讨全蝎醇提物(Ethanol Extracts of Scorpion,EES)对大鼠癫痫持续状态(SE)后海马神经元凋亡的影响.方法 建立氯化锂.匹罗卡品癫痫持续状态(Lithium-Pilocarpine induced status epilepticus,Li-Pilo SE)模型.使用TUNEL技术观察正常对照组、Li-Piio SE模型组、丙戊酸钠组(VPA)和EES低(L)、中(M)、高(H)剂量组大鼠SE后6h、24h、48h、72h和7d海马CA_1区和CA_3区TUNEL阳性细胞的动态变化,并进行组间比较.结果 正常对照组未见TUNEL阳性细胞.造模各组大鼠SE后6h海马可见部分TUNEL阳性细胞,主要分布在CA_1、CA_3区,其中模型组和EES(L)组72h达高峰,而VPA、EES(M)和EES(H)组高峰提前到SE后48h,以后各组逐渐下降.VPA、EES(M)和EES(H)组SE后各观察时间点TUNEL阳性细胞数较模型组极显著减少(P0.05),其中VPA和EES(H)组各时间点TUNEL阳性细胞数减少较EES(M)组(P0.05).结论 EES能防止Li-Pilo SE大鼠海马神经元凋亡,并呈明显的量-效关系,高剂量EES抗凋亡作用与VPA相近.

  2. Neuroaminidase reduces interictal spikes in a rat temporal lobe epilepsy model.

    Science.gov (United States)

    Isaev, Dmytro; Zhao, Qian; Kleen, Jonathan K; Lenck-Santini, Pierre Pascal; Adstamongkonkul, Dusit; Isaeva, Elena; Holmes, Gregory L

    2011-03-01

    Interictal spikes have been implicated in epileptogenesis and cognitive dysfunction in epilepsy. Unfortunately, antiepileptic drugs have shown poor efficacy in suppressing interictal discharges; novel therapies are needed. Surface charge on neuronal membranes provides a novel target for abolishing interictal spikes. This property can be modulated through the use of neuraminidase, an enzyme that decreases the amount of negatively charged sialic acid. In the present report we determined whether applying neuraminidase to brains of rats with a history of status epilepticus would reduce number of interictal discharges. Following pilocarpine-induced status epilepticus, rats received intrahippocampal injections of neuraminidase, which significantly decreased the number of interictal spikes recorded in the CA1 region. This study provides evidence that sialic acid degradation can reduce the number of interictal spikes. Furthermore, the results suggest that modifying surface charge created by negatively charged sialic acid may provide new opportunities for reducing aberrant epileptiform events in epilepsy.

  3. Altered expression and localization of hippocampal A-type potassium channel subunits in the pilocarpine-induced model of temporal lobe epilepsy.

    Science.gov (United States)

    Monaghan, M M; Menegola, M; Vacher, H; Rhodes, K J; Trimmer, J S

    2008-10-15

    Altered ion channel expression and/or function may contribute to the development of certain human epilepsies. In rats, systemic administration of pilocarpine induces a model of human temporal lobe epilepsy, wherein a brief period of status epilepticus (SE) triggers development of spontaneous recurrent seizures that appear after a latency of 2-3 weeks. Here we investigate changes in expression of A-type voltage-gated potassium (Kv) channels, which control neuronal excitability and regulate action potential propagation and neurotransmitter release, in the pilocarpine model of epilepsy. Using immunohistochemistry, we examined the expression of component subunits of somatodendritic (Kv4.2, Kv4.3, KChIPl and KChIP2) and axonal (Kv1.4) A-type Kv channels in hippocampi of pilocarpine-treated rats that entered SE. We found that Kv4.2, Kv4.3 and KChIP2 staining in the molecular layer of the dentate gyrus changes from being uniformly distributed across the molecular layer to concentrated in just the outer two-thirds. We also observed a loss of KChIP1 immunoreactive interneurons, and a reduction of Kv4.2 and KChIP2 staining in stratum radiatum of CA1. These changes begin to appear 1 week after pilocarpine treatment and persist or are enhanced at 4 and 12 weeks. As such, these changes in Kv channel distribution parallel the acquisition of recurrent spontaneous seizures as observed in this model. We also found temporal changes in Kv1.4 immunoreactivity matching those in Timm's stain, being expanded in stratum lucidum of CA3 and in the inner third of the dentate molecular layer. Among pilocarpine-treated rats, changes were only observed in those that entered SE. These changes in A-type Kv channel expression may contribute to hyperexcitability of dendrites in the associated hippocampal circuits as observed in previous studies of the effects of pilocarpine-induced SE.

  4. Zinc chelation reduces hippocampal neurogenesis after pilocarpine-induced seizure.

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    Jin Hee Kim

    Full Text Available Several studies have shown that epileptic seizures increase hippocampal neurogenesis in the adult. However, the mechanism underlying increased neurogenesis after seizures remains largely unknown. Neurogenesis occurs in the subgranular zone (SGZ of the hippocampus in the adult brain, although an understanding of why it actively occurs in this region has remained elusive. A high level of vesicular zinc is localized in the presynaptic terminals of the SGZ. Previously, we demonstrated that a possible correlation may exist between synaptic zinc localization and high rates of neurogenesis in this area after hypoglycemia. Using a lithium-pilocarpine model, we tested our hypothesis that zinc plays a key role in modulating hippocampal neurogenesis after seizure. Then, we injected the zinc chelator, clioquinol (CQ, 30 mg/kg, into the intraperitoneal space to reduce brain zinc availability. Neuronal death was detected with Fluoro Jade-B and NeuN staining to determine whether CQ has neuroprotective effects after seizure. The total number of degenerating and live neurons was similar in vehicle and in CQ treated rats at 1 week after seizure. Neurogenesis was evaluated using BrdU, Ki67 and doublecortin (DCX immunostaining 1 week after seizure. The number of BrdU, Ki67 and DCX positive cell was increased after seizure. However, the number of BrdU, Ki67 and DCX positive cells was significantly decreased by CQ treatment. Intracellular zinc chelator, N,N,N0,N-Tetrakis (2-pyridylmethyl ethylenediamine (TPEN, also reduced seizure-induced neurogenesis in the hippocampus. The present study shows that zinc chelation does not prevent neurodegeneration but does reduce seizure-induced progenitor cell proliferation and neurogenesis. Therefore, this study suggests that zinc has an essential role for modulating hippocampal neurogenesis after seizure.

  5. Gonadal status-dependent effects of in vivo β-estradiol administration to female rats on in vitro epileptiform activity induced by low [Mg2+]₀ in combined hippocampus-entorhinal cortex slices.

    Science.gov (United States)

    Velíšková, Jana; Velíšek, Libor

    2013-12-01

    There are controversial data regarding estrogen effects on neuronal excitability. We investigated whether β-estradiol (EB) administration to ovariectomized (OVX) or gonadally intact female rats alters epileptiform activity within the dentate gyrus network induced in vitro by removing [Mg2+]o in combined hippocampus-entorhinal cortex slices. In vivo EB administration significantly influenced the epileptiform activity in gonadal status-dependent manner. The onset of epileptiform discharges was modestly delayed in slices from OVX rats replaced with physiologically relevant doses of EB but the number of discharges was not affected. In contrast, EB administration to gonadally intact rats had robust effects such that: EB delayed the onset of discharges but significantly increased their number within the dentate gyrus network. Our data suggest that EB in physiologically relevant concentrations does not seem to negatively affect hippocampal neuronal excitability, nevertheless supraphysiological EB levels may enhance seizure severity.

  6. The Initiation of Spontaneous Epileptiform Events in the Rat Neocortex, In Vivo

    OpenAIRE

    Ma, Hong-Tao; Wu, Cai-Hong; Wu, Jian-young

    2003-01-01

    We used voltage-sensitive dye imaging to visualize the distribution of initiation sites of the spontaneous interictal-like spikes (sISs) in rat neocortex, in vivo, induced by bicuculline or picrotoxin over the exposed cortex. The initiation site was small (~200 µm in diameter). On average each initiation site initiated 2.0±0.8 sISs (nine animals, 499 sISs, 251 sites). This is significantly different from that in neocortical slices, where each initiation site initiated 30–100 sISs. The initiat...

  7. Acute toxicity and anticonvulsant activity of liposomes containing nimodipine on pilocarpine-induced seizures in mice.

    Science.gov (United States)

    Moreno, Lina Clara Gayoso e Almendra Ibiapina; Cavalcanti, Isabella Macário Ferro; Satyal, Prabodh; Santos-Magalhães, Nereide Stela; Rolim, Hercília Maria Lins; Freitas, Rivelilson Mendes

    2015-01-12

    Nimodipine has been shown to have an inhibitory action on seizures and brain damage in rodents. However, the pharmaceutical applicability of this drug is limited by its low solubility in gastrointestinal fluids and high first-pass effect in the liver, which leads to low bioavailability. These difficulties can be overcome through the use of liposomes. The aim of the present study is to evaluate the toxicity and anticonvulsant activity of liposomes containing nimodipine (NMD-Lipo) on pilocarpine-induced seizures. NMD-Lipo was prepared using the lipid-film hydration method. Central nervous system toxicity of NMD-Lipo was assessed by Hippocratic screening. Systemic toxicity was evaluated by analyses of biochemical and hematological parameters and by observing possible signs of toxicity. The possible anticonvulsant activity was tested by the pilocarpine model. The administration of the NMD-Lipo at doses of 0.1, 1, and 10 mg/kg caused no toxicity in animals. Furthermore, NMD-Lipo prevented the installation of 100% of the pilocarpine-induced seizures and prevented the death of 100% of the mice treated with pilocarpine. These data shown that NMD-Lipo has an anticonvulsant activity significantly superior to free NMD, suggesting that the liposomes promoted a drug controlled release by improving its bioavailability and consequently increasing its pharmacological activity. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  8. Progranulin promotes activation of microglia/macrophage after pilocarpine-induced status epilepticus.

    Science.gov (United States)

    Zhu, Shanshan; Tai, Chao; Petkau, Terri L; Zhang, Si; Liao, Chengyong; Dong, Zhifang; Wen, Wendy; Chang, Qing; Tian Wang, Yu; MacVicar, Brian A; Leavitt, Blair R; Jia, William; Cynader, Max S

    2013-09-12

    Progranulin (PGRN) haploinsufficiency accounts for up to 10% of frontotemporal lobe dementia. PGRN has also been implicated in neuroinflammation in acute and chronic neurological disorders. Here we report that both protein and mRNA levels of cortical and hippocampal PGRN are significantly enhanced following pilocarpine-induced status epilepticus. We also identify intense PGRN immunoreactivity that colocalizes with CD11b in seizure-induced animals, suggesting that PGRN elevation occurs primarily in activated microglia and macrophages. To test the role of PGRN in activation of microglia/macrophages, we apply recombinant PGRN protein directly into the hippocampal formation, and observe no change in the number of CD11b(+) microglia/macrophages in the dentate gyrus. However, with pilocarpine-induced status epilepticus, PGRN application significantly increases the number of CD11b(+) microglia/macrophages in the dentate gyrus, without affecting the extent of hilar cell death. In addition, the number of CD11b(+) microglia/macrophages induced by status epilepticus is not significantly different between PGRN knockout mice and wildtype. Our findings suggest that status epilepticus induces PGRN expression, and that PGRN potentiates but is not required for seizure-induced microglia/macrophage activation.

  9. Lovastatin modulates glycogen synthase kinase-3β pathway and inhibits mossy fiber sprouting after pilocarpine-induced status epilepticus.

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    Chun-Yao Lee

    Full Text Available This study was undertaken to assay the effect of lovastatin on the glycogen synthase kinase-3 beta (GSK-3β and collapsin responsive mediator protein-2 (CRMP-2 signaling pathway and mossy fiber sprouting (MFS in epileptic rats. MFS in the dentate gyrus (DG is an important feature of temporal lobe epilepsy (TLE and is highly related to the severity and the frequency of spontaneous recurrent seizures. However, the molecular mechanism of MFS is mostly unknown. GSK-3β and CRMP-2 are the genes responsible for axonal growth and neuronal polarity in the hippocampus, therefore this pathway is a potential target to investigate MFS. Pilocarpine-induced status epilepticus animal model was taken as our researching material. Western blot, histological and electrophysiological techniques were used as the studying tools. The results showed that the expression level of GSK-3β and CRMP-2 were elevated after seizure induction, and the administration of lovastatin reversed this effect and significantly reduced the extent of MFS in both DG and CA3 region in the hippocampus. The alteration of expression level of GSK-3β and CRMP-2 after seizure induction proposes that GSK-3β and CRMP-2 are crucial for MFS and epiletogenesis. The fact that lovastatin reversed the expression level of GSK-3β and CRMP-2 indicated that GSK-3β and CRMP-2 are possible to be a novel mechanism of lovatstain to suppress MFS and revealed a new therapeutic target and researching direction for studying the mechanism of MFS and epileptogenesis.

  10. Microglial ablation and lipopolysaccharide preconditioning affects pilocarpine-induced seizures in mice

    Energy Technology Data Exchange (ETDEWEB)

    Mirrione, M.M.; Mirrione, M.M.; Konomosa, D.K.; Ioradanis, G.; Dewey, S.L.; Agzzid, A.; Heppnerd, F.L.; Tsirka, St.E.

    2010-04-01

    Activated microglia have been associated with neurodegeneration in patients and in animal models of Temporal Lobe Epilepsy (TLE), however their precise functions as neurotoxic or neuroprotective is a topic of significant investigation. To explore this, we examined the effects of pilocarpine-induced seizures in transgenic mice where microglia/macrophages were conditionally ablated. We found that unilateral ablation of microglia from the dorsal hippocampus did not alter acute seizure sensitivity. However, when this procedure was coupled with lipopolysaccharide (LPS) preconditioning (1 mg/kg given 24 h prior to acute seizure), we observed a significant pro-convulsant phenomenon. This effect was associated with lower metabolic activation in the ipsilateral hippocampus during acute seizures, and could be attributed to activity in the mossy fiber pathway. These findings reveal that preconditioning with LPS 24 h prior to seizure induction may have a protective effect which is abolished by unilateral hippocampal microglia/macrophage ablation.

  11. Pilocarpine-induced status epilepticus alters hippocampal PKC expression in mice.

    Science.gov (United States)

    Liu, Jian Xin; Liu, Yong; Tang, Feng Ru

    2011-01-01

    We investigated the protein expression of different protein kinase C (PKC) isoforms (PKC-alpha, PKC-beta1, PKC-beta2, PKC-gamma, PKC-delta, PKC-epsilon, PKC-eta and PKC-zeta) in the hippocampus of normal control mice and progressive changes in PKC isoforms expression during and after pilocarpine induced status epilepticus (PISE). We showed the reduced expression of PKC-delta, PKC-eta and PKC-zeta in interneurons in the CA1 area and in the hilus of the dentate gyrus during or after PISE. Increased expression of PKC-alpha and PKC-beta1 was demonstrated in the stratum pyramidale of CA3 area, and PKC-epsilon was up-regulated in the stratum lucidum of the CA3 area during or after PISE. Our results suggest that hippocampal PKC isoforms may play different roles in seizure generation, and be targets for development of anti-convulsive drugs.

  12. Effects of Low-frequency Repetitive Transcranial Magnetic Stimulation on Expressions of Hippocampus CA3 Region Annexin A7 in Rats after Pilocarpine-induced Seizures%低频重复经颅磁刺激的抗(癎)作用及其对癫(癎)大鼠海马CA3区膜连蛋白A7表达的影响

    Institute of Scientific and Technical Information of China (English)

    余琴; 王莉; 余巨明; 贾朝均

    2012-01-01

    目的:观察低频重复经颅磁刺激(rTMS)对大鼠(癎)性发作行为及海马CA3区膜连蛋白A7表达的影响.方法:取85只健康雄性SD大鼠,按预处理方式将其分成rTMS组(rTMS刺激+毛果芸香碱致(癎))、对照组(假刺激+毛果芸香碱致(癎))及生理盐水对照组(假刺激+生理盐水).各组大鼠经相应处理后,rTMS组和对照组(各n=30)大鼠制作氯化锂-毛果芸香碱癫(癎)持续状态(SE)模型;生理盐水对照组(n=25)则腹腔注射生理盐水.观察各组大鼠行为表现及SE潜伏期,应用免疫组化法观察膜连蛋白A7表达的动态变化(6h、24h、1周、3周、6周).结果:①rTMS组SE潜伏期为(41.37±5.45)min,与对照组(23.86±4.42)min比较明显延长(P<0.01);②海马CA3区膜连蛋白A7阳性细胞数在各时间点均为对照组最多,rTMS组次之,生理盐水对照组最少(均P<0.05).但是膜连蛋白A7的表达随时间变化的趋势rTMS组与对照组明显不同.结论:低频rTMS有一定抗(癎)作用;低频rTMS可影响大鼠海马CA3区膜连蛋白A7表达并呈现独特的动态变化特点.%Aim: To observe the effects of low-frequency repetitive transcranial magnetic stimulation (rTMS) on rat behavior and the expressions of hippocampus CA3 region annexin A7 in rats after pilocarpine-induced seizures, and explore the possible anti-epileptic mechanisms of rTMS. Methods: 85 healthy male SD rats were randomly divided into rTMS group (rTMS+pilocarpine), control group (sham stimulation+ pilocarpine), and NS control group (sham stimulation+normal saline), with 30 rats in each of rTMS group and control group, and 25 rats in NS control group. After consecutive corresponding stimulation for 2 weeks respectively, the status epilepticus rat models were established in rTMS group and control group, their behavior were observed and the latent time to status epilepticus was measured. The rats in all groups were killed in different time (6 h, 24 h, 1 week, 3 weeks, 6 weeks

  13. Anticonvulsant effect of time-restricted feeding in a pilocarpine-induced seizure model: Metabolic and epigenetic implications.

    Directory of Open Access Journals (Sweden)

    Jorge eLandgrave-Gómez

    2016-01-01

    Full Text Available A new generation of antiepileptic drugs has emerged; however, one-third of epilepsy patients do not properly respond to pharmacological treatments. The purpose of the present study was to investigate whether time-restricted feeding has an anticonvulsant effect and whether this restrictive diet promotes changes in energy metabolism and epigenetic modifications in a pilocarpine-induced seizure model. To resolve our hypothesis, one group of rats had free access to food and water ad libitum (AL and a second group underwent a time-restricted feeding (TRF schedule. We used the lithium-pilocarpine model to induce status epilepticus (SE, and behavioral seizure monitoring was analyzed. Additionally, an electroencephalography (EEG recording was performed to verify the effect of TRF on cortical electrical activity after a pilocarpine injection. For biochemical analysis, animals were sacrificed 24 hours after SE and hippocampal homogenates were used to evaluate the proteins related to metabolism and chromatin structure. Our results showed that TRF had an anticonvulsant effect as measured by the prolonged latency of forelimb clonus seizure, a decrease in the seizure severity score and fewer animals reaching SE. Additionally, the power of the late phase EEG recordings in the AL group was significantly higher than the TRF group. Moreover, we found that TRF is capable of inducing alterations in signaling pathways that regulate energy metabolism, including an increase in the phosphorylation of AMP dependent kinase (AMPK and a decrease in the phosphorylation of Akt kinase. Furthermore, we found that TRF was able to significantly increase the beta hydroxybutyrate (β-HB concentration, an endogenous inhibitor of histone deacetylases (HDACs. Finally, we found a significant decrease in HDAC activity as well as an increase in acetylation on histone 3 (H3 in hippocampal homogenates from the TRF group. These findings suggest that alterations in energy metabolism and the

  14. Autistic epileptiform regression.

    Science.gov (United States)

    Canitano, Roberto; Zappella, Michele

    2006-01-01

    Autistic regression is a well known condition that occurs in one third of children with pervasive developmental disorders, who, after normal development in the first year of life, undergo a global regression during the second year that encompasses language, social skills and play. In a portion of these subjects, epileptiform abnormalities are present with or without seizures, resembling, in some respects, other epileptiform regressions of language and behaviour such as Landau-Kleffner syndrome. In these cases, for a more accurate definition of the clinical entity, the term autistic epileptifom regression has been suggested. As in other epileptic syndromes with regression, the relationships between EEG abnormalities, language and behaviour, in autism, are still unclear. We describe two cases of autistic epileptiform regression selected from a larger group of children with autistic spectrum disorders, with the aim of discussing the clinical features of the condition, the therapeutic approach and the outcome.

  15. Effects of Carbamazepineon on the Hippocampal BrdU/NeuN space memory in Lithium Pilocarpine-induced Rat Model of Seizure%卡马西平对成年癫癎大鼠海马齿状回BrdU/NeuN表达水平及其对空间记忆的影响

    Institute of Scientific and Technical Information of China (English)

    权青云; 杨嫣华; 李宏图; 李峰; 赵晓娟; 林芝惠

    2012-01-01

    Objective To study the effects of carbamazepinc on the expression of BrdU/NcuN in the hippocampal dentate gyrus of adult rats after lithium pilocarpinc induced seizures,and its effect on space memory. Methods The adult rats were injected with lithium and pilocarpinc to induce status cpilcpticus. Bromodc-oxyuridinc was injected to label the newborn inherent neural precursor cells in hippocampus dentate gyrus. By using immunofluorcsccncc, the expression of BrdU/NcuN was observed on the 28th days after injection of Br-dU. Space memory function performance was assessed with behavioral analysis. Results (1) Carbamazepinc increased the number of matured neurons in the dentate gyrus in the rat model of status cpilcpticus(P?). 05). (2)Carbamazepinc improved space memory of adult rats after lithium pilocarpinc induced seizures (P<0. 01). Conclusions The effects of carbamazepinc on the expression of BrdU/NcuN in the hippocampal dentate gyrus of adult rats after lithium pilocarpinc induced seizures arc possibly one of the mechanisms of improving epilepsy space memory function.%目的 研究卡马西平对成年癫癎大鼠海马齿状回新生神经元的影响及其与空间记忆之间的关系.方法 采用氯化锂和匹罗卡品联合诱导大鼠癫痫 间模型,利用5-溴脱氧尿苷嘧啶与神经元核性蛋白双标记观察海马齿状回内源性神经前体细胞分化为成熟神经元的情况;利用行为学分析评价大鼠的空间记忆.结果 (1)卡马西平可增加癫癎大鼠海马齿状回新生成熟神经元的数量(P<0.05);(2)卡马西平对癫癎大鼠的空间记忆有明显改善作用(P<0.01).结论 卡马西平增加癫癎大鼠海马齿状回新生成熟神经元形成,是其改善癫癎大鼠空间记忆的可能机制之一.

  16. Alterações agudas dos níveis de neurotransmissores em corpo estriado de ratos jovens após estado epiléptico induzido por pilocarpina Acute alterations of neurotransmitters levels in striatum of young rat after pilocarpine-induced status epilepticus

    Directory of Open Access Journals (Sweden)

    Rivelilson Mendes de Freitas

    2003-06-01

    Full Text Available Altas doses de agonista colinérgico muscarínico, pilocarpina, produzem alterações comportamentais, convulsões e estado epiléptico em ratos. O objetivo desse estudo foi verificar as alterações nas concentrações dos neurotransmissores em corpo estriado de ratos em desenvolvimento após estado epiléptico induzido pela pilocarpina. Ratas Wistar foram tratadas com uma única dose de pilocarpina (400mg/Kg; s.c.. Controles receberam salina. A concentração dos neurotransmissores foi determinada através do HPLC, no corpo estriado de ratos que no período de observação de 1 e 24h desencadearam estado epiléptico e não sobreviveram à fase aguda do quadro convulsivo. Foi observada redução nos níveis de dopamina, serotonina, ácido dihidroxifenilacético, ácido 5-hidroxiindolacético, e aumento no ácido 4-hidroxi-3-metoxi-fenilacético. Os resultados mostraram que a ativação do sistema colinérgico pode interagir com os sistemas dopaminérgico e serotonérgico nos mecanismos referentes à fase aguda do processo convulsivo.High doses of the muscarinic cholinergic agonist, pilocarpine, result in behavioural changes, seizures and status epilepticus in rats. The purpose of the present work is to invetigate the striatal neurotransmissors level in young rats after status epilepticus induced by pilocarpine. Wistar rats were treated with a single dose of pilocarpine (400mg/Kg; s.c.. Controls received saline. Young animals were closed observed for behavioural changes during 1 and 24h. In these periods, the animals that developed status epilepticus and didn't survive this acute phase of seizures had the brains removed and striatal neurotransmissors level determined by HPLC. The concentration of dopamine, serotonine, dihydroxyphenylacetic acid, 5-hydroxyindolacetic acid was reduced and an increase in 4-hydroxy-3-methoxy-phenylacetic acid was observed. These results suggest that cholinergic activation can interage with dopaminergic and

  17. Cannabidivarin is anticonvulsant in mouse and rat

    Science.gov (United States)

    Hill, AJ; Mercier, MS; Hill, TDM; Glyn, SE; Jones, NA; Yamasaki, Y; Futamura, T; Duncan, M; Stott, CG; Stephens, GJ; Williams, CM; Whalley, BJ

    2012-01-01

    Background and Purpose Phytocannabinoids in Cannabis sativa have diverse pharmacological targets extending beyond cannabinoid receptors and several exert notable anticonvulsant effects. For the first time, we investigated the anticonvulsant profile of the phytocannabinoid cannabidivarin (CBDV) in vitro and in in vivo seizure models. Experimental Approach The effect of CBDV (1–100 μM) on epileptiform local field potentials (LFPs) induced in rat hippocampal brain slices by 4-aminopyridine (4-AP) application or Mg2+-free conditions was assessed by in vitro multi-electrode array recordings. Additionally, the anticonvulsant profile of CBDV (50–200 mg·kg−1) in vivo was investigated in four rodent seizure models: maximal electroshock (mES) and audiogenic seizures in mice, and pentylenetetrazole (PTZ) and pilocarpine-induced seizures in rats. The effects of CBDV in combination with commonly used antiepileptic drugs on rat seizures were investigated. Finally, the motor side effect profile of CBDV was investigated using static beam and grip strength assays. Key Results CBDV significantly attenuated status epilepticus-like epileptiform LFPs induced by 4-AP and Mg2+-free conditions. CBDV had significant anticonvulsant effects on the mES (≥100 mg·kg−1), audiogenic (≥50 mg·kg−1) and PTZ-induced seizures (≥100 mg·kg−1). CBDV (200 mg·kg−1) alone had no effect against pilocarpine-induced seizures, but significantly attenuated these seizures when administered with valproate or phenobarbital at this dose. CBDV had no effect on motor function. Conclusions and Implications These results indicate that CBDV is an effective anticonvulsant in a broad range of seizure models. Also it did not significantly affect normal motor function and, therefore, merits further investigation as a novel anti-epileptic in chronic epilepsy models. Linked Articles This article is part of a themed section on Cannabinoids. To view the other articles in this section visit http

  18. Number changes and axonal sprouting of somatostatin positive interneurons in the hippocampus of pilocarpine-induced epileptic rats%匹罗卡品致(癎)大鼠海马中表达生长抑素的中间神经元数目变化及其轴突出芽

    Institute of Scientific and Technical Information of China (English)

    冯莉; 龙莉莉; 肖波; 龙小艳; 李蜀渝; 易芳; 陈锶; 吴小妹

    2009-01-01

    Objective To investigate the roles of somatostatin(SS)positive intemeurons in the development and compensation of temporal lobe epilepsy.Methods Piloearpine-induced epilepsy rat model was established.Immunohistochemistry method was used to detect number changes and axonal sprouting of SS positive intemeurons in different domains of the hippocampus at difierent time points.Degeneration of SS positive interneurons and their neurophils were detected by the double immunofluorescence staining with SS and Fluoro-Jade B(FJB)at 7 and 60 days after status epilepticus (SE).Results In the exoerimental rat group,the number of SS positive neurons decreased in each hippocampal domain,and it reached the lowest at 7 days post-SE(There were 11.1±3.3 in hilus,2.8±0.9 in CA1region and 1.8±0.7 in CA1region,t=13.519,9.644 and 8.808,all P<0.01).In chronic phase,the number of SS neurons gradually recovered,and exceeded the control group in CA1 area at 60 days post-SE(12.8±1.5 vs 8.8±1.3,t=-4.506,P<0.01),however,the number of SS neurons in the hilus(25.5±4.6)and CA1 area(4.8±0.8)remained significantly less than normal levels(t value were 4.691 and 3.953.both P<0.01).Increased SS positive fibers were found in the lacunosum-molecular (1m)layer and outer molecular layer of dentate gyrus after 30 days post-SE,and numerous SS positive fibers were seen threnghout the layers of area CA1 at 60 days post-SE.Double immunofluuorescence revealed that a few SS positive interneurons and fibers were also labeled by FJB in area CA1 at 7 days post-SE and in CA domain/hilus at 60 days post-SE.Conclusions SS intemeurons loss plays an important role in the development of temporal lobe epilepsy.The loss is partially caIlsed by the degeneration and death of neurons;SS positive neurophils increase within area CA1 in chronic phase may play a significant role in the generation and compensation of temporal lobe epilepsy.%目的 探讨表达生长抑素(SS)的中间神经元在颞叶癫(癎)的发生和

  19. Acute desensitization of presynaptic GABA(B)-mediated inhibition and induction of epileptiform discharges in the neonatal rat hippocampus

    NARCIS (Netherlands)

    Tosetti, P; Bakels, R; Colin-Le Brun, [No Value; Ferrand, N; Gaiarsa, JL; Caillard, O

    2004-01-01

    The consequences of sustained activation of GABA(B) receptors on GABA(B)-mediated inhibition and network activity were investigated in the neonatal rat hippocampus using whole-cell and extracellular field recordings. GABA(B)-mediated presynaptic control of gamma-aminobutyric acid (GABA) release prog

  20. Afterpotentials of penicillin-induced epileptiform neuronal discharges in the motor cortex of the rat in vivo.

    Science.gov (United States)

    Witte, O W

    1994-05-01

    Interictal spikes and sharp waves in the EEG are followed by intervals in which the excitability of the brain seems to be normal or decreased. Often interictal spikes even appear in rhythmical patterns with intervals in the order of 0.5-2 s. These observations suggest that intrinsic and synaptic inhibitory and excitatory processes are activated which outlast the duration of the interictal discharge. In the present study such afterpotentials were analyzed in penicillin foci of the rat motor cortex in vivo using intracellular recording techniques. Paroxysmal depolarizations (PDS) of neurons within the focus were followed by afterpotentials comprising several components. Fast afterpotentials with a duration of 640 ms were associated with a sevenfold increase in membrane conductance. The fast afterpotentials were depolarizing in the majority of recordings and had an average equilibrium potential of -62 mV. This equilibrium potential was Cl(-)-dependent and was not affected by intracellular EGTA or Cs+. It is suggested that these afterpotentials represent GABAA responses. In 38% of the neurons slow afterhyperpolarizations with a twofold increase in membrane conductance and a duration of 2 s were observed. These afterhyperpolarizations had a reversal potential of -79 mV, were blocked by intracellular Cs+, were reduced in duration and amplitude by intracellular EGTA, and are suggested to present a combination of a GABAB response and a calcium-dependent potassium current. In addition, slow afterdepolarizations with a duration of about 1900 ms were registered in 16% of the recordings. It is concluded that afterpotentials with several intrinsic and synaptic components follow penicillin-induced PDS. Among these are giant Cl(-)-dependent potentials which probably represent GABAA responses, GABAB responses and a slow calcium-dependent potassium current. It is suggested that the depolarizing equilibrium potential of the Cl(-)-dependent component is due to intracellular Cl

  1. Dexamethasone exacerbates cerebral edema and brain injury following lithium-pilocarpine induced status epilepticus.

    Science.gov (United States)

    Duffy, B A; Chun, K P; Ma, D; Lythgoe, M F; Scott, R C

    2014-03-01

    Anti-inflammatory therapies are the current most plausible drug candidates for anti-epileptogenesis and neuroprotection following prolonged seizures. Given that vasogenic edema is widely considered to be detrimental for outcome following status epilepticus, the anti-inflammatory agent dexamethasone is sometimes used in clinic for alleviating cerebral edema. In this study we perform longitudinal magnetic resonance imaging in order to assess the contribution of dexamethasone on cerebral edema and subsequent neuroprotection following status epilepticus. Lithium-pilocarpine was used to induce status epilepticus in rats. Following status epilepticus, rats were either post-treated with saline or with dexamethasone sodium phosphate (10mg/kg or 2mg/kg). Brain edema was assessed by means of magnetic resonance imaging (T2 relaxometry) and hippocampal volumetry was used as a marker of neuronal injury. T2 relaxometry was performed prior to, 48 h and 96 h following status epilepticus. Volume measurements were performed between 18 and 21 days after status epilepticus. Unexpectedly, cerebral edema was worse in rats that were treated with dexamethasone compared to controls. Furthermore, dexamethasone treated rats had lower hippocampal volumes compared to controls 3 weeks after the initial insult. The T2 measurements at 2 days and 4 days in the hippocampus correlated with hippocampal volumes at 3 weeks. Finally, the mortality rate in the first week following status epilepticus increased from 14% in untreated rats to 33% and 46% in rats treated with 2mg/kg and 10mg/kg dexamethasone respectively. These findings suggest that dexamethasone can exacerbate the acute cerebral edema and brain injury associated with status epilepticus.

  2. 反复惊厥阈下痫样放电致大鼠持续性情绪唤醒障碍%Recurrent subconvulsive epileptiform discharges facilitate persistent emotionality disorder in rats

    Institute of Scientific and Technical Information of China (English)

    向阳; 王庆松; 郑宇

    2011-01-01

    Objective To investigate whether or not recurrent subconvulsive epileptiform discharges may facilitate the persistent emotionality disorder in rats. Methods Sixty-two male SD rats aged from 6 to 7 weeks old were selected and divided randomly into 4 groups: SED group (n = 16)for rats with recurrent subconvulsive epileptiform discharges, HK group (n = 16) for hippocampal kindling, EC group (n = 15) for control of electrode, NC group(n =15) for normal control. The changes in emotionality of experimental rats were tested by locomotor activity, exploratory behavior, capture-resistance and elevated plus-maze(EPM) test at 1,7,30 d after electrical stimulations. Results Compared with the EC group, at 7 d after electrical stimulation,rats in the HK,SED group displayed a significantly decrease in number of creeping(P < 0.01), and the standing on hind limbs, the percentages of open-arm entries and open-arm retention time in EPM test was decresed (P < 0.05), and the difference still existed at 30 day after electrical stimulation (P < 0.05). And the capture-resistance in rats in the HK, SED group was significantly increased at 30 day after electrical stimulation (P < 0.01). Conclusions Recurrent subconvulsive epileptiform discharges causes the persistent emotionality as decreased locomotor activities, suppressed exploratory behavior, enhanced startle, delayed habituation, increased anxiety and defense reaction.%目的 探讨反复惊厥阈下痫样放电是否可引发实验大鼠较长时间的情绪唤醒障碍.方法 选择6~7周龄雄性SD大鼠62只,成组设计,随机分为惊厥阈下痫样放电组(subelinical epileptifor mdis charges group,SED组,n=16)、海马快速电点燃组(hippoeampal kindling group,HK组,n=16)、海马电极埋植对照组(control of electrode group,EC组,n=15)、正常对照组(normal control group,NC组,n=15),建立大鼠反复SED动物模型,通过运动活性、探究行为、拒俘反应性、高架十字迷宫

  3. Increased levels of acidic calponin during dendritic spine plasticity after pilocarpine-induced seizures.

    Science.gov (United States)

    Ferhat, Lotfi; Esclapez, Monique; Represa, Alfonso; Fattoum, Abdellatif; Shirao, Tomoaki; Ben-Ari, Yezekiel

    2003-01-01

    We have previously shown that, in HEK 293 cells, overexpression of acidic calponin, an actin-binding protein, induces remodeling of actin filaments, leading to a change in cell morphology. In addition, this protein is found in dendritic spines of adult hippocampal neurons. We hypothesized that this protein plays a role in regulating actin-based filaments during dendritic spine plasticity. To assess this hypothesis, the pilocarpine model of temporal lobe epilepsy was selected because an important reorganization of the glutamatergic network, which includes an aberrant sprouting of granule cell axons, neo-synaptogenesis, and dendritic spine remodeling, is well established in the dentate gyrus. This reorganization begins after the initial period of status epilepticus after pilocarpine injection, during the silent period when animals display a normal behavior, and reaches a plateau at the chronic stage when the animals have developed spontaneous recurrent seizures. Our data show that the intensity of immunolabeling for acidic calponin was clearly increased in the inner one-third of the molecular layer of the dentate gyrus, the site of mossy fiber sprouting, and neo-synaptogenesis, at 1 and 2 weeks after pilocarpine injection (silent period) when the reorganization was taking place. In contrast, in chronic pilocarpine-treated animals, when the reorganization was established, the levels of labeling for acidic calponin in the inner molecular layer were similar to those observed in control rats. In addition, double immunostaining studies suggested that the increase in acidic calponin levels occurred within the dendritic spines. Altogether, these results are consistent with an involvement of acidic calponin in dendritic spine plasticity.

  4. Gabapentin administration reduces reactive gliosis and neurodegeneration after pilocarpine-induced status epilepticus.

    Directory of Open Access Journals (Sweden)

    Alicia Raquel Rossi

    Full Text Available The lithium-pilocarpine model of epilepsy reproduces in rodents several features of human temporal lobe epilepsy, by inducing an acute status epilepticus (SE followed by a latency period. It has been proposed that the neuronal network reorganization that occurs during latency determines the subsequent appearance of spontaneous recurrent seizures. The aim of this study was to evaluate neuronal and glial responses during the latency period that follows SE. Given the potential role of astrocytes in the post-SE network reorganization, through the secretion of synaptogenic molecules such as thrombospondins, we also studied the effect of treatment with the α2δ1 thrombospondin receptor antagonist gabapentin. Adult male Wistar rats received 3 mEq/kg LiCl, and 20 h later 30 mg/kg pilocarpine. Once SE was achieved, seizures were stopped with 20 mg/kg diazepam. Animals then received 400 mg/kg/day gabapentin or saline for either 4 or 14 days. In vitro experiments were performed in dissociated mixed hippocampal cell culture exposed to glutamate, and subsequently treated with gabapentin or vehicle. During the latency period, the hippocampus and pyriform cortex of SE-animals presented a profuse reactive astrogliosis, with increased GFAP and nestin expression. Gliosis intensity was dependent on the Racine stage attained by the animals and peaked 15 days after SE. Microglia was also reactive after SE, and followed the same pattern. Neuronal degeneration was present in SE-animals, and also depended on the Racine stage and the SE duration. Polysialic-acid NCAM (PSA-NCAM expression was increased in hippocampal CA-1 and dentate gyrus of SE-animals. Gabapentin treatment was able to reduce reactive gliosis, decrease neuronal loss and normalize PSA-NCAM staining in hippocampal CA-1. In vitro, gabapentin treatment partially prevented the dendritic loss and reactive gliosis caused by glutamate excitotoxicity. Our results show that gabapentin treatment during the

  5. 大鼠海马神经元癫痫样放电模型的构建%Establishment of the epileptiform discharge model in rat hippocampal neuron

    Institute of Scientific and Technical Information of China (English)

    董长征; 赵文清; 李文玲; 岳向勇; 孔艳莉; 康进生; 梁传栋; 王蕴欣

    2014-01-01

    目的:探讨“无镁细胞外液”诱导体外培养大鼠海马神经元产生癫痫样放电的可行性,以期建立难治性癫痫离体细胞模型。方法选取24 h内新生Wistar大鼠,分离海马神经元后进行原代培养,体外培养至第12天时,用“无镁细胞外液”处理3 h,应用全细胞膜片钳技术记录海马神经元的放电情况。结果在培养第12天时,神经元突起间彼此接触形成神经网络。在“无镁细胞外液”处理3h后神经元产生稳定的放电,恢复正常细胞培养液培养24 h,神经元仍可检测到自发的“癫痫样放电”。结论体外培养第12天海马神经元,在“无镁细胞外液”处理后可形成稳定的自发性癫痫样放电,为今后在细胞分子水平研究癫痫发病机制提供了一种理想模型。%Objectvie To explore the feasibility of epileptiform discharge of rat hippocampal neurons cultured in vitro and induced by magnesium-free extracellular fluid in order to establish refractory epilepsy model in cultured cells .Mtehods The neonatal Wistar rats within 24h were used to isolate hippocampal neuron to carry out primary culture in vitro .After 12d, the hippocampal neurons were treated with magnesium free extracellular fluid for 3h,then neuronal discharge activities were recorded by whole cell patch clamping technique .Results After 12-day cell culture ,neuronal dendrites touched each other to form neural network .After 3-hour treatment by magnesium-free extracellular fluid ,the neurons produced stable discharge , however ,after 24-hour treatment with normal cell culture fluid ,the spontaneous epileptiform activity in neurons could still be observed .Conclusion The stable spontaneous epileptiform activity can be formed in hippocanlpal neurons cultured in vitro for 12d,after exposed in magnesium free extracellular fluid for 3h,which provides an ideal model for pathogenetic research about epilepsy at cell and molecular level .

  6. Anticonvulsive effects of nimodipine on penicillin-induced epileptiform activity.

    Science.gov (United States)

    Bağirici, Faruk; Bostanci, M Omer

    2006-01-01

    The common features of all types of epilepsy are synchronized and uncontrolled discharges of nerve cell assemblies. It is believed that calcium ions play an important role in the generation of epileptic activity. Excessive calcium influx into neurons is the first step toward a seizure. The aim of the present study is to investigate whether the calcium channel blocker nimodipine has anticonvulsive effects. The left cerebral cortex was exposed by craniotomy in anaesthetized rats. An epileptic focus was produced by injection of penicillin G potassium (500 units) into the somatomotor cortex. After the epileptiform activity reached maximum frequency and amplitude; nimodipine was injected into the same area. Application of nimodipine caused an inhibition in the electrocorticograms (ECoG). Solvent alone did not affect the epileptiform activity. The results of this study indicate that nimodipine may have anticonvulsant effects.

  7. Effects of isoflurane anesthesia and pilocarpine on rat parotid saliva flow

    DEFF Research Database (Denmark)

    Knudsen, Jacob Dronninglund; Nauntofte, Birgitte; Josipovic, M

    2011-01-01

    rats was 50% slower than that of the sham-irradiated rats. In conclusion, 1.5% isoflurane was found to be a good compromise between proper anesthesia and isoflurane-induced inhibition of saliva secretion. Pilocarpine induces saliva secretion in a dose-dependent matter, with supra-maximal stimulation...

  8. Suppression of spontaneous epileptiform activity with applied currents.

    Science.gov (United States)

    Nakagawa, M; Durand, D

    1991-12-20

    It has been well established that both applied and endogenous electric fields can modulate neuronal activity in various preparations. In this paper, we present the effects of applied currents on spontaneous epileptiform activity in the CA1 region of the rat hippocampus. A computer-controlled system was designed to detect the spontaneous abnormal activity and then apply current pulses of programmable amplitude with monopolar electrodes in the stratum pyramidale. The epileptiform activity was generated by subperfusion of the neural tissue with an elevated potassium artificial cerebrospinal fluid (CSF) solution. Extracellular recordings showed that the interictal bursts could be fully suppressed in 90% of the slices by subthreshold currents with an average amplitude of 12.5 microA. Intracellular recordings showed that the anodic currents generated hyperpolarization of the somatic membrane thereby suppressing neuronal firing. This inhibitory effect of applied current pulses is important for the understanding of electric field effects on abnormal neuronal activity and could be an effective means of preventing the spread of epileptiform activity.

  9. Differential expression of brain-derived neurotrophic factor transcripts after pilocarpine-induced seizure-like activity is related to mode of Ca2+ entry.

    Science.gov (United States)

    Poulsen, F R; Lauterborn, J; Zimmer, J; Gall, C M

    2004-01-01

    Activity-dependent brain-derived neurotrophic factor (BDNF) expression is Ca2+-dependent, yet little is known about the Ca2+ channel contributions that might direct selective expression of the multiple BDNF transcripts. Here, effects of pilocarpine-induced seizure activity on total BDNF expression and on the individual sensitivity of BDNF transcripts to glutamate receptor and Ca2+ channel blockers were evaluated using hippocampal slice cultures and in situ hybridization of transcript-specific cRNA probes directed against mRNAs for the four 5' exons (I-IV) of the BDNF gene. mRNAs for nerve growth factor (NGF) and tyrosine kinase B (trkB) also were studied. Pilocarpine (5 mM) induced a dose- and time-dependent increase in total BDNF (exon V) mRNA expression in the dentate granule cells and CA3-CA1 pyramidal cells with maximal effects at 6 and 24 h, respectively. Increases were blocked by co-treatment with the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid/kainate 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX: 25 microM) and the N-methyl-d-aspartic acid receptor antagonist 2-amino-5-phosphonovaleric acid (APV; 25 microM), whereas the L-type voltage sensitive Ca2+ channel blocker nifedipine (20 microM) was without detectable effect. Maximal NGF and trkB mRNA expression was induced by pilocarpine at 4 and 12 h, respectively. For the individual BDNF transcripts, APV blocked pilocarpine-induced increases in transcript II, whereas nifedipine blocked increases in transcripts I and III. Transcript IV levels were not altered by treatment. These results indicate that transcript II makes the greatest contribution to pilocarpine effects on total BDNF mRNA content in this model and provides evidence for regional and Ca2+ channel-specific differences in activity-dependent regulation of the different BDNF transcripts in hippocampus.

  10. Identification of epileptiform patterns in electroencephalogram

    Science.gov (United States)

    Popov, Anton O.; Fesechko, Volodymyr O.; Kanaykin, Alexey M.

    2006-03-01

    The paper concerns the analysis of electroencephalogram (EEG) signals with the purpose of revealing particular waveforms in the signal - the epileptiform oscillation's complexes, which are of great importance in epileptology. We consider the pattern recognition as equivalent to EEG visual analysis and advance the template matching approach to the identification of the complexes in the signal. New type of epileptiform oscillation's complexes' template consists of generic complex and parameters of its deformations. The methodology of constructing these templates is proposed. Direct applicabilty of the proposed template creating methodology to adaptive classification of EEG complexes is highlighted. The performance of the template is evaluated with simulated and real EEG data. Experimental application of the template resulted in correct identification of 62 of 81 epileptiform oscillation's complexes from the sample signals with moderated number of false positive identifications.

  11. Differential expression of brain-derived neurotrophic factor transcripts after pilocarpine-induced seizure-like activity is related to mode of Ca2+ entry

    DEFF Research Database (Denmark)

    Poulsen, F R; Lauterborn, J; Zimmer, J;

    2004-01-01

    ) and tyrosine kinase B (trkB) also were studied. Pilocarpine (5 mM) induced a dose- and time-dependent increase in total BDNF (exon V) mRNA expression in the dentate granule cells and CA3-CA1 pyramidal cells with maximal effects at 6 and 24 h, respectively. Increases were blocked by co-treatment with the alpha......Activity-dependent brain-derived neurotrophic factor (BDNF) expression is Ca2+-dependent, yet little is known about the Ca2+ channel contributions that might direct selective expression of the multiple BDNF transcripts. Here, effects of pilocarpine-induced seizure activity on total BDNF expression...... and on the individual sensitivity of BDNF transcripts to glutamate receptor and Ca2+ channel blockers were evaluated using hippocampal slice cultures and in situ hybridization of transcript-specific cRNA probes directed against mRNAs for the four 5' exons (I-IV) of the BDNF gene. mRNAs for nerve growth factor (NGF...

  12. Antiepileptic and neuroprotective effects of human umbilical cord blood mononuclear cells in a pilocarpine-induced epilepsy model.

    Science.gov (United States)

    Costa-Ferro, Zaquer Suzana Munhoz; de Borba Cunha, Fernanda; de Freitas Souza, Bruno Solano; Leal, Marcos Maurício Tosta; da Silva, Adelson Alves; de Bellis Kühn, Telma Ingrid Borges; Forte, Andresa; Sekiya, Eliseo Joji; Soares, Milena Botelho Pereira; Dos Santos, Ricardo Ribeiro

    2014-03-01

    Status epilepticus (SE) is a condition of persistent seizure that leads to brain damage and, frequently, to the establishment of chronic epilepsy. Cord blood is an important source of adult stem cells for the treatment of neurological disorders. The present study aimed to evaluate the effects of human umbilical cord blood mononuclear cells (HUCBC) transplanted into rats after induction of SE by the administration of lithium and pilocarpine chloride. Transplantation of HUCBC into epileptic rats protected against neuronal loss in the hippocampal subfields CA1, CA3 and in the hilus of the dentate gyrus, up to 300 days after SE induction. Moreover, transplanted rats had reduced frequency and duration of spontaneous recurrent seizures (SRS) 15, 120 and 300 days after the SE. Our study shows that HUCBC provide prominent antiepileptic and neuroprotective effects in the experimental model of epilepsy and reinforces that early interventions can protect the brain against the establishment of epilepsy.

  13. Effect of Music on Interictal Epileptiform Spikes

    OpenAIRE

    J Gordon Millichap

    2004-01-01

    The effect of listening to Mozart’s Sonata for Two Pianos (K448) on the frequency of interictal epileptiform discharges (IEDs) in the EEGs of four children, ages 5 – 9 years, with benign childhood epilepsy with centrotemporal spikes (BCECTS) was studied in a prospective, randomized, crossover, placebo-controlled trial at the Medical University of South Carolina, Charleston, SC.

  14. Effect of Music on Interictal Epileptiform Spikes

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2004-10-01

    Full Text Available The effect of listening to Mozart’s Sonata for Two Pianos (K448 on the frequency of interictal epileptiform discharges (IEDs in the EEGs of four children, ages 5 – 9 years, with benign childhood epilepsy with centrotemporal spikes (BCECTS was studied in a prospective, randomized, crossover, placebo-controlled trial at the Medical University of South Carolina, Charleston, SC.

  15. Evaluation of potential gender-related differences in behavioral and cognitive alterations following pilocarpine-induced status epilepticus in C57BL/6 mice.

    Science.gov (United States)

    Oliveira, Clarissa Vasconcelos de; Grigoletto, Jéssica; Funck, Vinícius Rafael; Ribeiro, Leandro Rodrigo; Royes, Luiz Fernando Freire; Fighera, Michele Rechia; Furian, Ana Flávia; Oliveira, Mauro Schneider

    2015-05-01

    Together with pharmacoresistant seizures, the quality of life of temporal lobe epilepsy (TLE) patients is negatively impacted by behavioral comorbidities including but not limited to depression, anxiety and cognitive deficits. The pilocarpine model of TLE has been widely used to study characteristics of human TLE, including behavioral comorbidities. Since the outcomes of pilocarpine-induced TLE might vary depending on several experimental factors, we sought to investigate potential gender-related differences regarding selected behavioral alterations in C57BL6 mice. We found that epileptic mice, independent of gender, displayed increased anxiety-like behavior in the open-field test. In the object recognition test, epileptic mice, regardless of gender, showed a decreased recognition index at 24 (but not at 4) hours after training. On the other hand, no significant differences were found regarding mice learning and memory performance in the Barnes maze paradigm. Motor coordination and balance as assessed by the beam walk and rotarod tests were not impaired in epileptic mice of both genders. However, female mice, independent of epilepsy, performed the beam walk and rotarod tasks better than their male counterparts. We also found that only male epileptic mice displayed disturbed behavior in the forced swim test, but the mice of both genders displayed anhedonia-like behavior in the taste preference test. Lastly, we found that the extent of hilar cell loss is similar in both genders. In summary, both genders can be successfully employed to study behavioral comorbidities of TLE; however, taking the potential gender differences into account may help choose the more appropriated gender for a given task, which may be of value for the minimization of the number of animals used during the experiments.

  16. Sexual response in female rats with status epilepticus

    OpenAIRE

    2013-01-01

    Purpose Female sexual function is complex and may be disrupted by disease, in particular epilepsy. Chronic seizures in women can have adverse effects on reproductive function, but it has been difficult to dissociate the effects of epilepsy from those related to anticonvulsant medications. the purpose of this study was to evaluate sexual behavior in female rats submitted to pilocarpine-induced status epilepticus (SE). Methods Adult female Wistar rats were given saline or pilocarpine (350mg/kg,...

  17. Validation of suitable reference genes for expression studies in different pilocarpine-induced models of mesial temporal lobe epilepsy.

    Directory of Open Access Journals (Sweden)

    Thalita Ewellyn Batista Sales Marques

    Full Text Available It is well recognized that the reference gene in a RT-qPCR should be properly validated to ensure that gene expression is unaffected by the experimental condition. We investigated eight potential reference genes in two different pilocarpine PILO-models of mesial temporal lobe epilepsy (MTLE performing a stability expression analysis using geNorm, NormFinder and BestKepeer softwares. Then, as a validation strategy, we conducted a relative expression analysis of the Gfap gene. Our results indicate that in the systemic PILO-model Actb, Gapdh, Rplp1, Tubb2a and Polr1a mRNAs were highly stable in hippocampus of rats from all experimental and control groups, whereas Gusb revealed to be the most variable one. In fact, we observed that using Gusb for normalization, the relative mRNA levels of the Gfap gene differed from those obtained with stable genes. On the contrary, in the intrahippocampal PILO-model, all softwares included Gusb as a stable gene, whereas B2m was indicated as the worst candidate gene. The results obtained for the other reference genes were comparable to those observed for the systemic Pilo-model. The validation of these data by the analysis of the relative expression of Gfap showed that the upregulation of the Gfap gene in the hippocampus of rats sacrificed 24 hours after status epilepticus (SE was undetected only when B2m was used as the normalizer. These findings emphasize that a gene that is stable in one pathology model may not be stable in a different experimental condition related to the same pathology and therefore, the choice of reference genes depends on study design.

  18. Interictal discharges in the hippocampus of rats with long-term pilocarpine seizures.

    Science.gov (United States)

    Nagao, T; Avoli, M; Gloor, P

    1994-06-20

    Systemic administration of pilocarpine to adult rats induces an acute status epilepticus followed by spontaneous recurrent seizures after a 1-2-week silent period. We recorded field potentials in hippocampal slices obtained from rats with spontaneous recurrent seizures after pilocarpine-induced status. The frequency of the interictal discharges induced in these slices by 4-aminopyridine (4AP) was reduced and their duration was increased. Cutting the Schaffer collaterals caused interictal discharges in CA1 to disappear in normal rats and in rats 3 weeks after pilocarpine-induced status. However, 12 weeks after pilocarpine, these discharges remained in CA1 after such a cut but occurred at a lower frequency. These findings show that in rat hippocampi with a lesion similar to that of human Ammon's horn sclerosis some electrophysiological features of 4AP-induced interictal discharges are altered in comparison to those induced in normal hippocampi.

  19. Cognitive functions after pilocarpine-induced status epilepticus: changes during silent period precede appearance of spontaneous recurrent seizures.

    Science.gov (United States)

    Hort, J; Broźek, G; Mares, P; Langmeier, M; Komárek, V

    1999-09-01

    To study the possible relation between spontaneous recurrent seizures (SRS) and the derangement of cognitive memory. Status epilepticus (SE) was induced in adult Long-Evans rats by pilocarpine (320 mg/kg, i.p.) and interrupted after 2 h by clonazepam (CZPs mg/kg, i.p.). In addition to the animals that were given pilocarpine and CZP (group P), two groups received ketamine (100 mg/kg, i.p.): the first group 15 minutes after SE onset (group K15), and the second immediately after the CZP (group K120). Control groups were formed from animals not treated with pilocarpine as well as animals that received pilocarpine but did not develop motor seizures. Spatial cognitive memory was tested in the Morris water maze. Testing was impossible for more than 6 days after SE in group P. Ketamine shortened this period for the two groups that received it. During the silent period, deteriorated cognitive memory progressively improved, but the performance of group P started to worsen before the appearance of SRS. Group K120 only expressed a tendency toward declining performance, whereas group K15 never developed SRS, and the behavior of these animals did not differ from that of the controls after the postseizure period was over. Histologically, massive hippocampal cell loss was seen in group P. Ketamine protected hippocampal cells in a time-dependent manner; group K15 did not exhibit any obvious necrosis in the hippocampus. There is no close relation between cognitive functions and the appearance of SRS, because ketamine, administered 120 min after the beginning of SE, prevented the derangment of cognitive functions but not the appearance of SRSs.

  20. Effects of valproate sodium on extracellular signal-regulated kinase 1/2 phosphorylation after hippocampal neuronal epileptiform discharge in rats%丙戊酸钠对大鼠海马神经元癫痫样放电后细胞外信号调节激酶磷酸化水平的影响

    Institute of Scientific and Technical Information of China (English)

    徐祖才; 王学峰; 雷显泽; 徐忠祥; 徐平

    2012-01-01

    目的 细胞外信号调节激酶(extracellular signal-regulated kinase 1/2,ERK1/2)参与癫痫的发生,但其与抗癫痫药物之间的关系不明确,文中旨在观察丙戊酸钠对大鼠海马神经元癫痫样放电后磷酸化ERK1/2(p-ERK1/2)的影响.方法 取24h内新生Wistar大鼠,雌雄不拘,迅速断头取脑.建立神经元癫痫样放电模型,将神经元分为空白对照组和丙戊酸钠组,量效实验中,于神经元癫痫样放电前30min时加入不同浓度的丙戊酸钠(50mg/L、75mg/L、100mg/L),运用免疫荧光技术测定p-ERK1/2在不同浓度时的表达;时效实验中,分别于癫痫样放电前30min,放电后0min、30min、2h和6h加入50mg/L丙戊酸钠,采用 Wester blot观察p-ERK1/2的变化.结果 量效实验中,不同浓度的丙戊酸钠均能降低ERK1/2的磷酸化水平,且无显著性差异.时效实验中,于放电前30min时加入丙戊酸钠对ERK1/2的磷酸化水平抑制最明显,与以后各时间点间都有显著性差异.结论 海马神经元癫痫样放电后ERK1/2被过度持久的激活,在早期小剂量有效浓度的丙戊酸钠能显著抑制此反应中ERK1/2的磷酸化水平.%Objective Extracellular signal-regulated kinase l/2(ERKl/2) plays a role in the occurrence of epilepsy , but the mechanism of the involvement of ERK1/2 and its association with antiepileptic drugs remain unclear . The aim of this study is to investi -gate the effects of valproate sodium on ERK 1/2 phosphorylation (p-ERKl/2) after hippocampal neuronal epileptiform discharge in rats. Methods The epileptiform discharge model of the neuron was established in female and male neonate Wistar rats by rapid de -capitation. The neurons were divided into a blank control and a valproate sodium group , the latter incubated with valproate sodium at 50, 75 and 100 mg/L 30 min before epileptiform discharge in the concentration response experiment, and the expression of p-ERKl/2 at different concentrations detected using

  1. ANOMALIES ON EEG IN PATIENTS WITH COGNITIVE EPILEPTIFORM DISINTEGRATION AND EPILEPTIC ENCEPHALOPATHIES, ASSOCIATED WITH С BENIGN EPILEPTIFORM PATTERNS OF CHILDHOOD

    Directory of Open Access Journals (Sweden)

    M. B. Mironov

    2012-01-01

    Full Text Available On background of review and discussion of current scientific literature è own data the article presents the main clinical characteristics and anomalies on EEG in patients with cognitive epileptiform disintegration and epileptic encephalopathies, associated with ñ benign epileptiform patterns of childhood. The author describes in detail EEGpatterns — continuous spike and wave activity during sleep and benign epileptiform patterns of childhood, the role of these patterns and their special features in different syndromes of cognitive epileptiform disintegration. The article illustrated own data of the author.

  2. Cannabinoid and nitric oxide signaling interplay in the modulation of hippocampal hyperexcitability: Study on electrophysiological and behavioral models of temporal lobe epilepsy in the rat.

    Science.gov (United States)

    Carletti, F; Gambino, G; Rizzo, V; Ferraro, G; Sardo, P

    2015-09-10

    A growing bulk of evidence suggests that cannabinoid system plays a pivotal role in the control of hyperexcitability phenomena. Notwithstanding, the anticonvulsant action of cannabinoids has not been fully addressed, in particular the involvement of potential cellular neuromodulators, for instance nitric oxide. In the current study, we focused on two distinct rat models of temporal lobe epilepsy, the Maximal Dentate Activation and the pilocarpine-induced acute seizures, providing both electrophysiological and behavioral data on cannabinoid and nitrergic system interplay. We evaluated the antiepileptic effects of WIN 55,212-2, (R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl) pyrrolo[1,2,3-de]-1,4-benzoxazin-6-Yl]-1-naphthalenylmethanone (WIN), a CB agonist, and of 7-Nitroindazole (7NI), a preferential neuronal nitric oxide synthase (nNOS) inhibitor, at different doses, alone and in combination. MDA study showed that these drugs protected animals in a dose-dependent manner from electrically induced epileptiform discharges. In pilocarpine model, a dose-related activity of 7NI and WIN: a) decreased the behavioral scoring, used to describe the severity of chemically induced acute seizures; b) affected latency of the onset of acute convulsions; c) dampened mortality rate. Interestingly, the combination of the treatments brought to light that individually ineffective doses of WIN turn into effective when nNOS activity is pharmacologically inhibited in both experimental conditions. This effect is mediated by CB1 receptor since the co-administration of N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251), a CB1 receptor specific antagonist, thwarted the 7NI-WIN convergent action. In the light of this, our findings suggest a putative antagonism between CBr-activated pathway and NO signaling in the context of neuronal hyperexcitability and contribute to elucidate possible synaptic processes underlying neuroprotective

  3. The "Mozart effect" on epileptiform activity.

    Science.gov (United States)

    Hughes, J R; Daaboul, Y; Fino, J J; Shaw, G L

    1998-07-01

    The "Mozart Effect," using the Piano Sonata in D Major (K.448), was examined in patients with seizures. In 23 of 29 instances significant decreases in epileptiform activity were noted from patients even in coma, with status epilepticus or with periodic lateralized epileptiform discharges (PLEDs). The effect may be immediate or require 40-300 sec to manifest itself. The change in the amount of ictal activity in one patient in coma was from 62% before the music to 21% during Mozart. Amplitudes of these discharges also have often decreased. Examples of PLEDs on both temporal areas are shown in which the effect was only on the left temporal area but in other patients only on the right temporal area. Brain maps during the music showed theta and alpha activity decreased on the central areas, while delta waves increased on the frontal midline area. The basis of this effect is likely that the superorganization of the cerebral cortex with its highly structured radial columns seen throughout both hemispheres may resonate with the superior architecture of Mozart's music.

  4. Development of epileptiform excitability in the deep entorhinal cortex after status epilepticus

    Science.gov (United States)

    Bragin, Denis E.; Sanderson, Jennifer L.; Peterson, Steven; Connor, John A.; Müller, Wolfgang S.

    2009-01-01

    Epileptiform neuronal activity during seizures is observed in many brain areas, but its origins following status epilepticus (SE) are unclear. We have used the Li-low dose pilocarpine rat model of temporal lobe epilepsy (TLE) to examine early development of epileptiform activity in the deep entorhinal cortex (EC). We show that during the 3 week latent period that follows SE, an increasing percentage of neurons in EC layer 5 respond to a single synaptic stimulus with polysynaptic burst depolarizations. This change is paralleled by a progressive depolarizing shift of the IPSP reversal potential in layer 5 neurons, apparently caused by upregulation of the Cl- inward transporter NKCC1 and concurrent downregulation of the Cl- outward transporter KCC2, both changes favoring intracellular Cl- accumulation. Inhibiting Cl- uptake in the latent period restored more negative GABAergic reversal potentials and eliminated polysynaptic bursts. The changes in the Cl- transporters were highly specific to the deep entorhinal cortex. They did not occur in layers 1-3, perirhinal cortex, subiculum or dentate gyrus during this period. We propose that the changes in Cl- homeostasis facilitate hyperexcitability in the deep entorhinal cortex leading to epileptiform discharge there, which subsequently affects downstream cortical regions. PMID:19674083

  5. Cellular hybridization for BDNF, trkB, and NGF mRNAs and BDNF-immunoreactivity in rat forebrain after pilocarpine-induced status epilepticus.

    Science.gov (United States)

    Schmidt-Kastner, R; Humpel, C; Wetmore, C; Olson, L

    1996-01-01

    The messenger RNAs (mRNAs) for the neurotrophins, brain-derived neurotrophic factor (BDNF), and nerve growth factor (NGF), are upregulated during epileptic seizure activity, as visualized by in situ hybridization techniques. Neurotrophins might be protective against excitotoxic cell stress, and the upregulation during seizures might provide such cell protection. In this study, a high dose of pilocarpine (300 mg/kg) was used to induce long-lasting, limbic motor status epilepticus and a selective pattern of brain damage. The regulation of BDNF, trkB, and NGF mRNA was studied by in situ hybridization at 1, 3, 6, and 24 h after induction of limbic motor status epilepticus. BDNF immunoreactivity was examined with an anti-peptide antibody and the neuropathological process studied in parallel. BDNF mRNA increased in hippocampus, neocortex, piriform cortex, striatum, and thalamus with a maximum at 3-6 h. Hybridization levels increased earlier in the resistant granule and CA1 cells as compared to the vulnerable CA3 neurons. BDNF immunoreactivity was elevated in dentate gyrus at 3-6 h. trkB mRNA increased in the entire hippocampus. NGF mRNA in hippocampus appeared in dentate gyrus at 3-6 h and declined in hilar neurons at 6-24 h. Cell damage was found in the CA3 area, entire basal cortex, and layers II/III of neocortex. Endogenous neurotrophins are upregulated during status epilepticus caused by pilocarpine, which is related to the coupling between neuronal excitation and trophic factor expression. This upregulation of neurotrophic factors may serve endogenous protective effects; however, the excessive levels of neuronal hyperexcitation resulting from pilocarpine seizures lead to cell damage which cannot be prevented by endogenous neurotrophins.

  6. MicroRNA profiles in hippocampal granule cells and plasma of rats with pilocarpine-induced epilepsy--comparison with human epileptic samples

    DEFF Research Database (Denmark)

    Roncon, Paolo; Soukupovà, Marie; Binaschi, Anna

    2015-01-01

    The identification of biomarkers of the transformation of normal to epileptic tissue would help to stratify patients at risk of epilepsy following brain injury, and inform new treatment strategies. MicroRNAs (miRNAs) are an attractive option in this direction. In this study, miRNA microarrays wer...

  7. Lovastatin reduces neuronal cell death in hippocampal CA1 subfield after pilocarpine-induced status epilepticus: preliminary results Lovastatina reduz a lesão celular na região CA1 do hipocampo após o status epilepticus induzido pela pilocarpina: resultados preliminares

    Directory of Open Access Journals (Sweden)

    Pauline Rangel

    2005-12-01

    Full Text Available OBJECTIVE: To further characterize the capacity of lovastatin to prevent hippocampal neuronal loss after pilocarpine-induced status epilepticus (SE METHOD: Adult male Wistar rats were divided into four groups: (A control rats, received neither pilocarpine nor lovastatin (n=5; (B control rats, received just lovastatin (n=5; (C rats that received just pilocarpine (n=5; (D rats that received pilocarpine and lovastatin (n=5. After pilocarpine injection (350mg/kg, i.p., only rats that displayed continuous, convulsive seizure activity were included in our study. Seizure activity was monitored behaviorally and terminated with an injection of diazepam (10 mg/kg, i.p. after 4 h of convulsive SE. The rats treated with lovastatin received two doses of 20mg/kg via an oesophagic probe immediately and 24 hours after SE induction. Seven days after pilocarpine-induced SE, all the animals were perfused and their brains were processed for histological analysis through Nissl method. RESULTS: The cell counts in the Nissl-stained sections performed within the hippocampal formation showed a significant cell loss in rats that received pilocarpine and presented SE (CA1= 26.8 ± 13.67; CA3= 38.1 ± 7.2; hilus= 43.8 ± 3.95 when compared with control group animals (Group A: CA1= 53.2 ± 9.63; CA3= 63.5 ± 13.35; hilus= 59.08 ± 10.24; Group B: CA1= 74.3 ± 8.16; CA3= 70.1 ± 3.83; hilus= 70.6 ± 5.10. The average neuronal cell number of CA1 subfield of rats that present SE and received lovastatin (44.4 ± 17.88 was statically significant increased when compared with animals that just presented SE. CONCLUSION: Lovastatin exert a neuroprotective role in the attenuation of brain damage after SE.OBJETIVO: Capacidade da lovastatina em prevenir a perda de neurônios hipocampais após o status epilepticus (SE induzido pela pilocarpina. MÉTODO: Ratos adultos Wistar foram divididos em 4 grupos: (A ratos controles que não receberam pilocarpina nem lovastatina (n=5; (B ratos

  8. The lesional and epileptogenic consequences of lithium-pilocarpine-induced status epilepticus are affected by previous exposure to isolated seizures: effects of amygdala kindling and maximal electroshocks.

    Science.gov (United States)

    André, V; Ferrandon, A; Marescaux, C; Nehlig, A

    2000-01-01

    In temporal lobe epilepsy, the occurrence of seizures seems to correlate with the presence of lesions underlying the establishment of a hyperexcitable circuit. However, in the lithium-pilocarpine model of epilepsy, neuronal damage occurs both in the structures belonging to the circuit of initiation and maintenance of the seizures (forebrain limbic system) as in the propagation areas (cortex and thalamus) and in the circuit of remote control of seizures (substantia nigra pars reticulata). To determine whether or not we could protect the brain from lesions and epileptogenesis induced by status epilepticus and identify cerebral structures involved in the genesis of epilepsy, we studied the effects of the chronic exposure to non-deleterious seizures, either focalized with secondary generalization (amygdala kindling, kindled-pilocarpine rats), or primary generalized (ear-clip electroshocks, electroshock-pilocarpine rats) on neuronal damage and epileptogenesis induced by lithium-pilocarpine status epilepticus. These animals were compared to rats subjected to status epilepticus but not pretreated with seizures (sham-kindled-pilocarpine or sham-electroshock-pilocarpine rats). Compared to sham-pilocarpine rats, neuronal damage was prevented in the limbic system of the kindled-pilocarpine rats, except in the hilus of the dentate gyrus and the entorhinal cortex, while it was enhanced in rats pretreated with electroshocks, mainly in the entorhinal and perirhinal cortices. Most sham-kindled- and sham-electroshock-pilocarpine rats (92-100%) developed recurrent seizures after a silent period of 40-54days. Likewise, all kindled-pilocarpine rats developed spontaneous seizures after the same latency as their sham controls, while only two of 10 electroshock-pilocarpine rats became epileptic after a delay of 106-151days. The present data show that the apparent antiepileptic properties of electroshocks correlate with extensive damage in midbrain cortical regions, which may prevent the

  9. Diurnal Variation Has Effect on Differential Gene Expression Analysis in the Hippocampus of the Pilocarpine-Induced Model of Mesial Temporal Lobe Epilepsy.

    Directory of Open Access Journals (Sweden)

    Evelin Antonieli da Silva Santos

    Full Text Available The molecular mechanisms underlying epileptogenesis have been widely investigated by differential gene expression approach, especially RT-qPCR methodology. However, controversial findings highlight the occurrence of unpredictable sources of variance in the experimental designs. Here, we investigated if diurnal rhythms of transcript's levels may impact on differential gene expression analysis in hippocampus of rats with experimental epilepsy. For this, we have selected six core clock genes (Per1, Per3, Bmal1, Clock, Cry1 and Cry2, whose rhythmic expression pattern in hippocampus had been previously reported. Initially, we identified Tubb2a/Rplp1 and Tubb2a/Ppia as suitable normalizers for circadian studies in hippocampus of rats maintained to 12:12 hour light:dark (LD cycle. Next, we confirmed the temporal profiling of Per1, Per3, Bmal1, Cry1 and Cry2 mRNA levels in the hippocampus of naive rats by both Acrophase and CircWave statistical tests for circadian analysis. Finally, we showed that temporal differences of sampling can change experimental results for Per1, Per3, Bmal1, Cry1 and Cry2, but not for Clock, which was consistently decreased in rats with epilepsy in all comparison to the naive group. In conclusion, our study demonstrates it is mandatory to consider diurnal oscillations, in order to avoid erroneous conclusions in gene expression analysis in hippocampus of rats with epilepsy. Investigators, therefore, should be aware that genes with circadian expression could be out of phase in different animals of experimental and control groups. Moreover, our results indicate that a sub-expression of Clock may be involved in epileptogenicity, although the functional significance of this remains to be investigated.

  10. Clinical Impact of Epileptiform Discharge in Children With Attention-Deficit/Hyperactivity Disorder (ADHD).

    Science.gov (United States)

    Lee, Eun Hye; Choi, Yong Sung; Yoon, Hoi Soo; Bahn, Geon Ho

    2016-04-01

    The aim of this study was to investigate the prevalence and clinical significance of epileptiform discharges in patients with attention-deficit/hyperactivity disorder (ADHD). The authors retrospectively reviewed 180 children who were diagnosed with ADHD and had an electroencephalography (EEG) recording. Epileptiform discharges were found in 29 (16.1%) of 180 patients with ADHD. Of these, 15 (8.3%) had generalized epileptiform discharges and 14 (7.7%) had focal epileptiform discharges. The focal epileptiform discharges were most prevalent from the frontal (5/14) and rolandic area (5/14). Among the 29 patients with epileptiform discharges and ADHD, 5 patients had previous history of epilepsy and 4 patients developed epilepsy later, whereas none of the normal EEG group developed epilepsy. The authors suggest that interictal epileptiform discharges appear to be associated with seizure occurrence in children with ADHD and might reflect maturational pathophysiology overlapping with epilepsy.

  11. Global optogenetic activation of inhibitory interneurons during epileptiform activity.

    Science.gov (United States)

    Ledri, Marco; Madsen, Marita Grønning; Nikitidou, Litsa; Kirik, Deniz; Kokaia, Merab

    2014-02-26

    Optogenetic techniques provide powerful tools for bidirectional control of neuronal activity and investigating alterations occurring in excitability disorders, such as epilepsy. In particular, the possibility to specifically activate by light-determined interneuron populations expressing channelrhodopsin-2 provides an unprecedented opportunity of exploring their contribution to physiological and pathological network activity. There are several subclasses of interneurons in cortical areas with different functional connectivity to the principal neurons (e.g., targeting their perisomatic or dendritic compartments). Therefore, one could optogenetically activate specific or a mixed population of interneurons and dissect their selective or concerted inhibitory action on principal cells. We chose to explore a conceptually novel strategy involving simultaneous activation of mixed populations of interneurons by optogenetics and study their impact on ongoing epileptiform activity in mouse acute hippocampal slices. Here we demonstrate that such approach results in a brief initial action potential discharge in CA3 pyramidal neurons, followed by prolonged suppression of ongoing epileptiform activity during light exposure. Such sequence of events was caused by massive light-induced release of GABA from ChR2-expressing interneurons. The inhibition of epileptiform activity was less pronounced if only parvalbumin- or somatostatin-expressing interneurons were activated by light. Our data suggest that global optogenetic activation of mixed interneuron populations is a more effective approach for development of novel therapeutic strategies for epilepsy, but the initial action potential generation in principal neurons needs to be taken in consideration.

  12. Mozart K.545 Mimics Mozart K.448 in Reducing Epileptiform Discharges in Epileptic Children

    OpenAIRE

    Lung-Chang Lin; Mei-Wen Lee; Ruey-Chang Wei; Hin-Kiu Mok; Hui-Chuan Wu; Chin-Lin Tsai; Rei-Cheng Yang

    2012-01-01

    Mozart K.448 has been shown to improve cognitive function, leading to what is known as the Mozart Effect. Our previous work reveals positive effects of Mozart K.448 in reducing epileptiform discharges in epileptic children. In this study, we evaluated the effect of Mozart K.545 and compared the effects with those of Mozart K.448 on epileptiform discharges in children with epilepsy. Thirty-nine epileptic children with epileptiform discharges were included in the study. They received electroenc...

  13. Mozart K.545 Mimics Mozart K.448 in Reducing Epileptiform Discharges in Epileptic Children

    OpenAIRE

    Lung-Chang Lin; Mei-Wen Lee; Ruey-Chang Wei; Hin-Kiu Mok; Hui-Chuan Wu; Chin-Lin Tsai; Rei-Cheng Yang

    2012-01-01

    Mozart K.448 has been shown to improve cognitive function, leading to what is known as the Mozart Effect. Our previous work reveals positive effects of Mozart K.448 in reducing epileptiform discharges in epileptic children. In this study, we evaluated the effect of Mozart K.545 and compared the effects with those of Mozart K.448 on epileptiform discharges in children with epilepsy. Thirty-nine epileptic children with epileptiform discharges were included in the study. They received electroenc...

  14. Identification of endogenous reference genes for the analysis of microRNA expression in the hippocampus of the pilocarpine-induced model of mesial temporal lobe epilepsy.

    Directory of Open Access Journals (Sweden)

    Mykaella Andrade de Araújo

    Full Text Available Real-time quantitative RT-PCR (qPCR is one of the most powerful techniques for analyzing miRNA expression because of its sensitivity and specificity. However, in this type of analysis, a suitable normalizer is required to ensure that gene expression is unaffected by the experimental condition. To the best of our knowledge, there are no reported studies that performed a detailed identification and validation of suitable reference genes for miRNA qPCR during the epileptogenic process. Here, using a pilocarpine (PILO model of mesial temporal lobe epilepsy (MTLE, we investigated five potential reference genes, performing a stability expression analysis using geNorm and NormFinder softwares. As a validation strategy, we used each one of the candidate reference genes to measure PILO-induced changes in microRNA-146a levels, a gene whose expression pattern variation in the PILO injected model is known. Our results indicated U6SnRNA and SnoRNA as the most stable candidate reference genes. By geNorm analysis, the normalization factor should preferably contain at least two of the best candidate reference genes (snoRNA and U6SnRNA. In fact, when normalized using the best combination of reference genes, microRNA-146a transcripts were found to be significantly increased in chronic stage, which is consistent with the pattern reported in different models. Conversely, when reference genes were individually employed for normalization, we failed to detect up-regulation of the microRNA-146a gene in the hippocampus of epileptic rats. The data presented here support that the combination of snoRNA and U6SnRNA was the minimum necessary for an accurate normalization of gene expression at the different stages of epileptogenesis that we tested.

  15. Loss of interneurons innervating pyramidal cell dendrites and axon initial segments in the CA1 region of the hippocampus following pilocarpine-induced seizures.

    Science.gov (United States)

    Dinocourt, Celine; Petanjek, Zdravko; Freund, Tamas F; Ben-Ari, Yezekiel; Esclapez, Monique

    2003-05-12

    In the pilocarpine model of chronic limbic seizures, vulnerability of GABAergic interneurons to excitotoxic damage has been reported in the hippocampal CA1 region. However, little is known about the specific types of interneurons that degenerate in this region. In order to characterize these interneurons, we performed quantitative analyses of the different populations of GABAergic neurons labeled for their peptide or calcium-binding protein content. Our data demonstrate that the decrease in the number of GAD mRNA-containing neurons in the stratum oriens of CA1 in pilocarpine-treated rats involved two subpopulations of GABAergic interneurons: interneurons labeled for somatostatin only (O-LM and bistratified cells) and interneurons labeled for parvalbumin only (basket and axo-axonic cells). Stratum oriens interneurons labeled for somatostatin/calbindin or somatostatin/parvalbumin were preserved. The decrease in number of somatostatin- and parvalbumin-containing neurons was observed as early as 72 hours after the sustained seizures induced by pilocarpine injection. Many degenerating cell bodies in the stratum oriens and degenerating axon terminals in the stratum lacunosum-moleculare were observed at 1 and 2 weeks after injection. In addition, the synaptic coverage of the axon initial segment of CA1 pyramidal cells was significantly decreased in pilocarpine-treated animals. These results indicate that the loss of somatostatin-containing neurons corresponds preferentially to the degeneration of interneurons with an axon projecting to stratum lacunosum-moleculare (O-LM cells) and suggest that the death of these neurons is mainly responsible for the deficit of dendritic inhibition reported in this region. We demonstrate that the loss of parvalbumin-containing neurons corresponds to the death of axo-axonic cells, suggesting that perisomatic inhibition and mechanisms controlling action potential generation are also impaired in this model.

  16. Excitatory effects of parvalbumin-expressing interneurons maintain hippocampal epileptiform activity via synchronous afterdischarges.

    Science.gov (United States)

    Ellender, Tommas J; Raimondo, Joseph V; Irkle, Agnese; Lamsa, Karri P; Akerman, Colin J

    2014-11-12

    Epileptic seizures are characterized by periods of hypersynchronous, hyperexcitability within brain networks. Most seizures involve two stages: an initial tonic phase, followed by a longer clonic phase that is characterized by rhythmic bouts of synchronized network activity called afterdischarges (ADs). Here we investigate the cellular and network mechanisms underlying hippocampal ADs in an effort to understand how they maintain seizure activity. Using in vitro hippocampal slice models from rats and mice, we performed electrophysiological recordings from CA3 pyramidal neurons to monitor network activity and changes in GABAergic signaling during epileptiform activity. First, we show that the highest synchrony occurs during clonic ADs, consistent with the idea that specific circuit dynamics underlie this phase of the epileptiform activity. We then show that ADs require intact GABAergic synaptic transmission, which becomes excitatory as a result of a transient collapse in the chloride (Cl(-)) reversal potential. The depolarizing effects of GABA are strongest at the soma of pyramidal neurons, which implicates somatic-targeting interneurons in AD activity. To test this, we used optogenetic techniques to selectively control the activity of somatic-targeting parvalbumin-expressing (PV(+)) interneurons. Channelrhodopsin-2-mediated activation of PV(+) interneurons during the clonic phase generated excitatory GABAergic responses in pyramidal neurons, which were sufficient to elicit and entrain synchronous AD activity across the network. Finally, archaerhodopsin-mediated selective silencing of PV(+) interneurons reduced the occurrence of ADs during the clonic phase. Therefore, we propose that activity-dependent Cl(-) accumulation subverts the actions of PV(+) interneurons to perpetuate rather than terminate pathological network hyperexcitability during the clonic phase of seizures.

  17. Effects of thyroxine and dexamethasone on rat submandibular glands

    Energy Technology Data Exchange (ETDEWEB)

    Sagulin, G.B.; Roomans, G.M. (Karolinska Institutet, Huddinge (Sweden))

    1989-08-01

    Glucocorticoids and thyroxine are known to have a marked effect on the flow rate and protein composition of rat parotid saliva in hormonally intact animals. In the present study, the effects of a one-week treatment of male rats with dexamethasone and thyroxine were studied by electron microscopy and x-ray micro-analysis, and by measurement of the flow rate and determination of the chemical composition of pilocarpine-induced submandibular saliva. Thyroxine had the most extensive effects on the submandibular gland. The acinar cells were enlarged and filled with mucus; the cellular calcium concentration was significantly increased. The flow rate of the submandibular saliva was significantly reduced compared with that in saline-injected control animals. Thyroxine caused an increase in the concentrations of protein, total calcium, and potassium in the saliva. Dexamethasone had no significant effects on gland ultrastructure or on the elemental composition of the acinar cells; flow rate was not affected, but the concentrations of protein, calcium, and potassium were significantly increased. The effects of dexamethasone and thyroxine on the flow rate and protein composition of pilocarpine-induced rat submandibular saliva differ from those reported earlier for rat parotid saliva after simultaneous stimulation with pilocarpine and isoproterenol.

  18. Identification of the epileptogenic zone in patients with tuberous sclerosis : Concordance of interictal and ictal epileptiform activity

    NARCIS (Netherlands)

    van der Heide, Astrid; van Huffelen, Alexander C.; Spetgens, Willy P. J.; Ferrier, Cyrille H.; van Nieuwenhuizen, Onno; Jansen, Floor E.

    2010-01-01

    Objective: In the majority of patients with tuberous sclerosis complex (TSC) multifocal epileptiform activity is present interictally. Therefore, its value in identifying epilepsy surgery candidates has been doubted. We hypothesize that dominant interictal epileptiform foci are concordant with the i

  19. Computer-assisted detection of epileptiform focuses on SPECT images

    Science.gov (United States)

    Grzegorczyk, Dawid; Dunin-Wąsowicz, Dorota; Mulawka, Jan J.

    2010-09-01

    Epilepsy is a common nervous system disease often related to consciousness disturbances and muscular spasm which affects about 1% of the human population. Despite major technological advances done in medicine in the last years there was no sufficient progress towards overcoming it. Application of advanced statistical methods and computer image analysis offers the hope for accurate detection and later removal of an epileptiform focuses which are the cause of some types of epilepsy. The aim of this work was to create a computer system that would help to find and diagnose disorders of blood circulation in the brain This may be helpful for the diagnosis of the epileptic seizures onset in the brain.

  20. Mozart K.545 Mimics Mozart K.448 in Reducing Epileptiform Discharges in Epileptic Children

    Directory of Open Access Journals (Sweden)

    Lung-Chang Lin

    2012-01-01

    Full Text Available Mozart K.448 has been shown to improve cognitive function, leading to what is known as the Mozart Effect. Our previous work reveals positive effects of Mozart K.448 in reducing epileptiform discharges in epileptic children. In this study, we evaluated the effect of Mozart K.545 and compared the effects with those of Mozart K.448 on epileptiform discharges in children with epilepsy. Thirty-nine epileptic children with epileptiform discharges were included in the study. They received electroencephalogram examinations before, during, and after listening to Mozart K.448 and K.545, one week apart, respectively. The frequencies of epileptiform discharges were compared. There was a significant decrease in the frequency of epileptiform discharges during and right after listening to Mozart K.448 and K.545 (reduced by 35.7±32.7% during Mozart K.448 and 30.3±44.4% after Mozart K.448; and 34.0±39.5% during Mozart K.545 and 31.8±39.2% after Mozart K.545. Spectrogrammatic analysis of the two pieces of music demonstrated that both share similar spectrogrammatic characteristics. Listening to Mozart K.448 and K.545 decreased the epileptiform discharges in epileptic children. This suggests that Mozart K.448 is not the only piece of music to have beneficial effects on children with epilepsy. Other music with lower harmonics may also decrease epileptiform discharges in epileptic children.

  1. Mozart k.545 mimics mozart k.448 in reducing epileptiform discharges in epileptic children.

    Science.gov (United States)

    Lin, Lung-Chang; Lee, Mei-Wen; Wei, Ruey-Chang; Mok, Hin-Kiu; Wu, Hui-Chuan; Tsai, Chin-Lin; Yang, Rei-Cheng

    2012-01-01

    Mozart K.448 has been shown to improve cognitive function, leading to what is known as the Mozart Effect. Our previous work reveals positive effects of Mozart K.448 in reducing epileptiform discharges in epileptic children. In this study, we evaluated the effect of Mozart K.545 and compared the effects with those of Mozart K.448 on epileptiform discharges in children with epilepsy. Thirty-nine epileptic children with epileptiform discharges were included in the study. They received electroencephalogram examinations before, during, and after listening to Mozart K.448 and K.545, one week apart, respectively. The frequencies of epileptiform discharges were compared. There was a significant decrease in the frequency of epileptiform discharges during and right after listening to Mozart K.448 and K.545 (reduced by 35.7 ± 32.7% during Mozart K.448 and 30.3 ± 44.4% after Mozart K.448; and 34.0 ± 39.5% during Mozart K.545 and 31.8 ± 39.2% after Mozart K.545). Spectrogrammatic analysis of the two pieces of music demonstrated that both share similar spectrogrammatic characteristics. Listening to Mozart K.448 and K.545 decreased the epileptiform discharges in epileptic children. This suggests that Mozart K.448 is not the only piece of music to have beneficial effects on children with epilepsy. Other music with lower harmonics may also decrease epileptiform discharges in epileptic children.

  2. Epileptiform synchronization and high-frequency oscillations in brain slices comprising piriform and entorhinal cortices.

    Science.gov (United States)

    Hamidi, S; Lévesque, M; Avoli, M

    2014-12-05

    We employed field potential recordings in extended in vitro brain slices form Sprague-Dawley rats containing the piriform and entorhinal cortices (PC and EC, respectively) to identify the characteristics of epileptiform discharges and concomitant high-frequency oscillations (HFOs, ripples: 80-200Hz, fast ripples: 250-500Hz) during bath application of 4-aminopyridine (4AP, 50μM). Ictal-like discharges occurred in PC and EC either synchronously or independently of each other; synchronous ictal discharges always emerged from a synchronous "fast" interictal background whereas asynchronous ictal discharges were preceded by a "slow" interictal event. In addition, asynchronous ictal discharges had longer duration and interval of occurrence than synchronous ictal discharges, and contained a higher proportion of ripples and fast ripples. Cutting the connections between PC and EC made synchronicity disappear and increased ictal discharges duration in the EC but failed in changing HFO occurrence in both areas. Finally, antagonizing ionotropic glutamatergic receptors abolished ictal activity in all experiments, increased the duration and rate of occurrence of interictal discharges occurring in PC-EC interconnected slices while it did not influence the slow asynchronous interictal discharges in both areas. Our results identify some novel in vitro interactions between olfactory (PC) and limbic (EC) structures that presumably contribute to in vivo ictogenesis as well.

  3. Neurosteroids modulate epileptiform activity and associated high-frequency oscillations in the piriform cortex.

    Science.gov (United States)

    Herrington, R; Lévesque, M; Avoli, M

    2014-01-03

    Allotetrahydrodeoxycorticosterone (THDOC) belongs to a class of pregnane neurosteroidal compounds that enhance brain inhibition by interacting directly with GABAA signaling, mainly through an increase in tonic inhibitory current. Here, we addressed the role of THDOC in the modulation of interictal- and ictal-like activity and associated high-frequency oscillations (HFOs, 80-500 Hz; ripples: 80-200 Hz, fast ripples: 250-500 Hz) recorded in vitro in the rat piriform cortex, a highly excitable brain structure that is implicated in seizure generation and maintenance. We found that THDOC: (i) increased the duration of interictal discharges in the anterior piriform cortex while decreasing ictal discharge duration in both anterior and posterior piriform cortices; (ii) reduced the occurrence of HFOs associated to both interictal and ictal discharges; and (iii) prolonged the duration of 4-aminopyridine-induced, glutamatergic independent synchronous field potentials that are known to mainly result from the activation of GABAA receptors. Our results indicate that THDOC can modulate epileptiform synchronization in the piriform cortex presumably by potentiating GABAA receptor-mediated signaling. This evidence supports the view that neurosteroids regulate neuronal excitability and thus control the occurrence of seizures.

  4. Automatic Identification of Interictal Epileptiform Discharges in Secondary Generalized Epilepsy

    Directory of Open Access Journals (Sweden)

    Won-Du Chang

    2016-01-01

    Full Text Available Ictal epileptiform discharges (EDs are characteristic signal patterns of scalp electroencephalogram (EEG or intracranial EEG (iEEG recorded from patients with epilepsy, which assist with the diagnosis and characterization of various types of epilepsy. The EEG signal, however, is often recorded from patients with epilepsy for a long period of time, and thus detection and identification of EDs have been a burden on medical doctors. This paper proposes a new method for automatic identification of two types of EDs, repeated sharp-waves (sharps, and runs of sharp-and-slow-waves (SSWs, which helps to pinpoint epileptogenic foci in secondary generalized epilepsy such as Lennox-Gastaut syndrome (LGS. In the experiments with iEEG data acquired from a patient with LGS, our proposed method detected EDs with an accuracy of 93.76% and classified three different signal patterns with a mean classification accuracy of 87.69%, which was significantly higher than that of a conventional wavelet-based method. Our study shows that it is possible to successfully detect and discriminate sharps and SSWs from background EEG activity using our proposed method.

  5. Control of epileptiform bursting in the leech heart interneuron

    Science.gov (United States)

    Barnett, William; Anquez, Martin; Harris, Torrey; Cymbalyuk, Gennady

    2009-11-01

    The network controlling heartbeat in the medicinal leech contains leech heart interneurons (HNs). We modeled them under specific pharmacological conditions. The Ca^2+ currents were blocked by Co^2+. The K^+ currents, apart from the non-inactivating current, IK2, were blocked by 4AP. The hyperpolarization-activated current, Ih, was blocked by Cs^+. Under these conditions, epileptiform bursting characterized by long interburst intervals (IBI) has been shown. We considered three distinct cases. Model 1 included IK2, Ih, and the fast Na^+ current, INa. Model 2 was characterized by INa, IK2, and the persistent Na^+ current, INaP. Model 3 consisted of INa, IK2, Ih, and INaP. We also investigated the bi-stability of bursting and silence as the leak conductance, gleak, was varied. We showed that in 1 and 3, model HNs demonstrated bi-stability of silence and bursting. We analyzed how IBI and burst duration are controlled by the manipulation of Ih and INaP. In 1, as V1/2 of Ih decreased, IBI grew towards infinity one over the square root of the parameter difference. In 2, we showed that as gNaP decreased from 6.156 nS to 6.155 nS, IBI grew in accordance with the one over square root law. The system underwent a saddle-node bifurcation just below 6.155 nS. Supported by NSF PHY-0750456.

  6. The expression of Rho kinase 2 in the brain of rat after pilocarpine-induced status epilepticus%Rho激酶2在急性期癫痫大鼠脑内表达变化的研究

    Institute of Scientific and Technical Information of China (English)

    靳俊功; 张华; 刘备; 武昊; 李焕发; 杨倩丽

    2013-01-01

    目的 观察Rbo激酶2(ROCK2)在癫痫大鼠脑内的表达情况及其抑制剂法舒地尔对癫痫大鼠脑电图的影响.方法 75只SD大鼠随机分入正常对照组、6h组、1d组、3d组、5d组、7d组、空白组、癫痫组和法舒地尔组.腹腔注射氯化锂—匹鲁卡品建立癫痫模型.通过免疫组织化学和Westem blot方法,比较各组大鼠颞叶、海马区ROCK2表达的差异;对空白组、癫痫组及法舒地尔组大鼠进行脑电监测,分析脑电图变化.结果 在海马组织中,3d组、5d组ROCK2的表达水平较对照组升高,差异有统计学意义(P<0.05);在颞叶脑组织中,3d组、5d组、7d组ROCK2的表达水平较对照组均明显升高,差异有统计学意义(P<0.05).免疫荧光结果显示正常组大鼠与实验组大鼠的海马组织中ROCK2(绿色)与NeuN(红色)在神经元中共表达;颞叶脑组织中ROCK2(绿色)与GFAP(红色)在星形胶质细胞中共表达.脑电监测结果显示空白组大鼠脑电正常.癫痫组大鼠在给予匹鲁卡品约28min后出现痫样放电波形.与癫痫组大鼠相比,法舒地尔组大鼠出现痫样波形的潜伏时间明显延长,频率明显降慢、幅度明显降低(P<0.05)).结论 癫痫发作将上调大鼠颞叶和海马区ROCK2的表达,ROCK2抑制剂法舒地尔具有一定的抗癫痫作用.

  7. Effects of UPP on PSD95/NR2B expression in rats with pilocarpine-induced epilepsy%UPP对匹罗卡品致痫大鼠PSD95/NR2B表达的影响

    Institute of Scientific and Technical Information of China (English)

    张杰; 陈阳美

    2010-01-01

    目的 研究泛素-蛋白酶体途径(UPP)对匹罗卡品致痫大鼠海马突触后致密物质-95(PSD95)/ N-甲基-D-天(门)冬氨酸2B受体(NR2B)表达的影响及其在癫痫发生和发展中的作用.方法 用免疫荧光方法检测匹罗卡品致痫大鼠及经UPP抑制剂(MG-132)预处理大鼠海马PSD95/NR2B的表达,并观察组织病理学变化.结果 MG-132能明显抑制匹罗卡品致痫大鼠海马PSD95/NR2B表达下调,并且明显加重致痫大鼠海马神经元损伤.结论 UPP能调控匹罗卡品致痫大鼠海马PSD95/NR2B的表达.

  8. Effect of medication withdrawal on the interictal epileptiform EEG discharges in presurgical evaluation

    DEFF Research Database (Denmark)

    Andersen, N.B.; Alving, J.; Beniczky, S.

    2010-01-01

    Medication withdrawal (MW) is an important method of provoking seizures and activating epileptiform EEG activity during the diagnostic work-up of patients evaluated for epilepsy surgery. Previously it was suggested that MW might influence the seizure-type and activate cortical areas otherwise...... not producing epileptiform discharges, leading to a false localization of the irritative zone. In order to investigate this we reviewed 42 consecutive cases of MW, of 36 patients, during a 3-year period. We compared seizure frequency, seizure-types and the localization of interictal epileptiform discharges...... MW. In one-third of the patients the interictal EEGs after the MW were different from those recorded before the MW. However, in these discordant cases the EEG findings after the MW (and not before the MW) were concordant with the seizure onset zone and the lesional zone. We conclude that MW...

  9. Effects of Cornus mas L. and Morus rubra L. extracts on penicillin-induced epileptiform activity: an electrophysiological and biochemical study.

    Science.gov (United States)

    Tubaş, Filiz; Per, Sedat; Taşdemir, Abdulkadir; Bayram, Ayşe Kaçar; Yıldırım, Mehmet; Uzun, Aydın; Saraymen, Recep; Gümüş, Hakan; Elmalı, Ferhan; Per, Hüseyin

    2017-01-01

    Traditionally, Morus rubra L. (Moraceae) (red mulberry) and Cornus mas L. (Cornacea) (cornelian cherry) fruits are eaten fresh and are also used in marmalades, juices, jam, natural dyes in Turkey and are believed to have beneficial effects in case of multiple health issues such as antipyretic, diarrhea and intestinal parasites. However, the effects of M. rubra and C. mas on epilepsy has not been known. This study evaluates the effects of M. rubra and C. mas extracts on penicillin-induced epileptiform activity. Sixty Wistar rats randomly divided into ten groups (n=6): control, sham, penicillin, penicillin+M. rubra extract (2.5, 5, 10, 20 mg/kg) and penicillin+C. mas extract (2.5, 5, 10 mg/kg). Epileptiform activity was induced by using penicillin (500 IU, i.c.) and electrocorticogram records (150 min) were obtained. Also, biochemical analysis in blood samples were evaluated. According to the electrocorticogram analysis, the effective dose was detected as 10 mg/kg for both C. mas and M. rubra. This dose decreased the spike frequencies of convulsions while amplitude wasn't changed by both substances. In erythrocyte studies, there were significant differences regarding nitric oxide in the control, sham and penicillin groups. There were significant differences regarding malondialdehyde in all groups. In the plasma, there were significant differences among groups regarding xanthine oxidase in the penicillin‑C. mas and penicillin‑M. rubra groups. There were differences regarding malondialdehyde in the penicillin-C. mas and M. rubra-C. mas groups. Both extracts reduced the frequency of epileptiform activity. After administration of the extracts malondialdehyde levels decreased also in both erythrocytes and plasma.

  10. Resilience of developing brain networks to interictal epileptiform discharges is associated with cognitive outcome.

    Science.gov (United States)

    Ibrahim, George M; Cassel, Daniel; Morgan, Benjamin R; Smith, Mary Lou; Otsubo, Hiroshi; Ochi, Ayako; Taylor, Margot; Rutka, James T; Snead, O Carter; Doesburg, Sam

    2014-10-01

    The effects of interictal epileptiform discharges on neurocognitive development in children with medically-intractable epilepsy are poorly understood. Such discharges may have a deleterious effect on the brain's intrinsic connectivity networks, which reflect the organization of functional networks at rest, and in turn on neurocognitive development. Using a combined functional magnetic resonance imaging-magnetoencephalography approach, we examine the effects of interictal epileptiform discharges on intrinsic connectivity networks and neurocognitive outcome. Functional magnetic resonance imaging was used to determine the location of regions comprising various intrinsic connectivity networks in 26 children (7-17 years), and magnetoencephalography data were reconstructed from these locations. Inter-regional phase synchronization was then calculated across interictal epileptiform discharges and graph theoretical analysis was applied to measure event-related changes in network topology in the peri-discharge period. The magnitude of change in network topology (network resilience/vulnerability) to interictal epileptiform discharges was associated with neurocognitive outcomes and functional magnetic resonance imaging networks using dual regression. Three main findings are reported: (i) large-scale network changes precede and follow interictal epileptiform discharges; (ii) the resilience of network topologies to interictal discharges is associated with stronger resting-state network connectivity; and (iii) vulnerability to interictal discharges is associated with worse neurocognitive outcomes. By combining the spatial resolution of functional magnetic resonance imaging with the temporal resolution of magnetoencephalography, we describe the effects of interictal epileptiform discharges on neurophysiological synchrony in intrinsic connectivity networks and establish the impact of interictal disruption of functional networks on cognitive outcome in children with epilepsy. The

  11. Topographic congruence of calcified parenchymal neurocysticercosis and other structural brain lesions with epileptiform activity

    Science.gov (United States)

    Saito, Erin K; Nagpal, Meera; Leon, Amanda; Mehta, Bijal; McMurtray, Aaron Matthew

    2016-01-01

    Introduction: Calcified parenchymal neurocysticercosis (NCC) lesions are commonly detected in many individuals with refractory epilepsy. However, the relationship between these lesions and epilepsy is not fully determined. We sought to determine if calcified parenchymal NCC demonstrated topographic congruence with epileptiform activity in refractory epilepsy patients. Additional patients with other structural brain lesions were included for comparison. Subjects and Methods: Retrospective cross-sectional analysis of all patients treated at a community-based neurology clinic for refractory epilepsy during a 3-month period and with structural brain lesions detected by neuroimaging studies. Results: A total of 105 patients were included in the study, including 63 with calcified parenchymal NCC lesions and 42 with other structural brain lesions. No significant relationship was detected between hemispheric localization of calcified parenchymal NCC lesions and epileptiform activity. For those with other structural brain lesions, the hemispheric localization was significantly related to the side of epileptiform activity (Chi-square = 11.13, P = 0.025). In addition, logistic regression models showed that those with right-sided non-NCC lesions were more likely to have right-sided epileptiform activity (odds ratio = 4.36, 95% confidence interval [CI] =1.16–16.31, P = 0.029), and those with left-sided non-NCC lesions were more likely to have left-sided epileptiform activity (odds ratio = 7.60, 95% CI = 1.89–30.49, P = 0.004). Conclusion: The lack of correlation between the side of calcified parenchymal NCC lesions and the side of the epileptiform activity suggests that these lesions may be incidental findings in many patients. PMID:26998434

  12. Mozart K.448 and epileptiform discharges: effect of ratio of lower to higher harmonics.

    Science.gov (United States)

    Lin, Lung-Chang; Lee, Wei-Te; Wu, Hui-Chuan; Tsai, Chin-Lin; Wei, Ruey-Chang; Jong, Yuh-Jyh; Yang, Rei-Cheng

    2010-05-01

    Certain music has been shown to improve mental function, leading to what is known as the Mozart effect. This study measured the impact of Mozart's Sonata for two pianos in D major, K.448, on different epileptic foci of epileptiform discharge in Taiwanese children (n=58) with seizure disorders and investigated the characteristics of the musical stimulus presented that resulted in epileptiform discharge reduction. We examined the relationship between the number of discharges with the foci of epileptiform discharge (n=6), sleep state, gender, and mentality. A continuous electroencephalogram was recorded before, during and after exposure to Mozart's Sonata for two pianos in D major, K.448 (piano K.448), and the frequencies of discharges were compared. The study was repeated a week later using digitally computerized string version of the same musical stimulus (string K.448), in patients who responded to piano K.448 with the largest reduction in interictal discharges (n=11). Interictal discharges were reduced in most (81.0%) patients and varied greatly (33.10+/-28.33%) as they listened to the piano K.448 (more fundamental tones and lower harmonics). Patients with generalized or central discharge showed the most improvement. In most patients (76.1%), the decrease in epileptiform discharges continued after the music ended. The state of wakefulness, gender and mentality did not affect the results. Although the string K.448 had a larger number of higher harmonics in the spectrogram analysis, the discharges were not reduced at all when listening to this music. These results suggest that listening to Mozart K.448 for two pianos reduced epileptiform discharges in children with epilepsy. This study suggests that it is possible to reduce the number of epileptiform discharges in some patients by optimizing the fundamental tones and minimizing the higher frequency harmonics. Copyright 2010 Elsevier B.V. All rights reserved.

  13. Protective Effects of Cannabidiol against Seizures and Neuronal Death in a Rat Model of Mesial Temporal Lobe Epilepsy.

    Science.gov (United States)

    Do Val-da Silva, Raquel A; Peixoto-Santos, Jose E; Kandratavicius, Ludmyla; De Ross, Jana B; Esteves, Ingrid; De Martinis, Bruno S; Alves, Marcela N R; Scandiuzzi, Renata C; Hallak, Jaime E C; Zuardi, Antonio W; Crippa, Jose A; Leite, Joao P

    2017-01-01

    The present study reports the behavioral, electrophysiological, and neuropathological effects of cannabidiol (CBD), a major non-psychotropic constituent of Cannabis sativa, in the intrahippocampal pilocarpine-induced status epilepticus (SE) rat model. CBD was administered before pilocarpine-induced SE (group SE+CBDp) or before and after SE (group SE+CBDt), and compared to rats submitted only to SE (SE group), CBD, or vehicle (VH group). Groups were evaluated during SE (behavioral and electrophysiological analysis), as well as at days one and three post-SE (exploratory activity, electrophysiological analysis, neuron density, and neuron degeneration). Compared to SE group, SE+CBD groups (SE+CBDp and SE+CBDt) had increased SE latency, diminished SE severity, increased contralateral afterdischarge latency and decreased relative powers in delta (0.5-4 Hz) and theta (4-10 Hz) bands. Only SE+CBDp had increased vertical exploratory activity 1-day post SE and decreased contralateral relative power in delta 3 days after SE, when compared to SE group. SE+CBD groups also showed decreased neurodegeneration in the hilus and CA3, and higher neuron density in granule cell layer, hilus, CA3, and CA1, when compared to SE group. Our findings demonstrate anticonvulsant and neuroprotective effects of CBD preventive treatment in the intrahippocampal pilocarpine epilepsy model, either as single or multiple administrations, reinforcing the potential role of CBD in the treatment of epileptic disorders.

  14. Parasympathetic activation is involved in reducing epileptiform discharges when listening to Mozart music.

    Science.gov (United States)

    Lin, Lung-Chang; Chiang, Ching-Tai; Lee, Mei-Wen; Mok, Hin-Kiu; Yang, Yi-Hsin; Wu, Hui-Chuan; Tsai, Chin-Lin; Yang, Rei-Cheng

    2013-08-01

    Listening to Mozart K.448 has been demonstrated to improve spatial task scores, leading to what is known as the Mozart effect. Our previous work revealed the positive effects of Mozart K.448 in reducing epileptiform discharges in children with epilepsy. However, the mechanism remains unclear. parasympathetic activation has been shown to help seizure control in many studies. In this study, we investigated the effect of Mozart music on epileptiform discharges and autonomic activity. Sixty-four epileptic children with epileptiform discharges were included. They all received electroencephalogram and electrocardiogram examinations simultaneously before, during, and after listening to Mozart K.448 or K.545. The total number of epileptiform discharges during each session (before, during, and after music) were divided by the duration (in minutes) of the session and then compared. Heart rate variability including time and frequency domain analysis was used to represent the autonomic function. The results showed that epileptiform discharges were significantly reduced during and right after listening to Mozart music (33.3 ± 31.1% reduction, pMozart K.448 and 38.6 ± 43.3% reduction, pMozart K.545) (28.1 ± 43.2% reduction, pMozart K.448 and 46.0 ± 40.5% reduction, pMozart K.545). No significant difference was noticed between the two pieces of music. The reduction was greatest in patients with generalized seizures and discharges. Significant increases in high-frequency (HF), the square root of the mean squared differences of successive RR intervals (RMSSD), the standard deviation of differences between adjacent RR intervals (SDSD), and a decrease in mean beats per minute (bpm) were found during listening to Mozart music. Most of the patients with reduced epileptiform discharges also showed a decreased LF/HF ratio, low-frequency normalized units (LF nu), mean bpm, and an increased high-frequency normalized units (HF nu). Listening to Mozart music decreased epileptiform

  15. Characterization of the in vitro propagation of epileptiform electrophysiological activity in organotypic hippocampal slice cultures coupled to 3D microelectrode arrays

    DEFF Research Database (Denmark)

    Pisciotta, Marzia; Morgavi, Giovanna; Jahnsen, Henrik

    2010-01-01

    Dynamic aspects of the propagation of epileptiform activity have so far received little attention. With the aim of providing new insights about the spatial features of the propagation of epileptic seizures in the nervous system, we studied in vitro the initiation and propagation of traveling epil......AnimalsAnimals, NewbornConvulsants/pharmacologyElectric Stimulation/methodsElectrophysiological Phenomena/drug effectsElectrophysiological Phenomena/physiology*Evoked Potentials/drug effectsEvoked Potentials/physiology*Hippocampus/anatomy & histologyHippocampus/drug effects......Hippocampus/physiology*Microelectrodes*Organ Culture TechniquesPicrotoxin/pharmacologyRatsRats, WistarReaction Time/drug effectsReaction Time/physiologyTime FactorsSubstancesConvulsantsPicrotoxin LinkOut - more resourcesFull Text SourcesElsevier ScienceEBSCOOhioLINK Electronic Journal CenterSwets Information ServicesMolecular Biology Databases...

  16. Effects of isoflurane anesthesia and pilocarpine on rat parotid saliva flow

    DEFF Research Database (Denmark)

    Knudsen, Jacob Dronninglund; Nauntofte, Birgitte; Josipovic, M

    2011-01-01

    The purpose of this study was to investigate the effects of isoflurane on unstimulated and pilocarpine-stimulated parotid saliva secretion. Ten male Sprague-Dawley rats weighing 350-400 g were randomized into two groups, and the saliva flow rate and lag phase were measured at two doses...... of isoflurane in a crossover study design. Increasing the isoflurane concentration from 1% to 2% was associated with a 19% decrease in saliva secretion rate, and the lag to saliva secretion was increased by 155%. To clarify whether the effect of isoflurane (1.5%) on the parotid flow varied with stimulus...... rats was 50% slower than that of the sham-irradiated rats. In conclusion, 1.5% isoflurane was found to be a good compromise between proper anesthesia and isoflurane-induced inhibition of saliva secretion. Pilocarpine induces saliva secretion in a dose-dependent matter, with supra-maximal stimulation...

  17. Epileptiform activity and spreading depolarization in the blood-brain barrier-disrupted peri-infarct hippocampus are associated with impaired GABAergic inhibition and synaptic plasticity.

    Science.gov (United States)

    Lippmann, Kristina; Kamintsky, Lyn; Kim, Soo Young; Lublinsky, Svetlana; Prager, Ofer; Nichtweiss, Julia Friederike; Salar, Seda; Kaufer, Daniela; Heinemann, Uwe; Friedman, Alon

    2017-05-01

    Peri-infarct opening of the blood-brain barrier may be associated with spreading depolarizations, seizures, and epileptogenesis as well as cognitive dysfunction. We aimed to investigate the mechanisms underlying neural network pathophysiology in the blood-brain barrier-dysfunctional hippocampus. Photothrombotic stroke within the rat neocortex was associated with increased intracranial pressure, vasogenic edema, and peri-ischemic blood-brain barrier dysfunction that included the ipsilateral hippocampus. Intrahippocampal recordings revealed electrographic seizures within the first week in two-thirds of animals, accompanied by a reduction in gamma and increase in theta frequency bands. Synaptic interactions were studied in parasagittal hippocampal slices at 24 h and seven days post-stroke. Field potential recordings in CA1 and CA3 uncovered multiple population spikes, epileptiform episodes, and spreading depolarizations at 24 h. Input-output analysis revealed that fEPSP-spike coupling was significantly enhanced at seven days. In addition, CA1 feedback and feedforward inhibition were diminished. Slices generating epileptiform activity at seven days revealed impaired bidirectional long-term plasticity following high and low-frequency stimulation protocols. Microarray and PCR data confirmed changes in expression of astrocyte-related genes and suggested downregulation in expression of GABAA-receptor subunits. We conclude that blood-brain barrier dysfunction in the peri-infarct hippocampus is associated with early disinhibition, hyperexcitability, and abnormal synaptic plasticity.

  18. Ongoing epileptiform activity in the post-ischemic hippocampus is associated with a permanent shift of the excitatory-inhibitory synaptic balance in CA3 pyramidal neurons.

    Science.gov (United States)

    Epsztein, Jérôme; Milh, Mathieu; Bihi, Rachid Id; Jorquera, Isabel; Ben-Ari, Yehezkel; Represa, Alfonso; Crépel, Valérie

    2006-06-28

    Ischemic strokes are often associated with late-onset epilepsy, but the underlying mechanisms are poorly understood. In the hippocampus, which is one of the regions most sensitive to ischemic challenge, global ischemia induces a complete loss of CA1 pyramidal neurons, whereas the resistant CA3 pyramidal neurons display a long-term hyperexcitability several months after the insult. The mechanisms of this long-term hyperexcitability remain unknown despite its clinical implication. Using chronic in vivo EEG recordings and in vitro field recordings in slices, we now report spontaneous interictal epileptiform discharges in the CA3 area of the hippocampus from post-ischemic rats several months after the insult. Whole-cell recordings from CA3 pyramidal neurons, revealed a permanent reduction in the frequency of spontaneous and miniature GABAergic IPSCs and a parallel increase in the frequency of spontaneous and miniature glutamatergic postsynaptic currents. Global ischemia also induced a dramatic loss of GABAergic interneurons and terminals together with an increase in glutamatergic terminals in the CA3 area of the hippocampus. Altogether, our results show a morpho-functional reorganization in the CA3 network several months after global ischemia, resulting in a net shift in the excitatory-inhibitory balance toward excitation that may constitute a substrate for the generation of epileptiform discharges in the post-ischemic hippocampus.

  19. SYNDROMES OF BEHAVIORAL AND SPEECH DISORDERS ASSOCIATED WITH BENIGN EPILEPTIFORM DISCHARGES OF CHILDHOOD ON ELECTROENCEPHALOGRAM

    Directory of Open Access Journals (Sweden)

    I. A. Sadekov

    2017-01-01

    Full Text Available Objective: to assess the role and significance of benign epileptiform discharges of childhood (BEDC on electroencephalogram (EEG in development of speech and behaviorial disorders in children.Materials and methods. 90 children aged 3–7 years were included in the study: 30 of them were healthy, 30 had attention deficit hyperactivity disorder (ADHD, and 30 had expressive language disorder (ELD. We analyzed the role of persistent epileptiform activity (BEDC type in EEG as well as frontal intermittent rhythmic delta activity in the development of some neuropsychiatric disorders and speech disorders in children.Results. We suggest to allocate a special variant of ADHD – epileptiform disintegration of behavior; we also propose the strategies for its therapeutic correction.Conclusion. Detection of epileptiform activity (BEDC type on EEG in children with ELD is a predictor of cognitive disorders development and requires therapeutic correction, which should be aimed at stimulation of brain maturation. Detection of frontal intermittent rhythmic delta activity in children with ELD requires neurovisualization with further determining of treatment strategy.

  20. A self-adapting system for the automated detection of inter-ictal epileptiform discharges

    NARCIS (Netherlands)

    Lodder, S.S.; Putten, van M.J.A.M.

    2014-01-01

    Purpose Scalp EEG remains the standard clinical procedure for the diagnosis of epilepsy. Manual detection of inter-ictal epileptiform discharges (IEDs) is slow and cumbersome, and few automated methods are used to assist in practice. This is mostly due to low sensitivities, high false positive rates

  1. Spatiotemporal mapping of interictal epileptiform discharges in human absence epilepsy: A MEG study

    NARCIS (Netherlands)

    Rozendaal, Y.J.W.; Luijtelaar, E.L.J.M. van; Ossenblok, P.P.W.

    2016-01-01

    PURPOSE: Although absence epilepsy is considered to be a prototypic type of generalized epilepsy, it is still under debate whether generalized 3 Hz spike-and-wave discharges (SWDs) might have a cortical focal origin. Here it is investigated whether focal interictal epileptiform discharges (IEDs),

  2. Chlordiazepoxide and diazepam induced mouse killing by rats.

    Science.gov (United States)

    Leaf, R C; Wnek, D J; Gay, P E; Corcia, R M; Lamon, S

    1975-10-14

    Chlordiazepoxide HCl, at dose levels from 2.5 mg/kg to 80 mg/kg, significantly increased the low base rates of mouse killing (3-9%) observed in large samples (N = 100/dose) of Holtzman strain albino male rats. Maximal killing rates were obtained at doses from 7.5 mg/kg to 20 mg/kg. Diazepam was equally effective, and several times more potent than chlordiazepoxide. Pentobarbital did not increase killing. Killing induced by chlordiazepoxide was blocked by d-amphetamine SO4, but not by l-amphetamine, at dose levels similar to those that block undrugged killing in this strain (ED50 = 1.5 mg/kg). Unlike pilocarpine-induced killing, the effects of chlordiazepoxide were not increased or decreased significantly by either peripherally or centrally active anticholinergic drugs, over wide dose ranges of these agents; nor were the effects of chlordiazepoxide increased by repeated daily administration.

  3. Incidence of epileptiform EEG activity in children during mask induction of anaesthesia with brief administration of 8% sevoflurane.

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    Barbara Schultz

    Full Text Available BACKGROUND: A high incidence of epileptiform activity in the electroencephalogram (EEG was reported in children undergoing mask induction of anaesthesia with administration of high doses of sevoflurane for 5 minutes and longer. This study was performed to investigate whether reducing the time of exposure to a high inhaled sevoflurane concentration would affect the incidence of epileptiform EEG activity. It was hypothesized that no epileptiform activity would occur, when the inhaled sevoflurane concentration would be reduced from 8% to 4% immediately after the loss of consciousness. METHODOLOGY/PRINCIPAL FINDINGS: 70 children (age 7-96 months, ASA I-II, premedication with midazolam were anaesthetized with 8% sevoflurane in 100% oxygen via face mask. Immediately after loss of consciousness, the sevoflurane concentration was reduced to 4%. EEGs were recorded continuously and were later analyzed visually with regard to epileptiform EEG patterns. Sevoflurane at a concentration of 8% was given for 1.2 ± 0.4 min (mean ± SD. In 14 children (20% epileptiform EEG patterns without motor manifestations were observed (delta with spikes (DSP, rhythmic polyspikes (PSR, epileptiform discharges (PED in 10, 10, 4 children (14%, 14%, 6%. 38 children (54% had slow, rhythmic delta waves with high amplitudes (DS appearing on average before DSP. CONCLUSIONS/SIGNIFICANCE: The hypothesis that no epileptiform potentials would occur during induction of anaesthesia with a reduction of the inspired sevoflurane concentration from 8% to 4% directly after LOC was not proved. Even if 8% sevoflurane is administered only briefly for induction of anaesthesia, epileptiform EEG activity may be observed in children despite premedication with midazolam.

  4. The long-term effect of listening to Mozart K.448 decreases epileptiform discharges in children with epilepsy.

    Science.gov (United States)

    Lin, Lung-Chang; Lee, Wei-Te; Wu, Hui-Chuan; Tsai, Chin-Lin; Wei, Ruey-Chang; Mok, Hin-Kiu; Weng, Chia-Fen; Lee, Mei-wen; Yang, Rei-Cheng

    2011-08-01

    Mozart's Sonata for Two Pianos in D major, K.448 (Mozart K.448), has been shown to improve mental function, leading to what is known as the Mozart Effect. Our previous work revealed that epileptiform discharges in children with epilepsy decrease during and right after listening to Mozart K.448. However, the duration of the effect was not studied. In the study described here, we evaluated the long-term effect of Mozart K.448 on epileptiform discharges in children with epilepsy. Eighteen children with epilepsy whose seizures were clinically well controlled with antiepileptic drugs were included. For each child, EEGs had revealed persistent epileptiform discharges for at least 6 months. These patients listened to Mozart K.448 for 8 minutes once a day before bedtime for 6 months. Epileptiform discharges were recorded and compared before and after 1, 2, and 6 months of listening to Mozart K.448. All of the children remained on the same antiepileptic drug over the 6 months. Relationships between number of epileptiform discharges and foci of discharges, intelligence, epilepsy etiology, age, and gender were analyzed. Epileptiform discharges significantly decreased by 53.2±47.4, 64.4±47.1, and 71.6±45.8%, respectively, after listening to Mozart K.448 for 1, 2, and 6 months. All patients except those with occipital discharges showed a significant decrease in epileptiform discharges. Patients with normal intelligence and idiopathic epilepsy had greater decreases than those with mental retardation and symptomatic epilepsy. Age and gender did not affect the results. We conclude that long-term listening to Mozart K.448 may be effective in decreasing epileptiform discharges in children with epilepsy in a chronologically progressive manner. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Watch the language! Language and linguistic-cognitive abilities in children with nocturnal epileptiform activity.

    Science.gov (United States)

    Systad, Silje; Bjørnvold, Marit; Markhus, Rune; Lyster, Solveig-Alma H

    2017-01-01

    We studied the language and linguistic-cognitive abilities of a group of children with nocturnal epileptiform activity (NEA; N=33) who were hospitalized at a tertiary epilepsy hospital. The children were compared with two groups: one age- and gender-matched group (N=33) and one group matched on language ability (vocabulary) and gender (N=66). We also examined how NEA-related variables affected language abilities. Overall, the children with NEA showed delayed language abilities and a trend for specific difficulties with phonology and naming speed. We did not find firm evidence that the amount of NEA, the use of antiepileptic drugs (AEDs), and the lateralization and localization of NEA had an effect on language. However, we found that children with right-lateralized epileptiform activity seemed to have specific difficulties with naming speed. Additionally, our results indicated that NEA located in the centrotemporal areas particularly affected phonology and orthographic skills. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Transient epileptiform signaling during neuronal network development: regulation by external stimulation and bimodal GABAergic activity.

    Science.gov (United States)

    Zemianek, Jill M; Shultz, Abraham M; Lee, Sangmook; Guaraldi, Mary; Yanco, Holly A; Shea, Thomas B

    2013-04-01

    A predominance of excitatory activity, with protracted appearance of inhibitory activity, accompanies cortical neuronal development. It is unclear whether or not inhibitory neuronal activity is solicited exclusively by excitatory neurons or whether the transient excitatory activity displayed by developing GABAergic neurons contributes to an excitatory threshold that fosters their conversion to inhibitory activity. We addressed this possibility by culturing murine embryonic neurons on multi-electrode arrays. A wave of individual 0.2-0.4 mV signals ("spikes") appeared between approx. 20-30 days in culture, then declined. A transient wave of high amplitude (>0.5 mV) epileptiform activity coincided with the developmental decline in spikes. Bursts (clusters of ≥3 low-amplitude spikes within 0.7s prior to returning to baseline) persisted following this decline. Addition of the GABAergic antagonist bicuculline initially had no effect on signaling, consistent with delayed development of GABAergic synapses. This was followed by a period in which bicuculline inhibited overall signaling, confirming that GABAergic neurons initially display excitatory activity in ex vivo networks. Following the transient developmental wave of epileptiform signaling, bicuculline induced a resurgence of epileptiform signaling, indicating that GABAergic neurons at this point displayed inhibitory activity. The appearance of transition after the developmental and decline of epileptiform activity, rather than immediately after the developmental decline in lower-amplitude spikes, suggests that the initial excitatory activity of GABAergic neurons contributes to their transition into inhibitory neurons, and that inhibitory GABAergic activity is essential for network development. Prior studies indicate that a minority (25%) of neurons in these cultures were GABAergic, suggesting that inhibitory neurons regulate multiple excitatory neurons. A similar robust increase in signaling following cessation of

  7. Millimeter-scale epileptiform spike propagation patterns and their relationship to seizures

    Science.gov (United States)

    Vanleer, Ann C.; Blanco, Justin A.; Wagenaar, Joost B.; Viventi, Jonathan; Contreras, Diego; Litt, Brian

    2016-04-01

    Objective. Current mapping of epileptic networks in patients prior to epilepsy surgery utilizes electrode arrays with sparse spatial sampling (∼1.0 cm inter-electrode spacing). Recent research demonstrates that sub-millimeter, cortical-column-scale domains have a role in seizure generation that may be clinically significant. We use high-resolution, active, flexible surface electrode arrays with 500 μm inter-electrode spacing to explore epileptiform local field potential (LFP) spike propagation patterns in two dimensions recorded from subdural micro-electrocorticographic signals in vivo in cat. In this study, we aimed to develop methods to quantitatively characterize the spatiotemporal dynamics of epileptiform activity at high-resolution. Approach. We topically administered a GABA-antagonist, picrotoxin, to induce acute neocortical epileptiform activity leading up to discrete electrographic seizures. We extracted features from LFP spikes to characterize spatiotemporal patterns in these events. We then tested the hypothesis that two-dimensional spike patterns during seizures were different from those between seizures. Main results. We showed that spatially correlated events can be used to distinguish ictal versus interictal spikes. Significance. We conclude that sub-millimeter-scale spatiotemporal spike patterns reveal network dynamics that are invisible to standard clinical recordings and contain information related to seizure-state.

  8. Prevalence of epileptiform discharges in healthy 11- and 12-year-old children.

    Science.gov (United States)

    Grant, Arthur C; Chau, Larissa; Arya, Kapil; Schneider, Margaret

    2016-09-01

    We sought to determine the prevalence of interictal epileptiform discharges (IEDs) in healthy 11- and 12-year-old children. Sixth grade students with no history of seizure, or neurologic or psychiatric disease, were enrolled in a longitudinal physical activity intervention study. Per study protocol, each student had two EEG recordings approximately 6months apart. Epileptiform discharges were present in 4 (2.9%) of 140 students: centrotemporal in three and generalized in one. In three children, the discharges were still present six months later. None of the children had developed seizures a minimum of one year after the second EEG. These results are consistent with those of two landmark European studies performed nearly a half century ago, before the modern era of digital EEG. Healthy 11- and 12-year-old children with no history of seizure may have centrotemporal or generalized epileptiform discharges on EEG, which can persist for at least 6months. Based on both our results and those of the two prior European studies, such discharges, if found incidentally in otherwise healthy children in this age group, should not prompt further evaluation or treatment.

  9. Patients with electrical status epilepticus in sleep share similar clinical features regardless of their focal or generalized sleep potentiation of epileptiform activity.

    Science.gov (United States)

    Fernández, Iván Sánchez; Peters, Jurriaan; Takeoka, Masanori; Rotenberg, Alexander; Prabhu, Sanjay; Gregas, Matt; Riviello, James J; Kothare, Sanjeev; Loddenkemper, Tobias

    2013-01-01

    The study objective was to compare qualitatively the clinical features of patients with electrical status epilepticus in sleep with focal versus generalized sleep potentiated epileptiform activity. We enrolled patients 2 to 20 years of age, studied between 2001 and 2009, and with sleep potentiated epileptiform activity defined as an increase of epileptiform activity of 50% or more during non-rapid eye movement sleep compared with wakefulness. Eighty-five patients met the inclusion criteria, median age was 7.3 years, and 54 (63.5%) were boys. Sixty-seven (78.8%) patients had focal sleep potentiated epileptiform activity, whereas 18 (21.2%) had generalized sleep potentiated epileptiform activity. The 2 groups did not differ with respect to sex, age, presence of a structural brain abnormality, epilepsy, or other qualitative cognitive, motor, or behavioral problems. Our data suggest that there are no qualitative differences in the clinical features of patients with focal versus generalized sleep potentiated epileptiform activity.

  10. Behavioral deficit and decreased GABA receptor functional regulation in the hippocampus of epileptic rats: effect of Bacopa monnieri.

    Science.gov (United States)

    Mathew, Jobin; Gangadharan, Gireesh; Kuruvilla, Korah P; Paulose, C S

    2011-01-01

    In the present study, alterations of the General GABA and GABA(A) receptors in the hippocampus of pilocarpine-induced temporal lobe epileptic rats and the therapeutic application of Bacopa monnieri and its active component Bacoside-A were investigated. Bacopa monnieri (Linn.) is a herbaceous plant belonging to the family Scrophulariaceae. Hippocampus is the major region of the brain belonging to the limbic system and plays an important role in epileptogenesis, memory and learning. Scatchard analysis of [³H]GABA and [³H]bicuculline in the hippocampus of the epileptic rat showed significant decrease in B(max) (P Bacoside-A treatment reverses all these changes near to control. Our results suggest that decreased GABA receptors in the hippocampus have an important role in epilepsy associated behavioral deficit, Bacopa monnieri and Bacoside-A have clinical significance in the management of epilepsy.

  11. Modulation of seizures and synaptic plasticity by adenosinergic receptors in an experimental model of temporal lobe epilepsy induced by pilocarpine in rats.

    Science.gov (United States)

    Vianna, Eduardo Paulo Morowsky; Ferreira, Alice Teixeira; Doná, Flávia; Cavalheiro, Esper Abrão; da Silva Fernandes, Maria José

    2005-01-01

    Adenosine is a major negative neuromodulator of synaptic activity in the central nervous system and can exert anticonvulsant and neuroprotective effects in many experimental models of epilepsy. Extracellular adenosine can be formed by a membrane-anchored enzyme ecto-5'-nucleotidase. The purposes of this study were to characterize the role of adenosine receptors in modulating status epilepticus (SE) induced by pilocarpine and evaluate its neuroprotective action. Ecto-5'-nucleotidase activity was studied during the different phases of pilocarpine-induced epilepsy in rats. Adult rats were pretreated with different adenosinergic agents to evaluate the latency and incidence of SE induced by pilocarpine in rats. The neuroprotective effect also was evaluated. A proconvulsant effect was observed with DPCPX and DMPX that reduced the latency of SE in almost all rats. Pretreatment with the MRS 1220 did not alter the incidence of SE but reduced the latency to develop SE. An anticonvulsant and neuroprotective effect was detected with R-PIA. Rats pretreated with R-PIA had a decreased number of apoptotic cells in the hippocampus, whereas pretreatment with DPCPX did not modify the hippocampal damage. An intensification of neuronal death was observed in the dentate gyrus and CA3 when rats were pretreated with DMPX. MRS-1220 did not modify the number of apoptotic cells in the hippocampus. An increase in the ecto-5 -nucleotidase staining was detected in the hippocampus during silent and chronic phases. The present data show that adenosine released during pilocarpine-induced SE via A1-receptor stimulation can exhibit neuroprotective and anticonvulsant roles. Similar effects could also be inferred with A2a and A3 adenosinergic agents, but further experiments are necessary to confirm their roles. Ecto-5 -nucleotidase activity during silent and chronic phases might have a role in blocking spontaneous seizures by production of inhibitory neuromodulator adenosine, besides taking part in

  12. Involvement of the neuronal phosphotyrosine signal adaptor N-Shc in kainic acid-induced epileptiform activity.

    Science.gov (United States)

    Baba, Shiro; Onga, Kazuko; Kakizawa, Sho; Ohyama, Kyoji; Yasuda, Kunihiko; Otsubo, Hiroshi; Scott, Brian W; Burnham, W McIntyre; Matsuo, Takayuki; Nagata, Izumi; Mori, Nozomu

    2016-06-08

    BDNF-TrkB signaling is implicated in experimental seizures and epilepsy. However, the downstream signaling involved in the epileptiform activity caused by TrkB receptor activation is still unknown. The aim of the present study was to determine whether TrkB-mediated N-Shc signal transduction was involved in kainic acid (KA)-induced epileptiform activity. We investigated KA-induced behavioral seizures, epileptiform activities and neuronal cell loss in hippocampus between N-Shc deficient and control mice. There was a significant reduction in seizure severity and the frequency of epileptiform discharges in N-Shc deficient mice, as compared with wild-type and C57BL/6 mice. KA-induced neuronal cell loss in the CA3 of hippocampus was also inhibited in N-Shc deficient mice. This study demonstrates that the activation of N-Shc signaling pathway contributes to an acute KA-induced epileptiform activity and neuronal cell loss in the hippocampus. We propose that the N-Shc-mediated signaling pathway could provide a potential target for the novel therapeutic approaches of epilepsy.

  13. Intervention effects of ganoderma lucidum spores on epileptiform discharge hippocampal neurons and expression of neurotrophin-4 and N-cadherin.

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    Shu-Qiu Wang

    Full Text Available Epilepsy can cause cerebral transient dysfunctions. Ganoderma lucidum spores (GLS, a traditional Chinese medicinal herb, has shown some antiepileptic effects in our previous studies. This was the first study of the effects of GLS on cultured primary hippocampal neurons, treated with Mg(2+ free medium. This in vitro model of epileptiform discharge hippocampal neurons allowed us to investigate the anti-epileptic effects and mechanism of GLS activity. Primary hippocampal neurons from <1 day old rats were cultured and their morphologies observed under fluorescence microscope. Neurons were confirmed by immunofluorescent staining of neuron specific enolase (NSE. Sterile method for GLS generation was investigated and serial dilutions of GLS were used to test the maximum non-toxic concentration of GLS on hippocampal neurons. The optimized concentration of GLS of 0.122 mg/ml was identified and used for subsequent analysis. Using the in vitro model, hippocampal neurons were divided into 4 groups for subsequent treatment i control, ii model (incubated with Mg(2+ free medium for 3 hours, iii GLS group I (incubated with Mg(2+ free medium containing GLS for 3 hours and replaced with normal medium and incubated for 6 hours and iv GLS group II (neurons incubated with Mg(2+ free medium for 3 hours then replaced with a normal medium containing GLS for 6 hours. Neurotrophin-4 and N-Cadherin protein expression were detected using Western blot. The results showed that the number of normal hippocampal neurons increased and the morphologies of hippocampal neurons were well preserved after GLS treatment. Furthermore, the expression of neurotrophin-4 was significantly increased while the expression of N-Cadherin was decreased in the GLS treated group compared with the model group. This data indicates that GLS may protect hippocampal neurons by promoting neurotrophin-4 expression and inhibiting N-Cadherin expression.

  14. Alcohol abuse promotes changes in non-synaptic epileptiform activity with concomitant expression changes in cotransporters and glial cells.

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    Luiz Eduardo Canton Santos

    Full Text Available Non-synaptic mechanisms are being considered the common factor of brain damage in status epilepticus and alcohol intoxication. The present work reports the influence of the chronic use of ethanol on epileptic processes sustained by non-synaptic mechanisms. Adult male Wistar rats administered with ethanol (1, 2 e 3 g/kg/d during 28 days were compared with Control. Non-synaptic epileptiform activities (NEAs were induced by means of the zero-calcium and high-potassium model using hippocampal slices. The observed involvement of the dentate gyrus (DG on the neurodegeneration promoted by ethanol motivated the monitoring of the electrophysiological activity in this region. The DG regions were analyzed for the presence of NKCC1, KCC2, GFAP and CD11b immunoreactivity and cell density. The treated groups showed extracellular potential measured at the granular layer with increased DC shift and population spikes (PS, which was remarkable for the group E1. The latencies to the NEAs onset were more prominent also for the treated groups, being correlated with the neuronal loss. In line with these findings were the predispositions of the treated slices for neuronal edema after NEAs induction, suggesting that restrict inter-cell space counteracts the neuronal loss and subsists the hyper-synchronism. The significant increase of the expressions of NKCC1 and CD11b for the treated groups confirms the existence of conditions favorable to the observed edematous necrosis. The data suggest that the ethanol consumption promotes changes on the non-synaptic mechanisms modulating the NEAs. For the lower ethanol dosage the neurophysiological changes were more effective suggesting to be due to the less intense neurodegenertation.

  15. Effect of low potassium concentration on cadmium induced epileptiform activity of leech retzius neurons

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    Milićević Nebojša

    2016-01-01

    Full Text Available Epilepsies have a large significance and require detailed investigation of cellular mechanisms that lead to this disorder. Environmental, especially industrial, toxins are having increasingly more prominent role in these investigations. The aim of our research was to investigate the significance of Cd2+ in generation of epileptiform electrical activity of neurons, and the role of Na+/K+ pump in mechanisms that lead to cessation of this activity. Experiments were performed on Retzius nerve cells of the leech Haemopis sanguisuga. Intracellularly placed microelectrodes were used to measure membrane potential changes upon administration of Cd2+ (100 µmol/l, and the same concentration of Cd2+ in low K+ (1 mmol/l solution. In our experiments Cd2+ led to generation of rhythmic repetitive oscillatory activity. This activity closely resembles paroxysmal depolarizing shifts (PDS which represent the cellular basis of epilepsy. Cd2+ induced epileptiform activity had the following characteristics: frequency of 3.9±0.8 PDS/minute, PDS duration of 4.0±0.3 s, and PDS amplitude of 8.1±0.7 mV. Cd2+ induces effects similar to those of Ni2+ and Co2+, but in 30 times smaller concentration. Application of Cd2+ in low K+ solution led to a significant reduction of PDS frequency (by 2.34±0.55 PDS/minute, p<0.05, Student's t-test, highly significant increase in PDS duration (by 2.84±0.23 s, p<0.01, Student's t-test and highly significant reduction in PDS amplitude (by 1.91±0.33 mV, p=0.01, Student's t-test. Our results show that Cd2+ is a potent initiator of epileptiform activity, and that Na+/K+ pump significantly affects this activity and has a potentially important role in mechanisms that lead to its cessation.

  16. [The importance of sleep deprivation as a mechanism for activating interictal epileptiform paroxysms].

    Science.gov (United States)

    Navas, Patricia; Rodríguez-Santos, Lucía; Bauzano-Poley, Enrique; Lara, José Pablo; Barbancho, Miguel Ángel

    2016-04-01

    Introduccion. Aunque la privacion de sueño se ha utilizado durante años en electroencefalografia (EEG) como metodo de activacion de descargas epileptiformes intercriticas (DEI) en pacientes con alta sospecha de epilepsia, su sensibilidad y especificidad estan aun en discusion. Pacientes y metodos. Estudio descriptivo y retrospectivo de pacientes pediatricos derivados a neurofisiologia clinica para valoracion de epilepsia. Se han comparado los resultados de los EEG de privacion de sueño (EEG-PS) con los EEG de vigilia (EEG-V) en cada paciente para describir su rendimiento como mecanismo activador de DEI. Resultados. Se han analizado 500 pacientes (830 EEG-PS y 1.018 EEG-V). En los EEG-V se detectaron DEI en el 44%. El EEG-PS aumento en un 35% la capacidad del test para detectar las DEI. En los EEG-PS en los que se alcanzo sueño espontaneo se observaron DEI (no detectadas en el EEG-V) en un 25,1%. En el grupo de epilepsias focales se constato que el EEG-V detecto DEI en el 60,1% frente al 79,12% demostradas con el EEG-PS. En las epilepsias generalizadas esta diferencia fue mas marcada (27,2% y 77,2%, respectivamente). En los pacientes en los que tras un EEG-PS no se detectaron DEI (23,7%) y la sospecha clinica de epilepsia seguia siendo alta, se realizo polisomnografia nocturna y se llego a objetivar actividad epileptiforme intercritica en un 13,6%. Conclusiones. El EEG-PS aumenta la posibilidad de recoger DEI en un 35% con respecto al EEG-V. La privacion de sueño es un metodo activador de paroxismos epileptiformes, independientemente de si hay sueño o no durante la realizacion del EEG, aunque este efecto es mas marcado en los pacientes que alcanzan sueño.

  17. A self-adapting system for the automated detection of inter-ictal epileptiform discharges.

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    Shaun S Lodder

    Full Text Available PURPOSE: Scalp EEG remains the standard clinical procedure for the diagnosis of epilepsy. Manual detection of inter-ictal epileptiform discharges (IEDs is slow and cumbersome, and few automated methods are used to assist in practice. This is mostly due to low sensitivities, high false positive rates, or a lack of trust in the automated method. In this study we aim to find a solution that will make computer assisted detection more efficient than conventional methods, while preserving the detection certainty of a manual search. METHODS: Our solution consists of two phases. First, a detection phase finds all events similar to epileptiform activity by using a large database of template waveforms. Individual template detections are combined to form "IED nominations", each with a corresponding certainty value based on the reliability of their contributing templates. The second phase uses the ten nominations with highest certainty and presents them to the reviewer one by one for confirmation. Confirmations are used to update certainty values of the remaining nominations, and another iteration is performed where ten nominations with the highest certainty are presented. This continues until the reviewer is satisfied with what has been seen. Reviewer feedback is also used to update template accuracies globally and improve future detections. KEY FINDINGS: Using the described method and fifteen evaluation EEGs (241 IEDs, one third of all inter-ictal events were shown after one iteration, half after two iterations, and 74%, 90%, and 95% after 5, 10 and 15 iterations respectively. Reviewing fifteen iterations for the 20-30 min recordings 1 took approximately 5 min. SIGNIFICANCE: The proposed method shows a practical approach for combining automated detection with visual searching for inter-ictal epileptiform activity. Further evaluation is needed to verify its clinical feasibility and measure the added value it presents.

  18. Modulation of epileptiform EEG discharges in juvenile myoclonic epilepsy: An investigation of reflex epileptic traits

    DEFF Research Database (Denmark)

    Beniczky, Sándor; Guaranha, Mirian Salvadori Bittar; Conradsen, Isa

    2012-01-01

    Purpose: Previous studies have suggested that cognitive tasks modulate (provoke or inhibit) the epileptiform electroencephalography (EEG) discharges (EDs) in patients with juvenile myoclonic epilepsy (JME). Their inhibitory effect was found to be especially frequent (64–90%). These studies...... of the EDs we divided the baseline period into 5‐min epochs and calculated the 95% confidence interval for the baseline EDs in each patient. Modulation was assumed when the number of EDs during any 5‐min test period was outside the 95% confidence interval. Key Findings: Using the arbitrary method, our...

  19. Pilocarpine诱导小鼠癫痫持续状态发作后海马神经元的兴奋激活、损伤和死亡%Neuron activation, degeneration and death in the hippocampus of mice after pilocarpine induced status epilepticus

    Institute of Scientific and Technical Information of China (English)

    刘建新; 唐锋儒; 刘勇

    2011-01-01

    目的:研究癫痫持续状态发作后海马神经元兴奋激活、细胞损伤和细胞死亡的发生和相互关系.方法:采用pilocarpine诱导Swiss小鼠癫痫持续状态(status epilepticus,SE)模型,分别以c-Fos,Fluoro Jade B和CFV染色分析SE后不同时间点齿状回和CA1区锥体细胞的兴奋激活、损伤和细胞存活状况.结果:在齿状回颗粒细胞层,c-Fos阳性细胞在SE后1,2和24 h增多(P<0.01或0.05),但各组齿状回颗粒细胞层均无明显Fluoro Jade B阳性细胞,CFV染色标记的阳性细胞数量在对照组和各实验组之间差异无统计学意义(P>0.05);门区神经元在SE后没有明显的c-Fos诱导表达,但SE后2和24 h,门区Fluoro Jade B阳性细胞数量较对照组增多(P<0.01),CFV染色显示SE后1d门区残存的神经元数量较对照组减少(P<0.01);CA1区锥体细胞层c-Fos阳性细胞数量在SE后30 min,1,2和24 h后增多(P<0.01或0.05),Fluoro Jade B 阳性细胞数量在SE后2和24 h也较对照组增多(P<0.01),但CFV染色CA1区锥体细胞数量在各组间差异无统计学意义(P>0.05).结论:齿状回颗粒细胞、门区中间神经元以及CA1区锥体细胞在SE后的兴奋激活、颗粒细胞的损伤和死亡之间无直接的必然关系.%Objective To examine the occurrence of neuron activation,neurodegeneraion and cell death,and the correlation among them in the hippocampus after status epilepticus.Methods CFV,Fluoro Jade B and c-Fos staining were done at multiple time points after pilocarpine induced status epilepticus.Results In the stratum granulosum of dentate gyrus,c-Fos positive neurons increased significantly at 1 h,2 h and 1 d after status epilepticus (P <0.01 or 0.05).However,almost no Fluoro Jade B staining cell was found in the stratum granulosum in the experiment and control groups,and no obvious difference was shown on the numbers of CFV staining cells in this area among all groups.In the hilus of dentate gyrus of different groups

  20. INCREASED TISSUE TRANSGLUTAMINASE LEVELS ARE ASSOCIATED WITH INCREASED EPILEPTIFORM ACTIVITY IN ELECTROENCEPHALOGRAPHY AMONG PATIENTS WITH CELIAC DISEASE

    Directory of Open Access Journals (Sweden)

    Sedat IŞIKAY

    2015-12-01

    Full Text Available Background - Celiac disease is an autoimmune systemic disorder in genetically predisposed individuals precipitated by gluten ingestion. Objective - In this study, we aimed to determine asymptomatic spike-and-wave findings on electroencephalography in children with celiac disease. Methods - A total of 175 children with the diagnosis of celiac disease (study group and 99 age- and sex-matched healthy children as controls (control group were included in the study. In order to determine the effects of gluten free diet on laboratory and electroencephalography findings, the celiac group is further subdivided into two as newly-diagnosed and formerly-diagnosed patients. Medical histories of all children and laboratory findings were all recorded and neurologic statuses were evaluated. All patients underwent a sleep and awake electroencephalography. Results - Among 175 celiac disease patients included in the study, 43 were newly diagnosed while 132 were formerly-diagnosed patients. In electroencephalography evaluation of patients the epileptiform activity was determined in 4 (9.3% of newly diagnosed and in 2 (1.5% of formerly diagnosed patients; on the other hand the epileptiform activity was present in only 1 (1.0% of control cases. There was a statistically significant difference between groups in regards to the presence of epileptiform activity in electroencephalography. Pearson correlation analysis revealed that epileptiform activity in both sleep and awake electroencephalography were positively correlated with tissue transglutaminase levels (P=0.014 and P=0.019, respectively. Conclusion - We have determined an increased epileptiform activity frequency among newly-diagnosed celiac disease patients compared with formerly-diagnosed celiac disease patients and control cases. Moreover the tissue transglutaminase levels were also correlated with the presence of epileptiform activity in electroencephalography. Among newly diagnosed celiac disease patients

  1. Pilocarpine-induced seizures in rodents--17 years on.

    Science.gov (United States)

    Turski, W A

    2000-01-01

    In 1983, we reported that intracerebral or systemic administration of cholinergic agents produced seizures and seizure-related brain damage in rodents. During the following 17 years, seizures induced by cholinomimetic drugs became a popular model of epilepsy. Seizures can by produced by cholinergic agonists acting directly at muscarinic receptors or by drugs enhancing cholinergic transmission due to the inhibition of acetylcholinesterase activity. Status epilepticus evoked by pilocarpine in rodents triggers long-lasting changes which can be described as: (I) acute-onset seizures lasting for several hours, (II) a silent period characterized by normalization of electroencephalographic patterns lasting for days, and (III) spontaneous recurrent seizures lasting for life. Therefore, seizures induced by cholinomimetics in rodents are of value for studies of basic mechanisms of epileptogenesis and action of antiepileptic drugs.

  2. Complexity and multifractality of neuronal noise in mouse and human hippocampal epileptiform dynamics

    Science.gov (United States)

    Serletis, Demitre; Bardakjian, Berj L.; Valiante, Taufik A.; Carlen, Peter L.

    2012-10-01

    Fractal methods offer an invaluable means of investigating turbulent nonlinearity in non-stationary biomedical recordings from the brain. Here, we investigate properties of complexity (i.e. the correlation dimension, maximum Lyapunov exponent, 1/fγ noise and approximate entropy) and multifractality in background neuronal noise-like activity underlying epileptiform transitions recorded at the intracellular and local network scales from two in vitro models: the whole-intact mouse hippocampus and lesional human hippocampal slices. Our results show evidence for reduced dynamical complexity and multifractal signal features following transition to the ictal epileptiform state. These findings suggest that pathological breakdown in multifractal complexity coincides with loss of signal variability or heterogeneity, consistent with an unhealthy ictal state that is far from the equilibrium of turbulent yet healthy fractal dynamics in the brain. Thus, it appears that background noise-like activity successfully captures complex and multifractal signal features that may, at least in part, be used to classify and identify brain state transitions in the healthy and epileptic brain, offering potential promise for therapeutic neuromodulatory strategies for afflicted patients suffering from epilepsy and other related neurological disorders. This paper is based on chapter 5 of Serletis (2010 PhD Dissertation Department of Physiology, Institute of Biomaterials and Biomedical Engineering, University of Toronto).

  3. Parvalbumin-Positive Inhibitory Interneurons Oppose Propagation But Favor Generation of Focal Epileptiform Activity.

    Science.gov (United States)

    Sessolo, Michele; Marcon, Iacopo; Bovetti, Serena; Losi, Gabriele; Cammarota, Mario; Ratto, Gian Michele; Fellin, Tommaso; Carmignoto, Giorgio

    2015-07-01

    Parvalbumin (Pv)-positive inhibitory interneurons effectively control network excitability, and their optogenetic activation has been reported to block epileptic seizures. An intense activity in GABAergic interneurons, including Pv interneurons, before seizures has been described in different experimental models of epilepsy, raising the hypothesis that an increased GABAergic inhibitory signal may, under certain conditions, initiate seizures. It is therefore unclear whether the activity of Pv interneurons enhances or opposes epileptiform activities. Here we use a mouse cortical slice model of focal epilepsy in which the epileptogenic focus can be identified and the role of Pv interneurons in the generation and propagation of seizure-like ictal events is accurately analyzed by a combination of optogenetic, electrophysiological, and imaging techniques. We found that a selective activation of Pv interneurons at the focus failed to block ictal generation and induced postinhibitory rebound spiking in pyramidal neurons, enhancing neuronal synchrony and promoting ictal generation. In contrast, a selective activation of Pv interneurons distant from the focus blocked ictal propagation and shortened ictal duration at the focus. We revealed that the reduced ictal duration was a direct consequence of the ictal propagation block, probably by preventing newly generated afterdischarges to travel backwards to the original focus of ictal initiation. Similar results were obtained upon individual Pv interneuron activation by intracellular depolarizing current pulses. The functional dichotomy of Pv interneurons here described opens new perspectives to our understanding of how local inhibitory circuits govern generation and spread of focal epileptiform activities.

  4. Laterization of epileptiform discharges in patients with epilepsy and precocious destructive brain insults

    Directory of Open Access Journals (Sweden)

    Teixeira Ricardo A.

    2004-01-01

    Full Text Available Unilateral destructive brain lesions of early development can result in compensatory thickening of the ipsilateral cranial vault. The aim of this study was to determine the frequency of these bone changes among patients with epilepsy and precocious destructive lesions, and whether a relationship exists between these changes and epileptiform discharges lateralization. Fifty-one patients had their ictal / interictal scalp EEG and skull thickness symmetry on MRI analyzed. Patients were divided into three main groups according to the topographic distribution of the lesion on the MRI: hemispheric (H (n=9; main arterial territory (AT (n=25; arterial borderzone (Bdz (n=17. The EEG background activity was abnormal in 26 patients and were more frequent among patients of group H (p= 0.044. Thickening of the skull was more frequent among patients of group H (p= 0.004. Five patients (9.8% showed discordant lateralization between epileptiform discharges and structural lesion (four of them with an abnormal background, and only two of them with skull changes. In one of these patients, ictal SPECT provided strong evidence for scalp EEG false lateralization. The findings suggest that compensatory skull thickening in patients with precocious destructive brain insults are more frequent among patients with unilateral and large lesions. However, EEG lateralization discordance among these patients seems to be more related to EEG background abnormalities and extent of cerebral damage than to skull changes.

  5. Pontas evocadas por estímulos somatossensitivos e atividade epileptiforme no eletrencefalograma em crianças "normais" Somatosensory evoked spikes and epileptiform activity in "normal" children

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    Lineu C. Fonseca

    2003-09-01

    Full Text Available Estudamos a ocorrência de potenciais de alta voltagem evocados por estímulos somatossensitivos - pontas evocadas (PE - e de atividade epileptiforme espontânea (AE no EEG de 173 crianças normais de 7 a 11 anos de idade. Durante o EEG, dez percussões foram realizadas nas mãos e pés. Foi avaliada a ocorrência de PE acompanhando cada um dos estímulos e a presença de AE. AE foi observada em quatro crianças (2,3%: pontas centroparietais em duas, complexos de ponta-onda lenta generalizados em uma e pontas parietais e temporais médias em uma. Uma menina de 10 anos de idade (0,58% teve ao EEG pontas parietais medianas evocadas pela percussão do pé esquerdo. Este EEG era normal quanto a outros aspectos. Nossos achados de AE em crianças normais são similares aos encontrados em estudos de outros países. Constatamos que espículas somatossensitivas podem ser observadas em crianças normais o que sugere uma natureza funcional ligada à idade.Little is known about somatosensory evoked spikes (SES in the EEG of normal children. We studied the occurrence of SES and spontaneous epileptiform activity (SEA in 173 normal children ageg 7 to 11 years. During the EEG ten taps were applied to both hands and feet. The occurrence of high voltage potentials evoked by each stimulation of one or both heels or hands (SES and the occurrence of SEA were evaluated. SEA was observed in four children (2.3 %: central/parietal spikes in two cases, generalized spike-and-wave in one, and parietal/midtemporal spikes in one case. A ten years old girl (0,58% had SES on median parietal region by tapping the left foot. This EEG was otherwise normal. Our findings of SEA are similar to those obtained in other normal populations. SES can be observed in normal children. These SES suggest that we are dealing with an age-related functional phenomenon.

  6. L-pGlu-(2-propyl)-L-His-L-ProNH₂ attenuates 4-aminopyridine-induced epileptiform activity and sodium current: a possible action of new thyrotropin-releasing hormone analog for its anticonvulsant potential.

    Science.gov (United States)

    Sah, N; Rajput, S K; Singh, J N; Meena, C L; Jain, R; Sikdar, S K; Sharma, S S

    2011-12-29

    L-PGlu-(2-propyl)-L-His-L-ProNH₂ (NP-647) is a CNS active thyrotropin-releasing hormone (TRH) analog with potential application in various CNS disorders including seizures. In the present study, mechanism of action for protective effect of NP-647 was explored by studying role of NP-647 on epileptiform activity and sodium channels by using patch-clamp methods. Epileptiform activity was induced in subicular pyramidal neurons of hippocampal slice of rat by perfusing 4-aminopyridine (4-AP) containing Mg⁺²-free normal artificial cerebrospinal fluid (nACSF). Increase in mean firing frequency was observed after perfusion of 4-AP and zero Mg⁺² (2.10±0.47 Hz) as compared with nACSF (0.12±0.08 Hz). A significant decrease in mean firing frequency (0.61±0.22 Hz), mean frequency of epileptiform events (0.03±0.02 Hz vs. 0.22±0.05 Hz of 4-AP+0 Mg), and average number of action potentials in paroxysmal depolarization shift-burst (2.54±1.21 Hz vs. 8.16±0.88 Hz of 4-AP+0 Mg) was observed. A significant reduction in peak dV/dt (246±19 mV ms⁻¹ vs. 297±18 mV ms⁻¹ of 4-AP+0 Mg) and increase (1.332±0.018 ms vs. 1.292±0.019 ms of 4-AP+0 Mg) in time required to reach maximum depolarization were observed indicating role of sodium channels. Concentration-dependent depression of sodium current was observed after exposure to dorsal root ganglion neurons to NP-647. NP-647 at different concentrations (1, 3, and 10 μM) depressed sodium current (15±0.5%, 50±2.6%, and 75±0.7%, respectively). However, NP-647 did not show change in the peak sodium current in CNa18 cells. Results of present study demonstrated potential of NP-647 in the inhibition of epileptiform activity by inhibiting sodium channels indirectly.

  7. Chronic deficit in the expression of voltage-gated potassium channel Kv3.4 subunit in the hippocampus of pilocarpine-treated epileptic rats.

    Science.gov (United States)

    Pacheco Otalora, Luis F; Skinner, Frank; Oliveira, Mauro S; Farrell, Bianca; Arshadmansab, Massoud F; Pandari, Tarun; Garcia, Ileana; Robles, Leslie; Rosas, Gerardo; Mello, Carlos F; Ermolinsky, Boris S; Garrido-Sanabria, Emilio R

    2011-01-12

    Voltage gated K(+) channels (Kv) are a highly diverse group of channels critical in determining neuronal excitability. Deficits of Kv channel subunit expression and function have been implicated in the pathogenesis of epilepsy. In this study, we investigate whether the expression of the specific subunit Kv3.4 is affected during epileptogenesis following pilocarpine-induced status epilepticus. For this purpose, we used immunohistochemistry, Western blotting assays and comparative analysis of gene expression using TaqMan-based probes and delta-delta cycle threshold (ΔΔCT) method of quantitative real-time polymerase chain reaction (qPCR) technique in samples obtained from age-matched control and epileptic rats. A marked down-regulation of Kv3.4 immunoreactivity was detected in the stratum lucidum and hilus of dentate gyrus in areas corresponding to the mossy fiber system of chronically epileptic rats. Correspondingly, a 20% reduction of Kv3.4 protein levels was detected in the hippocampus of chronic epileptic rats. Real-time quantitative PCR analysis of gene expression revealed that a significant 33% reduction of transcripts for Kv3.4 (gene Kcnc4) occurred after 1 month of pilocarpine-induced status epilepticus and persisted during the chronic phase of the model. These data indicate a reduced expression of Kv3.4 channels at protein and transcript levels in the epileptic hippocampus. Down-regulation of Kv3.4 in mossy fibers may contribute to enhanced presynaptic excitability leading to recurrent seizures in the pilocarpine model of temporal lobe epilepsy.

  8. Synchrotron FTIR micro-spectroscopy study of the rat hippocampal formation after pilocarpine-evoked seizures.

    Science.gov (United States)

    Chwiej, J; Dulinska, J; Janeczko, K; Dumas, P; Eichert, D; Dudala, J; Setkowicz, Z

    2010-10-01

    In the present work, synchrotron radiation Fourier transform infrared (SRFTIR) micro-spectroscopy and imaging were used for topographic and semi-quantitative biochemical analysis of rat brain tissue in cases of pilocarpine-induced epilepsy. The tissue samples were analyzed with a beam defined by small apertures and spatial resolution steps of 10 microm which allowed us to probe the selected cellular layers of hippocampal formation. Raster scanning of the samples has generated 2D chemical cartographies revealing the distribution of proteins, lipids and nucleic acids. Spectral analysis has shown changes in the saturation level of phospholipids and relative secondary structure of proteins. Special interest was put in the analysis of two areas of the hippocampal formation (sector 3 of the Ammon's horn, CA3 and dentate gyrus, DG) in which elemental abnormalities were observed during our previous studies. Statistically significant increase in the saturation level of phospholipids (increased ratio of the absorption intensities at around 2921 and 2958 cm(-1)) as well as conformational changes of proteins (beta-type structure discrepancies as shown by the increased ratio of the absorbance intensities at around 1631 and 1657 cm(-1) as well as the ratio of the absorbance at 1548 and 1657 cm(-1)) were detected in pyramidal cells of CA3 area as well as in the multiform and molecular layers of DG. The findings presented here suggest that abnormalities in the protein secondary structure and increases in the level of phospholipid saturation could be involved in mechanisms of neurodegenerative changes following the oxidative stress evoked in brain areas affected by pilocarpine-induced seizures.

  9. Occurrence of epileptiform discharges and sleep during EEG recordings in children after melatonin intake versus sleep-deprivation.

    Science.gov (United States)

    Gustafsson, Greta; Broström, Anders; Ulander, Martin; Vrethem, Magnus; Svanborg, Eva

    2015-08-01

    To determine if melatonin is equally efficient as partial sleep deprivation in inducing sleep without interfering with epileptiform discharges in EEG recordings in children 1-16 years old. We retrospectively analysed 129 EEGs recorded after melatonin intake and 113 EEGs recorded after partial sleep deprivation. Comparisons were made concerning occurrence of epileptiform discharges, the number of children who fell asleep and the technical quality of EEG recordings. Comparison between different age groups was also made. No significant differences were found regarding occurrence of epileptiform discharges (33% after melatonin intake, 36% after sleep deprivation), or proportion of unsuccessful EEGs (8% and 10%, respectively). Melatonin and sleep deprivation were equally efficient in inducing sleep (70% in both groups). Significantly more children aged 1-4 years obtained sleep after melatonin intake in comparison to sleep deprivation (82% vs. 58%, p⩽0.01), and in comparison to older children with melatonin induced sleep (58-67%, p⩽0.05). Sleep deprived children 9-12 years old had higher percentage of epileptiform discharges (62%, p⩽0.05) compared to younger sleep deprived children. Melatonin is equally efficient as partial sleep deprivation to induce sleep and does not affect the occurrence of epileptiform discharges in the EEG recording. Sleep deprivation could still be preferable in older children as melatonin probably has less sleep inducing effect. Melatonin induced sleep have advantages, especially in younger children as they fall asleep easier than after sleep deprivation. The procedure is easier for the parents than keeping a young child awake for half the night. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  10. Caramiphen edisylate as Adjunct to Standard Therapy attenuates soman-induced Seizures and Cognitive Deficits in Rats

    Science.gov (United States)

    2014-06-16

    SUBJECT TERMS soman, caramiphen, anticonvulsant , behavior, rats, chemical warfare nerve agents, medical chemical defense , medical countermeasures 16...Keywords: Soman Caramiphen Anticonvulsant Behavior Chemical warfare nerve agents Rats The progression of epileptiform activity following soman (GD...whichmay lead to neuropathological damage and behavioral deficits. Caramiphen edisylate is an anticholinergic drug with antiglutamatergic properties

  11. Effect of medication withdrawal on the interictal epileptiform EEG discharges in presurgical evaluation

    DEFF Research Database (Denmark)

    Andersen, N.B.; Alving, J.; Beniczky, S.

    2010-01-01

    Medication withdrawal (MW) is an important method of provoking seizures and activating epileptiform EEG activity during the diagnostic work-up of patients evaluated for epilepsy surgery. Previously it was suggested that MW might influence the seizure-type and activate cortical areas otherwise...... MW. In one-third of the patients the interictal EEGs after the MW were different from those recorded before the MW. However, in these discordant cases the EEG findings after the MW (and not before the MW) were concordant with the seizure onset zone and the lesional zone. We conclude that MW...... is an effective and reliable seizure provoking method, and it does not lead to false localization of the irritative zone. (C) 2010 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved...

  12. Nonconvulsive status epilepticus associated with periodic lateralized epileptiform discharges in a patient with syphilis

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    Xin Yu

    2016-09-01

    Full Text Available Nonconvulsive status epilepticus (NCSE has been increasingly recognized as a cause of impaired level of consciousness in the ICU and emergency rooms. The confirmation of NCSE is largely based on the EEG, given the nonspecific and pleomorphic clinical manifestations. Debate remains over electroencephalograms (EEG criteria for NCSE. Periodic lateralized epileptiform discharges (PLEDs, have sparked controversy with regard to being part of the ictal vs. interictal spectrum. We report a case of a patient with syphilis who had cognitive decline and damaged consciousness with PLEDs and T2 hyperintensity at temporal and occipital lobe in MRI. After antiepileptic treatment only, his consciousness improved markedly together with the EEG in few days, while the change of MRI was still serious. In this case PLEDs is the sign of NCSE and change of MRI is limbic encephalitis (LE. This report discusses the association of PLEDs and NCSE, and supports the concept of PLEDs as an ictal pattern in some condition.

  13. Epileptiform activity in the mouse visual cortex interferes with cortical processing in connected areas

    Science.gov (United States)

    Petrucco, L.; Pracucci, E.; Brondi, M.; Ratto, G. M.; Landi, S.

    2017-01-01

    Epileptiform activity is associated with impairment of brain function even in absence of seizures, as demonstrated by failures in various testing paradigm in presence of hypersynchronous interictal spikes (ISs). Clinical evidence suggests that cognitive deficits might be directly caused by the anomalous activity rather than by its underlying etiology. Indeed, we seek to understand whether ISs interfere with neuronal processing in connected areas not directly participating in the hypersynchronous activity in an acute model of epilepsy. Here we cause focal ISs in the visual cortex of anesthetized mice and we determine that, even if ISs do not invade the opposite hemisphere, the local field potential is subtly disrupted with a modulation of firing probability imposed by the contralateral IS activity. Finally, we find that visual processing is altered depending on the temporal relationship between ISs and stimulus presentation. We conclude that focal ISs interact with normal cortical dynamics far from the epileptic focus, disrupting endogenous oscillatory rhythms and affecting information processing. PMID:28071688

  14. Epileptiform activity in the electroencephalogram of 6-year-old children of women with epilepsy

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    Unnikrishnan Krishnan Syam

    2016-01-01

    Full Text Available Purpose: To study the epileptiform discharges (EDs in the electroencephalogram (EEG of 6-8-year-old children of women with epilepsy (WWE. Materials and Methods: All children born to women with epilepsy and prospectively followed up through the Kerala Registry of Epilepsy and Pregnancy (KREP, aged 6-8 years, were invited (n = 532. Out of the 254 children who responded, clinical evaluations and a 30-min digital 18 channel EEG were completed in 185 children. Results: Of the 185 children examined, 37 (20% children (19 males, 18 females had ED in their EEG. The EDs were generalized in 7 children, and focal in 30 children. The EDs were present in the sleep record only of 16 (43% children and in the awake record only of 6 (16% children. Out of the 94 children for whom seizure history was available, 7 children (7.4% had seizures (neonatal seizures: 4, febrile seizure: 1, and single nonfebrile seizure: 2 and none had history of epilepsy or recurrent nonfebrile seizures. The odds ratio (OR for occurrence of ED in the EEG was significantly higher for children of WWE [OR = 3.5, 95% confidence interval (CI 2.3-6.0] when compared to the published data for age-matched children of mothers without epilepsy. There was no association between the occurrence of ED and the children′s maternal characteristics [epilepsy syndrome, seizures during pregnancy, maternal intelligence quotient (IQ] or the children′s characteristics [antenatal exposure to specific antiepileptic drugs (AEDs, birth weight, malformations, IQ]. Conclusion: Children of WWE have a higher risk of epileptiform activity in their EEG when compared to healthy children in the community though none had recurrent seizures.

  15. The Effect of Morphine on Low Mg2+ ACSF Induced Epileptiform Activity in Mice Whole Hippocampus

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    B. Heshmatian

    2008-10-01

    Full Text Available Introduction & Objective: Morphine has both anti and proconvulsive actions on the epileptiform activity depending on the exact experimental conditions. Study of the contraversy effects of morphine on certain neural activities such as epilepsy leads to clearify some neural events and neuronal adaptations. This study was designed to determine the effect of morphine on seizure induced by Low Mg2+ Artificial Cerebrospinal Fluid (ACSF in whole hippocampus preparation of mice. Materials & Methods: C57/BL6 mice 11 to 19 days of age, were used. Animals anaesthetized and the brain was removed(n=25 and placed in ice-cold, continuously oxygenated ACSF for 3 min. Then the hippocampi were dissected and incubated in normal ACSF at room temperature for an hour before electrophysiologic recording. Seizure activity was induced by per fusing the hippocampus with Low Mg2+ ACSF. Extra cellular recordings were performed mainly in the CA1 pyramidal cell layer. Seizure activity was quantified by measuring the duration and number of the ictal events and the percent of seizure time. Results: Both low and high doses of morphine(10, 200μM, respectively suppressed seizure length and percent of seizure time, whereas moderate doses of morphine (30,100 μM potentates them. Naloxone (10μM not only inhibited the excitatory effects of morphine on seizure but also suppressed the Low Mg2+ ACSF induced epileptiform activities. Combined application of morphine and naloxone attenuated the seizure.Conclusion: Our results indicate that morphine in moderate concentration of 30 and 100 μM may potentate seizure activity and it should be used with caution in epileptic patients, while naloxone has anticonvulsant actions and can probably be used in clinical trials especially to control temporal lob epilepsy.

  16. Implacable images: why epileptiform events continue to be featured in film and television.

    Science.gov (United States)

    Kerson, Toba Schwaber; Kerson, Lawrence A

    2006-06-01

    Epileptiform events have been portrayed in film since 1900 and on television since the 1950's. Over time, portrayals have not reflected medicine's understanding of epilepsy. At present, it is unlikely that individuals who do not have a close relationship with someone with a seizure-disorder will witness a seizure. Because fictive and often incorrect images appear increasingly, many think of them as accurate depictions. The research addresses three questions in relation to these images: How do directors use the images? Why do uses of seizures in visual media not reflect contemporary scientific knowledge? Why have they persisted and increased in use? Data consist of material from 192 films and television episodes. The general category of seizures includes seizures in characters said to have epilepsy or some other condition, seizures related to drug or alcohol use, pseudoseizures and feigned seizures, and, a category in which, for example, someone is described as "having a fit." The research demonstrates how epileptiform events drive the narrative, support the genre, evoke specific emotional reactions, accentuate traits of characters with seizures, highlight qualities of other characters through their responses to the seizures, act as catalysts for actions, and enhance the voyeuristic experience of the audience. Twenty video sequences are included in the manuscript. The authors conclude that the visual experience of seizures remains so enthralling that its use is most likely to increase particularly on television, and that as the public has less experience with real seizures, depictions in film will continue to be more concerned with what the image can do for the show and less interested in accurate portrayals. Ways to influence depictions are suggested.

  17. Serotonin Depletion Does not Modify the Short-Term Brain Hypometabolism and Hippocampal Neurodegeneration Induced by the Lithium-Pilocarpine Model of Status Epilepticus in Rats.

    Science.gov (United States)

    García-García, Luis; Shiha, Ahmed Anis; Bascuñana, Pablo; de Cristóbal, Javier; Fernández de la Rosa, Rubén; Delgado, Mercedes; Pozo, Miguel A

    2016-05-01

    It has been reported that fluoxetine, a selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitor, has neuroprotective properties in the lithium-pilocarpine model of status epilepticus (SE) in rats. The aim of the present study was to investigate the effect of 5-HT depletion by short-term administration of p-chlorophenylalanine (PCPA), a specific tryptophan hydroxylase inhibitor, on the brain hypometabolism and neurodegeneration induced in the acute phase of this SE model. Our results show that 5-HT depletion did modify neither the brain basal metabolic activity nor the lithium-pilocarpine-induced hypometabolism when evaluated 3 days after the insult. In addition, hippocampal neurodegeneration and astrogliosis triggered by lithium-pilocarpine were not exacerbated by PCPA treatment. These findings point out that in the early latent phase of epileptogenesis, non-5-HT-mediated actions may contribute, at least in some extent, to the neuroprotective effects of fluoxetine in this model of SE.

  18. Particle swarm optimization algorithm based parameters estimation and control of epileptiform spikes in a neural mass model

    Science.gov (United States)

    Shan, Bonan; Wang, Jiang; Deng, Bin; Wei, Xile; Yu, Haitao; Zhang, Zhen; Li, Huiyan

    2016-07-01

    This paper proposes an epilepsy detection and closed-loop control strategy based on Particle Swarm Optimization (PSO) algorithm. The proposed strategy can effectively suppress the epileptic spikes in neural mass models, where the epileptiform spikes are recognized as the biomarkers of transitions from the normal (interictal) activity to the seizure (ictal) activity. In addition, the PSO algorithm shows capabilities of accurate estimation for the time evolution of key model parameters and practical detection for all the epileptic spikes. The estimation effects of unmeasurable parameters are improved significantly compared with unscented Kalman filter. When the estimated excitatory-inhibitory ratio exceeds a threshold value, the epileptiform spikes can be inhibited immediately by adopting the proportion-integration controller. Besides, numerical simulations are carried out to illustrate the effectiveness of the proposed method as well as the potential value for the model-based early seizure detection and closed-loop control treatment design.

  19. Mozart K.448 listening decreased seizure recurrence and epileptiform discharges in children with first unprovoked seizures: a randomized controlled study

    OpenAIRE

    Lin, Lung-Chang; Lee, Mei-Wen; Wei, Ruey-Chang; Mok, Hin-Kiu; Yang, Rei-Cheng

    2014-01-01

    Background Increasing numbers of reports show the beneficial effects of listening to Mozart music in decreasing epileptiform discharges as well as seizure frequency in epileptic children. There has been no effective method to reduce seizure recurrence after the first unprovoked seizure until now. In this study, we investigated the effect of listening to Mozart K.448 in reducing the seizure recurrence rate in children with first unprovoked seizures. Methods Forty-eight children who experienced...

  20. Mozart K.448 listening decreased seizure recurrence and epileptiform discharges in children with first unprovoked seizures: a randomized controlled study.

    Science.gov (United States)

    Lin, Lung-Chang; Lee, Mei-Wen; Wei, Ruey-Chang; Mok, Hin-Kiu; Yang, Rei-Cheng

    2014-01-13

    Increasing numbers of reports show the beneficial effects of listening to Mozart music in decreasing epileptiform discharges as well as seizure frequency in epileptic children. There has been no effective method to reduce seizure recurrence after the first unprovoked seizure until now. In this study, we investigated the effect of listening to Mozart K.448 in reducing the seizure recurrence rate in children with first unprovoked seizures. Forty-eight children who experienced their first unprovoked seizure with epileptiform discharges were included in the study. They were randomly placed into treatment (n = 24) and control (n = 24) groups. Children in the treatment group listened to Mozart K.448 daily before bedtime for at least six months. Two patients in the treatment group were excluded from analysis due to discontinuation intervention. Finally, forty-six patients were analyzed. Most of these patients (89.1%) were idiopathic in etiology. Seizure recurrence rates and reduction of epileptiform discharges were compared. The average follow-up durations in the treatment and control groups were 18.6 ± 6.6 and 20.1 ± 5.1 months, respectively. The seizure recurrence rate was estimated to be significantly lower in the treatment group than the control group over 24 months (37.2% vs. 76.8%, p = 0.0109). Significant decreases in epileptiform discharges were also observed after 1, 2, and 6 months of listening to Mozart K.448 when compared with EEGs before listening to music. There were no significant differences in gender, mentality, seizure type, and etiology between the recurrence and non-recurrence groups. Although the case number was limited and control music was not performed in this study, the study revealed that listening to Mozart K.448 reduced the seizure recurrence rate and epileptiform discharges in children with first unprovoked seizures, especially of idiopathic etiology. We believe that Mozart K.448 could be a promising alternative treatment in patients with

  1. Periodic Lateralized Epileptiform Discharges can Survive Anesthesia and Result in Asymmetric Drug-induced Burst Suppression

    Science.gov (United States)

    Mader, Edward C.; Cannizzaro, Louis A.; Williams, Frank J.; Lalan, Saurabh; Olejniczak, Piotr W.

    2017-01-01

    Drug-induced burst suppression (DIBS) is bihemispheric and bisymmetric in adults and older children. However, asymmetric DIBS may occur if a pathological process is affecting one hemisphere only or both hemispheres disproportionately. The usual suspect is a destructive lesion; an irritative or epileptogenic lesion is usually not invoked to explain DIBS asymmetry. We report the case of a 66-year-old woman with new-onset seizures who was found to have a hemorrhagic cavernoma and periodic lateralized epileptiform discharges (PLEDs) in the right temporal region. After levetiracetam and before anesthetic antiepileptic drugs (AEDs) were administered, the electroencephalogram (EEG) showed continuous PLEDs over the right hemisphere with maximum voltage in the posterior temporal region. Focal electrographic seizures also occurred occasionally in the same location. Propofol resulted in bihemispheric, but not in bisymmetric, DIBS. Remnants or fragments of PLEDs that survived anesthesia increased the amplitude and complexity of the bursts in the right hemisphere leading to asymmetric DIBS. Phenytoin, lacosamide, ketamine, midazolam, and topiramate were administered at various times in the course of EEG monitoring, resulting in suppression of seizures but not of PLEDs. Ketamine and midazolam reduced the rate, amplitude, and complexity of PLEDs but only after producing substantial attenuation of all burst components. When all anesthetics were discontinued, the EEG reverted to the original preanesthesia pattern with continuous non-fragmented PLEDs. The fact that PLEDs can survive anesthesia and affect DIBS symmetry is a testament to the robustness of the neurodynamic processes underlying PLEDs. PMID:28286626

  2. Correlation Networks for Identifying Changes in Brain Connectivity during Epileptiform Discharges and Transcranial Magnetic Stimulation

    Directory of Open Access Journals (Sweden)

    Elsa Siggiridou

    2014-07-01

    Full Text Available The occurrence of epileptiform discharges (ED in electroencephalographic (EEG recordings of patients with epilepsy signifies a change in brain dynamics and particularly brain connectivity. Transcranial magnetic stimulation (TMS has been recently acknowledged as a non-invasive brain stimulation technique that can be used in focal epilepsy for therapeutic purposes. In this case study, it is investigated whether simple time-domain connectivity measures, namely cross-correlation and partial cross-correlation, can detect alterations in the connectivity structure estimated from selected EEG channels before and during ED, as well as how this changes with the application of TMS. The correlation for each channel pair is computed on non-overlapping windows of 1 s duration forming weighted networks. Further, binary networks are derived by thresholding or statistical significance tests (parametric and randomization tests. The information for the binary networks is summarized by statistical network measures, such as the average degree and the average path length. Alterations of brain connectivity before, during and after ED with or without TMS are identified by statistical analysis of the network measures at each state.

  3. Association of Interictal Epileptiform Discharges with Sleep and Anti-Epileptic Drugs.

    Science.gov (United States)

    Mohan, Latika; Singh, Jayvardhan; Singh, Yogesh; Kathrotia, Rajesh; Goel, Arun

    2016-10-01

    The presence of interictal epileptiform discharges (IEDs) in electroencephalogram (EEG) is diagnostic of epilepsy. Latent IEDs are activated during sleep. Anti-epileptic drugs (AEDs) improve sleep. AEDs, sleep, and IEDs may interact and affect epilepsy management. To explore the occurrence of IEDs and its association with sleep and AED status in suspected patients of epilepsy. EEG records were collected of suspected patients of epilepsy who reported to the electrophysiology laboratory of a tertiary care hospital during 1 year. The anthropometric details, clinical presentations, and AED status of the patients were recorded from the EEG records. Patients were divided into 2 categories based on whether AEDs had been started prior to the EEG evaluation (category-I) or not (category-II). The occurrences of IEDs in EEG recordings in both categories were analyzed. In 1 year, 138 patients were referred for diagnostic EEG evaluation. One-hundred-two patients fulfilled the inclusion criteria, of which 57 patients (53%) belonged to category-I and 45 patients (47%) belonged to category-II. Incidence of IEDs, suggestive of definite diagnosis of epilepsy in category-I was 88% and in category-II was 69%, and this difference was statistically significant (p = 0.02). The increased proportion of IEDs in category-I patients may be due to high clinical suspicion or compounding interaction of AEDs and sleep. More extensive studies are required to delineate the complex interaction of AEDs, sleep, and IEDs so that judicious yet prompt management of epilepsy can be carried out.

  4. Epileptiform activity in alcohol dependent patients and possibilities of its indirect measurement.

    Directory of Open Access Journals (Sweden)

    Petr Bob

    Full Text Available BACKGROUND: Alcohol dependence during withdrawal and also in abstinent period in many cases is related to reduced inhibitory functions and kindling that may appear in the form of psychosensory symptoms similar to temporal lobe epilepsy frequently in conditions of normal EEG and without seizures. Because temporal lobe epileptic activity tend to spread between hemispheres, it is possible to suppose that measures reflecting interhemispheric information transfer such as electrodermal activity (EDA might be related to the psychosensory symptoms. METHODS AND FINDINGS: We have performed measurement of bilateral EDA, psychosensory symptoms (LSCL-33 and alcohol craving (ACQ in 34 alcohol dependent patients and 32 healthy controls. The results in alcohol dependent patients show that during rest conditions the psychosensory symptoms (LSCL-33 are related to EDA transinformation (PTI between left and right EDA records (Spearman r = 0.44, p<0.01. CONCLUSIONS: The result may present potentially useful clinical finding suggesting a possibility to indirectly assess epileptiform changes in alcohol dependent patients.

  5. Interictal epileptiform discharges have an independent association with cognitive impairment in children with lesional epilepsy.

    Science.gov (United States)

    Glennon, Jennifer M; Weiss-Croft, Louise; Harrison, Sue; Cross, J Helen; Boyd, Stewart G; Baldeweg, Torsten

    2016-09-01

    The relative contribution of interictal epileptiform discharges (IEDs) to cognitive dysfunction in comparison with the underlying brain pathology is not yet understood in children with lesional focal epilepsy. The current study investigated the association of IEDs with intellectual functioning in 103 children with medication-resistant focal epilepsy. Hierarchical multiple regression analyses were used to determine the independent contribution of IED features on intellectual functioning, after controlling for effects of lesional pathology, epilepsy duration, and medication. Exploratory analyses were conducted for language and memory scores as well as academic skills available in a subset of participants. The results reveal that IEDs have a negative association with IQ with independent, additive effects documented for frequent and bilaterally distributed IEDs as well as discharge enhancement in sleep. Left-lateralized IEDs had a prominent effect on verbal intelligence, in excess of the influence of left-sided brain pathology. These effects extended to other cognitive functions, most prominently for sleep-enhanced IEDs to be associated with deficits in expressive and receptive language, reading, spelling and numerical skills. Overall, IED effects on cognition were of a magnitude similar to lesional influences or drug effects (topiramate use). This study demonstrates an association between IEDs and cognitive dysfunction, independent of the underlying focal brain pathology. Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.

  6. Periodic lateralized epileptiform discharges can survive anesthesia and result in asymmetric drug-induced burst suppression

    Directory of Open Access Journals (Sweden)

    Edward C. Mader Jr.

    2017-02-01

    Full Text Available Drug-induced burst suppression (DIBS is bihemispheric and bisymmetric in adults and older children. However, asymmetric DIBS may occur if a pathological process is affecting one hemisphere only or both hemispheres disproportionately. The usual suspect is a destructive lesion; an irritative or epileptogenic lesion is usually not invoked to explain DIBS asymmetry. We report the case of a 66-year-old woman with new-onset seizures who was found to have a hemorrhagic cavernoma and periodic lateralized epileptiform discharges (PLEDs in the right temporal region. After levetiracetam and before anesthetic antiepileptic drugs (AEDs were administered, the electroencephalogram (EEG showed continuous PLEDs over the right hemisphere with maximum voltage in the posterior temporal region. Focal electrographic seizures also occurred occasionally in the same location. Propofol resulted in bihemispheric, but not in bisymmetric, DIBS. Remnants or fragments of PLEDs that survived anesthesia increased the amplitude and complexity of the bursts in the right hemisphere leading to asymmetric DIBS. Phenytoin, lacosamide, ketamine, midazolam, and topiramate were administered at various times in the course of EEG monitoring, resulting in suppression of seizures but not of PLEDs. Ketamine and midazolam reduced the rate, amplitude, and complexity of PLEDs but only after producing substantial attenuation of all burst components. When all anesthetics were discontinued, the EEG reverted to the original preanesthesia pattern with continuous non-fragmented PLEDs. The fact that PLEDs can survive anesthesia and affect DIBS symmetry is a testament to the robustness of the neurodynamic processes underlying PLEDs.

  7. Subacute administration of fluoxetine prevents short-term brain hypometabolism and reduces brain damage markers induced by the lithium-pilocarpine model of epilepsy in rats.

    Science.gov (United States)

    Shiha, Ahmed Anis; de Cristóbal, Javier; Delgado, Mercedes; Fernández de la Rosa, Rubén; Bascuñana, Pablo; Pozo, Miguel A; García-García, Luis

    2015-02-01

    The role of serotonin (5-hydroxytryptamine; 5-HT) in epileptogenesis still remains controversial. In this regard, it has been reported that serotonergic drugs can alter epileptogenesis in opposite ways. The main objective of this work was to investigate the effect of the selective 5-HT selective reuptake inhibitor (SSRI) fluoxetine administered subacutely (10mg/kg/day×7 days) on the eventual metabolic impairment induced by the lithium-pilocarpine model of epilepsy in rats. In vivo 2-deoxy-2-[(18)F]fluoro-d-glucose ([(18)F] FDG) positron emission tomography (PET) was performed to assess the brain glucose metabolic activity on days 3 and 30 after the insult. In addition, at the end of the experiment (day 33), several histochemical and neurochemical assessments were performed for checking the neuronal functioning and integrity. Three days after the insult, a marked reduction of [(18)F] FDG uptake (about 30% according to the brain region) was found in all brain areas studied. When evaluated on day 30, although a hypometabolism tendency was observed, no statistically significant reduction was present in any region analyzed. In addition, lithium-pilocarpine administration was associated with medium-term hippocampal and cortical damage, since it induced neurodegeneration, glial activation and augmented caspase-9 expression. Regarding the effect of fluoxetine, subacute treatment with this SSRI did not significantly reduce the mortality rate observed after pilocarpine-induced seizures. However, fluoxetine did prevent not only the short-term metabolic impairment, but also the aforementioned signs of neuronal damage in surviving animals to lithium-pilocarpine protocol. Finally, fluoxetine increased the density of GABAA receptor both at the level of the dentate gyrus and CA1-CA2 regions in pilocarpine-treated animals. Overall, our data suggest a protective role for fluoxetine against pilocarpine-induced brain damage. Moreover, this action may be associated with an increase of

  8. 癫癎样放电在抗癫癎药物应用及复发预测中的意义%Signiifcance of epileptiform discharges in anti-epileptiform drug therapy and prediction of relapse Reviewer

    Institute of Scientific and Technical Information of China (English)

    袁凯杰(综述); 侯梅(审校)

    2013-01-01

    EEGs performed for new-onset seizures show epileptiform discharge in approximately 18% to 56% of children and 12%to 50%of adults. EEG is the most commonly used means of neurological examination for epilepsy. Speciifc EEG abnormalities help characterize the seizure type and epilepsy syndrome, which allows more informed decisions regarding therapy and more accurate prediction of seizure control and ultimate remission. In certain cases, the EEG may detect more subtle seizures, including absence, myoclonic or partial seizures. In the therapy of epilepsy, the effect of different antiepileptic drugs on the inhibition of epileptiform discharges is different. Epileptiform discharges play a very important role in the prediction of recurrence and the decision to remove antiepileptic drugs.%  癫癎首次发作后脑电图检出癫样放电异常率在儿童为18%~56%,成人为10%~50%,脑电技术是最常用的癫神经病学检查手段,特征性脑电图异常能够帮助对发作类型及癫综合征的分类、确定治疗方案及判断预后。在特定病例,脑电图能检测到更加细微的发作,包括失神、肌阵挛或部分性发作。癫治疗中不同的抗癫药物对癫样放电的抑制存在差异,癫样放电在复发预测及决定撤除抗癫药物方面起着重要作用。

  9. Epileptiform abnormalities and quantitative EEG in children with attention-deficit / hyperactivity disorder Atividade epileptiforme e eletrencefalograma quantitativo em crianças com transtorno de déficit de atenção/hiperatividade

    Directory of Open Access Journals (Sweden)

    Lineu Corrêa Fonseca

    2008-09-01

    Full Text Available There is much controversy about the importance of the electroencephalogram (EEG in assessing the attention-deficit/hyperactivity disorder (ADHD. The objective of this study was to assess the use of EEG and quantitative EEG (qEEG in ADHD children. Thirty ADHD children and 30 sex- and age-matched controls with no neurological or psychiatric problems were studied. The EEG was recorded from 15 electrode sites during an eyes-closed resting condition. Epileptiform activity was assessed, as were the absolute and relative powers in the classical bands after application of the Fast Fourier transform. Epileptiform activity was found in 3 (10% ADHD children. As compared to the controls, the ADHD group showed significantly greater absolute delta and theta powers in a diffuse way, and also greater absolute beta power and smaller relative alpha 1 and beta powers at some electrodes. A logistic multiple regression model, allowed for 83.3% sensibility and specificity in diagnosing ADHD.Há controvérsias sobre a importância do eletrencefalogama (EEG na avaliação do transtorno de déficit de atenção/hiperatividade (TDAH. O objetivo deste estudo foi avaliar, em crianças com TDAH, o EEG digital e quantitativo. Foram estudadas 30 crianças com TDAH e 30 sadias, sem evidências de problemas neurológicos ou psiquiátricos e pareadas por idade e gênero. Foi registrado o EEG em 15 posições de eletrodos, durante repouso e olhos fechados. Foi realizada pesquisa de atividade epileptiforme e feita análise de freqüências nas faixas clássicas, após aplicação da transformada rápida de Fourier. Foi encontrada atividade epileptiforme em 3 (10% crianças com TDAH. O grupo TDAH teve, em relação ao grupo controle, significativamente, maior potência absoluta delta e teta, de modo difuso, assim como maior potência absoluta beta e menor potência relativa alfa 1 e beta, em alguns eletrodos. Um modelo de regressão múltipla logística possibilitou sensibilidade e

  10. Enhanced nonsynaptic epileptiform activity in the dentate gyrus after kainate-induced status epilepticus.

    Science.gov (United States)

    Nogueira, G S; Santos, L E C; Rodrigues, A M; Scorza, C A; Scorza, F A; Cavalheiro, E A; de Almeida, A-C G

    2015-09-10

    Understanding the mechanisms that influence brain excitability and synchronization provides hope that epileptic seizures can be controlled. In this scenario, non-synaptic mechanisms have a critical role in seizure activity. The contribution of ion transporters to the regulation of seizure-like activity has not been extensively studied. Here, we examined how non-synaptic epileptiform activity (NEA) in the CA1 and dentate gyrus (DG) regions of the hippocampal formation were affected by kainic acid (KA) administration. NEA enhancement in the DG and suppression in area CA1 were associated with increased NKCC1 expression in neurons and severe neuronal loss accompanied by marked glial proliferation, respectively. Twenty-four hours after KA, the DG exhibited intense microglial activation that was associated with reduced cell density in the infra-pyramidal lamina; however, cellular density recovered 7 days after KA. Intense Ki67 immunoreactivity was observed in the subgranular proliferative zone of the DG, which indicates new neuron incorporation into the granule layer. In addition, bumetanide, a selective inhibitor of neuronal Cl(-) uptake mediated by NKCC1, was used to confirm that the NKCC1 increase effectively contributed to NEA changes in the DG. Furthermore, 7 days after KA, prominent NKCC1 staining was identified in the axon initial segments of granule cells, at the exact site where action potentials are preferentially initiated, which endowed these neurons with increased excitability. Taken together, our data suggest a key role of NKCC1 in NEA in the DG. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  11. Influence of metallic artifact filtering on MEG signals for source localization during interictal epileptiform activity

    Science.gov (United States)

    Migliorelli, Carolina; Alonso, Joan F.; Romero, Sergio; Mañanas, Miguel A.; Nowak, Rafał; Russi, Antonio

    2016-04-01

    Objective. Medical intractable epilepsy is a common condition that affects 40% of epileptic patients that generally have to undergo resective surgery. Magnetoencephalography (MEG) has been increasingly used to identify the epileptogenic foci through equivalent current dipole (ECD) modeling, one of the most accepted methods to obtain an accurate localization of interictal epileptiform discharges (IEDs). Modeling requires that MEG signals are adequately preprocessed to reduce interferences, a task that has been greatly improved by the use of blind source separation (BSS) methods. MEG recordings are highly sensitive to metallic interferences originated inside the head by implanted intracranial electrodes, dental prosthesis, etc and also coming from external sources such as pacemakers or vagal stimulators. To reduce these artifacts, a BSS-based fully automatic procedure was recently developed and validated, showing an effective reduction of metallic artifacts in simulated and real signals (Migliorelli et al 2015 J. Neural Eng. 12 046001). The main objective of this study was to evaluate its effects in the detection of IEDs and ECD modeling of patients with focal epilepsy and metallic interference. Approach. A comparison between the resulting positions of ECDs was performed: without removing metallic interference; rejecting only channels with large metallic artifacts; and after BSS-based reduction. Measures of dispersion and distance of ECDs were defined to analyze the results. Main results. The relationship between the artifact-to-signal ratio and ECD fitting showed that higher values of metallic interference produced highly scattered dipoles. Results revealed a significant reduction on dispersion using the BSS-based reduction procedure, yielding feasible locations of ECDs in contrast to the other two approaches. Significance. The automatic BSS-based method can be applied to MEG datasets affected by metallic artifacts as a processing step to improve the localization of

  12. Enhanced Synaptic Activity and Epileptiform Events in the Embryonic KCC2 Deficient Hippocampus.

    Science.gov (United States)

    Khalilov, Ilgam; Chazal, Geneviève; Chudotvorova, Ilona; Pellegrino, Christophe; Corby, Séverine; Ferrand, Nadine; Gubkina, Olena; Nardou, Romain; Tyzio, Roman; Yamamoto, Sumii; Jentsch, Thomas J; Hübner, Christian A; Gaiarsa, Jean-Luc; Ben-Ari, Yehezkel; Medina, Igor

    2011-01-01

    The neuronal potassium-chloride co-transporter 2 [indicated thereafter as KCC2 (for protein) and Kcc2 (for gene)] is thought to play an important role in the post natal excitatory to inhibitory switch of GABA actions in the rodent hippocampus. Here, by studying hippocampi of wild-type (Kcc2(+/+)) and Kcc2 deficient (Kcc2(-/-)) mouse embryos, we unexpectedly found increased spontaneous neuronal network activity at E18.5, a developmental stage when KCC2 is thought not to be functional in the hippocampus. Embryonic Kcc2(-/-) hippocampi have also an augmented synapse density and a higher frequency of spontaneous glutamatergic and GABA-ergic postsynaptic currents than naïve age matched neurons. However, intracellular chloride concentration ([Cl(-)](i)) and the reversal potential of GABA-mediated currents (E(GABA)) were similar in embryonic Kcc2(+/+) and Kcc2(-/-) CA3 neurons. In addition, KCC2 immunolabeling was cytoplasmic in the majority of neurons suggesting that the molecule is not functional as a plasma membrane chloride co-transporter. Collectively, our results show that already at an embryonic stage, KCC2 controls the formation of synapses and, when deleted, the hippocampus has a higher density of GABA-ergic and glutamatergic synapses and generates spontaneous and evoked epileptiform activities. These results may be explained either by a small population of orchestrating neurons in which KCC2 operates early as a chloride exporter or by transporter independent actions of KCC2 that are instrumental in synapse formation and networks construction.

  13. Attention deficit/hyperactivity disorder and interictal epileptiform discharges: it is safe to use methylphenidate?

    Science.gov (United States)

    Socanski, Dobrinko; Aurlien, Dag; Herigstad, Anita; Thomsen, Per Hove; Larsen, Tor Ketil

    2015-02-01

    This study investigated whether interictal epileptiform discharges (IED) on a baseline routine EEG in children with ADHD was associated with the occurrence of epileptic seizures (Sz) or influenced the use of methylphenidate (MPH) during 2 years follow-up. A retrospective chart-review of 517 ADHD children with EEG revealed IED in 39 cases. These patients (IED group) were matched on age and gender with 39 patients without IED (non-IED group). We measured at baseline, 1 year and 2 years Sz occurrence, the use of MPH and antiepileptic drug (AED). At baseline, 12 patients in the IED group had active epilepsy and three of them had Sz during the last year. 36 (92.3%) patients were treated with MPH. Initial positive response to MPH was achieved in 83.3% compared with 89.2% in the non-IED group. At 1 and 2 years follow-up, three patients who also had Sz at baseline and difficult to treat epilepsy, had Sz, without changes in seizure frequency. We found no statistically significant differences between the groups with respect to MPH use at 1 year and at 2 years. Ten patients from IED group, who did not have confirmed epilepsy diagnosis, temporarily used AEDs during the first year of follow-up. Despite the occurrence of IED, the use of MPH was safe during 2 years follow-up. IED predict the Sz occurrence in children with previous epilepsy, but does not necessarily suggest an increased seizure risk. A caution is warranted in order not to overestimate the significance of temporarily occurrence of IED. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  14. The relationship between sleep-activated interictal epileptiform discharges and intelligence in children.

    Science.gov (United States)

    Scott, Christine M

    2013-12-01

    This study investigates the relationship between interictal epileptiform discharges (IEDs) during sleep in children with benign rolandic epilepsy (BRE) and cognitive test scores as measured by the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) with the hypothesis that, as IEDs increase, cognitive test scores decrease. Studies have shown that generalized seizures and status epilepticus can negatively impact cognition (Dodrill 2004), that children with epilepsy have lower cognitive function on average than children without epilepsy and that children with epilepsy and abnormal electroencephalograms (EEGs) have lower cognitive function than children with epilepsy and normal EEGs (Bailet et al. 2000). Studies have also indicated that as IEDs decrease, neurocognitive test scores increase (Baglietto et al. 2001). The current study evaluated sleep-activated IEDs in children with the specific syndrome of benign rolandic epilepsy based on the frequency of LEDs in sleep in relation to cognitive test scores. Neuropsychological test scores from the WISC-IV were gathered along with the number of spikes per minute detected in EEG recordings. Statistical analysis revealed a negative correlation between spike frequency and both processing speed and coding scores, though the relationship did not reach statistical significance. This study concludes that there may be correlations between increased spike density and cognitive test scores, or there might be other factors impacting cognition in BRE, but a larger sample is needed to further investigate. In addition, it is possible that a negative result in the present study represents good news, that the number of IEDs in BRE does not harm the brain by negatively impacting cognition.

  15. Slow pseudoperiodic lateralized epileptiform discharges in nonconvulsive status epilepticus in a patient with cerebral palsy and a large central meningioma

    Directory of Open Access Journals (Sweden)

    Y.Z. Imam

    2014-01-01

    Full Text Available The presence of cerebral palsy and that of slow growing brain tumors are risk factors for convulsive and nonconvulsive status epilepticus. Nonconvulsive status epilepticus (NCSE needs electroencephalographic (EEG monitoring to be confirmed as it may be clinically subtle. Furthermore, it may present with a variety of ictal EEG morphologies. We report a case of a patient with cerebral palsy and a large central meningioma. Electroencephalogram showed a slow pattern of periodic lateralized epileptiform discharges (PLEDs (a pattern considered as being situated in the ictal–interictal continuum on an alpha background. The patient was treated for NCSE successfully with benzodiazepines followed by up-titration of his antiepileptic drug doses.

  16. Regulation of the spatial code for BDNF mRNA isoforms in the rat hippocampus following pilocarpine-treatment: a systematic analysis using laser microdissection and quantitative real-time PCR.

    Science.gov (United States)

    Baj, Gabriele; Del Turco, Domenico; Schlaudraff, Jessica; Torelli, Lucio; Deller, Thomas; Tongiorgi, Enrico

    2013-05-01

    Brain-derived neurotrophic factor (BDNF) is essential for neuronal survival, differentiation, and plasticity and is one of those genes that generate multiple mRNAs with different alternatively spliced 5'UTRs. The functional significance of many BDNF transcripts, each producing the same protein, is emerging. On the basis of the analysis of the four most abundant brain BDNF transcripts, we recently proposed the "spatial code hypothesis of BDNF splice variants" according to which the BDNF transcripts, through their differential subcellular localization in soma or dendrites, represent a mechanism to synthesize the protein at distinct locations and produce local effects. In this study, using laser microdissection of hippocampal laminae and reverse transcription-quantitative real-time PCR (RT-qPCR), we analyzed all known BDNF mRNA variants at resting conditions or following 3 h pilocarpine-induced status epilepticus. In untreated rats, we found dendritic enrichment of BDNF transcripts encoding exons 6 and 7 in CA1; exons 1, 6, and 9a in CA3; and exons 5, 6, 7, and 8 in DG. Considering the low abundance of the other transcripts, exon 6 was the main transcript in dendrites under resting conditions. Pilocarpine treatment induced an increase of BDNF transcripts encoding exons 4 and 6 in all dendritic laminae and, additionally, of exon 2 in CA1 stratum radiatum and exons 2, 3, 9a in DG molecular layer while the other transcripts were decreased in dendrites, suggesting restriction to the soma. These results support the hypothesis of a spatial code to differentially regulate BDNF in the somatic or dendritic compartment under conditions of pilocarpine-induced status epilepticus and, furthermore, highlight the existence of subfield-specific differences.

  17. Neuronal chloride accumulation and excitatory GABA underlie aggravation of neonatal epileptiform activities by phenobarbital.

    Science.gov (United States)

    Nardou, Romain; Yamamoto, Sumii; Chazal, Geneviève; Bhar, Asma; Ferrand, Nadine; Dulac, Olivier; Ben-Ari, Yehezkel; Khalilov, Ilgam

    2011-04-01

    Phenobarbital produces its anti-epileptic actions by increasing the inhibitory drive of γ-aminobutyric acid. However, following recurrent seizures, γ-aminobutyric acid excites neurons because of a persistent increase of chloride raising the important issue of whether phenobarbital could aggravate persistent seizures. Here we compared the actions of phenobarbital on initial and established ictal-like events in an in vitro model of mirror focus. Using the in vitro three-compartment chamber preparation with the two hippocampi and their commissural fibres placed in three different chambers, kainate was applied to one hippocampus and phenobarbital contralaterally, either after one ictal-like event or after many recurrent ictal-like events that produce an epileptogenic mirror focus. Field, perforated patch and single-channel recordings were used to determine the effects of γ-aminobutyric acid and their modulation by phenobarbital, and alterations of the chloride cotransporters were investigated using sodium-potassium-chloride cotransporter 1 and potassium chloride cotransporter 2 antagonists, potassium chloride cotransporter 2 immunocytochemistry and sodium-potassium-chloride cotransporter 1 knockouts. Phenobarbital reduced initial ictal-like events and prevented the formation of a mirror focus when applied from the start. In contrast, phenobarbital aggravated epileptiform activities when applied after many ictal-like events by enhancing the excitatory actions of γ-aminobutyric acid due to increased chloride. The accumulation of chloride and the excitatory actions of γ-aminobutyric acid in mirror foci neurons are mediated by the sodium-potassium-chloride cotransporter 1 chloride importer and by downregulation and internalization of the chloride-exporter potassium-chloride cotransporter 2. Finally, concomitant applications of the sodium-potassium-chloride cotransporter 1 antagonist bumetanide and phenobarbital decreased excitatory actions of γ-aminobutyric acid and

  18. Computational modeling of seizure dynamics using coupled neuronal networks: factors shaping epileptiform activity.

    Directory of Open Access Journals (Sweden)

    Sebastien Naze

    2015-05-01

    Full Text Available Epileptic seizure dynamics span multiple scales in space and time. Understanding seizure mechanisms requires identifying the relations between seizure components within and across these scales, together with the analysis of their dynamical repertoire. Mathematical models have been developed to reproduce seizure dynamics across scales ranging from the single neuron to the neural population. In this study, we develop a network model of spiking neurons and systematically investigate the conditions, under which the network displays the emergent dynamic behaviors known from the Epileptor, which is a well-investigated abstract model of epileptic neural activity. This approach allows us to study the biophysical parameters and variables leading to epileptiform discharges at cellular and network levels. Our network model is composed of two neuronal populations, characterized by fast excitatory bursting neurons and regular spiking inhibitory neurons, embedded in a common extracellular environment represented by a slow variable. By systematically analyzing the parameter landscape offered by the simulation framework, we reproduce typical sequences of neural activity observed during status epilepticus. We find that exogenous fluctuations from extracellular environment and electro-tonic couplings play a major role in the progression of the seizure, which supports previous studies and further validates our model. We also investigate the influence of chemical synaptic coupling in the generation of spontaneous seizure-like events. Our results argue towards a temporal shift of typical spike waves with fast discharges as synaptic strengths are varied. We demonstrate that spike waves, including interictal spikes, are generated primarily by inhibitory neurons, whereas fast discharges during the wave part are due to excitatory neurons. Simulated traces are compared with in vivo experimental data from rodents at different stages of the disorder. We draw the conclusion

  19. Protection of pyrrolidine dithiocarbamate on the piriform cortex of pilocarpine-induced status epileptic rats%核因子-κB抑制剂吡咯烷二硫氨基甲酸盐对毛果芸香碱诱导癫痫大鼠梨状皮层的保护性作用

    Institute of Scientific and Technical Information of China (English)

    徐海元; 徐晓云; 吕日琅

    2013-01-01

    目的 观察核因子-κB(NF-κB)抑制剂吡咯烷二硫氮基甲酸盐(PDTC)对毛果芸香碱诱导癫痫大鼠梨状皮层的保护性作用.方法 将26只正常雄性SD大鼠随机分为3组:正常对照组(NS组,n=6)、毛果芸香碱诱导癫痫组(SE组,n=10)和PDTC干预组(PDTC组,n=10).SE组一次性腹腔注射毛果芸香碱诱导大鼠癫痫发作;PDTC干预组分别于造模前24 h、20 min、SE发作后24 h腹腔注射PDTC 100 mg·kg-;NS组给予等量生理盐水.于造模成功后48 h处死各组大鼠,采用Nissl染色和Fluoro-Jade C (FJC)染色法分别检测并比较各组大鼠梨状皮层存活神经细胞情况和退行性神经元数目.结果 Nissl染色结果显示,SE组大鼠梨状皮层大量神经细胞丢失,胞体结构完整性遭到破坏.FJG染色结果显示,SE组FJC阳性细胞数目明显增多;经PDTC干预后可明显改善梨状皮层神经损伤,FJC阳性细胞数明显减少,差异有统计学意义(P<0.05).结论 PDTC对毛果芸香碱诱导癫痫大鼠梨状皮层损伤具有明显的保护性作用.

  20. 匹罗卡品致痫大鼠海马神经肽Y中间神经元数目变化及其轴突出芽%Number changes and axonal sprouting of neuropeptide Y interneurons in the hippocampus of pilocarpine-induced rats

    Institute of Scientific and Technical Information of China (English)

    吴志国; 龙莉莉; 肖波; 陈锶; 易芳

    2009-01-01

    目的:探讨神经肽Y(neuropeptide Y,NPY)中间神经元在颞叶癫痫的发生和自我修复中的作用.方法:建立匹罗卡品致痫模型,应用免疫组织化学技术动态观察大鼠海马NPY中间神经元的数目变化及其轴突出芽.结果:实验组大鼠腹腔注射氯化锂-匹罗卡品后,癫痫持续状态(status epilepticus, SE)诱发成功率为92.9%,死亡率19.2%.免疫组织化学结果显示,实验组大鼠海马门区NPY中间神经元数目在SE后下降,至7 d时降至最低(P0.05);SE后30 d齿状回分子层可见增多的NPY阳性纤维.结论:NPY中间神经元在不同部位不同时段对颞叶癫痫所致损伤的敏感性不同,NPY中间神经元的缺失在颞叶癫痫发生中起重要作用,NPY中间神经元的轴突出芽在颞叶癫痫的自我修复中起作用.

  1. Persistent Hyperactivity of Hippocampal Dentate Interneurons after a Silent Period in the Rat Pilocarpine Model of Epilepsy

    Directory of Open Access Journals (Sweden)

    Xiaochen eWang

    2016-04-01

    Full Text Available Profile of GABAergic interneuron activity after pilocarpine-induced status epilepticus (SE was examined in the rat hippocampal dentate gyrus by analyzing immediate early gene expression and recording spontaneous firing at near resting membrane potential.SE for exact 2 hours or more than 2 hours was induced in the male Sprague-Dawley rats by an intraperitoneal injection of pilocarpine. Expression of immediate early genes was examined at 1 hour, 1 week, 2 weeks or more than 10 weeks after SE. For animals to be examined at 1 hour after SE, SE lasted for exact 2 hours was terminated by an intraperitoneal injection of diazepam. Spontaneous firing at near the resting membrane potential was recorded in interneurons located along the border between the granule cell layer and the hilus more than 10 weeks after SE. Results showed that both c-fos and activity-regulated cytoskeleton associated protein (Arc in hilar GABAergic interneurons were up-regulated after SE in a biphasic manner; they were increased at 1 hour and more than 2 weeks, but not at 1 week after SE. Ten weeks after SE, nearly 60% of hilar GABAergic cells expressed c-fos. With the exception of calretinin (CR-positive cells, percentages of hilar neuronal nitric oxide synthase (nNOS-, neuropeptide Y (NPY-, parvalbumin (PV-, and somatostatin (SOM-positive cells with c-fos expression are significantly higher than those of controls more than 10 weeks after SE. Without the resting membrane potential to be more depolarizing and changed threshold potential level in SE-induced rats, cell-attached recording revealed that nearly 90% of hilar interneurons fired spontaneously at near the resting membrane potential while only 22% of the same cell population did so in the controls.In conclusion, pilocarpine-induced SE eventually leads to a state in which surviving dentate GABAergic interneurons become hyperactive with a subtype-dependent manner; this implies that a fragile balance between excitation and

  2. Comparison of impact on seizure frequency and epileptiform discharges of children with epilepsy from topiramate and phenobarbital.

    Science.gov (United States)

    Wang, Y-Y; Wang, M-G; Yao, D; Huang, X-X; Zhang, T; Deng, X-Q

    2016-03-01

    To study the impact on seizure frequency and epileptiform discharges of children with epilepsy from topiramate (TPM) and phenobarbital (PB). Two hundred cases children with epilepsy from August 2010 to August 2013 in our hospital were sampled and randomly divided into two groups. The observation group was treated with TPM while the control group with PB, and then comparing seizure frequency, efficiency, and adverse reactions of two groups. The reduced number of partial seizures, generalized seizures, and total seizures in the observation group were significantly higher than those in the control group, and the rate of cure, markedly effective and total efficiency in observation group were significantly higher than those in the control group. However, the adverse reactions in observation group were significantly lower than those in the control group. Thus, differences were statistically significant (p<0.05). Compared with PB, TPM showed a better effect on epilepsy treatment with less adverse reactions which were worthy of clinical recommendation.

  3. Automatic detection of epileptiform events in EEG by a three-stage procedure based on artificial neural networks.

    Science.gov (United States)

    Acir, Nurettin; Oztura, Ibrahim; Kuntalp, Mehmet; Baklan, Bariş; Güzeliş, Cüneyt

    2005-01-01

    This paper introduces a three-stage procedure based on artificial neural networks for the automatic detection of epileptiform events (EVs) in a multichannel electroencephalogram (EEG) signal. In the first stage, two discrete perceptrons fed by six features are used to classify EEG peaks into three subgroups: 1) definite epileptiform transients (ETs); 2) definite non-ETs; and 3) possible ETs and possible non-ETs. The pre-classification done in the first stage not only reduces the computation time but also increases the overall detection performance of the procedure. In the second stage, the peaks falling into the third group are aimed to be separated from each other by a nonlinear artificial neural network that would function as a postclassifier whose input is a vector of 41 consecutive sample values obtained from each peak. Different networks, i.e., a backpropagation multilayer perceptron and two radial basis function networks trained by a hybrid method and a support vector method, respectively, are constructed as the postclassifier and then compared in terms of their classification performances. In the third stage, multichannel information is integrated into the system for contributing to the process of identifying an EV by the electroencephalographers (EEGers). After the integration of multichannel information, the overall performance of the system is determined with respect to EVs. Visual evaluation, by two EEGers, of 19 channel EEG records of 10 epileptic patients showed that the best performance is obtained with a radial basis support vector machine providing an average sensitivity of 89.1%, an average selectivity of 85.9%, and a false detection rate (per hour) of 7.5.

  4. Mitochondrial calcium ion and membrane potential transients follow the pattern of epileptiform discharges in hippocampal slice cultures.

    Science.gov (United States)

    Kovács, Richard; Kardos, Julianna; Heinemann, Uwe; Kann, Oliver

    2005-04-27

    Emerging evidence suggests that mitochondrial dysfunction contributes to the pathophysiology of epilepsy. Recurrent mitochondrial Ca2+ ion load during seizures might act on mitochondrial membrane potential (DeltaPsim) and proton motive force. By using electrophysiology and confocal laser-scanning microscopy, we investigated the effects of epileptiform activity, as induced by low-Mg2+ ion perfusion in hippocampal slice cultures, on changes in DeltaPsim and in mitochondrial Ca2+ ion concentration ([Ca2+]m). The mitochondrial compartment was identified by monitoring DeltaPsim in the soma and dendrites of patched CA3 pyramidal cells using the mitochondria-specific voltage-sensitive dye rhodamine-123 (Rh-123). Interictal activity was accompanied by localized mitochondrial depolarization that was restricted to a few mitochondria in small dendrites. In contrast, robust Rh-123 release into the cytosol was observed during seizure-like events (SLEs), indicating simultaneous depolarization of mitochondria. This was critically dependent on Ca2+ ion uptake and extrusion, because inhibition of the mitochondrial Ca2+ ion uniporter by Ru360 and the mitochondrial Na+/Ca2+ ion exchanger by 7-chloro-5-(2-chlorophenyl)-1,5-dihydro-4,1-benzothiazepin-2(3H)-one but not the inhibitor of mitochondrial permeability transition pore, cyclosporin A, decreased the SLE-associated mitochondrial depolarization. The Ca2+ ion dependence of simultaneous mitochondrial depolarization suggested enhanced Ca2+ ion cycling across mitochondrial membranes during epileptiform activity. Indeed, [Ca2+]m fluctuated during interictal activity in single dendrites, and these fluctuations spread over the entire mitochondrial compartment during SLEs, as revealed using mitochondria-specific dyes (rhod-2 and rhod-ff) and spatial frequency-based image analysis. These findings strengthen the hypothesis that epileptic activity results in Ca2+ ion-dependent changes in mitochondrial function that might contribute to the

  5. Episodic ataxia type 2 manifests as epileptiform electroencephalographic activity with no epileptic attacks in two family members.

    Science.gov (United States)

    Kaido, Misako; Furuta, Mitsuru; Nakamori, Masayuki; Yuasa, Yoshihito; Takahashi, Masanori P

    2016-04-28

    Here, we report two cases of episodic ataxia type 2 (EA2) in a 63-year-old woman and her 36-year-old daughter. The mother experienced recurrent attacks of cerebellar dysfunction lasting 4 to 5 hours since the age of 41 years. On several occasions, she was admitted to the emergency room, where she was diagnosed with epilepsy or stroke. Based on these diagnoses, she was treated with antiepileptic or anticoagulant drugs, but both treatments were eventually discontinued. The frequency of the attacks increased after the patient reached the age of 62. Interictal neurological examination demonstrated signs of slight cerebellar ataxia, i.e. saccadic eye movements, gaze-directed nystagmus, and mild truncal ataxia. Brain magnetic resonance imaging (MRI) showed cerebellar vermis atrophy. Electroencephalography (EEG) revealed various spike and wave patterns: solitary spikes, spike-and-slow wave complexes, and slow wave bursts. Photoparoxysmal response (PPR) type 3 was also observed. Treatment with acetazolamide abolished the patient's attacks almost completely. The daughter started experiencing 5- to 10-minute ataxic episodes at the age of 16 years. Based on her epileptiform EEG activities with PPR (type 2), antiepileptic drugs (valproate and zonisamide) were prescribed. Despite pharmacological treatment, the attacks recurred; however, their frequency gradually decreased with time, until they almost entirely disappeared when the patient was 33. Unfortunately, migraine-like headaches arose instead. Subtle truncal ataxia was observed during interictal periods. Sanger sequencing of the exons of the CACNA1A gene revealed a novel single base deletion (c.3575delA) in both patients. Despite the difference in age of onset and clinical course, both patients showed clearly epileptiform EEG activities without experiencing the concurrent epileptic episodes. Thus, EA2 is a disease that may be misdiagnosed as epilepsy or stroke in the field of emergency medicine.

  6. In vivo evaluation of anticonvulsant and antioxidant effects of phenobarbital microemulsion for transdermal administration in pilocarpine seizure rat model.

    Science.gov (United States)

    Figueiredo, Kayo Alves; Medeiros, Shirlene Cesário; Neves, Jamilly Kelly Oliveira; da Silva, José Alexsandro; da Rocha Tomé, Adriana; Carvalho, André Luis Menezes; de Freitas, Rivelilson Mendes

    2015-04-01

    This study aimed to evaluate a microemulsion system (ME) containing phenobarbital in epilepsy model induced by pilocarpine in rats and to oxidative stress and histologic lesions in hippocampus. The microemulsion was applied to the shaved back of Wistar rats. The animals were divided into the following groups: control group (P400); ME50 40mg/kg, topically-t.p.; ME100, 40mg/kg, t.p.; EM50, 40mg/kg, t.p.; phenobarbital solution 40mg/kg (PS), oral. After 60min, behavioral changes were evaluated for 1h in the model of epileptical crisis induced by pilocarpine. Phenobarbital in microemulsion was able to increase the latency for status epilepticus (SE) (p<0.05), decrease the number of epileptical crisis (ME50: p<0.001; ME100: p<0.01) and decrease mortality rate by 80% compared to P400. In EM50 and PS groups, deaths were decreased by 53.3% and 100% respectively. The ME50 and ME100 groups were able to reduce oxidative stress in experimental animals when compared to the P400. The microemulsion was still capable of reducing neuronal damage in the hippocampal areas. The results of this study come in an innovative way, demonstrating the ability of transdermal ME50 and ME100 to reduce pilocarpine-induced epileptical crisis, oxidative stress, besides neuronal damages. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. The function study of entorhinal cortex neuron GABAA receptor in an epilepsia rat model%癫痫大鼠内嗅皮层神经元GABAA受体功能的研究

    Institute of Scientific and Technical Information of China (English)

    李桀; 孙杨; 刘备; 王超; 井晓荣; 梁秦川; 李焕发; 张华; 高国栋

    2011-01-01

    Objective Established the lithium chloride-pilocarpine inducing epilepsia rat model, and initially study about the entorhinal cortex neuron GABAA receptor by patch clamp of whole-cell mode. Methods The SD rats were divided into control group and experiment group randomly. Intraperitoneal injection of lithium chloride-pilocarpine have been used in experiment group, and physiologic saline in control group. Observed the ethology characteristic and recorded the attenuation tendency of GABAa receptor electric current in whole cell mode. Results The e-lectric current attenuation tendency of GABAA Receptor of Epilepsia Rat greatly intensify in the experiment group. The group diveded have significant difference by variance test and interclass analyse (P<0. 05), and the datas of every point of time in experiment group and control group also have significant difference by t-text analyse(P<0. 05). Conclusion The electric current attenuation tendency of Entorhinal Cortex Neuron GABAA Receptor of lithium chloride-pilocarpine inducing epilepsia rat have intensified. This phenomenon could be the possible mechanism of lithium chloride-pilocarpine inducing epilepsia rat and hint that GABAA receptor may contribute to the epileptic attack and brain injured after epileptic attack.%目的 介绍建立氯化锂-匹鲁卡品致痫大鼠模型的方法,并且通过全细胞膜片钳记录,初步研究其内嗅皮层神经元GABAA受体功能.方法 将所有SD大鼠随机分为对照组和实验组.实验组大鼠腹腔注射氯化锂以及匹鲁卡品,对照组注射生理盐水,观察其行为学特征,并用全细胞膜片钳记录GABAA受体电流的衰减趋势.结果 与对照组相比,实验组癫痫大鼠内嗅皮层神经元的GABAA受体电流的衰减加剧.方差检验进行组间分析,分组的作用是有差异的(P<0.001),;固定时间,对每个时间点上的处理组和对照组进行t检验,分组都有统计学意义(P<0.001).结论 锂-匹罗卡品致病大鼠

  8. Change of MicroRNA-134, CREB and p-CREB expression in epileptic rat

    Institute of Scientific and Technical Information of China (English)

    Yan Zhu; Cheng-Shan Li; Yuan-Ye Wang; Sheng-Nian Zhou

    2015-01-01

    Objective: To To investigate the changes of MicroRNA-134, CREB and p-CREB expression in epileptic rat brains in order to elucidate the molecular mechanisms of epilepsy, providing new ideas for clinical treatment. Methods: Sixty-four Spraque-Dawley (SD) rats were divided into groups randomly, including control group, six hours after seizure group, 24-hour group, three-day group, one-week group, two-week group, four-week group, and eight-week group. All groups were placed under a pilocarpine-induced epilepsy model except the control group, and all rats were decapitated in different points of time. Brain specimens were taken for quantitative PCR experiments, immunohistochemistry and Western blot experiments. The results of the epilepsy model groups and the control group were compared. Results: There were no significant differences between the six hours after seizure group, the 24-hour group and the control group about the MicroRNA-134 levels. MicroRNA-134 in the hippocampus tissue of the three-day group significantly reduced compared with the control group; same result was observed with the one-week, two-week, four-week and eight-week groups. The CREB and p-CREB levels in the three-day group’s rat hippocampus significantly increased compared with the control group; and the high levels of CREB and p-CREB were constantly maintained in the one-week, two-week, four-week and eight-week groups. Conclusions: The MicroRNA-134 level of the epileptic rat hippocampus is significantly lower than normal after three days, and continues to maintain a low level; while CREB and p-CREB levels are rsignificantly increased after three days, and continue to remain at a high level. MicroRNA-134 plays a role in inhibiting synaptic plasticity by inhibiting CREB and p-CREB expressions.

  9. Ketogenic Diet Prevents Epileptogenesis and Disease Progression in Adult Mice and Rats

    Science.gov (United States)

    Lusardi, Theresa A.; Akula, Kiran K.; Coffman, Shayla Q.; Ruskin, David; Masino, Susan A.; Boison, Detlev

    2015-01-01

    Epilepsy is a highly prevalent seizure disorder which tends to progress in severity and become refractory to treatment. Yet no therapy is proven to halt disease progression or to prevent the development of epilepsy. Because a high fat low carbohydrate ketogenic diet (KD) augments adenosine signaling in the brain and because adenosine not only suppresses seizures but also affects epileptogenesis, we hypothesized that a ketogenic diet might prevent epileptogenesis through similar mechanisms. Here, we tested this hypothesis in two independent rodent models of epileptogenesis. Using a pentylenetetrazole kindling paradigm in mice, we first show that a KD, but not a conventional antiepileptic drug (valproic acid), suppressed kindling-epileptogenesis. Importantly, after treatment reversal, increased seizure thresholds were maintained in those animals kindled in the presence of a KD, but not in those kindled in the presence of valproic acid. Next, we tested whether a KD can halt disease progression in a clinically relevant model of progressive epilepsy. Epileptic rats that developed spontaneous recurrent seizures after a pilocarpine-induced status epilepticus were treated with a KD or control diet (CD). Whereas seizures progressed in severity and frequency in the CD-fed animals, KD-fed animals showed a prolonged reduction of seizures, which persisted after diet reversal. KD-treatment was associated with increased adenosine and decreased DNA methylation, the latter being maintained after diet discontinuation. Our findings demonstrate that a KD prevented disease progression in two mechanistically different models of epilepsy, and suggest an epigenetic mechanism underlying the therapeutic effects. PMID:26256422

  10. Effect of duct obstruction on structure, elemental composition, and function of rat submandibular glands

    Energy Technology Data Exchange (ETDEWEB)

    Sagstroem, S.S.; Sagulin, G.B.; Roomans, G.M. (Univ. of Uppsala (Sweden))

    1989-06-01

    Obstruction of salivary glands occurs in association with a number of pathological conditions. It has been suggested that the major changes found in the salivary glands of patients with cystic fibrosis are due to obstruction of the excretory duct by viscous mucus. In the present study, the effect of excretory duct obstruction on structure, elemental composition and function of rat submandibular gland was investigated. Obstruction was effected by infusion of a fast-hardening protein emulsion in the main excretory duct. After 1 week, and more pronounced after 2 weeks of obstruction the number of granular duct cells had decreased in the obstructed gland. X-ray microanalysis showed an increase in Mg, Ca and K, and a decrease in Na levels in the acinar cells, compared to normal glands. The contralateral glands apparently underwent compensatory hypertrophy and showed a similar pattern of changes in elemental composition. The composition of pilocarpine-induced submandibular saliva was neither in the obstructed nor in the contralateral gland significantly different from that in control glands. However, the flow rate was somewhat lower. Hence, increase in cellular Ca levels in submandibular gland acinar cells in cystic fibrosis could be secondary to duct obstruction, but the present study does not support the hypothesis that duct obstruction would result in changes in the composition of saliva.

  11. Ketogenic diet prevents epileptogenesis and disease progression in adult mice and rats.

    Science.gov (United States)

    Lusardi, Theresa A; Akula, Kiran K; Coffman, Shayla Q; Ruskin, David N; Masino, Susan A; Boison, Detlev

    2015-12-01

    Epilepsy is a highly prevalent seizure disorder which tends to progress in severity and become refractory to treatment. Yet no therapy is proven to halt disease progression or to prevent the development of epilepsy. Because a high fat low carbohydrate ketogenic diet (KD) augments adenosine signaling in the brain and because adenosine not only suppresses seizures but also affects epileptogenesis, we hypothesized that a ketogenic diet might prevent epileptogenesis through similar mechanisms. Here, we tested this hypothesis in two independent rodent models of epileptogenesis. Using a pentylenetetrazole kindling paradigm in mice, we first show that a KD, but not a conventional antiepileptic drug (valproic acid), suppressed kindling-epileptogenesis. Importantly, after treatment reversal, increased seizure thresholds were maintained in those animals kindled in the presence of a KD, but not in those kindled in the presence of valproic acid. Next, we tested whether a KD can halt disease progression in a clinically relevant model of progressive epilepsy. Epileptic rats that developed spontaneous recurrent seizures after a pilocarpine-induced status epilepticus were treated with a KD or control diet (CD). Whereas seizures progressed in severity and frequency in the CD-fed animals, KD-fed animals showed a prolonged reduction of seizures, which persisted after diet reversal. KD-treatment was associated with increased adenosine and decreased DNA methylation, the latter being maintained after diet discontinuation. Our findings demonstrate that a KD prevented disease progression in two mechanistically different models of epilepsy, and suggest an epigenetic mechanism underlying the therapeutic effects.

  12. SPASTIC FORM OF CEREBRAL PALSY, EPILEPSY WITH BENIGN EPILEPTIFORM DISCHARGE OF CHILDHOOD ON ELECTROENCEPHALOGRAM, AND IATROGENIC STEVENS–JOHNSON SYNDROME (CASE DESCRIPTION

    Directory of Open Access Journals (Sweden)

    A. S. Kotov

    2016-01-01

    Full Text Available The article describes the phenomenon of dual pathology – a combination of structural changes in the brain and benign epileptiform discharge of childhood on electroencephalogram. The uniqueness lies in the observation that the child, since birth suffering from spastic form of cerebral palsy and severe epilepsy, demonstrated the development of Stevens–Johnson syndrome due to intolerance of one of the antiepileptic drugs. Therapeutic approaches to overcome a whole range of violations are discussed in the article.

  13. [Threshold of sensitivity to epileptiform stimulus in intracerebral allotransplantation of embryonal nerve tissue of varying ergetics].

    Science.gov (United States)

    Ereniev, S I; Semchenko, V V; Genne, R I; Makovetskiĭ, K K

    1993-01-01

    Effect of intracerebral allotransplantation of neocortex, hippocampus, septum, cerebellum, substantia nigra embryonic nerve tissue have been studied in white non-inbred, Wistar and Krushinski-Molodkina rats with phenotypically (portal destruction of hippocampus, gyrus serratus, corpus amygdaloideum and cerebral hypoxia) and genotypically conditioned by the low threshold of convulsive cerebral activity (TCCA). In focal cerebral affection transplants with monoergic neurones increase TCCA, while polyergic neurones of embryonic neocortex increase TCCA in diffuse cerebral affection. Phenotypically conditioned low TCCA increases in 4-6 days after transplantation and genotypically one--in 39-44 days because of the more complicated mechanisms of cerebral epileptization.

  14. The afterhyperpolarizing potential following a train of action potentials is suppressed in an acute epilepsy model in the rat Cornu Ammonis 1 area.

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    Kernig, K; Kirschstein, T; Würdemann, T; Rohde, M; Köhling, R

    2012-01-10

    In hippocampal Cornu Ammonis 1 (CA1) neurons, a prolonged depolarization evokes a train of action potentials followed by a prominent afterhyperpolarizing potential (AHP), which critically dampens neuronal excitability. Because it is not known whether epileptiform activity alters the AHP and whether any alteration of the AHP is independent of inhibition, we acutely induced epileptiform activity by bath application of the GABA(A) receptor blocker gabazine (5 μM) in the rat hippocampal slice preparation and studied its impact on the AHP using intracellular recordings. Following 10 min of gabazine wash-in, slices started to develop spontaneous epileptiform discharges. This disinhibition was accompanied by a significant shift of the resting membrane potential of CA1 neurons to more depolarized values. Prolonged depolarizations (600 ms) elicited a train of action potentials, the number of which was not different between baseline and gabazine treatment. However, the AHP following the train of action potentials was significantly reduced after 20 min of gabazine treatment. When the induction of epileptiform activity was prevented by co-application of 6-cyano-7-nitroquinoxaline-2,3-dione disodium (CNQX, 10 μM) and D-(-)-2-amino-5-phosphonopentanoic acid (D-AP5, 50 μM) to block α-amino-3-hydroxy-5-methylisoxazolepropionate (AMPA) and N-methyl-d-aspartate (NMDA) receptors, respectively, the AHP was preserved despite of GABA(A) receptor inhibition suggesting that the epileptiform activity was required to suppress the AHP. Moreover, the AHP was also preserved when the slices were treated with the protein kinase blockers H-9 (100 μM) and H-89 (1 μM). These results demonstrate that the AHP following a train of action potentials is rapidly suppressed by acutely induced epileptiform activity due to a phosphorylation process-presumably involving protein kinase A.

  15. EFFECTS OF KAINIC ACID ON GLUTATIONE AND NITRITE IN RAT HIPPOCAMPUS

    OpenAIRE

    2011-01-01

    Epileptiformic activity could result in apoptotic neuronal death, in which oxidative stress could play an important role. In case of decreased antioxidant brain status cellular death could be facilitated. Kainic acid is often used in a model of epilepsy in rats. Up to now there is not enough data evaluating levels of glutathione and nitric oxide in kainic acid-induced epilepsy acutely and several days after the kainic acid exposure. This information will be useful for assessing long term pro...

  16. Effect of diazepam on sociability of rats submitted to neonatal seizures

    Directory of Open Access Journals (Sweden)

    Ingrid Stanize Leite

    2016-06-01

    Full Text Available Status epilepticus (SE, an acute condition characterized by repetitive or ongoing seizures activity, may produce long-term deleterious consequences. Previous data demonstrated that Wistar rats subjected to neonatal SE displayed autistic behavior, characterized by social play impairment, low preference by novelty, deficit in social discrimination; anxiety related behavior and stereotyped behavior with no changes in locomotor activity (doi: http://dx.doi.org/10.1007/s00702-010-0460-1, doi: http://dx.doi.org/10.3389/fnbeh.2013.00036, doi: http://dx.doi.org/10.1007/s00702-014-1291-2 [1–3]. Taking into account the bi-directional relationship between the state of anxiety and social interaction (doi: http://dx.doi.org/10.1007/s10567-009-0062-3 [4], we evaluated the impact of the state of anxiety on social interaction. Male Wistar rats at postnatal day 9 were subjected to pilocarpine-induced neonatal SE (380 mg/kg, ip and the controls received 0.9% saline (0.1 ml/10 g. The groups received saline or diazepam (1.0 mg/kg 45 min prior each behavioral testing that started from 60 days of postnatal life. In the open field, rats subjected to neonatal seizure exhibited less central zone activity as compared to animals treated with diazepam, with no changes in the total locomotor activity. In elevated plus maze, rats subjected to neonatal seizure and treated with diazepam exhibited higher locomotor activity and spent more time on the open arms as compared to untreated animals. In approach phase of sociability paradigm, animals subjected to neonatal seizures similarly to controls, regardless the treatment, spent more time with social stimulus as compared to non social stimulus. In social novelty phase of sociability paradigm, animals subjected to neonatal seizures differently of controls, regardless the treatment, spent similar time with familiar and novel stimulus.

  17. The relationship of interictal epileptiform discharges to clinical epilepsy severity: a study of routine electroencephalograms and review of the literature.

    Science.gov (United States)

    Selvitelli, Megan F; Walker, Linsey M; Schomer, Donald L; Chang, Bernard S

    2010-04-01

    Electroencephalograms are widely used to detect interictal epileptiform discharges (IEDs) in patients with a known history of seizures. However, previous studies have not found a consistent association between the presence or frequency of IEDs and clinical epilepsy severity, possibly because of differences in subject characteristics and recording techniques. We sought to investigate this relationship in a population and setting reflective of the most common clinical usage. We analyzed electroencephalograms and clinical records of all consenting patients with a history of at least two presumed focal-onset seizures who presented for routine electroencephalograms recording over 1-year time in an academic neurophysiology laboratory (n = 129). Despite adequate statistical power, we did not find an association between the presence or absence of IEDs or IED frequency and the most recently determined seizure frequency (median, 4 per year). A higher IED incidence was seen in subjects with longer epilepsy duration (P = 0.04). Neither IED incidence nor frequency (median, 10.0 per hour) correlated with age or antiepileptic drug use. Our results differ from those of some previous studies, most of which focused on more narrow subject populations, suggesting that the patient's clinical circumstances must be taken into account before assuming the utility of IEDs on routine electroencephalography in predicting epilepsy severity.

  18. Diphenytoin, riluzole and lidocaine: three sodium channel blockers, with different mechanisms of action, decrease hippocampal epileptiform activity.

    Science.gov (United States)

    Diao, Lihong; Hellier, Jennifer L; Uskert-Newsom, Jessica; Williams, Philip A; Staley, Kevin J; Yee, Audrey S

    2013-10-01

    Epilepsy is a condition affecting 1-2% of the population, characterized by the presence of spontaneous, recurrent seizures. The most common type of acquired epilepsy is temporal lobe epilepsy (TLE). Up to 30% of patients with TLE are refractory to currently available compounds, and there is an urgent need to identify novel targets for therapy. Here, we utilized the in-vitro CA3 burst preparation to examine alterations in network excitability, characterized by changes in interburst interval. Specifically, we show that bath application of three different sodium channel blockers-diphenytoin, riluzole, and lidocaine-slow spontaneous CA3 bursts. This in turn, decreased the epileptiform activity. These compounds work at different sites on voltage-gated sodium channels, but produce a similar network phenotype of decreased excitability. In the case of diphenytoin and riluzole, the change in network activity (i.e., increased interburst intervals) was persistent following drug washout. Lidocaine application, however, only increased the CA3 interburst interval when it was in the bath solution. Thus, its action was not permanent and resulted in returning CA3 bursting to baseline levels. These data demonstrate that the CA3 burst preparation provides a relatively easy and quick platform for identifying compounds that can decrease network excitability, providing the initial screen for further and more complex in-vivo, freely-behaving animal studies.

  19. Computerized epileptiform transient detection in the scalp electroencephalogram: obstacles to progress and the example of computerized ECG interpretation.

    Science.gov (United States)

    Halford, Jonathan J

    2009-11-01

    Computerized detection of epileptiform transients (ETs), also called spikes and sharp waves, in the electroencephalogram (EEG) has been a research goal for the last 40years. A reliable method for detecting ETs could improve efficiency in reviewing long EEG recordings and assist physicians in interpreting routine EEGs. Computer algorithms developed so far for detecting ETs are not as reliable as human expert interpreters, mostly due to the large number of false positive detections. Typical methods for ET detection include measuring waveform morphology, detecting signal non-stationarity, and power spectrum analysis. Some progress has been made by using more advanced algorithmic approaches including wavelet analysis, artificial neural networks, and dipole analysis. Comparing the performance of different algorithms is difficult since each study uses its own EEG test dataset. In order to overcome this problem, European researchers in the field of computerized electrocardiogram interpretation organized a large multi-center research workgroup to create a standardized dataset of ECG recordings which were interpreted by a large group of cardiologists. EEG researchers need to follow this as a model and seek funding for the creation of a standardized EEG research dataset to develop ET detection algorithms and certify commercial software.

  20. VEGF regulates hippocampal neurogenesis and reverses cognitive deficits in immature rats after status epilepticus through the VEGF R2 signaling pathway.

    Science.gov (United States)

    Han, Wei; Song, Xiaojie; He, Rong; Li, Tianyi; Cheng, Li; Xie, Lingling; Chen, Hengsheng; Jiang, Li

    2017-02-10

    Epilepsy is the most common chronic disease in children, who exhibit a higher risk for status epilepticus (SE) than adults. Hippocampal neurogenesis is altered by epilepsy, particularly in the immature brain, which may influence cognitive development. Vascular endothelial growth factor (VEGF) represents an attractive target to modulate brain function at the neurovascular interface and is a double-edged sword in seizures. We used the lithium-pilocarpine-induced epilepsy model in immature Sprague-Dawley rats to study the effects of VEGF on hippocampal neurogenesis in the acute phase and on long-term cognitive behaviors in immature rats following status epilepticus (SE). VEGF correlates with cell proliferation in the immature brain after SE. By preprocessing VEGF in the lateral ventricles prior to the induction of the SE model, we found that VEGF increased the proliferation of neural stem cells (NSCs) and promoted the migration of newly generated cells via the VEGF receptor 2 (VEGFR2) signaling pathway. VEGF also inhibited cell loss and reversed the cognitive deficits that accompany SE. Based on our results, VEGF positively contributes to the initial stages of neurogenesis and alleviates cognitive deficits following seizures; moreover, the VEGF/VEGFR2 signaling pathway may provide a novel treatment strategy for epilepsy.

  1. Dynamical regimes underlying epileptiform events: role of instabilities and bifurcations in brain activity

    Science.gov (United States)

    Perez Velazquez, Jose L.; Cortez, Miguel A.; Snead, O. Carter; Wennberg, Richard

    2003-12-01

    Epileptic seizures represent a sudden and transient change in the synchronised firing of neuronal brain ensembles. While the transition of the collective neuronal activity towards the ictal event is not well understood, some progress has been made using nonlinear time series analysis methods. We present here an analysis of the dynamical regimes of the epileptic activity in three patients suffering from intractable (drug-resistant) seizures, and compare these with the dynamics in rodent epilepsy models. We used the time interval between spikes found in the electroencephalographic recordings as our variable to construct interpeak interval (IPI) time delay plots to study the neuronal interictal (activity between seizures), preictal, and seizure activity. A one-dimensional mapping function was obtained by approximation of the IPI plots with a polynomial. Two main dynamical regimes are obtained from the analysis of the mapping function, derived from the subharmonic bifurcation present in the map: period doubling and intermittency, both of which are observed in human and rat seizures. Hence, our simple model obtained from experimental data captures essential phenomena for the collective dynamics of brain networks, that are found in recordings from human and animal epilepsies. The description of the neuronal dynamics based on one-dimensional maps, widely used in other systems, may prove useful for the understanding of the collective population dynamics of brain activity.

  2. Rats

    Directory of Open Access Journals (Sweden)

    Alexey Kondrashov

    2012-01-01

    Full Text Available We aimed to perform a chemical analysis of both Alibernet red wine and an alcohol-free Alibernet red wine extract (AWE and to investigate the effects of AWE on nitric oxide and reactive oxygen species production as well as blood pressure development in normotensive Wistar Kyoto (WKY and spontaneously hypertensive rats (SHRs. Total antioxidant capacity together with total phenolic and selected mineral content was measured in wine and AWE. Young 6-week-old male WKY and SHR were treated with AWE (24,2 mg/kg/day for 3 weeks. Total NOS and SOD activities, eNOS and SOD1 protein expressions, and superoxide production were determined in the tissues. Both antioxidant capacity and phenolic content were significantly higher in AWE compared to wine. The AWE increased NOS activity in the left ventricle, aorta, and kidney of SHR, while it did not change NOS activity in WKY rats. Similarly, increased SOD activity in the plasma and left ventricle was observed in SHR only. There were no changes in eNOS and SOD1 expressions. In conclusion, phenolics and minerals included in AWE may contribute directly to increased NOS and SOD activities of SHR. Nevertheless, 3 weeks of AWE treatment failed to affect blood pressure of SHR.

  3. Characterization of interictal epileptiform discharges with time-resolved cortical current maps using the helmholtz-hodge decomposition.

    Science.gov (United States)

    Slater, Jeremy D; Khan, Sheraz; Li, Zhimin; Castillo, Eduardo

    2012-01-01

    Source estimates performed using a single equivalent current dipole (ECD) model for interictal epileptiform discharges (IEDs) which appear unifocal have proven highly accurate in neocortical epilepsies, falling within millimeters of that demonstrated by electrocorticography. Despite this success, the single ECD solution is limited, best describing sources which are temporally stable. Adapted from the field of optics, optical flow analysis of distributed source models of MEG or EEG data has been proposed as a means to estimate the current motion field of cortical activity, or "cortical flow." The motion field so defined can be used to identify dynamic features of interest such as patterns of directional flow, current sources, and sinks. The Helmholtz-Hodge Decomposition (HHD) is a technique frequently applied in fluid dynamics to separate a flow pattern into three components: (1) a non-rotational scalar potential U describing sinks and sources, (2) a non-diverging scalar potential A accounting for vortices, and (3) an harmonic vector field H. As IEDs seem likely to represent periods of highly correlated directional flow of cortical currents, the U component of the HHD suggests itself as a way to characterize spikes in terms of current sources and sinks. In a series of patients with refractory epilepsy who were studied with magnetoencephalography as part of their evaluation for possible resective surgery, spike localization with ECD was compared to HHD applied to an optical flow analysis of the same spike. Reasonable anatomic correlation between the two techniques was seen in the majority of patients, suggesting that this method may offer an additional means of characterization of epileptic discharges.

  4. Truly enthralling: epileptiform events in film and on television--why they persist and what we can do about them.

    Science.gov (United States)

    Kerson, Toba Schwaber; Kerson, Lawrence A

    2008-01-01

    Seizures and epilepsy have been portrayed in film since 1900 and on television since the 1950s, but unlike many other conditions, their depictions have not improved with increased scientific understanding. At this time, most individuals who are under 45 years of age will never witness a seizure. Thus, their information about what seizures are comes from depictions in film and on television. Because especially on television these fictive and often erroneous images are increasing, many think of them as accurate. The research addresses three questions in relation to these images: How do directors use the images? Why do uses of seizures in visual media not reflect contemporary scientific knowledge? Why have they persisted and increased in use? Data consist of material from 242 films and television episodes. The general category of seizures includes seizures in characters said to have epilepsy or some other condition, seizures related to alcohol/drug use, feigned or pseudoseizures, and a "throwaway" category. The research demonstrates how epileptiform events drive the narrative, support the genre, evoke emotional reactions, highlight traits of characters with seizures, accentuate traits of other characters through their responses, act as catalysts for action, and enhance voyeuristic experience. Through connecting categories, we explain a basic social process (Glaser, 2007). The conclusion is that these images are so enthralling that their use is likely to persist. The authors suggest that advocates acknowledge this and then find ways to have more continuing characters with correctly depicted epilepsy be part of television series as a way of exploring the truly enthralling dimensions of the condition.

  5. Effect of the Anti-depressant Sertraline, the Novel Anti-seizure Drug Vinpocetine and Several Conventional Antiepileptic Drugs on the Epileptiform EEG Activity Induced by 4-Aminopyridine.

    Science.gov (United States)

    Sitges, Maria; Aldana, Blanca Irene; Reed, Ronald Charles

    2016-06-01

    Seizures are accompanied by an exacerbated activation of cerebral ion channels. 4-aminopyridine (4-AP) is a pro-convulsive agent which mechanism of action involves activation of Na(+) and Ca(2+) channels, and several antiepileptic drugs control seizures by reducing these channels permeability. The antidepressant, sertraline, and the anti-seizure drug vinpocetine are effective inhibitors of cerebral presynaptic Na(+) channels. Here the effectiveness of these compounds to prevent the epileptiform EEG activity induced by 4-AP was compared with the effectiveness of seven conventional antiepileptic drugs. For this purpose, EEG recordings before and at three intervals within the next 30 min following 4-AP (2.5 mg/kg, i.p.) were taken in anesthetized animals; and the EEG-highest peak amplitude values (HPAV) calculated. In control animals, the marked increase in the EEG-HPAV observed near 20 min following 4-AP reached its maximum at 30 min. Results show that this epileptiform EEG activity induced by 4-AP is prevented by sertraline and vinpocetine at a dose of 2.5 mg/kg, and by carbamazepine, phenytoin, lamotrigine and oxcarbazepine at a higher dose (25 mg/kg). In contrast, topiramate (25 mg/kg), valproate (100 mg/kg) and levetiracetam (100 mg/kg) failed to prevent the epileptiform EEG activity induced by 4-AP. It is concluded that 4-AP is a useful tool to elicit the mechanism of action of anti-seizure drugs at clinical meaningful doses. The particular efficacy of sertraline and vinpocetine to prevent seizures induced by 4-AP is explained by their high effectiveness to reduce brain presynaptic Na(+) and Ca(2+) channels permeability.

  6. Scorpion ethanol extract and valproic acid effects on hippocampal glial fibrillary acidic protein expression in a rat model of chronic-kindling epilepsy induced by lithium chloride-pilocarpine

    Institute of Scientific and Technical Information of China (English)

    Yi Liang; Hongbin Sun; Liang Yu; Baoming He; Yan Xie

    2012-01-01

    The present study analyzed the effects of ethanol extracts of scorpion on epilepsy prevention and hippocampal expression of glial fibrillary acidic protein in a lithium chloride-pilocarpine epileptic rat model. Results were subsequently compared with valproic acid. Results showed gradually-increased hippocampal glial fibrillary acidic protein expression following model establishment; glial fibrillary acidic protein mRNA expression was significantly increased at 3 days, reached a peak at 7 days, and then gradually decreased thereafter. Ethanol extracts of scorpion doses of 580 and 1 160 mg/kg, as well as 120 mg/kg valproic acid, led to a decreased number of glial fibrillary acidic protein-positive cells and glial fibrillary acidic protein mRNA expression, as well as decreased seizure grades and frequency of spontaneously recurrent seizures. The effects of 1 160 mg/kg ethanol extracts of scorpion were equal to those of 120 mg/kg valproic acid. These results suggested that the anti-epileptic effect of ethanol extracts of scorpion were associated with decreased hippocampal glial fibrillary acidic protein expression in a rat model of lithium chloride-pilocarpine induced epilepsy.

  7. Enhancement of asynchronous release from fast-spiking interneuron in human and rat epileptic neocortex.

    Directory of Open Access Journals (Sweden)

    Man Jiang

    Full Text Available Down-regulation of GABAergic inhibition may result in the generation of epileptiform activities. Besides spike-triggered synchronous GABA release, changes in asynchronous release (AR following high-frequency discharges may further regulate epileptiform activities. In brain slices obtained from surgically removed human neocortical tissues of patients with intractable epilepsy and brain tumor, we found that AR occurred at GABAergic output synapses of fast-spiking (FS neurons and its strength depended on the type of connections, with FS autapses showing the strongest AR. In addition, we found that AR depended on residual Ca²⁺ at presynaptic terminals but was independent of postsynaptic firing. Furthermore, AR at FS autapses was markedly elevated in human epileptic tissue as compared to non-epileptic tissue. In a rat model of epilepsy, we found similar elevation of AR at both FS autapses and synapses onto excitatory neurons. Further experiments and analysis showed that AR elevation in epileptic tissue may result from an increase in action potential amplitude in the FS neurons and elevation of residual Ca²⁺ concentration. Together, these results revealed that GABAergic AR occurred at both human and rat neocortex, and its elevation in epileptic tissue may contribute to the regulation of epileptiform activities.

  8. Rebaudioside A inhibits pentylenetetrazol-induced convulsions in rats.

    Science.gov (United States)

    Uyanikgil, Yigit; Cavusoglu, Turker; Balcıoglu, Huseyin A; Gurgul, Serkan; Solmaz, Volkan; Ozlece, Hatice K; Erten, Nilgun; Erbas, Oytun

    2016-09-01

    The safety of patients with epilepsy consuming sweetening agents, which is becoming increasingly prevalent for various reasons, is a topic that should be emphasized as sensitively as it is for other diseases. Patients with epilepsy consume sweetening agents for different reasons such being diabetic or overweight. They can occasionally be exposed to sweetening agents unrestrainedly through consuming convenience food, primarily beverages. This study aimed to investigate the effects of rebaudioside A (Reb-A), which is a steviol glycoside produced from the herb Stevia rebaudiana (Bertoni), on epileptic seizures and convulsions induced by pentylenetetrazole (PTZ). Forty-eight male rats were used. Twenty-four rats were administered 35 mg/kg PTZ to trigger epileptiform activity; the remaining 24 rats were administered 70 mg/kg PTZ to trigger the convulsion model. The epileptiform activity was evaluated by spike percentage, whereas convulsion was evaluated by Racine's Convulsion Scale and the onset time of the first myoclonic jerk. Statistical analysis revealed a statistically significant decrease in the Racine's Convulsion Scale score and increase in the latency of first myoclonic jerk in a dose-dependent manner for the rat groups in which PTZ epilepsy had been induced and Reb-A had been administered. For the groups that were administered Reb-A, the spike decrease was apparent in a dose-dependent manner, based on the spike percentage calculation. These results indicated that Reb-A has positive effects on PTZ-induced convulsions.

  9. Rebaudioside A inhibits pentylenetetrazol-induced convulsions in rats

    Directory of Open Access Journals (Sweden)

    Yigit Uyanikgil

    2016-09-01

    Full Text Available The safety of patients with epilepsy consuming sweetening agents, which is becoming increasingly prevalent for various reasons, is a topic that should be emphasized as sensitively as it is for other diseases. Patients with epilepsy consume sweetening agents for different reasons such being diabetic or overweight. They can occasionally be exposed to sweetening agents unrestrainedly through consuming convenience food, primarily beverages. This study aimed to investigate the effects of rebaudioside A (Reb-A, which is a steviol glycoside produced from the herb Stevia rebaudiana (Bertoni, on epileptic seizures and convulsions induced by pentylenetetrazole (PTZ. Forty-eight male rats were used. Twenty-four rats were administered 35 mg/kg PTZ to trigger epileptiform activity; the remaining 24 rats were administered 70 mg/kg PTZ to trigger the convulsion model. The epileptiform activity was evaluated by spike percentage, whereas convulsion was evaluated by Racine's Convulsion Scale and the onset time of the first myoclonic jerk. Statistical analysis revealed a statistically significant decrease in the Racine's Convulsion Scale score and increase in the latency of first myoclonic jerk in a dose-dependent manner for the rat groups in which PTZ epilepsy had been induced and Reb-A had been administered. For the groups that were administered Reb-A, the spike decrease was apparent in a dose-dependent manner, based on the spike percentage calculation. These results indicated that Reb-A has positive effects on PTZ-induced convulsions.

  10. Carbamazepine suppresses synchronized afterdischarging in disinhibited immature rat hippocampus in vitro.

    Science.gov (United States)

    Smith, K L; Swann, J W

    1987-01-06

    Bath application of therapeutic concentrations of the anticonvulsant carbamazepine suppressed penicillin-induced synchronized afterdischarging in immature rat CA3 hippocampal pyramidal cells. Afterdischarging was completely abolished in all preparations at a concentration of 30 microM (IC50 = 8.5 +/- 1.4 microM; mean +/- S.E.M.). The duration of the preceding epileptiform burst was not altered at this concentration and was diminished by only 24.4 +/- 1.2% at a supratherapeutic concentration of 100 microM. These results suggest that a carbamazepine-sensitive neurophysiological mechanism distinct from those responsible for epileptiform burst generation plays a key role in the generation of afterdischarges in developing hippocampus.

  11. Effects of pharmacological treatments on hippocampal NCAM1 and ERK2 expression in epileptic rats with cognitive dysfunction

    Science.gov (United States)

    Kong, Qingxia; Min, Xia; Sun, Ran; Gao, Jianying; Liang, Ruqing; Li, Lei; Chu, Xu

    2016-01-01

    The present study aimed to investigate the effects of various pharmacological agents on the hippocampal expression of neural cell adhesion molecule 1 (NCAM1) and extracellular signal-regulated kinase 2 (ERK2) in epileptic rats with cognitive dysfunction. The experiments were conducted using 120 Wistar rats: 20 controls and 100 with pilocarpine-induced status epilepticus (SE). The SE rats were randomly assigned to 5 groups (n=20/group) that received daily treatments for 1 month with one of the following: (i) saline (no effect on epilepsy); (ii) carbamazepine (an anticonvulsant); (iii) oxcarbazepine (an anticonvulsant); (iv) aniracetam (a nootropic); or (v) donepezil (an acetylcholinesterase inhibitor). Spatial learning and memory were assessed using a Morris Water Maze (MWM). Hippocampal tissue was assessed for NCAM1 and ERK2 messenger RNA (mRNA) expression by reverse transcription polymerase chain reaction, and protein expression by immunochemistry. The results revealed that SE rats had significantly poorer MWM performances compared with controls (P<0.01). Performance in SE rats was improved with donepezil treatment (P<0.01), but declined with carbamazepine (P<0.01). Compared with controls, saline-treated SE rats exhibited increased hippocampal NCAM1 mRNA expression (P<0.01). Among SE rats, NCAM1 mRNA expression was highest in those treated with donepezil, followed by aniracetam-, saline-, oxcarbazepine- and carbamazepine-treated rats. Compared to controls, saline-treated SE rats exhibited decreased hippocampal ERK2 mRNA expression (P<0.01). Among SE rats, ERK2 mRNA expression was highest in those treated with donepezil, followed by aniracetam, saline, oxcarbazepine and carbamazepine. NCAM1 and ERK2 protein expression levels were parallel to those of the mRNA. In saline-treated SE rats, hippocampal ERK2 expression was decreased and NCAM1 expression was increased; thus, these two molecules may be involved in the impairment of spatial memory. Carbamazepine augmented

  12. Attention deficit associated with early life interictal spikes in a rat model is improved with ACTH.

    Directory of Open Access Journals (Sweden)

    Amanda E Hernan

    Full Text Available Children with epilepsy often present with pervasive cognitive and behavioral comorbidities including working memory impairments, attention deficit hyperactivity disorder (ADHD and autism spectrum disorder. These non-seizure characteristics are severely detrimental to overall quality of life. Some of these children, particularly those with epilepsies classified as Landau-Kleffner Syndrome or continuous spike and wave during sleep, have infrequent seizure activity but frequent focal epileptiform activity. This frequent epileptiform activity is thought to be detrimental to cognitive development; however, it is also possible that these IIS events initiate pathophysiological pathways in the developing brain that may be independently associated with cognitive deficits. These hypotheses are difficult to address due to the previous lack of an appropriate animal model. To this end, we have recently developed a rat model to test the role of frequent focal epileptiform activity in the prefrontal cortex. Using microinjections of a GABA(A antagonist (bicuculline methiodine delivered multiple times per day from postnatal day (p 21 to p25, we showed that rat pups experiencing frequent, focal, recurrent epileptiform activity in the form of interictal spikes during neurodevelopment have significant long-term deficits in attention and sociability that persist into adulthood. To determine if treatment with ACTH, a drug widely used to treat early-life seizures, altered outcome we administered ACTH once per day subcutaneously during the time of the induced interictal spike activity. We show a modest amelioration of the attention deficit seen in animals with a history of early life interictal spikes with ACTH, in the absence of alteration of interictal spike activity. These results suggest that pharmacological intervention that is not targeted to the interictal spike activity is worthy of future study as it may be beneficial for preventing or ameliorating adverse

  13. Physical activity and neuroprotection in adult mice after pilocarpine induced status epilepticus

    OpenAIRE

    Cesar Renato Sartori

    2005-01-01

    Resumo: O modelo de epilepsia induzida por pilocarpina em camundongos reproduz a Epilepsia do Lobo Temporal (ELT) em humanos. Animais submetidos à indução de status epilepticus apresentam alterações comportamentais, eletroencefalográficas e lesão neuronal compatíveis com esta condição. Estudos recentes relatam relevantes efeitos positivos da prática de atividade física sobre o sistema nervoso tanto em humanos como em modelos animais. Dentre estes efeitos figuram o aumento da sobrevivência neu...

  14. Beneficial influence of physical exercise following status epilepticus in the immature brain of rats.

    Science.gov (United States)

    Gomes, F G Novaes; Gomes Da Silva, S; Cavalheiro, E A; Arida, R M

    2014-08-22

    Studies in adult animals have demonstrated a beneficial effect of physical exercise on epileptic insults. Although the effects of physical exercise on the mature nervous system are well documented, its influence on the developing nervous system subjected to injuries in childhood has been little explored. The purpose of our study was to investigate whether a physical exercise program applied during brain development could influence the hippocampal plasticity of rats submitted to status epilepticus (SE) induced by pilocarpine model at two different ages of the postnatal period. Male Wistar rats aged 18 (P18) and 28 (P28) days were randomly divided into four groups: Control (CTRL), Exercise (EX), SE (SE) and SE Exercise (SE/EX) (n=17 per group). After the aerobic exercise program, histological and behavioral (water maze) analyses were performed. Our results showed that only animals subjected to pilocarpine-induced SE at P28 presented spontaneous seizures during the observational period. A significant reduction in seizure frequency was observed in the SE/EX group compared to the SE group. In adulthood, animals submitted to early-life SE displayed impairment in long-term memory in the water maze task, while the exercise program reversed this deficit. Reduced mossy fiber sprouting in the dentate gyrus was noted in animals that presented spontaneous seizures (SE/EX vs SE). Exercise increased cell proliferation (Ki-67 staining) and anti-apoptotic response (bcl-2 staining) and reduced pro-apoptotic response (Bax staining) in animals of both ages of SE induction (P18/28). Exercise also modified the brain-derived neurotrophic factor (BDNF) levels in EX and SE/EX animals. Our findings indicate that in animals subjected to SE in the postnatal period a physical exercise program brings about beneficial effects on seizure frequency and hippocampal plasticity in later stages of life.

  15. Interictal spike frequency varies with ovarian cycle stage in a rat model of epilepsy.

    Science.gov (United States)

    D'Amour, James; Magagna-Poveda, Alejandra; Moretto, Jillian; Friedman, Daniel; LaFrancois, John J; Pearce, Patrice; Fenton, Andre A; MacLusky, Neil J; Scharfman, Helen E

    2015-07-01

    In catamenial epilepsy, seizures exhibit a cyclic pattern that parallels the menstrual cycle. Many studies suggest that catamenial seizures are caused by fluctuations in gonadal hormones during the menstrual cycle, but this has been difficult to study in rodent models of epilepsy because the ovarian cycle in rodents, called the estrous cycle, is disrupted by severe seizures. Thus, when epilepsy is severe, estrous cycles become irregular or stop. Therefore, we modified kainic acid (KA)- and pilocarpine-induced status epilepticus (SE) models of epilepsy so that seizures were rare for the first months after SE, and conducted video-EEG during this time. The results showed that interictal spikes (IIS) occurred intermittently. All rats with regular 4-day estrous cycles had IIS that waxed and waned with the estrous cycle. The association between the estrous cycle and IIS was strong: if the estrous cycles became irregular transiently, IIS frequency also became irregular, and when the estrous cycle resumed its 4-day pattern, IIS frequency did also. Furthermore, when rats were ovariectomized, or males were recorded, IIS frequency did not show a 4-day pattern. Systemic administration of an estrogen receptor antagonist stopped the estrous cycle transiently, accompanied by transient irregularity of the IIS pattern. Eventually all animals developed severe, frequent seizures and at that time both the estrous cycle and the IIS became irregular. We conclude that the estrous cycle entrains IIS in the modified KA and pilocarpine SE models of epilepsy. The data suggest that the ovarian cycle influences more aspects of epilepsy than seizure susceptibility.

  16. Correlation between IL-10 and microRNA-187 expression in epileptic rat hippocampus and patients with temporal lobe epilepsy

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    Walid A. Alsharafi

    2015-12-01

    Full Text Available Accumulating evidence is emerging that microRNAs (miRs are key regulators controlling neuroinflammatory processes, which are known to play a potential role in the pathogenesis of temporal lobe epilepsy (TLE. The aim of the present study was to investigate the dynamic expression pattern of interleukin (IL–10 as an anti-inflammatory cytokine and miR-187 and post-transcriptional inflammation-related miRNA in the hippocampus of a rat model of status epilepticus (SE and patients with TLE. We performed a real-time quantitative PCR and western blot on rat hippocampus (2 hours, 7 days, 21 days and 60 days following pilocarpine-induced SE, and on hippocampus obtained from TLE patients and normal controls. To detect the relationship between IL-10 and miR-187 on neurons, lipopolysaccharide (LPS and IL-10-stimulated neurons were prepared. Furthermore, we identified the effect of antagonizing of miR-187 by its antagomir on IL-10 secretion. Here we reported that that IL-10 secretion and miR-187 expression levels are inversely correlated after SE.. In patients with TLE, the expression levels of IL-10 was also significantly upregulated, whereas miR-187 expression was significantly downregulated. Moreover, miR-187 expression was significantly reduced following IL-10 stimulation in an IL-10–dependent manner. On the other hand, antagonizing miR-187 reduced the production of IL-10 in hippocampal tissues of rat model of SE. Our findings demonstrate a critical role of miR-187 in the physiological regulation of IL-10 anti-inflammatory responses and elucidate the role of neuro-inflammation in the pathogenesis of TLE. Therefore, modulation of the IL-10 / miR-187 axis may be a new therapeutic approach for TLE.

  17. Prevalence of Epileptiform Discharges in Children with Sensori-Neural Hearing Loss and Behavioral Problems Compared to Their Normal Hearing Peers

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    Susan AMIRSALARI

    2014-04-01

    Full Text Available 800x600 How to Cite This Article: Amirsalari S, Radfar Sh, Ajallouyean M, Saburi A, Yousefi J, Noohi S, Tavallaie SA, Hassanalifard M, Ghazavi Y. Prevalence of Epileptiform Discharges in Children with Sensori-Neural Hearing Loss and Behavioral Problems Compared to Their Normal Hearing Peers. Iran J Child Neurol. 2014 Spring 8(2:29-33.ObjectiveOveractivity and behavioral problems are common problems in children with prelingually profound sensorineural hearing loss (SNHL. Data on epileptiform electroencephalography (EEG discharges in deaf children with psychologicaldisorders are so limited. The primary focus of this study was to determine the prevalence of epileptiform discharges (EDs in children with SNHL and overactivity or behavioral problems.Materials & MethodsA total of 262 patients with prelingually profound SNHL who were referred to our cochlear implantation center between 2008 and 2010 were enrolled in this study. Children with SNHL who had diagnosis of overactivity and/or behavioralproblems by a pediatric psychiatrist, underwent electroencephalography (EEG.EEG analysis was carried out by a board-certified pediatric neurologist. The control group consisted of 45 cases with overactivity or behavioral problems and normal hearing.ResultsOne hundred thirty-eight children with mean age of 3.5±1.23 year were enrolled in the case group, of whom 88 cases (63.7% were boy. The control group consisted of 45 cases with mean age of 3.2±1.53 years, of whom 30 (66.6%cases were male. EDs were detected in 28 (20.02% children of the case group (with SNHL in comparison with 4 (8.88% in the control group (without SNHL, which was statistically significantly different.ConclusionIn this study, we obtained higher frequency of EDs in deaf children with overactivity and/or behavioral problem compared to the children without SNHL. Further studies are required to evaluate the possible association of SNHL withEDs in overactive children.References1

  18. Kinetic study of benzyl [1-14C]acetate as a potential probe for astrocytic energy metabolism in the rat brain: Comparison with benzyl [2-14C]acetate.

    Science.gov (United States)

    Okada, Maki; Yanamoto, Kazuhiko; Kagawa, Tomohiko; Yoshino, Keiko; Hosoi, Rie; Abe, Kohji; Zhang, Ming-Rong; Inoue, Osamu

    2016-02-01

    Brain uptake of [(14)C]acetate has been reported to be a useful marker of astrocytic energy metabolism. In addition to uptake values, the rate of radiolabeled acetate washout from the brain appears to reflect CO2 exhaustion and oxygen consumption in astrocytes. We measured the time-radioactivity curves of benzyl [1-(14)C]acetate ([1-(14)C]BA), a lipophilic probe of [1-(14)C]acetate, and compared it with that of benzyl [2-(14)C]acetate ([2-(14)C]BA) in rat brains. The highest brain uptake was observed immediately after injecting either [1-(14)C]BA or [2-(14)C]BA, and both subsequently disappeared from the brain in a single-exponential manner. Estimated [1-(14)C]BA washout rates in the cerebral cortex and cerebellum were higher than those of [2-(14)C]BA. These results suggested that [1-(14)C]BA could be a useful probe for estimating the astrocytic oxidative metabolism. The [1-(14)C]BA washout rate in the cerebral cortex of immature rats was lower than that of mature rats. An autoradiographic study showed that the washout rates of [1-(14)C]BA from the rat brains of a lithium-pilocarpine-induced status epilepticus model were not significantly different from the values in control rat brains except for the medial septal nucleus. These results implied that the enhancement of amino acid turnover rate rather than astrocytic oxidative metabolism was increased in status epilepticus. © The Author(s) 2015.

  19. Epileptiform activity in the CA1 region of the hippocampus becomes refractory to attenuation by cannabinoids in part because of endogenous γ-aminobutyric acid type B receptor activity.

    Science.gov (United States)

    Messer, Ricka D; Levine, Eric S

    2012-07-01

    The anticonvulsant properties of marijuana have been known for centuries. The recently characterized endogenous cannabinoid system thus represents a promising target for novel anticonvulsant agents; however, administration of exogenous cannabinoids has shown mixed results in both human epilepsy and animal models. The ability of cannabinoids to attenuate release of both excitatory and inhibitory neurotransmitters may explain the variable effects of cannabinoids in different models of epilepsy, but this has not been well explored. Using acute mouse brain slices, we monitored field potentials in the CA1 region of the hippocampus to characterize systematically the effects of the cannabinoid agonist WIN55212-2 (WIN) on evoked basal and epileptiform activity. WIN, acting presynaptically, significantly reduced the amplitude and slope of basal field excitatory postsynaptic potentials as well as stimulus-evoked epileptiform responses induced by omission of magnesium from the extracellular solution. In contrast, the combination of omission of magnesium plus elevation of potassium induced an epileptiform response that was refractory to attenuation by WIN. The effect of WIN in this model was partially restored by blocking γ-aminobutyric acid type B (GABA(B) ), but not GABA(A) , receptors. Subtle differences in models of epileptiform activity can profoundly alter the efficacy of cannabinoids. Endogenous GABA(B) receptor activation played a role in the decreased cannabinoid sensitivity observed for epileptiform activity induced by omission of magnesium plus elevation of potassium. These results suggest that interplay between presynaptic G protein-coupled receptors with overlapping downstream targets may underlie the variable efficacy of cannabinoids in different models of epilepsy.

  20. Saikosaponin a Enhances Transient Inactivating Potassium Current in Rat Hippocampal CA1 Neurons

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    Wei Xie

    2013-01-01

    Full Text Available Saikosaponin a (SSa, a main constituent of the Chinese herb Bupleurum chinense DC., has been demonstrated to have antiepileptic activity. Recent studies have shown that SSa could inhibit NMDA receptor current and persistent sodium current. However, the effects of SSa on potassium (K+ currents remain unclear. In this study, we tested the effect of SSa on 4AP-induced epileptiform discharges and K+ currents in CA1 neurons of rat hippocampal slices. We found that SSa significantly inhibited epileptiform discharges frequency and duration in hippocampal CA1 neurons in the 4AP seizure model in a dose-dependent manner with an IC50 of 0.7 μM. SSa effectively increased the amplitude of ITotal and IA, significantly negative-shifted the activation curve, and positive-shifted steady-state curve of IA. However, SSa induced no significant changes in the amplitude and activation curve of IK. In addition, SSa significantly increased the amplitude of 4AP-sensitive K+ current, while there was no significant change in the amplitude of TEA-sensitive K+ current. Together, our data indicate that SSa inhibits epileptiform discharges induced by 4AP in a dose-dependent manner and that SSa exerts selectively enhancing effects on IA. These increases in IA may contribute to the anticonvulsant mechanisms of SSa.

  1. Effects of the fruit essential oil of Cuminum cyminum Linn. (Apiaceae) on pentylenetetrazol-induced epileptiform activity in F1 neurones of Helix aspersa.

    Science.gov (United States)

    Janahmadi, Mahyar; Niazi, Farshad; Danyali, Samira; Kamalinejad, Mohammad

    2006-03-08

    The effect of the fruit essential oil of Cuminum cyminum Linn. (Apiaceae) (syn. Cuminum odorum Salisb) on the epileptiform activity induced by pentylenetetrazol (PTZ) was evaluated, using intracellular technique. The results demonstrated that extracellular application of the essential oil of Cuminum cyminum (1% and 3%) dramatically decreased the frequency of spontaneous activity induced by PTZ in a time and concentration dependent manner. In addition it showed protection against pentylenetetrazol-induced epileptic activity by increasing the duration, decreasing the amplitude of after hyperpolarization potential (AHP) following the action potential, the peak of action potential, and inhibition of the firing rate. These membrane effects suggest cellular mechanisms by which the essential oil of Cuminum cyminum can inhibit the PTZ-induced epileptic activity.

  2. Studies on the mechanism of the epileptiform activity induced by U18666A. II. concentration, half-life and distribution of radiolabeled U18666A in the brain

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    Cenedella, R.J.; Sarkar, C.P.; Towns, L.

    1982-06-01

    The concentration, half-life, and distribution in brain of U18666A, a drug that can drastically alter cerebral lipids and induce a chronic epileptiform state, was determined following both acute and chronic drug administration. U18666A specifically labeled with tritium was prepared by custom synthesis. Brain levels of 1 x 10(-6)M and higher were reached soon after giving an acute 10-mg/kg dose (i.p. or s.c.) of U18666A containing 7-/sup 3/H-U18666A of known specific activity. A steady state concentration of 1 to 2 x 10(-6)M was reached with chronic injection of 10 mg/kg every 4th day, a treatment schedule that results in altered brain lipids and induction of epilepsy if begun soon after birth. The disappearance of U18666A from both brain and serum was described by two similar biexponential processes, a brief rapid clearance (t1/2 . 10 h) and a sustained and much slower one (t1/2 . 65 h). Brain levels of the drug were about 10 times higher than serum at all times examined. Few differences were seen in the regional distribution of radiolabeled drug in brain as determined by both direct analysis and by autoradiographic examination; but the drug did concentrate in lipid-rich subcellular fractions. For example, the synaptosome and myelin fractions each contained about 25-35% of both the total /sup 3/H-labeled drug and total lipid in whole brain. The lipid composition of these fractions was drastically altered in treated animals. In conclusion, the chronic epileptiform state induced by U18666A does not appear to involve localization of the drug in a specific brain region or particular cell type. Rather, the condition could involve localization of the drug in lipid-rich membranes and marked changes in the composition of these membranes.

  3. Relationship between evolving epileptiform activity and delayed loss of mitochondrial activity after asphyxia measured by near-infrared spectroscopy in preterm fetal sheep.

    Science.gov (United States)

    Bennet, L; Roelfsema, V; Pathipati, P; Quaedackers, J S; Gunn, A J

    2006-04-01

    Early onset cerebral hypoperfusion after birth is highly correlated with neurological injury in premature infants, but the relationship with the evolution of injury remains unclear. We studied changes in cerebral oxygenation, and cytochrome oxidase (CytOx) using near-infrared spectroscopy in preterm fetal sheep (103-104 days of gestation, term is 147 days) during recovery from a profound asphyxial insult (n= 7) that we have shown produces severe subcortical injury, or sham asphyxia (n= 7). From 1 h after asphyxia there was a significant secondary fall in carotid blood flow (P < 0.001), and total cerebral blood volume, as reflected by total haemoglobin (P < 0.005), which only partially recovered after 72 h. Intracerebral oxygenation (difference between oxygenated and deoxygenated haemoglobin concentrations) fell transiently at 3 and 4 h after asphyxia (P < 0.01), followed by a substantial increase to well over sham control levels (P < 0.001). CytOx levels were normal in the first hour after occlusion, was greater than sham control values at 2-3 h (P < 0.05), but then progressively fell, and became significantly suppressed from 10 h onward (P < 0.01). In the early hours after reperfusion the fetal EEG was highly suppressed, with a superimposed mixture of fast and slow epileptiform transients; overt seizures developed from 8 +/- 0.5 h. These data strongly indicate that severe asphyxia leads to delayed, evolving loss of mitochondrial oxidative metabolism, accompanied by late seizures and relative luxury perfusion. In contrast, the combination of relative cerebral deoxygenation with evolving epileptiform transients in the early recovery phase raises the possibility that these early events accelerate or worsen the subsequent mitochondrial failure.

  4. Cellular anatomy, physiology and epileptiform activity in the CA3 region of Dcx knockout mice: a neuronal lamination defect and its consequences.

    Science.gov (United States)

    Bazelot, Michael; Simonnet, Jean; Dinocourt, Céline; Bruel-Jungerman, Elodie; Miles, Richard; Fricker, Desdemona; Francis, Fiona

    2012-01-01

    We report data on the neuronal form, synaptic connectivity, neuronal excitability and epileptiform population activities generated by the hippocampus of animals with an inactivated doublecortin gene. The protein product of this gene affects neuronal migration during development. Human doublecortin (DCX) mutations are associated with lissencephaly, subcortical band heterotopia, and syndromes of intellectual disability and epilepsy. In Dcx(-/Y) mice, CA3 hippocampal pyramidal cells are abnormally laminated. The lamination defect was quantified by measuring the extent of the double, dispersed or single pyramidal cell layer in the CA3 region of Dcx(-/Y) mice. We investigated how this abnormal lamination affected two groups of synapses that normally innervate defined regions of the CA3 pyramidal cell membrane. Numbers of parvalbumin (PV)-containing interneurons, which contact peri-somatic sites, were not reduced in Dcx(-/Y) animals. Pyramidal cells in double, dispersed or single layers received PV-containing terminals. Excitatory mossy fibres which normally target proximal CA3 pyramidal cell apical dendrites apparently contact CA3 cells of both layers in Dcx(-/Y) animals but sometimes on basilar rather than apical dendrites. The dendritic form of pyramidal cells in Dcx(-/Y) animals was altered and pyramidal cells of both layers were more excitable than their counterparts in wild-type animals. Unitary inhibitory field events occurred at higher frequency in Dcx(-/Y) animals. These differences may contribute to a susceptibility to epileptiform activity: a modest increase in excitability induced both interictal and ictal-like discharges more effectively in tissue from Dcx(-/Y) mice than from wild-type animals.

  5. Alterations of hippocampal GAbaergic system contribute to development of spontaneous recurrent seizures in the rat lithium-pilocarpine model of temporal lobe epilepsy.

    Science.gov (United States)

    André, V; Marescaux, C; Nehlig, A; Fritschy, J M

    2001-01-01

    Reorganization of excitatory and inhibitory circuits in the hippocampal formation following seizure-induced neuronal loss has been proposed to underlie the development of chronic seizures in temporal lobe epilepsy (TLE). Here, we investigated whether specific morphological alterations of the GABAergic system can be related to the onset of spontaneous recurrent seizures (SRS) in the rat lithium-pilocarpine model of TLE. Immunohistochemical staining for markers of interneurons and their projections, including parvalbumin (PV), calretinin (CR), calbindin (CB), glutamic acid decarboxylase (GAD), and type 1 GABA transporter (GAT1), was performed in brain sections of rats treated with lithium-pilocarpine and sacrificed after 24 h, during the silent phase (6 and 12 days), or after the onset of SRS (10-18 days after treatment). Semiquantitative analysis revealed a selective loss of interneurons in the stratum oriens of CA1, associated with a reduction of GAT1 staining in the stratum radiatum and stratum oriens. In contrast, interneurons in CA3 were largely preserved, although GAT1 staining was also reduced. These changes occurred within 6 days after treatment and were therefore insufficient to cause SRS. In the dentate gyrus, extensive cell loss occurred in the hilus. The pericellular innervation of granule cells by PV-positive axons was markedly reduced, although the loss of PV-interneurons was only partial. Most strikingly, the density of GABAergic axons, positive for both GAD and GAT1, was dramatically increased in the inner molecular layer. This change emerged during the silent period, but was most marked in animals with SRS. Finally, supernumerary CB-positive neurons were detected in the hilus, selectively in rats with SRS. These findings suggest that alterations of GABAergic circuits occur early after lithium-pilocarpine-induced status epilepticus and contribute to epileptogenesis. In particular, the reorganization of GABAergic axons in the dentate gyrus might

  6. Quantitative longitudinal imaging of activated microglia as a marker of inflammation in the pilocarpine rat model of epilepsy using [(11)C]-( R)-PK11195 PET and MRI.

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    Yankam Njiwa, J; Costes, N; Bouillot, C; Bouvard, S; Fieux, S; Becker, G; Levigoureux, E; Kocevar, G; Stamile, C; Langlois, J B; Bolbos, R; Bonnet, C; Bezin, L; Zimmer, L; Hammers, A

    2017-04-01

    Inflammation may play a role in the development of epilepsy after brain insults. [(11)C]-( R)-PK11195 binds to TSPO, expressed by activated microglia. We quantified [(11)C]-( R)-PK11195 binding during epileptogenesis after pilocarpine-induced status epilepticus (SE), a model of temporal lobe epilepsy. Nine male rats were studied thrice (D0-1, D0 + 6, D0 + 35, D0 = SE induction). In the same session, 7T T2-weighted images and DTI for mean diffusivity (MD) and fractional anisotropy (FA) maps were acquired, followed by dynamic PET/CT. On D0 + 35, femoral arterial blood was sampled for rat-specific metabolite-corrected arterial plasma input functions (AIFs). In multiple MR-derived ROIs, we assessed four kinetic models (two with AIFs; two using a reference region), standard uptake values (SUVs), and a model with a mean AIF. All models showed large (up to two-fold) and significant TSPO binding increases in regions expected to be affected, and comparatively little change in the brainstem, at D0 + 6. Some individuals showed increases at D0 + 35. AIF models yielded more consistent increases at D0 + 6. FA values were decreased at D0 + 6 and had recovered by D0 + 35. MD was increased at D0 + 6 and more so at D0 + 35. [(11)C]-( R)-PK11195 PET binding and MR biomarker changes could be detected with only nine rats, highlighting the potential of longitudinal imaging studies.

  7. Comparação por análise visual entre as espículas promediadas e as espículas individuais nas descargas epileptiformes rolândicas

    OpenAIRE

    Braga, Nadia I.o. [UNIFESP; Gilberto M. Manzano; Nóbrega,João Antonio M.

    2002-01-01

    PURPOSE:This study compared some morphological features of individual rolandic epileptiform discharges, used to obtain an averaged estimate, with those of the resulting estimate. METHOD: Twenty-four averaged discharges from EEGs of 24 children showing rolandic spikes were compared with 480 individual discharges used in the averaging. The analysis was based on the occurrence of tangential dipole and "double spike" patterns. RESULTS: In 15 averaged discharges the tangential dipole pattern was f...

  8. Akt pathway activation and increased neuropeptide Y mRNA expression in the rat hippocampus: implications for seizure blockade.

    Science.gov (United States)

    Goto, Eduardo M; Silva, Marcelo de Paula; Perosa, Sandra R; Argañaraz, Gustavo A; Pesquero, João B; Cavalheiro, Esper A; Naffah-Mazzacoratti, Maria G; Teixeira, Vicente P C; Silva, José A

    2010-04-01

    The aim of this study was to analyze the expression of survival-related molecules such Akt and integrin-linked kinase (ILK) to evaluate Akt pathway activation in epileptogenesis process. Furthermore, was also investigated the mRNA expression of neuropeptide Y, a considered antiepileptic neuropeptide, in the pilocarpine-induced epilepsy. Male Wistar rats were submitted to the pilocarpine model of epilepsy. Hippocampi were removed 6h (acute phase), 12h (late acute), 5d (silent) and 60d (chronic) after status epilepticus (SE) onset, and from animals that received pilocarpine but did not develop SE (partial group). Hippocampi collected were used to specify mRNA expression using Real-Time PCR. Immunohistochemistry assay was employed to place ILK distribution in the hippocampus and Western blot technique was used to determine Akt activation level. A decrease in ILK mRNA content was found during acute (0.39+/-0.03) and chronic (0.48+/-0.06) periods when compared to control group (0.87+/-0.10). Protein levels of ILK were also diminished during both periods. Partial group showed increased ILK mRNA expression (0.80+/-0.06) when compared with animals in the acute stage. Silent group had ILK mRNA and immunoreactivity similar to control group. Western blot assay showed an augmentation in Akt activation in silent period (0.52+/-0.03) in comparison with control group (0.44+/-0.01). Neuropeptide Y mRNA expression increased in the partial group (1.67+/-0.22) and in the silent phase (1.45+/-0.29) when compared to control group (0.36+/-0.12). Results suggest that neuropeptide Y (as anticonvulsant) might act in protective mechanisms occurred during epileptic phenomena. Together with ILK expression and Akt activation, these molecules could be involved in hippocampal neuroprotection in epilepsy. Copyright 2009 Elsevier Ltd. All rights reserved.

  9. Propagation of epileptiform activity can be independent of synaptic transmission, gap junctions, or diffusion and is consistent with electrical field transmission.

    Science.gov (United States)

    Zhang, Mingming; Ladas, Thomas P; Qiu, Chen; Shivacharan, Rajat S; Gonzalez-Reyes, Luis E; Durand, Dominique M

    2014-01-22

    The propagation of activity in neural tissue is generally associated with synaptic transmission, but epileptiform activity in the hippocampus can propagate with or without synaptic transmission at a speed of ∼0.1 m/s. This suggests an underlying common nonsynaptic mechanism for propagation. To study this mechanism, we developed a novel unfolded hippocampus preparation, from CD1 mice of either sex, which preserves the transverse and longitudinal connections and recorded activity with a penetrating microelectrode array. Experiments using synaptic transmission and gap junction blockers indicated that longitudinal propagation is independent of chemical or electrical synaptic transmission. Propagation speeds of 0.1 m/s are not compatible with ionic diffusion or pure axonal conduction. The only other means of communication between neurons is through electric fields. Computer simulations revealed that activity can indeed propagate from cell to cell solely through field effects. These results point to an unexpected propagation mechanism for neural activity in the hippocampus involving endogenous field effect transmission.

  10. Modulation of Long-Term Potentiation and Epileptiform Activity in the Rat Dentate Gyrus by the Group II Metabotropic Glutamate Receptor Subtype mGluR3

    Science.gov (United States)

    2006-05-31

    200 µM) blocked LTP of extracellular excitatory post-synaptic potentials ( EPSPs ) after high-frequency stimulation (100Hz; 2s) of the medial perforant...affect EPSPs recorded in a paired-pulse paradigm which argues against a presynaptic effect. These data are the first to indicate competitive effects...acetylaspartylglutamate (NAAG; 50 and 200 µM) blocked LTP of extracellular excitatory post-synaptic potentials ( EPSPs ) after high-frequency stimulation

  11. Tumor necrosis factor-α-mediated threonine 435 phosphorylation of p65 nuclear factor-κB subunit in endothelial cells induces vasogenic edema and neutrophil infiltration in the rat piriform cortex following status epilepticus

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    Kim Ji-Eun

    2012-01-01

    Full Text Available Abstract Background Status epilepticus (SE induces severe vasogenic edema in the piriform cortex (PC accompanied by neuronal and astroglial damages. To elucidate the mechanism of SE-induced vasogenic edema, we investigated the roles of tumor necrosis factor (TNF-α in blood-brain barrier (BBB disruption during vasogenic edema and its related events in rat epilepsy models provoked by pilocarpine-induced SE. Methods SE was induced by pilocarpine in rats that were intracerebroventricularly infused with saline-, and soluble TNF p55 receptor (sTNFp55R prior to SE induction. Thereafter, we performed Fluoro-Jade B staining and immunohistochemical studies for TNF-α and NF-κB subunits. Results Following SE, most activated microglia showed strong TNF-α immunoreactivity. In addition, TNF p75 receptor expression was detected in endothelial cells as well as astrocytes. In addition, only p65-Thr435 phosphorylation was increased in endothelial cells accompanied by SMI-71 expression (an endothelial barrier antigen. Neutralization of TNF-α by soluble TNF p55 receptor (sTNFp55R infusion attenuated SE-induced vasogenic edema and neuronal damages via inhibition of p65-Thr435 phosphorylation in endothelial cells. Furthermore, sTNFp55R infusion reduced SE-induced neutrophil infiltration in the PC. Conclusion These findings suggest that impairments of endothelial cell functions via TNF-α-mediated p65-Thr 485 NF-κB phosphorylation may be involved in SE-induced vasogenic edema. Subsequently, vasogenic edema results in extensive neutrophil infiltration and neuronal-astroglial loss.

  12. Neurocysticercosis : a possible cause of epileptiform seizures in people residing in villages served by the Bethanie clinic in the North West Province of South Africa

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    C.M. Veary

    2008-05-01

    Full Text Available A study to detect human taeniasis and cysticercosis was conducted in 4 village communities served by the Bethanie clinic in the North West Province, based on reports of people being diagnosed there with epileptiform episodes. Many home owners in the villages rear pigs in small numbers for both meat availability and an immediate income from live pig or pig meat sales. The primary aim of the work was to conduct in the study area a census of all small scale pig producers and a survey of rural village consumers, both by means of a structured questionnaire. The former reviewed pig husbandry practices, slaughter and marketing of pigs and the latter provided information on pork consumption, sanitation as well as people's basic knowledge of Taenia solium. Stool samples from consenting participants were screened by a contracted approved laboratory for T. solium. A descriptive analysis of retrospective data was conducted at the Bethanie clinic to determine the proportional morbidity of neurocysticercosis from the medical records of patients diagnosed with seizures in an attempt to establish possible sources of infection and routes of transmission. In addition, the total pig population in the study area was determined more accurately and the prevalence of cysticercosis investigated in pigs subjected to meat inspection at an approved abattoir. The questionnaires revealed a poor understanding of the disease, poor sanitation and hygiene, poor methods of pig husbandry and poor meat inspection and control in rural smallholder communities. There was no significant statistical difference in the proportion of households reporting evidence of epilepsy and owning pigs and those that did not. There is a strong evidence of a tendency towards an association between epilepsy, consumption habits and some identified epidemiological risk factors.

  13. Effects of the alkaloids 6-benzoylheteratisine and heteratisine on neuronal activity in rat hippocampal slices.

    Science.gov (United States)

    Ameri, A

    1997-08-01

    Alkaloids of different Aconitum species are employed as analgesics in traditional Chinese folk medicine. The present study was designed in order to investigate the effects of the structurally related alkaloids 6-benzoylheteratisine and heteratisine on neuronal activity in rat hippocampus. Experiments were performed as extracellular recordings of stimulus evoked population spikes in rat hippocampal slices. 6-Benzoylheteratisine (0.01-10 microM) inhibited the ortho- and antidromic population spike as well as the field EPSP in a concentration- and frequency-dependent manner. Heteratisine (1-100 microM) was a less potent inhibitor. It exerted a depression of the orthodromic spike, but failed to affect the antidromic population spike. 6-Benzoylheteratisine (10 microM) diminished epileptiform activity induced by bicuculline. In hippocampal neurons, this compound reduced the peak amplitude of the sodium current. There was no effect of heteratisine on the sodium current in concentrations up to 100 microM. It is concluded that the frequency-dependent action of 6-benzoylheteratisine suggests an inhibition of neuronal activity which underlies epileptiform burst discharges. The predominant effect is a suppression of neuronal activity due to a blockade of sodium channels.

  14. Neuronal mechanisms of the anoxia-induced network oscillations in the rat hippocampus in vitro.

    Science.gov (United States)

    Dzhala, V; Khalilov, I; Ben-Ari, Y; Khazipov, R

    2001-10-15

    1. A spindle of fast network oscillations precedes the ischaemia-induced rapid depolarisation in the rat hippocampus in vivo. However, this oscillatory pattern could not be reproduced in slices and the underlying mechanisms remain poorly understood. We have found that anoxia-induced network oscillations (ANOs, 20-40 Hz, lasting for 1-2 min) can be reproduced in the intact hippocampi of postnatal day P7-10 rats in vitro, and we have examined the underlying mechanisms using whole-cell and extracellular field potential recordings in a CA3 pyramidal layer. 2. ANOs were generated at the beginning of the anoxic depolarisation, when pyramidal cells depolarised to subthreshold values. Maximal power of the ANOs was attained when pyramidal cells depolarised to -56 mV; depolarisation above -47 mV resulted in a depolarisation block of pyramidal cells and a waning of ANOs. 3. A multiple unit activity in extracellular field recordings was phase locked to the negative and ascending phases of ANOs. Pyramidal cells recorded in current-clamp mode generated action potentials with an average probability of about 0.05 per cycle. The AMPA receptor-mediated EPSCs and the GABA receptor-mediated IPSCs in CA3 pyramidal cells were also phase locked with ANOs. 4. ANOs were prevented by tetrodotoxin and glutamate receptor antagonists CNQX and APV, and were slowed down by the allosteric GABA(A) receptor modulator diazepam. In the presence of the GABA(A) receptor antagonist bicuculline, ANOs were transformed to epileptiform discharges. 5. In the presence of the A1 adenosine receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), the anoxia induced an epileptiform activity and no ANOs were observed. 6. In normoxic conditions, a rise of extracellular potassium to 10 mM induced an epileptiform activity. Increasing extracellular potassium in conjunction with a bath application of the adenosine A1 receptor agonist cyclopentyladenosine induced oscillations similar to ANOs. 7. Multisite

  15. Pilocarpine-induced seizure-like activity with increased BNDF and neuropeptide Y expression in organotypic hippocampal slice cultures

    DEFF Research Database (Denmark)

    Poulsen, Frantz Rom; Jahnsen, Henrik; Blaabjerg, Morten

    2002-01-01

    with the muscarinic receptor antagonist atropine (100 microM). Regardless of dose and exposure time, the pilocarpine treatment induced very limited neuronal cell death, recorded as cellular propidium iodide uptake. Cultures exposed to 5 mM pilocarpine for up to 7 days displayed increased BDNF expression when analyzed...

  16. Linking crenarchaeal and bacterial nitrification to anammox in the Black Sea

    DEFF Research Database (Denmark)

    Lam, Phyllis; Jensen, Marlene Mark; Lavik, Gaute

    2007-01-01

    Generation of dentate granule cells and its modulation by glutamate receptor antagonists, growth factors and pilocarpine-induced seizure-like activity was investigated in rat hippocampal slice cultures derived from 1-week-old rats and grown for 2 weeks. Focussing on the dentate granule cell layer...

  17. Penicillin-induced epileptogenesis in immature rat CA3 hippocampal pyramidal cells.

    Science.gov (United States)

    Swann, J W; Brady, R J

    1984-02-01

    Penicillin's ability to produce epileptiform discharges in the CA3 region of hippocampus was examined both extracellularly and intracellularly in slices taken from immature rats 3-25 days of age. Comparisons were made to similar recordings from slices taken from mature rats. Between postnatal days 9 and 19 penicillin treatment resulted in spontaneous extracellular epileptiform bursts and coincident intracellular depolarization shifts. These events were more prolonged and less frequent than in slices from mature rats, and the bursts were followed by prolonged afterdischarges, often 20-30 s in duration. Intracellularly these afterdischarges consisted of large, rhythmic slow depolarizing potentials, which resulted in one or more action potentials in individual CA3 pyramidal cells. Extracellular field recordings showed these events to be simultaneous with synchronous discharges of a large population of CA3 pyramidal cells. In pups 1-2 weeks of age the ability of hippocampus to produce prolonged afterdischarges was associated with a slow depolarizing afterpotential, which followed the downstroke of the depolarization shift. Coincident with this afterpotential was a prolonged negative field in the CA3 pyramidal cell body layer. By postnatal days 24 and 25 the tendency to generate afterdischarges was greatly reduced. In addition, afterdischarges were observed infrequently in slices taken during the first postnatal week. Spike trains produced by prolonged intracellular current injection in slices taken on postnatal days 9-19 were followed by large afterhyperpolarizations and were unable to produce afterdischarges in individual CA3 pyramidal cells. Intracellular recordings from presumed glial cells suggest that extracellular K+ accumulation may play a role in the pronounced capacity of hippocampus from 1- and 2-week-old rat pups to generate prolonged afterdischarges.

  18. Altered Expression Pattern of Acid-Sensing Ion Channel Isoforms in Piriform Cortex After Seizures.

    Science.gov (United States)

    Wu, Hao; Wang, Chao; Liu, Bei; Li, Huanfa; Zhang, Yu; Dong, Shan; Gao, Guodong; Zhang, Hua

    2016-04-01

    The piriform cortex (PC) is highly susceptible to chemical and electrical seizure induction. Epileptiform activity is associated with an acid shift in extracellular pH, suggesting that acid-sensing ion channels (ASICs) expressed by PC neurons may contribute to this enhanced epileptogenic potential. In epileptic rats and surgical samples from patients with medial temporal lobe epilepsy (TLE), PC layer II ASIC1a-immunopositive neurons appeared swollen with dendritic elongation, and there was loss of ASIC1a-positive neurons in layer III, consistent with enhanced vulnerability to TLE-induced plasticity and cell death. In rats, pilocarpine-induced seizures led to transient downregulation of ASIC1a and concomitant upregulation of ASIC2a in the first few days post-seizure. These changes in expression may be due to seizure-induced oxidative stress as a similar reciprocal change in ASIC1a, and ASIC2a expression was observed in PC12 cells following H2O2 application. The proportion of ASIC1a/ASIC2a heteromers was reduced in the acute phase following status epilepticus (SE) but increased during the latent phase when rats developed spontaneous seizures. Knockdown of ASIC2a by RNAi reduced dendritic length and spine density in primary neurons, suggesting that seizure-induced upregulation of ASIC2a contributes to dendritic lengthening in PC layer II in rats. Administration of the ASIC inhibitor amiloride before pilocarpine reduced the proportion of rats reaching Racine level IV seizures, protected layer II and III neurons, and prolonged survival in the acute phase following SE. Our findings suggest that ASICs may enhance susceptibility to epileptogenesis in the PC. Inhibition of ASICs, particularly ASIC2a, may suppress seizures originating in the PC.

  19. Coalescence of deep and superficial epileptic foci into larger discharge units in adult rat neocortex.

    Science.gov (United States)

    Serafini, Ruggero; Andrade, Rodrigo; Loeb, Jeffrey A

    2015-04-30

    Epilepsy is a disease of neuronal hyper-synchrony that can involve both neocortical and hippocampal brain regions. While much is known about the network properties of the hippocampus little is known of how epileptic neocortical hyper-synchrony develops. We aimed at characterizing the properties of epileptic discharges of a neocortical epileptic focus. We established a multi-electrode-array method to record the spatial patterns of epileptiform potentials in acute adult rat brain slices evoked by 4-Aminopyridine in the absence of magnesium. Locations of discharges mapped to two anatomical regions over the somatosensory cortex and over the lateral convexity separated by a gap at a location matching the dysgranular zone. Focal epileptiform discharges were recorded in superficial and deep neocortical layers but over superficial layers, they exhibited larger surface areas. They were often independent even when closely spaced to one another but they became progressively coupled resulting in larger zones of coherent discharge. The gradual coupling of multiple, independent, closely spaced, spatially restricted, focal discharges between deep and superficial neocortical layers represents a possible mechanism of the development of an epileptogenic zone.

  20. COALESCENCE OF DEEP AND SUPERFICIAL EPILEPTIC FOCI INTO LARGER DISCHARGE UNITS IN ADULT RAT NEOCORTEX

    Science.gov (United States)

    SERAFINI, RUGGERO; ANDRADE, RODRIGO; LOEB, JEFFREY A.

    2016-01-01

    Epilepsy is a disease of neuronal hyper-synchrony that can involve both neocortical and hippocampal brain regions. While much is known about the network properties of the hippocampus little is known of how epileptic neocortical hyper-synchrony develops. We aimed at characterizing the properties of epileptic discharges of a neocortical epileptic focus. We established a multi-electrode-array method to record the spatial patterns of epileptiform potentials in acute adult rat brain slices evoked by 4-Aminopyridine in the absence of magnesium. Locations of discharges mapped to two anatomical regions over the somatosensory cortex and over the lateral convexity separated by a gap at a location matching the dysgranular zone. Focal epileptiform discharges were recorded in superficial and deep neocortical layers but over superficial layers, they exhibited larger surface areas. They were often independent even when closely spaced to one another but they became progressively coupled resulting in larger zones of coherent discharge. The gradual coupling of multiple, independent, closely spaced, spatially restricted, focal discharges between deep and superficial neocortical layers represents a possible mechanism of the development of an epileptogenic zone. PMID:25701714

  1. Protective effects of endoplasmic reticulum stress preconditioning on hippocampal neurons in rats with status epilepticus

    Directory of Open Access Journals (Sweden)

    Yi ZHANG

    2014-12-01

    Full Text Available Objective To evaluate the protective effects of endoplasmic reticulum stress preconditioning induced by 2-deoxyglucose (2-DG on hippocampal neurons of rats with status epilepticus (SE and the possible mechanism.  Methods Ninety Sprague-Dawley (SD rats were randomly enrolled into preconditioning group (N = 30, SE group (N = 30 and control group (N = 30. Each group was divided into 6 subsets (N = 5 according to six time points (before seizure, 6 h, 12 h, 1 d, 2 d and 7 d after seizure. The preconditioning group was administered 2-DG intraperitoneally with a dose of 150 mg/kg for 7 days, and the lithium-pilocarpine induced SE rat model was established on both preconditioning group and SE group. The rats were sacrificed at the above six time points, and the brains were removed to make paraffin sections. Nissl staining was performed by toluidine blue to evaluate the hippocampal neuronal damage after seizure, and the number of survival neurons in hippocampal CA1 and CA3 regions of the rats were counted. Immunohistochemical staining was performed to detect the expressions of glucose regulated protein 78 (GRP78 and X-box binding protein 1 (XBP-1 in hippocampal CA3 region of the rats.  Results The number of survival neurons in preconditioning group was much more than that in SE group at 7 d after seizure (t = 5.353, P = 0.000, and was more obvious in CA1 region. There was no significant hippocampal neuronal damage in control group. The expressions of GRP78 and XBP-1 in CA3 region of hippocampus in SE group at 6 h after seizure were significantly higher than that in control group (P = 0.000, and then kept increasing until reaching the peak at 2 d (P = 0.000, for all. The expressions of GRP78 and XBP-1 in hippocampal CA3 region in preconditioning group were significantly higher than that in control group before seizure (P = 0.000, for all. The level of GRP78 maintained the highest at 24 h and 2 d after seizure (P = 0.000, for all, while the XBP-1 level

  2. Characteristics of ictal temporal lobe epileptiform discharge on scalp or depth electrodes electroencephalograms%颞叶癫(癎)的头皮和深部电极脑电发作期特点

    Institute of Scientific and Technical Information of China (English)

    吴朝晖; 田增民; 赵全军; 张剑宁; 王红; 林鸿; 王福莉

    2012-01-01

    Objective:To investigate the characteristics of ictal temporal lobe epileptiform discharge on scalp or depth electrode electroencephalograms(EEGs). Methods: Twenty-five patients with temporal lobe epilepsy(TLE) were treated by stereotactic mesial temporal lobe radiofrequency thermocoagulation or routine operation( selective amygdalohippocampectomy, tumor resection or anterior temproal Ibectomy) with more than 12 months follow-ups. Of 21 patients with Engel's Class Ⅰ(cured)and 4 patients with Engel's Class Ⅱ (mostly cured) ,the characteristics of ictal epileptiform discharge on scalp or depth elec-trode EEGs was analysed. Results:In scalp EEGs,of 19 cases clinical seizures there were rhythmic ictal epileptiform waves in 5 to 13 Hz in 10 cases,with rhythmic ictal β waves in 14 to 20 Hz in 4 cases,sinu-soidal ictal epileptiform waves in 2 to 5 Hz in 3 cases and with background attenuation in 2 cases. In depth electrode EEGs of 6 cases with clinical seizures,all of them showed regular rhythmic ictal waves with 6 to 15 Hz. Conclusion:To the TLE,the ictal characteristics of scalp EEGs can locate the epileptic onset zone for most kinds of epileptic seizures, but for the electrode cremental events, more additional evidences were needed. Wave form of ictal depth EEGs was single.%目的:探讨手术治愈和基本治愈的颞叶癫(癎)(TLE)患者发作期头皮脑电图(EEG)和深部电极EEG的特点.方法:对25例立体定向射频热凝毁损颞叶内侧结构或常规手术切除后随访12月以上,Engel Ⅰ级(临床治愈)者21例和EngelⅡ级(临床基本治愈)者4例(共25例)的发作期头皮EEG和深部电极发作期特点进行分析.结果:头皮EEG描记时逢临床发作者19例,其中EEG为局限的5~13 Hz的典型阵发性节律波者10例,14~20 Hz的快波者4例,局限的2~5 Hz的正弦节律波者3例,EEG呈平坦化2例;深部EEG描记已临床发作者6例,均有15~6 Hz的节律波发放.结论:对于TLE头皮EEG对大多数发作能

  3. Neurotoxicity and toxicokinetics of norfloxacin in conscious rats

    Institute of Scientific and Technical Information of China (English)

    ZHANGLi-Rong; WANGYong-Ming; CHENBin-Yan; CHENGNeng-Neng

    2003-01-01

    AIM:To study the neurotoxicity and toxicokinetics of norfloxacin (NFLX) in freely moving rats. METHODS: Rats were assigned randomly to four treatment groups that received a single iv dose of 50, 100, 200 mg/kg of NFLX and 0.9% saline, respectively. Electroencephalogram (EEG) was continuously recorded with a computerized system in freely moving rats. Venous blood samples were collected for determination of the NFLX concentration by microbioassay method with Escherichia coli 441102 as the test strain. Toxicokinetic parameters were determined from serum concentration-time data with the 3p97 program. RESULTS: (1) The epileptiform discharges appeared in all NFLX groups with different latent periods, accompanied with limb twitching and clonictonic seizures. The relative total power of the EEG increased. (2) Drug serum concentration-time curves of different doses conformed to a two-compartmental model. The values of clearance, volume of distribution, and terminal half-life were dose-independent, while maximum serum concentrations(Cmax) and the areas under the concentration-time curve (AUC0→∞) of NFLX increased with dosage. (3) The relative total powers of EEG were lished a suitable approach to quantitatively determine central nervous system (CNS) stimulant effect of NFLX. There is a significant correlation between AUC0→∞ and the changes of relative total power, which may serve as the index for judgement and prediction of the CNS toxic effect induced by NFLX.

  4. The role of TNF-alpha in amygdala kindled rats.

    Science.gov (United States)

    Shandra, A A; Godlevsky, L S; Vastyanov, R S; Oleinik, A A; Konovalenko, V L; Rapoport, E N; Korobka, N N

    2002-02-01

    In the present study, the interaction between epileptogenesis and the immune system were studied in a kindling model. First, the effects of a single administration of TNF-alpha (5.0 microg/kg, i.p.) on seizure and EEG activity were investigated in amygdala-kindled rats. TNF-alpha treated rats showed more prolonged epileptiformic discharges than control rats. TNF-alpha also induced a decrease in the power of delta band and an increase in theta and alpha activity. In addition, a marked increase in the power of beta and gamma band was observed. The EEG changes were most numerous in the frontal cortex and amygdala. All effects were registered 24 h after TNF-alpha administration. Finally, electrical stimulation enhanced the level of TNF-alpha in blood serum from 1.9 +/- 1.5 to 12.7 +/- 3.8 pg/ml and in brain tissue 56.8 +/- 6.0 to 109.2 +/- 6.0 pg/mg, as was determined via the ELISA method. It can be concluded that there is a mutual facilitative interaction of both epileptogenic and cytokine-derived mechanisms on this type of seizure. The changes in the power spectrum of the EEG after TNF-alpha might contribute to intensify thalamic-derived facilitation of epileptic discharge in cortical structures.

  5. Diazepam prophylaxis for bicuculline-induced seizures: a rat dose-response model.

    Science.gov (United States)

    Anschel, David J; Ortega, Erik; Fisher, Robert S

    2004-02-06

    We developed a screening methodology to test the ability of putative antiepileptic drugs delivered directly to a seizure focus to prevent epileptiform activity. The left hippocampi of 15 rats were implanted with an injection cannula and bipolar recording electrodes. Bone screws were used to record neocortical EEG activity. Diazepam (DZP) at one of four possible concentrations or control solution was injected into the hippocampus, followed 5 min later by bicuculline methiodide. DZP suppressed spikes and ictal events in a dose-dependent manner (P<0.0001). At 100 mM, DZP reduced spikes from 678+/-128 to 87+/-35 for a 15 min segment. Numbers of ictal events (seizure) and latency to the first event were reduced by prophylactic DZP. The study establishes a protocol for testing of intracranially-injected drugs to prevent focal seizures.

  6. 神经群模型中癫痫状棘波的闭环控制性能研究%Performance of closed-loop control of epileptiform spikes in neural mass models

    Institute of Scientific and Technical Information of China (English)

    刘仙; 马百旺; 刘会军

    2013-01-01

    Neural mass models can produce electroencephalography (EEG) like signals corresponding to interical, pre-ictal and ictal activities. In this paper, a novel closed-loop feedback control strategy based on algebraic estimation is proposed to eliminate epileptiform spikes in neural mass models. Algebraic estimation plays a role in observing the states of the model in order to construct the controller. For a network of coupled neural populations, the characteristics regarding the closed-loop feedback control strategy, including the relationship between the type of controlled populations and the ability of eliminating epileptiform spikes, the relationship between the number of controlled populations and control energy, the relationship between the model parameters and control energy, are determined by numerical simulations. The purpose is to establish the rules for the proper control of eliminating epileptiform spikes with as less control energy as possible. Moreover, the proposed control-loop control strategy is compared with a direct proportional feedback control strategy by numerical simulations. It is shown that the use of algebraic estimation makes a reduction of control energy.%神经群模型可模拟产生癫痫发作间歇期、发作前期和发作期的脑电信号.本文基于代数估计法,给出一种新型的闭环反馈控制策略以消除神经群模型中的癫痫状棘波.代数估计法用以观测模型中的状态以进一步构造控制器.在多个神经群耦合的模型中,通过数值仿真研究了与所给的闭环反馈控制策略相关的一些特性,包括受控神经群的类型与消除棘波的能力之间的关系、受控神经群的数目与控制能量之间的关系、模型的参量和控制能量之间的关系,以期建立合适的控制规则实现利用尽可能小的控制能量消除癫痫状棘波.此外,通过数值仿真对基于代数估计法的闭环反馈控制策略和直接比例反馈控制策略进行比较,

  7. Efficiency of scalp epileptiform discharge dipole for stereotactic radiofrequency to refactory mesial temporal lobe epilepsy%(癎)样放电偶极子对颞叶内侧型顽固性癫(癎)的定位价值

    Institute of Scientific and Technical Information of China (English)

    吴朝晖; 田增民; 赵全军; 张剑宁; 肖霞; 王红; 林鸿; 王福莉

    2012-01-01

    目的:探讨(癎)样放电偶极子分析结合临床特征和其它无创检查对颞叶内侧型顽固性癫(癎)的定位价值.方法:对21例发作间期主要在颞区存在(癎)样放电且每月致残性发作1次以上的顽固性癫(癎)患者,结合临床特征和其它无创检查确诊为颞叶内侧型癫(癎)并定侧后,进行机器人辅助立体定向射频热凝毁损颞叶内侧结构治疗.结果:术后12~37个月,按照Engel分级系统:Ⅰ级6例(29%,其中Ⅰa级5例,Ⅰd级1例),Ⅱb级3例(14%),Ⅳa级4例(19%),Ⅳb级7例(30%),Ⅳc级1例(5%).术后患者的神经功能均无明显下降.结论:机器人辅助立体定向系统射频热凝毁损术安全、有效、方便、快捷,部分颞叶内侧型顽固性癫(癎)患者对立体定向射频热凝治疗反应良好.%To investigate the efficiency of scalp epileptiform discharge dipole,ictal character and other non-ivasive tests for stereotactic radiofrequency to refactory mesial temporgllobe epilepsy by robot assistant f rameless stereotaxy. Methods: Twenty-one patients with interictal epileptiform discharge in the temporal area located in mesial temporal lobe by spike-sharp dipole were diagnosed as the cases with mesial temporal lobe epilepsy with ictal character by epileptiform discharge dipole analysis and other non-ivasive tests. All the patients had disabling seizure at least once per month,and were refactory to antiepileptic drug. They all accepted transfrontal mesial temporal lobe radiofrequency thermocoagula-tion performed by robot assistant frameless system. Results: The postoperative outcomes were evaluated according to Engel classification: 6(29%) patients achieved Engel class I (including 5 I a,l I d),3 (14%) Engel classU.b, 4(19%) Engel class IVa,7(30%) Engel class IVb.and 1(5%) Engel IVc. No one had permanently functional disability. Conclusion; Robot assistant frameless stereotaxy for radiofrequency thermocoagulation is safe,effective,convenient and swift

  8. Correlation between synaptic protein expression and synaptic reorganization in the hippocampal CA3 region in a rat model of post-traumatic epilepsy

    Institute of Scientific and Technical Information of China (English)

    Gaolian Zhang; Jianmin Huang; Bang Zhao; Haineng Huang; Yuanyang Deng; Huadong Huang; Qirong He; Jianping Liang

    2010-01-01

    Postsynaptic density protein-95 and synaptophysin participate in synaptic reorganization in the forebrain of epilepsy models.However,the time-effect relationship between dynamic synapsin expression in hippocampus and synaptic reorganization in the post-traumatic epilepsy model remains unclear.FeCl2 was injected into the hippocampal CA3 region of the right forebrain in rats to induce post-traumatic epilepsy.Postsynaptic density protein-95 and synaptophysin expression was detected using immunohistochemistry.Epileptiform discharge induced by FeCl2 injection was determined in rat forebrain neurons,revealing decreased postsynaptic density protein-95expression at 24 hours and lowest levels at 7 days.Synaptophysin expression was markedly reduced at 24 hours,but increased at 7 days.Postsynaptic density protein-95 and synaptophysin expression was consistent with abnormal mossy fiber sprouting and synaptic reorganization following neuronal injury in the hippocampal CA3 region of FeCl2-induced epilepsy models.

  9. Anticonvulsant and neuroprotective effects of Pimpinella anisum in rat brain

    Directory of Open Access Journals (Sweden)

    Karimzadeh Fariba

    2012-06-01

    Full Text Available Abstract Background Essential oil of Pimpinella anisum L. Apiaceae (anise oil has been widely used in traditional Persian medicine to treat a variety of diseases, including some neurological disorders. This study was aimed to test the possible anti-seizure and anti-hypoxia effects of anise oil. Methods The effects of different concentrations of anise oil were tested on seizure attacks induced by pentylenetetrazol (PTZ injection and neuronal hypoxia induced by oxygen withdrawal as well as on production of dark neurons and induction of long-term potentiation (LTP in in vivo and in vitro experimental models of rat brain. Results Anise oil significantly prolonged the latency of seizure attacks and reduced the amplitude and duration of epileptiform burst discharges induced by injection of intraperitoneal PTZ. In addition, anise oil significantly inhibited production of dark neurons in different regions of the brain in epileptic rats. Anise oil also significantly enhanced the duration of the appearance of anoxic terminal negativity induced by oxygen withdrawal and inhibited induction of LTP in hippocampal slices. Conclusions Our data indicate the anticonvulsant and neuroprotective effects of anise oil, likely via inhibition of synaptic plasticity. Further evaluation of anise oil to use in the treatment of neurological disorders is suggested.

  10. Human fetal brain-derived neural stem/progenitor cells grafted into the adult epileptic brain restrain seizures in rat models of temporal lobe epilepsy.

    Science.gov (United States)

    Lee, Haejin; Yun, Seokhwan; Kim, Il-Sun; Lee, Il-Shin; Shin, Jeong Eun; Park, Soo Chul; Kim, Won-Joo; Park, Kook In

    2014-01-01

    Cell transplantation has been suggested as an alternative therapy for temporal lobe epilepsy (TLE) because this can suppress spontaneous recurrent seizures in animal models. To evaluate the therapeutic potential of human neural stem/progenitor cells (huNSPCs) for treating TLE, we transplanted huNSPCs, derived from an aborted fetal telencephalon at 13 weeks of gestation and expanded in culture as neurospheres over a long time period, into the epileptic hippocampus of fully kindled and pilocarpine-treated adult rats exhibiting TLE. In vitro, huNSPCs not only produced all three central nervous system neural cell types, but also differentiated into ganglionic eminences-derived γ-aminobutyric acid (GABA)-ergic interneurons and released GABA in response to the depolarization induced by a high K+ medium. NSPC grafting reduced behavioral seizure duration, afterdischarge duration on electroencephalograms, and seizure stage in the kindling model, as well as the frequency and the duration of spontaneous recurrent motor seizures in pilocarpine-induced animals. However, NSPC grafting neither improved spatial learning or memory function in pilocarpine-treated animals. Following transplantation, grafted cells showed extensive migration around the injection site, robust engraftment, and long-term survival, along with differentiation into β-tubulin III+ neurons (∼34%), APC-CC1+ oligodendrocytes (∼28%), and GFAP+ astrocytes (∼8%). Furthermore, among donor-derived cells, ∼24% produced GABA. Additionally, to explain the effect of seizure suppression after NSPC grafting, we examined the anticonvulsant glial cell-derived neurotrophic factor (GDNF) levels in host hippocampal astrocytes and mossy fiber sprouting into the supragranular layer of the dentate gyrus in the epileptic brain. Grafted cells restored the expression of GDNF in host astrocytes but did not reverse the mossy fiber sprouting, eliminating the latter as potential mechanism. These results suggest that human fetal

  11. Moxonidine and rilmenidine injected into the medial septal area reduces the salivation induced by pilocarpine.

    Science.gov (United States)

    Saad, Wilson Abrão; de Arruda Camargo, Luis Antonio; Simões, Silvio; Saad, William Abrão; Guarda, Renata Saad; Guarda, Ismael Francisco Mota Siqueira

    2004-05-31

    We determined the effects of moxonidine and rilmenidine 20 nmol (alpha(2)-adrenergic and imidazoline receptor agonists) injected into the medial septal area (MSA) on the pilocarpine-induced salivation, when injected intraperitoneally (i.p.), of male Holtzman rats weighing 250-300 g, with stainless-steel cannula implanted into the MSA. The rats were anesthetized with zoletil 50 mg kg(-1) b.wt. (tiletamine chloridrate 125.0 mg and zolazepan chloridrate 125.0 mg) into quadriceps muscle intramuscularly (IM), saliva was collected using pre-weighed small cotton balls inserted in the animal's mouth. The pre-treatment with moxonidine injected into the MSA reduced the salivation induced by pilocarpine (1 mg kg(-1)) injected i.p. (12+/-3 mg min(-1)) vs. control (99+/-9 mg min(-1)). The pre-treatment with rilmenidine 40 nmol also reduced the salivation induce by pilocarpine injected i.p. (20+/-5 mg min(-1)) vs. control (94+/-7 mg min(-1)). Idazoxan 40 nmol (imidazoline receptor antagonist) injected into the MSA previous to moxonidine and rilmenidine partially blocked the effect of moxonidine and totally blocked the rilmenidine effect in pilocarpine-induced salivation injected i.p. (60+/-8 and 95+/-10 mg min(-1), respectively). Yohimbine 40 nmol (alpha(2)-adrenergic receptor antagonist) injected into the MSA previously to moxonidine and rilmenidine partially blocked the moxonidine effect but produced no change on the rilmenidine effect on i.p. pilocarpine-induced salivation (70+/-6 and 24+/-6 mg min(-1), respectively). Injection of these alpha(2)-adrenergic and imidazoline agonists and antagonists agents i.p. produced no change on i.p. pilocarpine-induced salivation. These results show that central, but not peripheral, injection of alpha(2)-adrenergic and imidazoline agonists' agents inhibit pilocarpine-induced salivation. Idazoxan, an imidazoline receptor antagonist, totally inhibits the rilmenidine effect and partially inhibits the moxonidine effect on pilocarpine-induced

  12. Decreased resting functional connectivity after traumatic brain injury in the rat.

    Directory of Open Access Journals (Sweden)

    Asht Mangal Mishra

    Full Text Available Traumatic brain injury (TBI contributes to about 10% of acquired epilepsy. Even though the mechanisms of post-traumatic epileptogenesis are poorly known, a disruption of neuronal networks predisposing to altered neuronal synchrony remains a viable candidate mechanism. We tested a hypothesis that resting state BOLD-fMRI functional connectivity can reveal network abnormalities in brain regions that are connected to the lesioned cortex, and that these changes associate with functional impairment, particularly epileptogenesis. TBI was induced using lateral fluid-percussion injury in seven adult male Sprague-Dawley rats followed by functional imaging at 9.4T 4 months later. As controls we used six sham-operated animals that underwent all surgical operations but were not injured. Electroencephalogram (EEG-functional magnetic resonance imaging (fMRI was performed to measure resting functional connectivity. A week after functional imaging, rats were implanted with bipolar skull electrodes. After recovery, rats underwent pentyleneterazol (PTZ seizure-susceptibility test under EEG. For image analysis, four pairs of regions of interests were analyzed in each hemisphere: ipsilateral and contralateral frontal and parietal cortex, hippocampus, and thalamus. High-pass and low-pass filters were applied to functional imaging data. Group statistics comparing injured and sham-operated rats and correlations over time between each region were calculated. In the end, rats were perfused for histology. None of the rats had epileptiform discharges during functional imaging. PTZ-test, however revealed increased seizure susceptibility in injured rats as compared to controls. Group statistics revealed decreased connectivity between the ipsilateral and contralateral parietal cortex and between the parietal cortex and hippocampus on the side of injury as compared to sham-operated animals. Injured animals also had abnormal negative connectivity between the ipsilateral and

  13. Decreased resting functional connectivity after traumatic brain injury in the rat.

    Science.gov (United States)

    Mishra, Asht Mangal; Bai, Xiaoxiao; Sanganahalli, Basavaraju G; Waxman, Stephen G; Shatillo, Olena; Grohn, Olli; Hyder, Fahmeed; Pitkänen, Asla; Blumenfeld, Hal

    2014-01-01

    Traumatic brain injury (TBI) contributes to about 10% of acquired epilepsy. Even though the mechanisms of post-traumatic epileptogenesis are poorly known, a disruption of neuronal networks predisposing to altered neuronal synchrony remains a viable candidate mechanism. We tested a hypothesis that resting state BOLD-fMRI functional connectivity can reveal network abnormalities in brain regions that are connected to the lesioned cortex, and that these changes associate with functional impairment, particularly epileptogenesis. TBI was induced using lateral fluid-percussion injury in seven adult male Sprague-Dawley rats followed by functional imaging at 9.4T 4 months later. As controls we used six sham-operated animals that underwent all surgical operations but were not injured. Electroencephalogram (EEG)-functional magnetic resonance imaging (fMRI) was performed to measure resting functional connectivity. A week after functional imaging, rats were implanted with bipolar skull electrodes. After recovery, rats underwent pentyleneterazol (PTZ) seizure-susceptibility test under EEG. For image analysis, four pairs of regions of interests were analyzed in each hemisphere: ipsilateral and contralateral frontal and parietal cortex, hippocampus, and thalamus. High-pass and low-pass filters were applied to functional imaging data. Group statistics comparing injured and sham-operated rats and correlations over time between each region were calculated. In the end, rats were perfused for histology. None of the rats had epileptiform discharges during functional imaging. PTZ-test, however revealed increased seizure susceptibility in injured rats as compared to controls. Group statistics revealed decreased connectivity between the ipsilateral and contralateral parietal cortex and between the parietal cortex and hippocampus on the side of injury as compared to sham-operated animals. Injured animals also had abnormal negative connectivity between the ipsilateral and contralateral

  14. The effect of experimental epilepsy induced by injection of tetanus toxin into the amygdala of the rat on eating behaviour and response to novelty.

    Science.gov (United States)

    Mellanby, J; Oliva, M; Peniket, A; Nicholls, B

    1999-04-01

    A minute dose of tetanus toxin injected into the amygdala of rats produced an apparently reversible epileptiform syndrome similar to that previously described after injection of the toxin into the hippocampus. During the active epilepsy the toxin-injected rats occasionally exhibited 'paroxysmal eating' and also sometimes ran round in circles attempting to bite their own tails. When presented with a novel but palatable food (chocolate buttons or harvest crunch) the toxin-injected rats showed less neophobia than their controls--they ate sooner and ate more. This was found both during the active epilepsy and several weeks later when they had recovered. A similar effect of amygdala injections was found in a second experiment, in which the effect was compared with that of toxin injection in the hippocampus. These rats were tested also on the playground maze on their approach response to a neutral novel object (in a familiar environment in the context of seven familiar objects). The amygdala rats did not show any increase in their novelty response; thus their reduction in neophobia was specific to an appetitive behaviour. In contrast, the hippocampally-injected rats did not exhibit a novelty response in the playground maze, but showed normal neophobia to a new food.

  15. Protein tyrosine kinase inhibitors modify kainic acid-induced epileptiform activity and mossy fiber sprouting but do not protect against limbic cell death

    Directory of Open Access Journals (Sweden)

    C.M. Queiroz

    2008-05-01

    Full Text Available Intrahippocampal administration of kainic acid (KA induces synaptic release of neurotrophins, mainly brain-derived neurotrophic factor, which contributes to the acute neuronal excitation produced by the toxin. Two protein tyrosine kinase inhibitors, herbimycin A and K252a, were administered intracerebroventricularly, in a single dose, to attenuate neurotrophin signaling during the acute effects of KA, and their role in epileptogenesis was evaluated in adult, male Wistar rats weighing 250-300 g. The latency for the first Racine stage V seizure was 90 ± 8 min in saline controls (N = 4 which increased to 369 ± 71 and 322 ± 63 min in animals receiving herbimycin A (1.74 nmol, N = 4 and K252a (10 pmol, N = 4, respectively. Behavioral alterations were accompanied by diminished duration of EEG paroxysms in herbimycin A- and K252a-treated animals. Notwithstanding the reduction in seizure severity, cell death (60-90% of cell loss in KA-treated animals in limbic regions was unchanged by herbimycin A and K252a. However, aberrant mossy fiber sprouting was significantly reduced in the ipsilateral dorsal hippocampus of K252a-treated animals. In this model of temporal lobe epilepsy, both protein kinase inhibitors diminished the acute epileptic activity triggered by KA and the ensuing morphological alterations in the dentate gyrus without diminishing cell loss. Our current data indicating that K252a, but not herbimycin, has an influence over KA-induced mossy fiber sprouting further suggest that protein tyrosine kinase receptors are not the only factors which control this plasticity. Further experiments are necessary to elucidate the exact signaling systems associated with this K252a effect.

  16. The effects of high-frequency oscillations in hippocampal electrical activities on the classification of epileptiform events using artificial neural networks

    Science.gov (United States)

    Chiu, Alan W. L.; Jahromi, Shokrollah S.; Khosravani, Houman; Carlen, Peter L.; Bardakjian, Berj L.

    2006-03-01

    The existence of hippocampal high-frequency electrical activities (greater than 100 Hz) during the progression of seizure episodes in both human and animal experimental models of epilepsy has been well documented (Bragin A, Engel J, Wilson C L, Fried I and Buzsáki G 1999 Hippocampus 9 137-42 Khosravani H, Pinnegar C R, Mitchell J R, Bardakjian B L, Federico P and Carlen P L 2005 Epilepsia 46 1-10). However, this information has not been studied between successive seizure episodes or utilized in the application of seizure classification. In this study, we examine the dynamical changes of an in vitro low Mg2+ rat hippocampal slice model of epilepsy at different frequency bands using wavelet transforms and artificial neural networks. By dividing the time-frequency spectrum of each seizure-like event (SLE) into frequency bins, we can analyze their burst-to-burst variations within individual SLEs as well as between successive SLE episodes. Wavelet energy and wavelet entropy are estimated for intracellular and extracellular electrical recordings using sufficiently high sampling rates (10 kHz). We demonstrate that the activities of high-frequency oscillations in the 100-400 Hz range increase as the slice approaches SLE onsets and in later episodes of SLEs. Utilizing the time-dependent relationship between different frequency bands, we can achieve frequency-dependent state classification. We demonstrate that activities in the frequency range 100-400 Hz are critical for the accurate classification of the different states of electrographic seizure-like episodes (containing interictal, preictal and ictal states) in brain slices undergoing recurrent spontaneous SLEs. While preictal activities can be classified with an average accuracy of 77.4 ± 6.7% utilizing the frequency spectrum in the range 0-400 Hz, we can also achieve a similar level of accuracy by using a nonlinear relationship between 100-400 Hz and <4 Hz frequency bands only.

  17. Effects of low intensity radiofrequency electromagnetic fields on electrical activity in rat hippocampal slices.

    Science.gov (United States)

    Tattersall, J E; Scott, I R; Wood, S J; Nettell, J J; Bevir, M K; Wang, Z; Somasiri, N P; Chen, X

    2001-06-15

    Slices of rat hippocampus were exposed to 700 MHz continuous wave radiofrequency (RF) fields (25.2-71.0 V m(-1), 5-15 min exposure) in a stripline waveguide. At low field intensities, the predominant effect on the electrically evoked field potential in CA1 was a potentiation of the amplitude of the population spike by up to 20%, but higher intensity fields could produce either increases or decreases of up to 120 and 80%, respectively, in the amplitude of the population spike. To eliminate the possibility of RF-induced artefacts due to the metal stimulating electrode, the effect of RF exposure on spontaneous epileptiform activity induced in CA3 by 4-aminopyridine (50-100 microM) was investigated. Exposure to RF fields (50.0 V m(-1)) reduced or abolished epileptiform bursting in 36% of slices tested. The maximum field intensity used in these experiments, 71.0 V m(-1), was calculated to produce a specific absorption rate (SAR) of between 0.0016 and 0.0044 W kg(-1) in the slices. Measurements with a Luxtron fibreoptic probe confirmed that there was no detectable temperature change (+/- 0.1 degrees C) during a 15 min exposure to this field intensity. Furthermore, imposed temperature changes of up to 1 degrees C failed to mimic the effects of RF exposure. These results suggest that low-intensity RF fields can modulate the excitability of hippocampal tissue in vitro in the absence of gross thermal effects. The changes in excitability may be consistent with reported behavioural effects of RF fields.

  18. Long non-coding RNA expression profile of the hippocampus in a rat epilepsy model%癫痫大鼠海马组织长链非编码RNA差异表达的研究

    Institute of Scientific and Technical Information of China (English)

    韩春雷; 孟凡刚; 刘阳; 王开亮; 赵学敏; 张鑫; 张建国

    2015-01-01

    Objective To detect differentially expressed lncRNAs and mRNAs in hippocampus from epileptic rats using microarray and explore the role of lncRNAs in the pathogenesis of epilepsy.Methods The lithium-pilocarpine-induced status epilepticus model was established in Sprague-Dawley rats.Total RNA samples were isolated from hippocampus of 5 epileptic rats and 5 normal rats 24 hours after the induction of status epilepticus.Rat Gene 2.0 ST microarray was used to detect deregulated lncRNAs and mRNAs in the hippocampus.GO and Pathway analysis was performed.The coding-noncoding gene co-expression network was established.Results A total of 198 deregulated lncRNAs and 1 804 deregulated mRNAs were detected in epileptic rats.GO Term enrichment in the differentially expressed mRNAs list included ion transport,response to hydrogen peroxide,cell adhesion,inflammatory response etc.Differentially expressed mRNAs might involve in MAPK signaling pathway,focal adhesion,p53 signaling pathway,apoptosis,etc.Target regulated by lncRNAs was predicted with bioinformatic prediction.Conclusions This study explored the lncRNAs and mRNAs expression in epileptic rats using microarray.Differentially expressed lncRNAs might play a role in the pathogenesis of temporal lobe epilepsy.%目的 利用基因芯片筛选癫痫大鼠海马组织中差异表达的长链非编码RNA(lncRNAs)和mRNAs,分析lncRNAs在癫痫发病中的可能作用.方法 建立癫痫大鼠模型,提取海马RNA,利用Rat Gene 2.0 ST微阵列芯片分别检测5例癫痫及5例健康大鼠海马组织的lncRNAs和mRNAs表达,对差异表达的mRNAs进行GO、Pathway分析,构建lncRNAs和mRNAs的共表达网络,预测lncRNAs的可能功能.结果 按癫痫组与对照组的基因转录产物表达倍数大于1.2并且统计量P <0.05为标准筛选,得到差异lncRNAs 198个(上调92个,下调106个),差异表达mRNAs 1 804个(上调983个,下调821个).差异表达的mRNAs涉及离子转运、缺氧反应、细胞粘附、炎

  19. Protective Effect of Quinine on Chemical Kindling and Passive Avoidance Test in Rats

    Science.gov (United States)

    Faridkia, Zahra; Yaghmaei, Parichehr; Nassiri-Asl, Marjan

    2016-01-01

    Background In humans, convulsive diseases such as temporal lobe epilepsy are usually accompanied by learning and memory impairments. In recent years, the role of gap junction channels as an important target of antiepileptic drugs has been studied and discussed. Quinine, as a gap junction blocker of connexin 36, can abolish ictal epileptiform activity in brain slices. Objectives The role of quinine in memory retrieval in pentylenetetrazole (PTZ)-kindled rats was examined using a step-through passive avoidance task. Methods Forty rats were used in this experimental study in groups of 10 animals. Quinine (15, 30, and 60 mg/kg, i.p.) and PTZ (35 mg/kg, i.p.) were injected into the rats before the start of the learning test. Then, retention tests were conducted after the treatments ended. Results Quinine could attenuate seizure severity at doses of 15, 30 and 60 mg/kg compared with the control at the beginning of the kindling experiment by lowering the mean seizure stages (P 0.05). Conclusions Quinine may decrease the severity of seizure and improve the memory retrieval of animals by inhibiting the gap junction channel. However, further studies are needed to evaluate the molecular mechanism underlying the effects of quinine. PMID:28144451

  20. Effects of Chronic Dieldrin Ingestion on the Muscular Efficiency of Rats

    Science.gov (United States)

    Khaïry, Mélék

    1960-01-01

    Several cases of dieldrin poisoning were reported amongst sprayers following repeated exposure to this insecticide. The symptoms developed by some of the most severe cases of poisoning included epileptiform convulsions. The effect of dieldrin on muscular efficiency of rats was studied. A state of chronic toxicity was produced by maintaining two groups of rats on a diet containing 25 p.p.m. and 50 p.p.m. of dieldrin respectively. A third group receiving a diet containing no dieldrin acted as a control. Muscular efficiency was measured by training the rats to pull weights of increasing magnitude in a 250 cm. runway. The time taken to pull the weights through the standard distance was recorded. Dieldrin appeared to have no effect on body weight, food intake, or learning, but muscular efficiency (as measured here) seemed to be affected by this compound. A progressive deterioration in muscular efficiency was observed, and was related to the amount of dieldrin administered. Although the nature of the deterioration cannot be deduced from this study, the results obtained here suggest possible lines of investigating the early effects on human beings of exposure to dieldrin. Images PMID:14408763

  1. [Characteristics of electrographic and behavioral seizures induced by chronic tetanization of the right caudate-putamen in rats].

    Science.gov (United States)

    Gan, Li; Han, Dan; Liu, Hui-Lang; Zhang, Xian-Rong; Wu, Jun-Fang; Zou, Zu-Yu

    2003-11-01

    The electrographic and behavioral kindling effects were induced by chronic tetanization of the right caudate-putamen (CPu) to study the target-behavior expression involved in the CPu or hippocampus (HPC) network abnormalities. Experiments were performed on 58 SD rats. Tetanization (60Hz,0.4 - 0.6mA, 2s) was delivered into the CPu or the HPC, once a day, for 7-12 days. Animal behaviors were observed every day and depth electrographs were recorded at the beginning or at the end of the experiments. Chronic tetanization of the CPu or of the HPC induced: (1) Rhythmic sharp waves in the CPu and paroxysmal epileptiform events in the HPC electrographs. (2) Primary behavioral seizures, secondary behavioral seizures, and kindling effects, including wet dog shakes (WEDS), rearing, face washing, immobility, chewing and head nodding. (3) Lower rate of primary WEDS (P silent period of behavioral seizures before kindling appeared in the CPu-tetanized rats. Kindling effects in the CPu-tetanized rats resembles those in the HPC-tetanized rats. The CPu might participate in the origin of epileptic focus and be involved in reestablishment of limbic epileptic networks, which may be responsible for the target-behavioral seizures.

  2. GABAB R活性水平对致痫大鼠认知功能及Arc/Arg3.1表达的影响%Effects of GABAB receptor expression level on cognitive impairment and Arc/Arg3.1 expression in induced epileptic rats model

    Institute of Scientific and Technical Information of China (English)

    兰彦平; 孙涛; 张春; 袁聪聪; 杨征; 王峰

    2016-01-01

    目的 探讨GABABR活性变化对癫痫大鼠认知功能及Arc/Arg3.1的影响.方法 建立氯化锂-匹罗卡品致痫模型,随机分成正常组、巴氯酚组、CGP组、单纯点燃组.避暗、水迷宫实验观察大鼠认知情况,免疫组化、荧光定量PCR、免疫印迹检测海马组织内GABABR(GB1、GB2)、Arc/Arg3.1蛋白及mRNA表达情况.结果 避暗实验:4组大鼠穿梭次数为:6.8±0.6、1.2土0.2、5.4±0.5及3.6±0.3,潜伏期为:26.1 ±3.9、152.2±12.9、65.8 ±7.0、91.2±9.1,与水迷宫行为学变化趋势一致,显示致痫大鼠认知功能减退,巴氯酚进一步抑制致痫大鼠学习和记忆获取能力,CGP35348可改善致痫大鼠认知功能.Arc/Arg3.1及GB1、GB2相对表达量检测显:致痫大鼠较正常大鼠Arc/Arg3.1及GB1、GB2表达量明显增高,致痫组大鼠相对比,巴氯酚组Arc/Arg3.1表达量下降,GB1、GB2增高;而CGP35348组Arc/Arg3.1表达量增高,GB1、GB2降低.结论 GABABR活性水平可以调控Arc/Arg3.1表达,并影响致痫大鼠认知功能.%Objective To investigate the effects of GABAB receptor on cognitive impairment by using pilocarpine induced kindled rats model and also to check early gene (Arc/Arg3.1) expression.Methods Pilocarpine induced kindled rats were divided into four groups (Group normal,Baclofen,CGP and Kindled) randomly,and every group included 20 rats.We checked their cognitive impairment by using passive avoidance test and water maze test.The expression of GABAB receptor (GB1,GB2) and Arc/Arg3.1 was tested by immunohistochemical staining,RT-PCR and Western blot.Results Passive avoidance test showed four Group rats shuttle times were 6.8 ± 0.6,1.2 ± 0.2,5.4 ± 0.5,3.6 ± 0.3,incubation period were 26.1 ±3.9,152.2 ± 12.9,65.8 ±7.0,91.2 ±9.1,and water maze test had the same trend,with values in epilepsy groups significantly lower than the normal group of rats,which meant cognitive dysfunction.The above results also showed Baclofen further inhibited the learning

  3. The Predictability of Preoperative Pilocarpine-Induced Lens Shift on the Outcomes of Accommodating Intraocular Lenses Implanted in Senile Cataract Patients

    Science.gov (United States)

    Li, Jin; Chen, Qi; Lin, Zhibo; Leng, Lin; Huang, Fang

    2016-01-01

    Purpose. To evaluate the predictability of lens shift induced by pilocarpine (LSPilo) on the outcomes of accommodating intraocular lens (Acc-IOL) implantation. Methods. Twenty-four eyes of 24 senile cataract patients who underwent phacoemulsification and Acc-IOL implantation were enrolled. LSPilo was evaluated with anterior segment optical coherence tomography (AS-OCT). At 3 months postoperatively, the best corrected distance visual acuities (BCDVA), distance-corrected near visual acuities (DCNVA), and subjective and objective accommodations were measured. IOL shifts under accommodation stimulus (IOLSAcc) were evaluated with AS-OCT. Results. The mean LSPilo was 112.29 ± 30.72 µm. LSPilo was not associated with any preoperative parameters. The mean IOLSAcc was 130.46 ± 42.71 µm. The mean subjective and objective accommodation were 1.54 ± 0.39 D and 1.27 ± 0.41 D, respectively. The mean postoperative BCDVA and DCNVA (log MAR value) were 0.22 ± 0.11 and 0.24 ± 0.12, respectively. LSPilo positively correlated with IOLSAcc (r = 0.541; P = 0.006), subjective accommodation (r = 0.412; P = 0.022), and objective accommodation (r = 0.466; P = 0.045), respectively. Conclusion. LSPilo is an independent preoperative parameter associated with the postoperative Acc-IOL mobility and pseudophakic accommodation. It may offer valuable information for ophthalmologists in determining the suitable candidates for Acc-IOL implantation. PMID:27516899

  4. Expression pattern of NMDA receptors reveals antiepileptic potential of apigenin 8-C-glucoside and chlorogenic acid in pilocarpine induced epileptic mice.

    Science.gov (United States)

    Aseervatham, G Smilin Bell; Suryakala, U; Doulethunisha; Sundaram, S; Bose, P Chandra; Sivasudha, T

    2016-08-01

    The present study was aimed to evaluate the effect of apigenin 8-C-glucoside (Vitexin) and chlorogenic acid on epileptic mice induced by pilocarpine and explored its possible mechanisms. Intraperitonial administration of pilocarpine (85mg/kg) induced seizure in mice was assessed by behavior observations, which is significantly (p>0.05) reduced by apigenin 8-C-glucoside (AP8CG) (10mg/kg) and chlorogenic acid (CA) (5mg/kg), similar to diazepam. Seizure was accompanied by an imbalance in the levels of Gamma-aminobutyric acid (GABA) and glutamate in the pilocarpine administered group. Moreover, convulsion along with reduced acetylcholinesterase, increased monoamine oxidase and oxidative stress was observed in epileptic mice brain. AP8CG and CA significantly restored back to normal levels even at lower doses. Further, increased lipid peroxidation and nitrite content was also significantly attenuated by AP8CG and CA. However, CA was found to be more effective when compared to AP8CG. In addition, the mRNA expression of N-methyl-d-aspartate receptor (NMDAR), mGluR1 and mGlu5 was significantly (P≤0.05) inhibited by AP8CG and CA in a lower dose. The mRNA expression of GRIK1 did not differ significantly in any of the group and showed a similar pattern of expression. Our result shows that AP8CG and CA selectively inhibit NMDAR, mGluR1 and mGlu5 expression. Modification in the provoked NMDAR calcium response coupled with neuronal death. Hence, these findings underline that the polyphenolics, AP8CG and CA have exerted antiepileptic and neuroprotective activity by suppressing glutamate receptors.

  5. Loss of interneurons innervating pyramidal cell dendrites and axon initial segments in the CA1 region of the hippocampus following pilocarpine-induced seizures.

    OpenAIRE

    Dinocourt, Celine; Petanjek, Zdravko; Freund, Tamas,; Ben-Ari, Yezekiel; Esclapez, Monique

    2003-01-01

    International audience; In the pilocarpine model of chronic limbic seizures, vulnerability of GABAergic interneurons to excitotoxic damage has been reported in the hippocampal CA1 region. However, little is known about the specific types of interneurons that degenerate in this region. In order to characterize these interneurons, we performed quantitative analyses of the different populations of GABAergic neurons labeled for their peptide or calcium-binding protein content. Our data demonstrat...

  6. Antagomirs targeting microRNA-134 increase hippocampal pyramidal neuron spine volume in vivo and protect against pilocarpine-induced status epilepticus.

    Science.gov (United States)

    Jimenez-Mateos, Eva M; Engel, Tobias; Merino-Serrais, Paula; Fernaud-Espinosa, Isabel; Rodriguez-Alvarez, Natalia; Reynolds, James; Reschke, Cristina R; Conroy, Ronan M; McKiernan, Ross C; deFelipe, Javier; Henshall, David C

    2015-07-01

    Emerging data support roles for microRNA (miRNA) in the pathogenesis of various neurologic disorders including epilepsy. MicroRNA-134 (miR-134) is enriched in dendrites of hippocampal neurons, where it negatively regulates spine volume. Recent work identified upregulation of miR-134 in experimental and human epilepsy. Targeting miR-134 in vivo using antagomirs had potent anticonvulsant effects against kainic acid-induced seizures and was associated with a reduction in dendritic spine number. In the present study, we measured dendritic spine volume in mice injected with miR-134-targeting antagomirs and tested effects of the antagomirs on status epilepticus triggered by the cholinergic agonist pilocarpine. Morphometric analysis of over 6,400 dendritic spines in Lucifer yellow-injected CA3 pyramidal neurons revealed increased spine volume in mice given antagomirs compared to controls that received a scrambled sequence. Treatment of mice with miR-134 antagomirs did not alter performance in a behavioral test (novel object location). Status epilepticus induced by pilocarpine was associated with upregulation of miR-134 within the hippocampus of mice. Pretreatment of mice with miR-134 antagomirs reduced the proportion of animals that developed status epilepticus following pilocarpine and increased animal survival. In antagomir-treated mice that did develop status epilepticus, seizure onset was delayed and total seizure power was reduced. These studies provide in vivo evidence that miR-134 regulates spine volume in the hippocampus and validation of the seizure-suppressive effects of miR-134 antagomirs in a model with a different triggering mechanism, indicating broad conservation of anticonvulsant effects.

  7. One hour of pilocarpine-induced status epilepticus is sufficient to develop chronic epilepsy in mice, and is associated with mossy fiber sprouting but not neuronal death

    Institute of Scientific and Technical Information of China (English)

    Ling-Lin Chen; Hang-Feng Feng; Xue-Xia Mao; Qing Ye; Ling-Hui Zeng

    2013-01-01

    Determining the minimal duration of status epilepticus (SE) that leads to the development of subsequent spontaneous seizures (i.e.,epilepsy) is important,because it provides a critical time-window for seizure intervention and epilepsy prevention.In the present study,male ICR (Imprinting Control Region) mice were injected with pilocarpine to induce acute seizures.SE was terminated by diazepam at 10 min,30 min,1 h,2 h and 4 h after seizure onset.Spontaneous seizures occurred in the 1,2 and 4 h SE groups,and the seizure frequency increased with the prolongation of SE.Similarly,the Morris water maze revealed that the escape latency was significantly increased and the number of target quadrant crossings was markedly decreased in the 1,2 and 4 h SE groups.Robust mossy fiber sprouting was observed in these groups,but not in the 10 or 30 min group.In contrast,Fluoro-Jade B staining revealed significant cell death only in the 4 h SE group.The incidence and frequency of spontaneous seizures were correlated with Timm score (P =0.004) and escape latency (P =0.004).These data suggest that SE longer than one hour results in spontaneous motor seizures and memory deficits,and spontaneous seizures are likely associated with robust mossy fiber sprouting but not neuronal death.

  8. Antagonist targeting microRNA-155 protects against lithium-pilocarpine-induced status epilepticus in C57BL/6 mice by activating brain-derived neurotrophic factor

    Directory of Open Access Journals (Sweden)

    Zhengxu eCai

    2016-05-01

    Full Text Available Epilepsy is a severe brain disorder affecting numerous patients. Recently, it is inferred that modulation of microRNA-155 (miR-155 could serve as a promising treatment of mesial temporal lobe epilepsy (MTLE. In the current study, the therapeutic potential of miR-155 antagonist against TLE was evaluated and the underlying mechanism involved in this regulation was explored. TLE model was induced by lithium-pilocarpine method. The effect of miR-155 antagonist on epilepticus symptoms of TLE mice was assessed using Racine classification and electroencephalogram (EEG recordings. The expression of brain-derived neurotrophic factor (BDNF and its association with miR-155 were also assessed with a series of experiments. Our results showed that level of miR-155 was significantly up-regulated after induction of TLE model. Based on the results of EEG and behavior analyses, seizures in mice were alleviated by miR-155 antagonist. Moreover, administration of miR-155 antagonist also significantly increased the level of BDNF. The results of dual luciferase assay and western blotting showed that miR-155 antagonist exerted its action on status epilepticus by directly regulating the activity of BDNF. Taken all the information together, our results demonstrated that miR-155 antagonist might firstly induce the expression of BDNF, which then contributed to the alleviation of epilepsy in the current study.

  9. EFFECTS OF KAINIC ACID ON GLUTATIONE AND NITRITE IN RAT HIPPOCAMPUS

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    Nadka I. Boyadjieva

    2011-09-01

    Full Text Available Epileptiformic activity could result in apoptotic neuronal death, in which oxidative stress could play an important role. In case of decreased antioxidant brain status cellular death could be facilitated. Kainic acid is often used in a model of epilepsy in rats. Up to now there is not enough data evaluating levels of glutathione and nitric oxide in kainic acid-induced epilepsy acutely and several days after the kainic acid exposure. This information will be useful for assessing long term prognosis on a risk of further brain damage.We studied hippocampal levels of glutathione and nitric oxide at the 3th hour (acute group and after 7 days of kainic (chronic group acid exposure. We found that glutathione level is statistically significantly lower in the hippocampus 7 days after kainic acid exposure, as compared with values measured in the acute group. For both kainic acid treated groups glutathione levels were significantly lower than controls.Levels of nitric oxide were found to be significantly higher 7 days after kainic acid exposure as compared with acute group. For both kainic acid treated groups nitric oxyde levels were significantly lower than controls.We conclude that in kainic acid treated rats oxidative stress could be present even after a single treatment. This could be a potentially pathogenic factor for further brain damages.

  10. Anticonvulsant and neuroprotective effects of Rosa damascena hydro-alcoholic extract on rat hippocampus

    Directory of Open Access Journals (Sweden)

    Mansour Homayoun

    2015-04-01

    Full Text Available Objective: Previously, analgesic, hypnotic, and anticonvulsant effects have been suggested for Rosa damascena (R. damascena. In the present study, possible anti-seizure and neuro-protective effects of hydro-alcoholic extract of R. damascena has been investigated after inducing seizures in rats by pentylenetetrazole (PTZ. Materials and Methods: The rats were divided to five groups: (1 Control: received saline, (2 PTZ: 100 mg/kg, i.p., (3 PTZ-Extract 50 mg/kg(PTZ-Ext 50, (4 PTZ- Extract 100 mg/kg(PTZ-Ext 100, and (5 PTZ- Extract 200 mg/kg(PTZ-Ext 200 groups which were treated with 50, 100, and 200 mg/kg respectively of hydro-alcoholic extract of R. damascena for one week before PTZ injection. The animals were examined for electrocorticography (ECoG recording and finally, the brains were removed for histological study. Results: The hydro-alcoholic extract of R. damascena significantly prolonged the latency of seizure attacks and reduced the frequency and amplitude of epileptiform burst discharges induced by PTZ injection. Moreover, all three doses of the extract significantly inhibited production of dark neurons in different regions of the hippocampus in the mentioned animal model. Conclusion: The present study showed that the hydro-alcoholic extract of R. damascena has anticonvulsant and neuroprotective effects. More investigations are needed to be done in order to better understand the responsible compound(s as well as the possible mechanism(s.

  11. Neurogenesis induced by seizures in the dentate gyrus is not related to mossy fiber sprouting but is age dependent in developing rats A neurogênese induzida por crises no giro denteado não está relacionada ao brotamento de fibras musgosas, mas é dependente da idade, em ratos durante o desenvolvimento

    Directory of Open Access Journals (Sweden)

    Yaima del Carmen Garrido Sanabria

    2008-12-01

    Full Text Available Neurogenesis in the dentate gyrus (DG has attracted attention since abnormal supragranular mossy fiber sprouting occurs in the same region, in temporal lobe epilepsy. Thus, we submitted developing rats to pilocarpine-induced status epilepticus (SE to study the relationship between neurogenesis and mossy fiber sprouting. Groups were submitted to SE at: I-P9, II-P7, P8 and P9, III-P17 e IV-P21. Neurogenesis was quantified using BrdU protocol and confirmed through double staining, using neuronal pentraxin. Other animals were monitored by video system until P120 and their brain was studied (Timm and Nissl staining. The neurogenesis at P17 (p=0.007 and P21 (p=0.006 were increased. However, only P21 group showed recurrent seizures and the mossy fiber sprouting in the same region, during adult life, while P17 did not. Thus, our results suggest that neurogenesis is not related to mossy fiber sprouting neither to recurrent spontaneous seizures in pilocarpine model.A neurogênese no giro dentado tem atraído atenção já que ela ocorre na mesma região do hipocampo que o brotamento das fibras musgosas, na epilepsia do lobo temporal. Assim, submetemos ratos em desenvolvimento ao status epilepticus induzido (SE por pilocarpine. Grupos foram submetidos em I-P9, II-P7, P8, P9; III-P17 e IV-P21. A neurogênese foi observada usando o protocolo do BrdU e confirmada por dupla marcação com pentraxina neuronal. Outros animais foram monitorados até P120 e seus cérebros analisados (Nissl e Timm. A neurogênese nos grupos P17 (p=0,007 e P21 (p=0,006 aumentaram. Entretanto, o P21 apresentou crises espontâneas e brotamento de fibras musgosas, na mesma região onde ocorreu a neurogênese, enquanto o grupo P17 apresentou somente aumento na neurogênese. Assim, nossos resultados sugerem que o fenômeno da neurogênese não está relacionado com o brotamento de fibras musgosas nem com o aparecimento de crises espontâneas e recorrentes no modelo da pilocarpina.

  12. Epileptiform spike detection via convolutional neural networks

    DEFF Research Database (Denmark)

    Johansen, Alexander Rosenberg; Jin, Jing; Maszczyk, Tomasz

    2016-01-01

    The EEG of epileptic patients often contains sharp waveforms called "spikes", occurring between seizures. Detecting such spikes is crucial for diagnosing epilepsy. In this paper, we develop a convolutional neural network (CNN) for detecting spikes in EEG of epileptic patients in an automated fash...

  13. 痉挛型偏瘫脑电图癫癎样放电危险因素分析%Risk factors for interictal epileptiform discharges on electroencephalogram in children with spastic hemiplegic cerebral palsy

    Institute of Scientific and Technical Information of China (English)

    李素云; 钱旭光; 赵伊黎; 符文杰; 谭晓如; 刘振寰

    2015-01-01

    目的:探讨痉挛型偏瘫的临床表现及脑电图发作间期癫癎样放电(IED)特征,并分析IED相关危险因素。方法收集83例痉挛型偏瘫患儿的临床资料、视频脑电图、影像学检查及认知功能评定结果等。采用多因素logistic回归分析IED的影响因素。结果13%痉挛型偏瘫患儿伴有癫癎。34%患儿伴IED,IED组癫癎发生率(32%)较非IED组者(4%)显著升高(P<0.01)。存在合并症、皮层受累者IED发生率显著增高(P<0.01);不同认知水平组其IED发生率差异有统计学意义(P<0.01)。皮层受累、认知水平低下是痉挛型偏瘫伴IED的危险因素(OR分别为11.521、2.238,P<0.05)。结论痉挛型偏瘫常伴IED,存在IED者癫癎发生率更高。皮层受累及认知水平低下对痉挛型偏瘫伴IED有预测价值。%ObjectiveTo investigate the clinical symptoms and features of interictal epileptiform discharges (IED) on electroencephalogram (EEG) in children with spastic hemiplegic cerebral palsy (CP) and to analyze the risk factors for IED.MethodsEighty-three children with spastic hemiplegic CP were recruited, and their clinical data, results of video-electroencephalogram, imaging ifndings, and cognitive levels were collected. The inlfuencing factors for IED were determined by multiple logistic regression analysis.ResultsThe incidence of epilepsy was 13% in children with spastic hemiplegic CP; 34% of these cases had IED. The incidence of epilepsy in children with IED (32%) was signiifcantly higher than that in those without IED (4%) (P<0.01). The incidence of IED in children with complications and brain cortex impairment increased signiifcantly (P<0.01). The incidence of IED varied signiifcantly between patients with different cognitive levels (P<0.01). Brain cortex impairment (OR=11.521) and low cognitive level (OR=2.238) were risk factors for IED in children with spastic hemiplegic CP (P<0.05).ConclusionsSpastic hemiplegic CP

  14. Effects of Anterior Thalamic Nucleus Deep Brain Stimulation in Chronic Epileptic Rats

    Science.gov (United States)

    Amorim, Beatriz; Cavarsan, Clarissa; Miranda, Maisa Ferreira; Aarão, Mayra C.; Madureira, Ana Paula; Rodrigues, Antônio M.; Nobrega, José N.; Mello, Luiz E.; Hamani, Clement

    2014-01-01

    Deep brain stimulation (DBS) has been investigated for the treatment of epilepsy. In rodents, an increase in the latency for the development of seizures and status epilepticus (SE) has been reported in different animal models but the consequences of delivering stimulation to chronic epileptic animals have not been extensively addressed. We study the effects of anterior thalamic nucleus (AN) stimulation at different current intensities in rats rendered epileptic following pilocarpine (Pilo) administration. Four months after Pilo-induced SE, chronic epileptic rats were bilaterally implanted with AN electrodes or had sham-surgery. Stimulation was delivered for 6 h/day, 5 days/week at 130 Hz, 90 µsec. and either 100 µA or 500 µA. The frequency of spontaneous recurrent seizures in animals receiving stimulation was compared to that recorded in the preoperative period and in rats given sham treatment. To investigate the effects of DBS on hippocampal excitability, brain slices from animals receiving AN DBS or sham surgery were studied with electrophysiology. We found that rats treated with AN DBS at 100 µA had a 52% non-significant reduction in the frequency of seizures as compared to sham-treated controls and 61% less seizures than at baseline. Animals given DBS at 500 µA had 5.1 times more seizures than controls and a 2.8 fold increase in seizure rate as compared to preoperative values. In non-stimulated controls, the average frequency of seizures before and after surgery remained unaltered. In vitro recordings have shown that slices from animals previously given DBS at 100 µA had a longer latency for the development of epileptiform activity, shorter and smaller DC shifts, and a smaller spike amplitude compared to non-stimulated controls. In contrast, a higher spike amplitude was recorded in slices from animals given AN DBS at 500 µA. PMID:24892420

  15. TRPC6在匹罗卡品致痫大鼠海马苔藓纤维出芽中的作用%Effect of TRPC6 on mossy fiber sprouting in hippocampus of rats with pilocapine-induced epilepsy

    Institute of Scientific and Technical Information of China (English)

    唐薇婷; 曾畅; 李国良; 冯莉; 陈锶; 肖波

    2012-01-01

    Objective To observe the dynamic changes of canonical transient receptor potential channels 6 (TRPC6) expression in the rat hippocampus with pilocarpine-induced epilepsy, and to investigate its effect on mossy fiber sprouting in hippocampus. Methods Seventy-two healthy male Sprague-Dawley (SD) rats were divided randomly into experimental group (n =60) and control group (n - 12), The temporal lobe epilepsy model was established by intraperitoneal injection of lithium and pilocarpine, while the controls were injected with equal dose of saline (NS). The experimental rats were equally divided into 5 subgroups at time points 1 day、7 days、15 days、30 days and 60 days after status epileptics (SE). Each subgroup and the control rats were subsequently divided into 2 panels for the following tests respectively: ①expression of TRPC6 and Synaptophysin protein in rats' hippocampus by Western blot; ②Timm staining and score. Results The expression of TRPC6 was markedly increased and reached its peak on 1 days after SE (P <0. 01) , and it was higher than the control at all the other time points (P <0, 01). Compared with the control, the expression of Synaptophysin was markedly up-regulated on 15 days、30 days 、60 days after SE (P<0.05 or P <0. 01 ) , and reached the peak on 30 days after SE. Timm granules appeared in molecular layer of gyrus dentatus in the hippocampus of experimental rats since 7 days after SE, and then gradually increased. Conclusions TRPC6 may play a potential role in mossy fiber sprouting, in which BDNF may involve.%目的 观察传统型瞬时受体电位通道6(TRPC6)蛋白在匹罗卡品致痫大鼠海马中的表达变化,探讨其在海马苔藓纤维出芽中的作用.方法 72只SD大鼠随机分为实验组(n=60)和对照组(n=12).实验组采用氯化锂-匹罗卡品腹腔注射法建立颞叶癫痫模型;对照组腹腔注射等量无菌生理盐水.实验组按癫痫持续状态(SE)后1d、7d、15d、30 d和60 d分为5

  16. Study on concordance of ictal and interictal epileptiform activity in patients with tuberous sclerosis complex%结节性硬化症癫痫发作期与发作间期痫样放电的一致性研究

    Institute of Scientific and Technical Information of China (English)

    杨志仙; 郭庆辉; 庄嘉鑫; 刘晓燕; 熊晖; 吴晔; 王爽; 常杏芝; 张月华

    2014-01-01

    Objective To analyze the relationship between the ictal onset zone and dominant interictal epileptiform foci in tuberous sclerosis complex (TSC) patients.Method Clinical data of 20 patients with TSC which had epileptic seizures during Video-EEG monitoring was assessed.Consistency and dominance of focal interictal epileptiform activity and the ictal onset zone were identified.Concordance between interictal and ictal findings was analyzed.Result Of the 20 patients,7 were female,and 13 were male.The age of epilepsy onset was from 15 d to 6 years.The Video-EEG monitoring age was from 6 months to 11 years.Family history was found in three cases.Abnormality in neuroimaging existed in 17 of 18 patients who were examined.Interictal EEG showed hypsarrhythmia in 3 patients,multifocal epileptiform activity with a dominant focus in 12 patients,both focal and generalized discharges in 2 patients,and only focal discharges in 3 patients.The seizures types during EEG monitoring included epileptic spasms,partial seizure,atypical absence,and generalized or focal myoclonic seizure.The most common seizure type was partial seizure and then epileptic spasms.EEG in 4 patients with epileptic spasms showed ictal generalized discharges and interictal hypsarrhythmia or generalized discharges.Clinical manifestation of epileptic spasms was asymmetric in 3 patients.Lateralization and location of interictal and ictal discharges were consistent in 2 of the 3 patients,while only lateralization consistency in 1 of the 3 patients.Partial seizures as the only seizure type were monitored in 13 patients.Of the 13 patients,lateralization and location of interictal and ictal discharges were inconsistent in 2 patients (15%),consistent in 8 patients (62%),lateralization or location consistent in 2 patients (15%).One case could not be analyzed because of uncertainty of lateralization and location of seizure onset.Conclusion In the majority of patients with TSC,multifocal interictal epileptiform

  17. treated rats

    African Journals Online (AJOL)

    aghomotsegin

    2014-01-08

    Jan 8, 2014 ... Our results show, for the first time, that oral administration of C. edulis ... the exact mechanisms of these hematological changes produced by .... Hematological analysis .... rats are subjected to the additional stress of hypoxia to.

  18. A serotonin-1A receptor agonist and an N-methyl-D-aspartate receptor antagonist oppose each others effects in a genetic rat epilepsy model.

    Science.gov (United States)

    Filakovszky, J; Gerber, K; Bagdy, G

    1999-02-12

    The WAG/RIJ rats exhibit spontaneously occurring spike-wave discharges (SWD) accompanied by behavioural phenomena, with characteristics similar to the human absence type epilepsy. To study the mechanisms involved in this type of epileptiform activity we investigated the effects of the serotonin-1A (5-HT1A) receptor agonist 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT) and the N-methyl-D-aspartate (NMDA) receptor antagonist (+)-5-methyl-10,11-dihydro-5H-dibenzo [a,d]cyclohepten-5,10-imine maleate (MK-801). Intracerebroventricular (i.c.v.) injection of 8-OH-DPAT caused marked, dose dependent increase, MK-801 a decrease in the cumulative duration and number of spike-wave discharges. Pretreatment with MK-801 (10 microg/rat i.c.v.) abolished the increase caused by 8-OH-DPAT (20 microg/rat i.c.v.), but the decrease in SWD to MK-801 was counterbalanced by 8-OH-DPAT. These data provide evidence for an interaction of glutamatergic and serotonergic mechanisms in the triggering and maintenance of epileptic activity in this genetic model of absence epilepsy.

  19. Studies on the potential neurotoxic and convulsant effects of increased blood levels of quinolinic acid in rats with altered blood-brain barrier permeability

    Energy Technology Data Exchange (ETDEWEB)

    Vezzani, A.; Stasi, M.A.; Wu, H.Q.; Castiglioni, M.; Weckermann, B.; Samanin, R. (Istituto di Ricerche Farmacologiche Mario Negri, Milano (Italy))

    1989-10-01

    Intravenous injection of 450 mg/kg quinolinic acid (Quin), an endogenous kynurenine metabolite with excitotoxic properties, induced only minor electroencephalographic (EEG) modifications and no neurotoxicity in rats with a mature blood-brain barrier (BBB). BBB permeability was altered in rats by focal unilateral irradiation of the cortex (7 mm in diameter and 5 mm in depth) with protons (60 Gy, 9 Gy/min). Three days after irradiation, Evans blue dye staining showed BBB breakdown in the dorsal hippocampus of the irradiated hemisphere. No neurotoxic or convulsant effects were observed as a consequence of the radiation itself. When BBB-lesioned rats were challenged with 225 mg/kg Quin iv, epileptiform activity was observed on EEG analysis. Tonic-clonic seizures were induced by 225-450 mg/kg Quin. Light microscopic analysis showed a dose-related excitotoxic type of lesion restricted to the hippocampus ipsilateral to the irradiated side. Neuro-degeneration was prevented by local injection of 120 nmol D(-)2-amino-7-phosphonoheptanoic acid, a selective N-methyl-D-aspartate receptor antagonist. No lesions or EEG or behavioral modifications occurred after 450 mg/kg nicotinic acid, an inactive analog of Quin. The potential neurotoxic and convulsant effects of increased blood levels of Quin under conditions of altered BBB permeability are discussed.

  20. 睡眠中癎样放电对睡眠的影响%The influence of epileptiform discharges in spontaneous night sleep and quality of life in epileptic patients

    Institute of Scientific and Technical Information of China (English)

    李梦嘉; 赵合庆; 戴永萍; 邹蓉

    2016-01-01

    Objective:To evaluate the influence of epileptiform discharges on(EDs) sleep and quali‐ty of life(QOL) in patients with different types of seizures ,by observing the number of EDs in each stage of sleep .Methods:For all recruiters ,24‐hour video‐electroencephalogram(V‐EEG) monitoring and poly‐somnography (PSG) examination were conducted to detect EDs and the sleep structures were analyzed . The QOLIE‐31 was used to evaluate the QOL of patients with different types of seizures .Results:The detection rate of EDs was significantly different in wakefulness and sleep (P<0 .05) .Compared with pa‐tients who had normal brain electrical activity on sleep ,and the duration of NREM Ⅰ ~ Ⅱ sleep was pro‐longed (65 .93 ± 9 .1% and 58 .67 ± 5 .7% ) ,while NREM Ⅲ sleep were shortened (17 .78 ± 5 .2% and 26 .06 ± 8 .2% ) in the epileptic patients with EDs .The duration of REM sleep latency was definitely pro‐longed as the awakening time increased in patients with EDs ,while the duration of REM sleep latency and the awakening times were similar between patients with non‐epileptic abnormality and patients with nor‐mal brain electrical activity on sleep .Different types of epileptic seizures were no significantly different in sleep structure .QOL of patients with epilepsy was lower than in the control group according to a variety of indicators ,and the difference was statistically significant (P<0 .01) .All indicators of the cases with generalized seizures were lower than other types of seizures in patients except for the influence of antiepi‐leptic drugs ,and the difference was statistically significant ;different types of seizures in patients had no significant difference caused by the influence of drugs .Conclusion:The combination of V‐EEG with PSG is a useful method to detect EDs during sleep ,analyze the association among EDs sleep‐wake cycles in clinical treatment of epilepsy ,and improve the QOL .%目的:观察不同睡眠时相中�

  1. Proconvulsant actions of intrahippocampal botulinum neurotoxin B in the rat.

    Science.gov (United States)

    Bröer, S; Zolkowska, D; Gernert, M; Rogawski, M A

    2013-11-12

    Botulinum neurotoxins (BoNTs) may affect the excitability of brain circuits by inhibiting neurotransmitter release at central synapses. There is evidence that local delivery of BoNT serotypes A and E, which target SNAP-25, a component of the release machinery specific to excitatory synapses, can inhibit seizure generation. BoNT serotype B (BoNT/B) targets VAMP2, which is expressed in both excitatory and inhibitory terminals. Here we assessed the effects of unilateral intrahippocampal infusion of BoNT/B in the rat on intravenous pentylenetetrazol (PTZ) seizure thresholds, and on the expression of spontaneous behavioral and electrographic seizures. Infusion of BoNT/B (500 and 1,000 unit) by convection-enhanced delivery caused a reduction in myoclonic twitch and clonic seizure thresholds in response to intravenous PTZ beginning about 6 days after the infusion. Handling-evoked and spontaneous convulsive seizures were observed in many BoNT/B-treated animals but not in vehicle-treated controls. Spontaneous electrographic seizure discharges were recorded in the dentate gyrus of animals that received local BoNT/B infusion. In addition, there was an increased frequency of interictal epileptiform spikes and sharp waves at the same recording site. BoNT/B-treated animals also exhibited tactile hyperresponsivity in comparison with vehicle-treated controls. This is the first demonstration that BoNT/B causes a delayed proconvulsant action when infused into the hippocampus. Local infusion of BoNT/B could be useful as a focal epilepsy model.

  2. 临床下痫样放电对癫痫患者认知功能及胰岛素样生长因子1水平的影响%Cognitive function and insulin-like growth factor-1 levels in patients with subclicinal epileptiform discharges

    Institute of Scientific and Technical Information of China (English)

    李娜; 宋玉成

    2015-01-01

    目的:观察临床下痫样放电的癫痫患者认知功能、血清胰岛素样生长因子1( IGF-1)浓度及其临床意义。方法以全身强直阵挛性发作为临床表现的特发性癫痫患者86例,无临床发作均超过3个月,分为临床下痫样放电组(47例)以及脑电图正常组(39例)。选取性别、年龄与癫痫患者相匹配的健康体检者30例作为对照组。采用酶联免疫吸附试验( ELISA)测定血清IGF-1的浓度。采用连线测验、数字符号转换测验、语言流.性测验、数字广度测验等神经心理量表,分别检测各组心理运动速度、注意力、语言、工作记忆等认知功能。用t检验或方差分析统计各计量资料。结果临床下痫样放电组IGF-1浓度[(291±99.58)ng/ml]明显高于脑电图正常组[(189±75.63)ng/ml,t=13.29,P<0.01];脑电图正常组和对照组[(176±65.75) ng/ml ]间IGF-1含量差异无统计学意义( P>0.05)。临床下痫样放电组连线A、B耗时均高于脑电图正常组,数字符号、语言流.性及数字广度评分均低于脑电图正常组,差异有统计学意义( t值分别为4.12、3.18、3.09、4.15、5.01,均P<0.05)。临床下痫样放电组IGF-1含量与棘波指数、连线A、B耗时呈显著正相关,与数字符号分、语言流.性分、数字广度分呈显著负相关( P<0.05或0.01)。结论临床下痫样放电患者血清IGF-1表达上调,提示临床下痫样放电会导致神经损伤,并启动神经保护机制。针对临床下痫样放电应采取适当的干预措施。%Objective To investigate the cognitive function and serum levels of insulin -like growth factor-1(IGF-1)in patients with subclicinal epileptiform discharges and clinical significance .Mtehods The generalized tonic-clonic seizures as the clinical manifestations ,86 patients of idiopathic epilepsy who were free of clinical seizures more than three months ,included

  3. 小鼠海马脑片和海马-内嗅皮层联合脑片癫痫样放电特性的比较研究%Comparative study of the characteristics of epileptiform discharges in the hippocampal slices and combined entorhinal cortex-hippocampal slices

    Institute of Scientific and Technical Information of China (English)

    石叶军; 陆钦池; 宫新伟; 龚海庆; 张溥明; 梁培基

    2013-01-01

    Objective In order to explore the Mg 2+-free artificial cerebrospinal fluid ( ACSF ) induced different epileptiform discharge patterns in adult mouse hippocampal slices and combined entorhinal cortex -hippocampal slices in vitro.Methods Two brain slice models were prepared , and Mg2+-free-ACSF was used to induce epileptiform discharges , which were recorded by micro-electrode array ( MEA ) .The spatiotemporal characteristics of the discharge patterns were studied following successful induction of epileptiform discharges in the two slice models .Results Mg2+-free-ACSF induced interictal discharges in the hippocampal slice ,with frequency of (11.6 ±2.4)times/min,and lasted 149.0-202.6 ms.While in the combined entorhinal cortex-hippocampal slice,the discharge pattern was alternated between interictal and ictal discharges .The frequency of interictal discharges was (12.9 ±3.3) times/min,with duration of 181.3-223.7 ms.The frequency of ictal discharges was (0.26 ±0.07 ) times/min,with duration of 14.3-14.5 s.Conclusion Interictal as well as ictal discharges could be recorded in the combined entorhinal cortex-hippocampal slice network level .So the combined entorhinal cortex-hippocampal slice is an ideal model for epilepsy research .%目的探索离体条件下无镁人工脑脊液( ACSF )诱导的成年小鼠海马脑片和海马-内嗅皮层联合脑片的不同癫痫样放电模式。方法分别制备两种脑片模型,使用无镁ACSF诱导脑片产生癫痫样放电,并用多电极阵列记录脑片不同区域神经元的放电情况。在两种脑片模型上诱导出稳定的癫痫样放电后,分析不同类型癫痫样放电模式的时空特性。结果无镁ACSF诱导海马脑片产生间期放电,间期放电频率为(11.6±2.4)次/min,平均放电持续时间为149.0~202.6 ms。无镁ACSF诱导海马-内嗅皮层联合脑片产生间期和发作期放电交替出现的模式,间期放电的频率为(12.9±3.3)次/min,

  4. Inhibitory effects of recombinant neurotoxin BmK IM on seizures induced by pentylenetetrazol in Rats

    Institute of Scientific and Technical Information of China (English)

    何小华; 彭方; 章军建; 李文鑫; 曾宪春; 刘辉

    2003-01-01

    Objective To elucidate the inhibitory effects of recombinant Chinese scorpion neurotoxin BmK IM on seizures induced by pentylenetetrazol (PTZ) and the possible mechanism.Methods After purifying recombinant BmK IM from an E. coli cell line, its toxicity (both LD50 and minimum lethal dose) on rats was determined. BmK IM was then microinjected into the CA3 region of the right hippocampus and its ability to inhibit the effects of an intraperitoneal injection of PTZ was assessed. The effects of BmK IM on the electrophysiological properties of isolated CA3 pyramidal neurons were then studied using whole-cell patch clamp techniques.Results BmK IM can significantly prolong the latent period of epileptic seizures, decrease the degree of seizures, and decrease the frequency of epileptiform discharges induced by PTZ. At the same time, 24h after injection of BmK IM into the hippocampal tissue, BmK IM significantly reduces the concentration of the neurotransmitter glutamate and alleviates PTZ-induced lesions in the hippocampus. Whole-cell patch clamp recordings indicate that BmK IM inhibits INa of rat hippocampal neurons in a dose-dependent manner. BmK IM significantly shifts the activation curve of INa in a positive direction, indicating that BmK IM enhances the threshold potential of INa.Conclusions BmK IM has significant anti-epileptic properties, and may prove useful as a drug in the therapy of epilepsy. The inhibitory effects of BmK IM on seizures caused by pentylenetetrazol might depend on reductions in the release of presynaptic glutamate via the blocking of Na+ channels.

  5. Developmental changes in GABAergic actions and seizure susceptibility in the rat hippocampus.

    Science.gov (United States)

    Khazipov, Roustem; Khalilov, Ilgam; Tyzio, Roman; Morozova, Elena; Ben-Ari, Yezekiel; Holmes, Gregory L

    2004-02-01

    The immature brain is prone to seizures but the underlying mechanisms are poorly understood. We explored the hypothesis that increased seizure susceptibility during early development is due to the excitatory action of GABA. Using noninvasive extracellular field potential and cell-attached recordings in CA3 of Sprague-Dawley rat hippocampal slices, we compared the developmental alterations in three parameters: excitatory actions of GABA, presence of the immature pattern of giant depolarizing potentials (GDPs) and severity of epileptiform activity generated by high potassium. The GABA(A) receptor agonist isoguvacine increased firing of CA3 pyramidal cells in neonatal slices while inhibiting activity in adults. A switch in the GABA(A) signalling from excitation to inhibition occurred at postnatal day (P) 13.5 +/- 0.4. Field GDPs were present in the form of spontaneous population bursts until P12.7 +/- 0.3. High potassium (8.5 mm) induced seizure-like events (SLEs) in 35% of slices at P7-16 (peak at P11.3 +/- 0.4), but only interictal activity before and after that age. The GABA(A) receptor antagonist bicuculline reduced the frequency or completely blocked SLEs and induced interictal clonic-like activity accompanied by a reduction in the frequency but an increase in the amplitude of the population spikes. In slices with interictal activity, bicuculline typically caused a large amplitude interictal clonic-like activity at all ages; in slices from P5-16 rats it was often preceded by one SLE at the beginning of bicuculline application. These results suggest that, in the immature hippocampus, GABA exerts dual (both excitatory and inhibitory) actions and that the excitatory component in the action of GABA may contribute to increased excitability during early development.

  6. The selective GABAB antagonist CGP-35348 blocks spike-wave bursts in the cholesterol synthesis rat absence epilepsy model.

    Science.gov (United States)

    Smith, K A; Fisher, R S

    1996-08-12

    Slow IPSPs, which are believed to be involved in generation of the wave of spike-wave epileptiform discharges, are mediated by the GABAB receptor. We therefore examined the effect of the GABAB antagonist, Ciba Geigy Product, CGP-35348, in the cholesterol synthesis inhibitor model of absence epilepsy in rat. Rats received Ayerst-9944 (AY-9944), from 6-45 mg i.p. in the first few weeks of life. By 2 months after AY-9944 administration these rats exhibited recurrent spike-waves and behavioral arrests. In 10 such animals CGP-35348 was administered intraperitoneally in doses of 0 (vehicle), 10, 25 or 100 mg/kg. EEG recordings were obtained via previously implanted bone screws. Technologists blinded to treatment group counted spike-waves over a 4 h period post-injection. The average number of spike-wave burst seconds per 4 h of recording for all dosages and times was 52.4 +/- 81.4 (mean +/- S.D.) s. Mean burst times (seconds) were vehicle = 93.5 +/- 106.5; 10 mg/kg = 69.9 +/- 79.7; 25 mg/kg = 30.8 +/- 46.9; 100 mg/kg = 15.2 +/- 54, a mean 84% reduction at 100 mg/kg (ANOVA regression significant at 0.0001). Spike-waves were suppressed for at least 4 h after injection of CGP-35348. These findings supplement similar findings in other absence models, and support a potential role for GABAB antagonists in treatment of absence seizures.

  7. Delayed development of spontaneous seizures and prolonged convulsive state in rats after massed stimulation of the anterior piriform cortex.

    Science.gov (United States)

    Timofeeva, O A; Peterson, G M

    1997-04-18

    We studied the short- and long-term epileptogenic effects of massed stimulation (MS) of the piriform cortex. Sprague-Dawley rats with electrodes implanted bilaterally in the anterior piriform cortex and the dorsal and ventral hippocampi underwent MS: electrical stimulation of the left piriform cortex every 5 min for 6 h (afterdischarge threshold, 60 Hz, 1 ms, 1 s). Animals were retested (5 stimulations) 3-4 times later at different time points to check for the kindled state. Our data showed that MS resulted in delayed development of severe epilepsy. The interval between MS and the first appearance of convulsive response (2 weeks) was characterized by deep refractoriness to seizure (silent period). Unexpectedly, dramatic seizure activity occurred 4-7 weeks after MS. This was manifested by (1) generalized tonic-clonic convulsions with multiple failings, which were elicited repeatedly during retest; (2) frequent progression of elicited generalized convulsions into a prolonged (> 8 min) postictal convulsive state expressed mainly by continuous partial seizures and even new bouts of generalized seizures, and (3) development of mild spontaneous seizures. We found that epileptiform activity predominated in the ventral hippocampus. Mossy fiber sprouting was also most pronounced in this area. We propose that the MS resulted in formation of pathological circuits which involve both piriform cortex and ventral hippocampus and lead to severe epilepsy.

  8. Inhibition of rat hippocampal excitability by the plant alkaloid 3-acetylaconitine mediated by interaction with voltage-dependent sodium channels.

    Science.gov (United States)

    Ameri, A

    1997-02-01

    The effects of the Aconitum alkaloid 3-acetylaconitine on neuronal activity were investigated in the slice preparation and on cultivated neurons of rat hippocampus by extracellular and patch-clamp recordings, respectively. 3-Acetylaconitine (0.01-1 microM) diminished the orthodromic and antidromic population spike in a concentration-dependent manner. The inhibitory action of the drug was preceded by a transiently enhanced excitability. The latency of onset of the inhibition was accelerated by increased stimulation frequency, whereas recovery during washout of the alkaloid was accelerated by decreased stimulation frequency. Moreover, the inhibitory effect of 3-acetylaconitine was evaluated in two different models of epileptiform activity induced either by blockade of GABA receptors by bicuculline (10 microM) or by a nominal Mg(2+)-free bathing medium. In accordance with the activity-dependent mode of action, this compound abolished the synaptically evoked population spikes in the presence of bicuculline or nominal Mg(2+)-free bathing medium, respectively. Whole-cell patch-clamp recordings revealed an interaction of 3-acetylaconitine with the voltage-dependent sodium channel. At a concentration of 1 microM, 3-acetylaconitine did not affect the peak amplitude of the sodium current, but shifted the current-voltage relationship in the hyperpolarized direction such that sodium currents were already activated at the resting potential.

  9. Cortical kindling induces elevated levels of AMPA and GABA receptor subunit mRNA within the amygdala/piriform region and is associated with behavioral changes in the rat.

    Science.gov (United States)

    Henderson, Amy K; Galic, Michael A; Teskey, G Campbell

    2009-11-01

    Cortical kindling causes alterations within the motor cortex and results in long-standing motor deficits. Less attention has been directed to other regions that also participate in the epileptiform activity. We examined if cortical kindling could induce changes in excitatory and inhibitory receptor subunit mRNA in the amygdala/piriform regions and if such changes are associated with behavioral deficits. After cortical kindling, amygdala/piriform regions were dissected to analyze mRNA levels of NMDA, AMPA, and GABA receptor subunits using reverse transcription polymerase chain reaction, or rats were subjected to a series of behavioral tests. Kindled rats had significantly greater amounts of GluR1 and GluR2 AMPA receptor mRNA, and alpha1 and alpha2 GABA receptor subunit mRNA, compared with sham controls, which was associated with greater anxiety-like behaviors in the elevated plus maze and reduced freezing behaviors in the fear conditioning task. In summary, cortical kindling produces dynamic receptor subunit changes in regions in addition to the seizure focus.

  10. The Impact of Previous Physical Training on Redox Signaling after Traumatic Brain Injury in Rats: A Behavioral and Neurochemical Approach.

    Science.gov (United States)

    da Silva Fiorin, Fernando; de Oliveira Ferreira, Ana P; Ribeiro, Leandro R; Silva, Luiz F A; de Castro, Mauro R T; da Silva, Luís R H; da Silveira, Mauro E P; Zemolin, Ana P P; Dobrachinski, Fernando; Marchesan de Oliveira, Sara; Franco, Jeferson L; Soares, Félix A; Furian, Ana F; Oliveira, Mauro S; Fighera, Michele R; Freire Royes, Luiz F

    2016-07-15

    Throughout the world, traumatic brain injury (TBI) is one of the major causes of disability, which can include deficits in motor function and memory, as well as acquired epilepsy. Although some studies have shown the beneficial effects of physical exercise after TBI, the prophylactic effects are poorly understood. In the current study, we demonstrated that TBI induced by fluid percussion injury (FPI) in adult male Wistar rats caused early motor impairment (24 h), learning deficit (15 days), spontaneous epileptiform events (SEE), and hilar cell loss in the hippocampus (35 days) after TBI. The hippocampal alterations in the redox status, which were characterized by dichlorofluorescein diacetate oxidation and superoxide dismutase (SOD) activity inhibition, led to the impairment of protein function (Na(+), K(+)-adenosine triphosphatase [ATPase] activity inhibition) and glutamate uptake inhibition 24 h after neuronal injury. The molecular adaptations elicited by previous swim training protected against the glutamate uptake inhibition, oxidative stress, and inhibition of selected targets for free radicals (e.g., Na(+), K(+)-ATPase) 24 h after neuronal injury. Our data indicate that this protocol of exercise protected against FPI-induced motor impairment, learning deficits, and SEE. In addition, the enhancement of the hippocampal phosphorylated nuclear factor erythroid 2-related factor (P-Nrf2)/Nrf2, heat shock protein 70, and brain-derived neurotrophic factor immune content in the trained injured rats suggests that protein expression modulation associated with an antioxidant defense elicited by previous physical exercise can prevent toxicity induced by TBI, which is characterized by cell loss in the dentate gyrus hilus at 35 days after TBI. Therefore, this report suggests that previous physical exercise can decrease lesion progression in this model of brain damage.

  11. Rat Genome Database (RGD)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Rat Genome Database (RGD) is a collaborative effort between leading research institutions involved in rat genetic and genomic research to collect, consolidate,...

  12. Antiepileptic effect of fisetin in iron-induced experimental model of traumatic epilepsy in rats in the light of electrophysiological, biochemical, and behavioral observations.

    Science.gov (United States)

    Das, Jharana; Singh, Rameshwar; Sharma, Deepak

    2017-05-01

    Traumatic epilepsy is defined by episodes of recurring seizures secondary to severe brain injury. Though drugs are found effective to control seizures, their long-term use have been observed to increase reactive oxygen species in animals. Flavonoid fisetin, a natural bioactive phytonutrient reported to exert anticonvulsive effect in experimental seizure models. But, trauma-induced seizures could not be prevented by anticonvulsants was reported in some clinical studies. To study the effect of fisetin on epileptiform electrographic activity in iron-induced traumatic epilepsy and also the probable reason behind the effect in rats. Fisetin pretreatment (20 mg/kg body wt., p.o.) of rats for 12 weeks were chosen followed by injecting iron (5 µl, 100 mM) stereotaxically to generate iron-induced epilepsy. Experimental design include electrophysiological study (electroencephalograph in correlation with multiple unit activity (MUA) in the cortex and CA1 subfield of the hippocampus; spectral analysis of seizure and seizure-associated behavioral study (Morris water maze for spatial learning, open-field test for anxiety) and biochemical study (lipid peroxidation, Na(+),K(+)-ATPase activity) in both the cortex and the hippocampus. Fisetin pretreatment was found to prevent the development of iron-induced electrical seizure and decrease the corresponding MUA in the cortex (*P˂0.05) as well as in the hippocampus (***P˂0.001). Fisetin pretreatment decreased the lipid peroxides (*P˂0.05) and retained the Na(+),K(+)-ATPase activity (*P˂0.05) which was found altered in the epileptic animals and also found to attenuate the seizure-associated cognitive dysfunctions. This study demonstrated the antiepileptic action of fisetin in iron-induced model of epileptic rats by inhibiting oxidative stress.

  13. Carbenoxolone inhibits volume-regulated anion conductance in cultured rat cortical astroglia.

    Science.gov (United States)

    Benfenati, Valentina; Caprini, Marco; Nicchia, Grazia Paola; Rossi, Andrea; Dovizio, Melania; Cervetto, Chiara; Nobile, Mario; Ferroni, Stefano

    2009-01-01

    Accumulating evidence indicate that the gap-junction inhibitor carbenoxolone (CBX) regulates neuronal synchronization, depresses epileptiform activity and has a neuroprotective action. These CBX effects do not depend solely on its ability to inhibit gap junction channels formed by connexins (Cx), but the underlying mechanisms remain to be elucidated. Here we addressed the questions whether CBX modulates volume-regulated anion channels (VRAC) involved in the regulatory volume decrease and regulates the associated release of excitatory amino acids in cultured rat cortical astrocytes. We found that CBX inhibits VRAC conductance with potency comparable to that able to depress the activity of the most abundant astroglial gap junction protein connexin43 (Cx43). However, the knock down of Cx43 with small interfering RNA (siRNA) oligonucleotides and the use of various pharmacological tools revealed that VRAC inhibition was not mediated by interaction of CBX with astroglial Cx proteins. Comparative experiments in HEK293 cells stably expressing another putative target of CBX, the purinergic ionotropic receptor P2X7, indicate that the presence of this receptor was not necessary for CBX-mediated depression of VRAC. Finally, we show that in COS-7 cells, which are not endowed with pannexin-1 protein, another astroglial plasma membrane interactor of CBX, VRAC current retained its sensitivity to CBX. Complementary analyses indicate that the VRAC-mediated release of excitatory amino acid aspartate was decreased by CBX. Collectively, these findings support the notion that CBX could affect astroglial ability to modulate neuronal activity by suppressing excitatory amino acid release through VRAC, thereby providing a possible mechanistic clue for the neuroprotective effect of CBX in vivo.

  14. Genetically epilepsy-prone rats (GEPRs) and DBA/2 mice: Two animal models of audiogenic reflex epilepsy for the evaluation of new generation AEDs.

    Science.gov (United States)

    De Sarro, Giovambattista; Russo, Emilio; Citraro, Rita; Meldrum, Brian S

    2015-08-06

    This review summarizes the current knowledge about DBA/2 mice and genetically epilepsy-prone rats (GEPRs) and discusses the contribution of such animal models on the investigation of possible new therapeutic targets and new anticonvulsant compounds for the treatment of epilepsy. Also, possible chemical or physical agents acting as proconvulsant agents are described. Abnormal activities of enzymes involved in catecholamine and serotonin synthesis and metabolism were reported in these models, and as a result of all these abnormalities, seizure susceptibility in both animals is greatly affected by pharmacological manipulations of the brain levels of monoamines and, prevalently, serotonin. In addition, both genetic epileptic models permit the evaluation of pharmacodynamic and pharmacokinetic interactions among several drugs measuring plasma and/or brain level of each compound. Audiogenic models of epilepsy have been used not only for reflex epilepsy studies, but also as animal models of epileptogenesis. The seizure predisposition (epileptiform response to sound stimulation) and substantial characterization of behavioral, cellular, and molecular alterations in both acute and chronic (kindling) protocols potentiate the usefulness of these models in elucidating ictogenesis, epileptogenesis, and their mechanisms. This article is part of a Special Issue entitled "Genetic Models-Epilepsy".

  15. [Electrical activities of bursting-firing neurons in epileptic network reestablishment of rat hippocampus].

    Science.gov (United States)

    Wang, Wen-Ting; Qin, Xing-Kui; Yin, Shi-Jin; Han, Dan

    2003-12-25

    The purpose of our present work was to study the discharge of bursting-firing neurons (BFNs) in ipsilateral or contralateral hippocampus (HPC), and its relations to the reestablishment of local epileptic networks. The experiments were performed on 140 Sprague Dawley male rats (150-250 g). Acute tetanization (60 Hz, 2 s, 0.4 -0.6 mA) of the right posterior dorsal hippocampus (ATPDH) was administered to establish rat epilepsy model. The single unit discharges and the depth electrographs were simultaneously recorded from ipsilateral or contralateral HPC. In other experimental rats, acute tetanization of the right anterior dorsal HPC (ATADH) was used. Extracellular unit discharges in the CA1 region were simultaneously recorded from bilateral anterior dorsal hippocampi. Analysis of hippocampal BFN firing patterns before or after administration of the tetanization was focused on according to their location in the HPC epileptic networks in vivo. Single unit discharges of 138 hippocampal neurons were recorded from ipsilateral and/or contralateral anterior dorsal HPC. Of the 138 neurons recorded, 19 were BFNs. 13 BFNs were tetanus-evoked and the remaining 6 were spontaneous ones. The evoked reactions of the single hippocampal neuron induced by the tetanization mainly included: (1) the firing patterns of the BFNs in ipsilateral anterior dorsal HPC were obviously modulated by the ATPDH from tonic firing into rhythmic bursting. The bursting interspike intervals (BISI) decreased. (2) There were mild modulations of the firing patterns of the BFNs in contralateral anterior dorsal HPC following post-inhibition of the firing rate of single neuron induced by the ATPDH. The interspike intervals (ISI) increased obviously. (3) Post-facilitation of rhythmic bursting-firing of the BFNs in contralateral anterior dorsal HPC was induced by ATADH; both the ISI and the IBI increased. (4) Synchronous or asynchronous rhythmic bursting-firing of the BFNs and the network epileptiform events

  16. Expressional analysis of the astrocytic Kir4.1 channel in a pilocarpine–induced temporal lobe epilepsy model

    Science.gov (United States)

    Nagao, Yuki; Harada, Yuya; Mukai, Takahiro; Shimizu, Saki; Okuda, Aoi; Fujimoto, Megumi; Ono, Asuka; Sakagami, Yoshihisa; Ohno, Yukihiro

    2013-01-01

    The inwardly rectifying potassium (Kir) channel Kir4.1 in brain astrocytes mediates spatial K+ buffering and regulates neural activities. Recent studies have shown that loss-of-function mutations in the human gene KCNJ10 encoding Kir4.1 cause epileptic seizures, suggesting a close relationship between the Kir4.1 channel function and epileptogenesis. Here, we performed expressional analysis of Kir4.1 in a pilocarpine-induced rat model of temporal lobe epilepsy (TLE) to explore the role of Kir4.1 channels in modifying TLE epileptogenesis. Treatment of rats with pilocarpine (350 mg/kg, i.p.) induced acute status epilepticus, which subsequently caused spontaneous seizures 7–8 weeks after the pilocarpine treatment. Western blot analysis revealed that TLE rats (interictal condition) showed significantly higher levels of Kir4.1 than the control animals in the cerebral cortex, striatum, and hypothalamus. However, the expression of other Kir subunits, Kir5.1 and Kir2.1, remained unaltered. Immunohistochemical analysis illustrated that Kir4.1-immunoreactivity-positive astrocytes in the pilocarpine-induced TLE model were markedly increased in most of the brain regions examined, concomitant with an increase in the number of glial fibrillary acidic protein (GFAP)-positive astrocytes. In addition, Kir4.1 expression ratios relative to the number of astrocytes (Kir4.1-positive cells/GFAP-positive cells) were region-specifically elevated in the amygdala (i.e., medial and cortical amygdaloid nuclei) and sensory cortex. The present study demonstrated for the first time that the expression of astrocytic Kir4.1 channels was elevated in a pilocarpine-induced TLE model, especially in the amygdala, suggesting that astrocytic Kir4.1 channels play a role in modifying TLE epileptogenesis, possibly by acting as an inhibitory compensatory mechanism. PMID:23922547

  17. SWEEP Project RAT

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Madsen, Søren; Petersen, L. B.

    This report presents the results from the design analyses made for the clustered suction caisson used as foundation for a Riser Access Tower (RAT). The RAT is intended built next to the K15-FA-1 Platform in the Dutch Sector of the North Sea.......This report presents the results from the design analyses made for the clustered suction caisson used as foundation for a Riser Access Tower (RAT). The RAT is intended built next to the K15-FA-1 Platform in the Dutch Sector of the North Sea....

  18. Biotransformation of a novel positive allosteric modulator of metabotropic glutamate receptor subtype 5 contributes to seizure-like adverse events in rats involving a receptor agonism-dependent mechanism.

    Science.gov (United States)

    Bridges, Thomas M; Rook, Jerri M; Noetzel, Meredith J; Morrison, Ryan D; Zhou, Ya; Gogliotti, Rocco D; Vinson, Paige N; Xiang, Zixiu; Jones, Carrie K; Niswender, Colleen M; Lindsley, Craig W; Stauffer, Shaun R; Conn, P Jeffrey; Daniels, J Scott

    2013-09-01

    Activation of metabotropic glutamate receptor subtype 5 (mGlu5) represents a novel strategy for therapeutic intervention into multiple central nervous system disorders, including schizophrenia. Recently, a number of positive allosteric modulators (PAMs) of mGlu5 were discovered to exhibit in vivo efficacy in rodent models of psychosis, including PAMs possessing varying degrees of agonist activity (ago-PAMs), as well as PAMs devoid of agonist activity. However, previous studies revealed that ago-PAMs can induce seizure activity and behavioral convulsions, whereas pure mGlu5 PAMs do not induce these adverse effects. We recently identified a potent and selective mGlu5 PAM, VU0403602, that was efficacious in reversing amphetamine-induced hyperlocomotion in rats. The compound also induced time-dependent seizure activity that was blocked by coadministration of the mGlu5 antagonist, 2-methyl-6-(phenylethynyl) pyridine. Consistent with potential adverse effects induced by ago-PAMs, we found that VU0403602 had significant allosteric agonist activity. Interestingly, inhibition of VU0403602 metabolism in vivo by a pan cytochrome P450 (P450) inactivator completely protected rats from induction of seizures. P450-mediated biotransformation of VU0403602 was discovered to produce another potent ago-PAM metabolite-ligand (M1) of mGlu5. Electrophysiological studies in rat hippocampal slices confirmed agonist activity of both M1 and VU0403602 and revealed that M1 can induce epileptiform activity in a manner consistent with its proconvulsant behavioral effects. Furthermore, unbound brain exposure of M1 was similar to that of the parent compound, VU0403602. These findings indicate that biotransformation of mGlu5 PAMs to active metabolite-ligands may contribute to the epileptogenesis observed after in vivo administration of this class of allosteric receptor modulators.

  19. Descargas epileptiformes periódicas lateralizadas em neurocisticercose

    Directory of Open Access Journals (Sweden)

    Pauzanes de Carvalho-Filho

    1989-03-01

    Full Text Available Relatamos o caso de menina (10 anos que apresentava síndrome psicorgânica subaguda associada a cefaléia, sem sinais patentes de hipertensão intracraniana. O diagnóstico de neurocisticercose foi firmado com base no exame do LCR. Foi tratada com praziquantel (50 mg/kg/dia por 21 dias e apresentou PLEDs sobre o hemisfério esquerdo no dia seguinte ao término do tratamento. Posteriormente, passou a apresentar sinais de disfunção córtico-subcortical desse mesmo lado, nos EEG subseqüentes. A TC inicialmente normal confirmou, com a evolução, maior comprometimento do hemisfério esquerdo, embora houvesse disseminação parenquimatosa bilateral de cisticercos. Respondeu bem ao tratamento e evoluiu com recuperação total dos sintomas. Discutimos, também, aspectos neurofisiológicos dessa anormalidade eletrencefalográfica.

  20. Directed differential connectivity graph of interictal epileptiform discharges

    Science.gov (United States)

    Amini, Ladan; Jutten, Christian; Achard, Sophie; David, Olivier; Soltanian-Zadeh, Hamid; Hossein-Zadeh, Gh. Ali; Kahane, Philippe; Minotti, Lorella; Vercueil, Laurent

    2011-01-01

    In this paper, we study temporal couplings between interictal events of spatially remote regions in order to localize the leading epileptic regions from intracerebral electroencephalogram (iEEG). We aim to assess whether quantitative epileptic graph analysis during interictal period may be helpful to predict the seizure onset zone of ictal iEEG. Using wavelet transform, cross-correlation coefficient, and multiple hypothesis test, we propose a differential connectivity graph (DCG) to represent the connections that change significantly between epileptic and non-epileptic states as defined by the interictal events. Post-processings based on mutual information and multi-objective optimization are proposed to localize the leading epileptic regions through DCG. The suggested approach is applied on iEEG recordings of five patients suffering from focal epilepsy. Quantitative comparisons of the proposed epileptic regions within ictal onset zones detected by visual inspection and using electrically stimulated seizures, reveal good performance of the present method. PMID:21156385

  1. SVM detection of epileptiform activity in routine EEG.

    LENUS (Irish Health Repository)

    Kelleher, Daniel

    2010-01-01

    Routine electroencephalogram (EEG) is an important test in aiding the diagnosis of patients with suspected epilepsy. These recordings typically last 20-40 minutes, during which signs of abnormal activity (spikes, sharp waves) are looked for in the EEG trace. It is essential that events of short duration are detected during the routine EEG test. The work presented in this paper examines the effect of changing a range of input values to the detection system on its ability to distinguish between normal and abnormal EEG activity. It is shown that the length of analysis window in the range of 0.5s to 1s are well suited to the task. Additionally, it is reported that patient specific systems should be used where possible due to their better performance.

  2. Effects of Spider Venom Toxin PWTX-I (6-Hydroxytrypargine on the Central Nervous System of Rats

    Directory of Open Access Journals (Sweden)

    Mario S. Palma

    2011-02-01

    Full Text Available The 6-hydroxytrypargine (6-HT is an alkaloidal toxin of the group of tetrahydro-b-carbolines (THbC isolated from the venom of the colonial spider Parawixia bistriata. These alkaloids are reversible inhibitors of the monoamine-oxidase enzyme (MAO, with hallucinogenic, tremorigenic and anxiolytic properties. The toxin 6-HT was the first THbC chemically reported in the venom of spiders; however, it was not functionally well characterized up to now. The action of 6-HT was investigated by intracerebroventricular (i.c.v. and intravenous (i.v. applications of the toxin in adult male Wistar rats, followed by the monitoring of the expression of fos-protein, combined with the use of double labeling immunehistochemistry protocols for the detection of some nervous receptors and enzymes related to the metabolism of neurotransmitters in the central nervous system (CNS. We also investigated the epileptiform activity in presence of this toxin. The assays were carried out in normal hippocampal neurons and also in a model of chronic epilepsy obtained by the use of neurons incubated in free-magnesium artificial cerebro-spinal fluid (ACSF. Trypargine, a well known THbC toxin, was used as standard compound for comparative purposes. Fos-immunoreactive cells (fos-ir were observed in hypothalamic and thalamic areas, while the double-labeling identified nervous receptors of the sub-types rGlu2/3 and NMR1, and orexinergic neurons. The 6-HT was administrated by perfusion and ejection in “brain slices” of hippocampus, inducing epileptic activity after its administration; the toxin was not able to block the epileptogenic crisis observed in the chronic model of the epilepsy, suggesting that 6-HT did not block the overactive GluRs responsible for this epileptic activity.

  3. Nonspecific effects of the gap junction blocker mefloquine on fast hippocampal network oscillations in the adult rat in vitro.

    Science.gov (United States)

    Behrens, C J; Ul Haq, R; Liotta, A; Anderson, M L; Heinemann, U

    2011-09-29

    It has been suggested that gap junctions are involved in the synchronization during high frequency oscillations as observed during sharp wave-ripple complexes (SPW-Rs) and during recurrent epileptiform discharges (REDs). Ripple oscillations during SPW-Rs, possibly involved in memory replay and memory consolidation, reach frequencies of up to 200 Hz while ripple oscillations during REDs display frequencies up to 500 Hz. These fast oscillations may be synchronized by intercellular interactions through gap junctions. In area CA3, connexin 36 (Cx36) proteins are present and potentially sensitive to mefloquine. Here, we used hippocampal slices of adult rats to investigate the effects of mefloquine, which blocks Cx36, Cx43 and Cx50 gap junctions on both SPW-Rs and REDs. SPW-Rs were induced by high frequency stimulation in the CA3 region while REDs were recorded in the presence of the GABA(A) receptor blocker bicuculline (5 μM). Both, SPW-Rs and REDs were blocked by the gap junction blocker carbenoxolone. Mefloquine (50 μM), which did not affect stimulus-induced responses in area CA3, neither changed SPW-Rs nor superimposed ripple oscillations. During REDs, 25 and 50 μM mefloquine exerted only minor effects on the expression of REDs but significantly reduced the amplitude of superimposed ripples by ∼17 and ∼54%, respectively. Intracellular recordings of CA3 pyramidal cells revealed that mefloquine did not change their resting membrane potential and input resistance but significantly increased the afterhyperpolarization following evoked action potentials (APs) resulting in reduced probability of AP firing during depolarizing current injection. Similarly, mefloquine caused a reduction in AP generation during REDs. Together, our data suggest that mefloquine depressed RED-related ripple oscillations by reducing high frequency discharges and not necessarily by blocking electrical coupling.

  4. Rat Bite Fever

    Science.gov (United States)

    ... Español Text Size Email Print Share Rat Bite Fever Page Content Article Body Rat-bite fever is a disease that occurs in humans who ... ingestion of contaminated food or milk products (Haverhill fever). Most cases in the United States are caused ...

  5. SWEEP Project RAT

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Madsen, Søren; Petersen, L. B.

    This report presents the results from the design analyses made for the clustered suction caisson used as foundation for a Riser Access Tower (RAT). The RAT is intended built next to the K15-FA-1 Platform in the Dutch Sector of the North Sea....

  6. Effects of valproate sodium on phosphorylatted cAMP responsive element binding protein after hippocampal neuronal epileptiform discharge in rat%丙戊酸钠对大鼠海马神经元癫痫样放电后P-CREB1表达的影响

    Institute of Scientific and Technical Information of China (English)

    刘华; 徐祖才; 陈阳美

    2009-01-01

    目的:研究丙戊酸钠对大鼠海马神经元癫痫样放电后磷酸化腺感苷反应元件结合蛋白1(Phosphorylated cAMP responsiveelement binding protein1,P-CREB1)表达的影响.方法:wistar新生鼠,迅速断头取脑,体外培养海马神经元,建立神经元癫痫样放电模型.将神经元分为空白组、模型组、丙戊酸钠低剂量(50 mg/L)组、丙戊酸钠高剂量(100 mg/L)组,运用免疫荧光技术观察P-CREB1在神经元癫痫样放电后在细胞内的表达部位,采用wester blot技术测定P-CREB1在不同分组中的表达强度.结果:通过免疫荧光技术,在各组中都可以看到P-CREB1在细胞核内表达,以模型组最明显;运用Western blot,发现表达趋势与免疫荧光一致,并且,给予丙戊酸钠后,P-CREB1表达减弱,且高剂量组与低剂量组之间差异有统计学意义(P<0.05).结论:海马神经元无镁处理后呈癫痫样放电,同时P-CREB1被过度激活,而有效浓度的丙戊酸钠可抑制此反应P-CREB1的磷酸化水平.

  7. Effective connectivity of hippocampal neural network and its alteration in Mg2+-free epilepsy model.

    Science.gov (United States)

    Gong, Xin-Wei; Li, Jing-Bo; Lu, Qin-Chi; Liang, Pei-Ji; Zhang, Pu-Ming

    2014-01-01

    Understanding the connectivity of the brain neural network and its evolution in epileptiform discharges is meaningful in the epilepsy researches and treatments. In the present study, epileptiform discharges were induced in rat hippocampal slices perfused with Mg2+-free artificial cerebrospinal fluid. The effective connectivity of the hippocampal neural network was studied by comparing the normal and epileptiform discharges recorded by a microelectrode array. The neural network connectivity was constructed by using partial directed coherence and analyzed by graph theory. The transition of the hippocampal network topology from control to epileptiform discharges was demonstrated. Firstly, differences existed in both the averaged in- and out-degree between nodes in the pyramidal cell layer and the granule cell layer, which indicated an information flow from the pyramidal cell layer to the granule cell layer during epileptiform discharges, whereas no consistent information flow was observed in control. Secondly, the neural network showed different small-worldness in the early, middle and late stages of the epileptiform discharges, whereas the control network did not show the small-world property. Thirdly, the network connectivity began to change earlier than the appearance of epileptiform discharges and lasted several seconds after the epileptiform discharges disappeared. These results revealed the important network bases underlying the transition from normal to epileptiform discharges in hippocampal slices. Additionally, this work indicated that the network analysis might provide a useful tool to evaluate the neural network and help to improve the prediction of seizures.

  8. Morphological alterations in newly born dentate gyrus granule cells that emerge after status epilepticus contribute to make them less excitable.

    Directory of Open Access Journals (Sweden)

    Julián Tejada

    Full Text Available Computer simulations of external current stimulations of dentate gyrus granule cells of rats with Status Epilepticus induced by pilocarpine and control rats were used to evaluate whether morphological differences alone between these cells have an impact on their electrophysiological behavior. The cell models were constructed using morphological information from tridimensional reconstructions with Neurolucida software. To evaluate the effect of morphology differences alone, ion channel conductances, densities and distributions over the dendritic trees of dentate gyrus granule cells were the same for all models. External simulated currents were injected in randomly chosen dendrites belonging to one of three different areas of dentate gyrus granule cell molecular layer: inner molecular layer, medial molecular layer and outer molecular layer. Somatic membrane potentials were recorded to determine firing frequencies and inter-spike intervals. The results show that morphologically altered granule cells from pilocarpine-induced epileptic rats are less excitable than control cells, especially when they are stimulated in the inner molecular layer, which is the target area for mossy fibers that sprout after pilocarpine-induced cell degeneration. This suggests that morphological alterations may act as a protective mechanism to allow dentate gyrus granule cells to cope with the increase of stimulation caused by mossy fiber sprouting.

  9. Rosiglitazone Suppresses In Vitro Seizures in Hippocampal Slice by Inhibiting Presynaptic Glutamate Release in a Model of Temporal Lobe Epilepsy.

    Directory of Open Access Journals (Sweden)

    Shi-Bing Wong

    Full Text Available Peroxisomal proliferator-activated receptor gamma (PPARγ is a nuclear hormone receptor whose agonist, rosiglitazone has a neuroprotective effect to hippocampal neurons in pilocarpine-induced seizures. Hippocampal slice preparations treated in Mg2+ free medium can induce ictal and interictal-like epileptiform discharges, which is regarded as an in vitro model of N-methyl-D-aspartate (NMDA receptor-mediated temporal lobe epilepsy (TLE. We applied rosiglitazone in hippocampal slices treated in Mg2+ free medium. The effects of rosiglitazone on hippocampal CA1-Schaffer collateral synaptic transmission were tested. We also examined the neuroprotective effect of rosiglitazone toward NMDA excitotoxicity on cultured hippocampal slices. Application of 10 μM rosiglitazone significantly suppressed amplitude and frequency of epileptiform discharges in CA1 neurons. Pretreatment with the PPARγ antagonist GW9662 did not block the effect of rosiglitazone on suppressing discharge frequency, but reverse the effect on suppressing discharge amplitude. Application of rosiglitazone suppressed synaptic transmission in the CA1-Schaffer collateral pathway. By miniature excitatory-potential synaptic current (mEPSC analysis, rosiglitazone significantly suppressed presynaptic neurotransmitter release. This phenomenon can be reversed by pretreating PPARγ antagonist GW9662. Also, rosiglitazone protected cultured hippocampal slices from NMDA-induced excitotoxicity. The protective effect of 10 μM rosiglitazone was partially antagonized by concomitant high dose GW9662 treatment, indicating that this effect is partially mediated by PPARγ receptors. In conclusion, rosiglitazone suppressed NMDA receptor-mediated epileptiform discharges by inhibition of presynaptic neurotransmitter release. Rosiglitazone protected hippocampal slice from NMDA excitotoxicity partially by PPARγ activation. We suggest that rosiglitazone could be a potential agent to treat patients with TLE.

  10. Rat-bite fever

    Science.gov (United States)

    Streptobacillary fever; Streptobacillosis; Haverhill fever; Epidemic arthritic erythema; Spirillary fever; Sodoku ... Rat-bite fever can be caused by 2 different bacteria, Streptobacillus moniliformis or Spirillum minus. Both of these are found in ...

  11. Modulatory effects of nitric oxide-active drugs on the anticonvulsant activity of lamotrigine in an experimental model of partial complex epilepsy in the rat

    Directory of Open Access Journals (Sweden)

    Ferraro Giuseppe

    2007-07-01

    Full Text Available Abstract Background The effects induced by administering the anticonvulsant lamotrigine, the preferential inhibitor of neuronal nitric oxide synthase 7-nitroindazole and the precursor of NO synthesis L-arginine, alone or in combination, on an experimental model of partial complex seizures (maximal dentate gyrus activation were studied in urethane anaesthetized rats. The epileptic activity of the dentate gyrus was obtained through the repetitive stimulation of the angular bundle and maximal dentate gyrus activation latency, duration and post-stimulus afterdischarge duration were evaluated. Results Either Lamotrigine (10 mg kg-1 or 7-nitroindazole (75 mg kg-1 i.p. administration had an anticonvulsant effect, significantly reducing the number of animals responding to angular bundle stimulation. On the contrary, i.p. injection of L-arginine (1 g kg-1 induced an aggravation of the epileptiform phenomena, demonstrated by the significant augmentation of the duration of both maximal dentate activation and afterdischarge. Furthermore, the injection of lamotrigine and 7-nitroindazole in combination significantly increased the anticonvulsant effects induced by the same drugs separately, either reducing the number of responding animals or decreasing both maximal dentate gyrus activation and afterdischarge durations. On the contrary, the combined treatment with L-arginine and lamotrigine did not modify the maximal dentate gyrus activation parameters suggesting an adversative effect of L-arginine-increased nitric oxide levels on the lamotrigine-induced anticonvulsant action. Conclusion The present results indicate that the nitrergic neurotransmission exerts a significant modulatory role in the control of the development of paroxystic phenomena in the maximal dentate gyrus activation model of epilepsy. Finally, our data suggest a functional relationship between the nitric oxide system and the anticonvulsant effect of lamotrigine which could be enhanced by

  12. 匹罗卡品致痫大鼠慢性期海马神经元突触重建的实验研究%Neuronal synaptic reconstruction in hippocampus in chronic phase of pilocarpine-treated rats

    Institute of Scientific and Technical Information of China (English)

    易芳; 穆塔森; 龙莉莉; 李艺; 李蜀渝; 吴志国; 肖波

    2011-01-01

    Objective To explore the aberrant formation of excitatory and inhibitory circuit rearrangements of hippoeampus in temporal lobe epilepsy.Methods Pilocarpine-induced animal model was established.At around Day 60 post-modeling,retrograde tracer fluorogold(FG)was injected in vivo into CA1 and CA3 areas of hippocampus by stereotaxic apparatus.Immunohistochemistry of FG was used to observe the aberrant excitatory circuit rearrangements.Double immunofluorescence with NPY(neuropeptide Y)and FG was performed to observe the aberrant inhibitory circuit rearrangements.Results After an iniection of FG into CA1 area.the FG-labeled pyramidal cells could be observed distantly from the zone of dye soread in CA1 area.CA3 area and subiculm.And the FG-labeled non-principal neurons could be seen in stratum oriens of CA1 and hilus in experimental group.Double immunofluorescence revealed that the FG-labeled NPY interneurons were located distantly from the zone of dye spread in CA1 area.CA3 area and hilus in experimental rats.When injection was administered in CA3 area.the FG-labeled pyramidal cells were visible in the whole CA3 area and hilus in both groups.Some pyramidal cells were present in CA1 in experimental group.Also some FG-labeled non-principle cells were foand in hilus and distantly from the zone of dve spread in CA1 area,And the FG-labeled NPY neurons could be seen in hilus in experimental rats.Conclusion Aberrant excitatory and inhibitory synaptic reconstruction exist in hippocampus in chronic phase of temporal lobe epilepsy,including excitatory synaptic connections among pyramidal cells in CA1 area.pyramidal cells between CAl and subiculum and pyramidal cells between CA1 and CA3,inhibitory synaptie connections among dendritie intemeurons in CA1 area,CA3 to CA1,hilus to CA1 and hilus to CA3area,These circuit arrangements may play an important role in the pathogenesis of epilepsy.%目的 探讨颞叶癫痫海马的异常兴奋性与抑制性突触联系变化.方法 建立

  13. P2X7 receptor-mediated PARP1 activity regulates astroglial death in the rat hippocampus following status epilepticus

    Directory of Open Access Journals (Sweden)

    Ji Yang eKim

    2015-09-01

    Full Text Available Poly(ADP-ribose polymerase-1 (PARP1 plays a regulatory role in apoptosis, necrosis, and other cellular processes after injury. Recently, we revealed that PARP1 regulates the differential neuronal/astroglial responses to pilocarpine-induced status epilepticus (SE in the distinct brain regions. In addition, P2X7 receptor (P2X7R, an ATP-gated ion channel, activation accelerates astroglial apoptosis, while it attenuates clasmatodendrosis (lysosome-derived autophagic astroglial death. Therefore, we investigated whether P2X7R regulates regional specific astroglial PARP1 expression/activation in response to SE. In the present study, P2X7R activation exacerbates SE-induced astroglial apoptosis, while P2X7R inhibition attenuates it accompanied by increasing PARP1 activity in the molecular layer of the dentate gyrus following SE. In the CA1 region, however, P2X7R inhibition deteriorates SE-induced clasmatodendrosis via PARP1 activation following SE. Taken together, our findings suggest that P2X7R function may affect SE-induced astroglial death by regulating PARP1 activation/expression in regional-specific manner. Therefore, the selective modulation of P2X7R-mediated PARP1 functions may be a considerable strategy for controls in various types of cell deaths.

  14. Rat bite fever.

    NARCIS (Netherlands)

    Gaastra, W.; Boot, R.G.A.; Ho, H.; Lipman, L.J.A.

    2009-01-01

    Rat bite fever (RBF) is a bacterial zoonosis for which two causal bacterial species have been identified: Streptobacillis moniliformis and Spirillum minus. Haverhill fever (HF) is a form of S. moniliformis infection believed to develop after ingestion of contaminated food or water. Here the

  15. Attachment behavior in rats

    NARCIS (Netherlands)

    Sigling, H.O.

    2009-01-01

    This thesis describes studies into the rat as an animal model for attachment, along the lines of Bowlby's attachment theory. First, the relation between attachment and human psychopathology is reviewed. The conclusion is that psychopathology is more frequent in insecure attached persons and that the

  16. Culturing rat hippocampal neurons.

    Science.gov (United States)

    Audesirk, G; Audesirk, T; Ferguson, C

    2001-01-01

    Cultured neurons are widely used to investigate the mechanisms of neurotoxicity. Embryonic rat hippocampal neurons may be grown as described under a wide variety of conditions to suit differing experimental procedures, including electrophysiology, morphological analysis of neurite development, and various biochemical and molecular analyses.

  17. The Year of the Rat

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Do you know what your Chinese sign of the zodiac is? According to the Chinese lunar calendar,every year corre- sponds to one of twelve animals(rat,ox,tiger,rabbit,dragon, snake,horse,sheep,monkey,rooster,dog and pig)and these animals are used to identify years. After the Lunar New Year in 2008 we enter the rat year. All those born in 1996,1984,1972.1960,1948,1936 or 1924, also have a rat as their sign.

  18. Laughing rats are optimistic.

    Directory of Open Access Journals (Sweden)

    Rafal Rygula

    Full Text Available Emotions can bias human decisions- for example depressed or anxious people tend to make pessimistic judgements while those in positive affective states are often more optimistic. Several studies have reported that affect contingent judgement biases can also be produced in animals. The animals, however, cannot self-report; therefore, the valence of their emotions, to date, could only be assumed. Here we present the results of an experiment where the affect-contingent judgement bias has been produced by objectively measured positive emotions. We trained rats in operant Skinner boxes to press one lever in response to one tone to receive a food reward and to press another lever in response to a different tone to avoid punishment by electric foot shock. After attaining a stable level of discrimination performance, the animals were subjected to either handling or playful, experimenter-administered manual stimulation - tickling. This procedure has been confirmed to induce a positive affective state in rats, and the 50-kHz ultrasonic vocalisations (rat laughter emitted by animals in response to tickling have been postulated to index positive emotions akin to human joy. During the tickling and handling sessions, the numbers of emitted high-frequency 50-kHz calls were scored. Immediately after tickling or handling, the animals were tested for their responses to a tone of intermediate frequency, and the pattern of their responses to this ambiguous cue was taken as an indicator of the animals' optimism. Our findings indicate that tickling induced positive emotions which are directly indexed in rats by laughter, can make animals more optimistic. We demonstrate for the first time a link between the directly measured positive affective state and decision making under uncertainty in an animal model. We also introduce innovative tandem-approach for studying emotional-cognitive interplay in animals, which may be of great value for understanding the emotional

  19. Prevention of 3-methylcholanthrene-induced fibrosarcomas in rats pre-inoculated with endogenous rat retrovirus.

    OpenAIRE

    Fish, D C; Demarais, J T; Djurickovic, D B; Huebner, R J

    1981-01-01

    Weanling Fischer 344 rats received a single intraperitoneal injection of a 1000-fold concentrated preparation of endogenous nontransforming rat retrovirus. Ten days later, the rats were each given a single subcutaneous injection of 3-methylcholanthrene. The rats inoculated with the endogenous rat retrovirus were significantly protected against the development of cancer, whereas uninoculated rats and rats given one of several murine retroviruses or baboon retrovirus were not protected.

  20. Focal inhibitory interneuron loss and principal cell hyperexcitability in the rat hippocampus after microinjection of a neurotoxic conjugate of saporin and a peptidase-resistant analog of Substance P.

    Science.gov (United States)

    Martin, J L; Sloviter, R S

    2001-07-23

    Episodes of prolonged seizures or head trauma produce chronic hippocampal network hyperexcitability hypothesized to result primarily from inhibitory interneuron loss or dysfunction. The possibly causal role of inhibitory neuron failure in the development of epileptiform pathophysiology remains unclear because global neurologic injuries produce such a multitude of effects. The recent finding that Substance P receptors (SPRs) are expressed exclusively in the rat hippocampus by inhibitory interneurons provided the rationale for attempting to ablate interneurons selectively by using neurotoxic conjugates of SPR ligands and the ribosome inactivating protein saporin that specifically target Substance P receptor-expressing cells. Whereas intrahippocampal microinjection of a conjugate of native SP and saporin produced significant nonspecific damage at concentrations needed to produce even limited selective loss of SPR-positive cells, a conjugate of saporin and the more potent and peptidase-resistant SP analog [Sar(9), Met(O(2))(11)] Substance P (SSP-saporin) caused negligible nonspecific damage at the injection site, and a virtually complete loss of SPR-like immunoreactivity (LI) up to 1 mm from the injection site. Within the SPR depletion zone, immunoreactivities for most GABA-, parvalbumin-, somatostatin-, and cholecystokinin-immunoreactive cells and fibers were eliminated. The few interneurons detectable within the affected zone were devoid of SPR-LI. The apparent loss of interneurons was selective in that calbindin- and glutamate receptor subunit 2 (GluR2) -positive principal cells survived within the affected zone, as did myelinated fibers and the extrinsic calretinin- and tyrosine hydroxylase--immunoreactive terminals of subcortical afferents. An apparent lack of reactive synaptic reorganization in response to interneuron loss was indicated by zinc transporter-3 (ZnT3)-- and beta-synuclein--LI, as well as by Timm staining, all of which revealed relatively normal

  1. Rat traps: filling the toolbox for manipulating the rat genome

    OpenAIRE

    van Boxtel, Ruben; Cuppen, Edwin

    2010-01-01

    The laboratory rat is rapidly gaining momentum as a mammalian genetic model organism. Although traditional forward genetic approaches are well established, recent technological developments have enabled efficient gene targeting and mutant generation. Here we outline the current status, possibilities and application of these techniques in the rat.

  2. Involvement of upregulation of miR-210 in a rat epilepsy model

    Science.gov (United States)

    Chen, Licheng; Zheng, Hao; Zhang, Shimeng

    2016-01-01

    Epilepsy is a common type of neurological disorder with complex etiology. The mechanisms are still not clear. MicroRNAs are endogenous noncoding RNAs with many physiological activities. Multiple microRNAs were abnormally expressed in status epilepticus, including miR-210. In this study, we applied lithium chloride and pilocarpine to induce epileptic activity and aimed to disclose the potential mechanisms. Our data showed that miR-210 was significantly upregulated in hippocampus one day after modeling (P<0.05 vs control) and the high expression of miR-210 lasted for at least 30 days. By contrast, γ-aminobutyric acid (GABA) level significantly decreased concurrently after modeling (P<0.05 vs control). To question whether miR-210 could be a potential therapeutic target for epilepsy, miR-210 inhibitor was administrated through intrahippocampal injection after epilepsy modeling. Our data showed that morphological changes of hippocampal neurons and apoptosis triggered by epilepsy were mitigated by miR-210 inhibition. More importantly, the expressions of GABA-related proteins, including GABAA receptor α1, glutamate decarboxylase, and GABA transporter 1, were significantly elevated after epilepsy modeling in both mRNA and protein levels 3 days postmodeling (P<0.05 vs control), which were mitigated by miR-210 inhibitor treatment (P<0.05 vs model). In addition, epilepsy-induced upregulation of GABA transaminase was alleviated by miR-210 inhibitor. Taken together, these data implicated potential roles of miR-210 in lithium chloride–pilocarpine-induced epilepsy model and miR-210 could serve as a potential therapeutic target in status epilepticus. PMID:27471387

  3. Tubuloglomerular feedback in Dahl rats

    DEFF Research Database (Denmark)

    Karlsen, F M; Leyssac, P P; Holstein-Rathlou, N H

    1998-01-01

    in both Dahl-S and salt-resistant Dahl rats on high- and low-salt diets. TGF was investigated in the closed-loop mode with a videometric technique, in which the response in late proximal flow rate to perturbations in Henle flow rate was measured. All Dahl rats showed a similar compensatory response...

  4. Do rats have orgasms?

    Directory of Open Access Journals (Sweden)

    James G. Pfaus

    2016-10-01

    Full Text Available Background: Although humans experience orgasms with a degree of statistical regularity, they remain among the most enigmatic of sexual responses; difficult to define and even more difficult to study empirically. The question of whether animals experience orgasms is hampered by similar lack of definition and the additional necessity of making inferences from behavioral responses. Method: Here we define three behavioral criteria, based on dimensions of the subjective experience of human orgasms described by Mah and Binik, to infer orgasm-like responses (OLRs in other species: 1 physiological criteria that include pelvic floor and anal muscle contractions that stimulate seminal emission and/or ejaculation in the male, or that stimulate uterine and cervical contractions in the female; 2 short-term behavioral changes that reflect immediate awareness of a pleasurable hedonic reward state during copulation; and 3 long-term behavioral changes that depend on the reward state induced by the OLR, including sexual satiety, the strengthening of patterns of sexual arousal and desire in subsequent copulations, and the generation of conditioned place and partner preferences for contextual and partner-related cues associated with the reward state. We then examine whether physiological and behavioral data from observations of male and female rats during copulation, and in sexually-conditioned place- and partner-preference paradigms, are consistent with these criteria. Results: Both male and female rats display behavioral patterns consistent with OLRs. Conclusions: The ability to infer OLRs in rats offers new possibilities to study the phenomenon in neurobiological and molecular detail, and to provide both comparative and translational perspectives that would be useful for both basic and clinical research.

  5. Do rats have orgasms?

    Science.gov (United States)

    Pfaus, James G.; Scardochio, Tina; Parada, Mayte; Gerson, Christine; Quintana, Gonzalo R.; Coria-Avila, Genaro A.

    2016-01-01

    Background Although humans experience orgasms with a degree of statistical regularity, they remain among the most enigmatic of sexual responses; difficult to define and even more difficult to study empirically. The question of whether animals experience orgasms is hampered by similar lack of definition and the additional necessity of making inferences from behavioral responses. Method Here we define three behavioral criteria, based on dimensions of the subjective experience of human orgasms described by Mah and Binik, to infer orgasm-like responses (OLRs) in other species: 1) physiological criteria that include pelvic floor and anal muscle contractions that stimulate seminal emission and/or ejaculation in the male, or that stimulate uterine and cervical contractions in the female; 2) short-term behavioral changes that reflect immediate awareness of a pleasurable hedonic reward state during copulation; and 3) long-term behavioral changes that depend on the reward state induced by the OLR, including sexual satiety, the strengthening of patterns of sexual arousal and desire in subsequent copulations, and the generation of conditioned place and partner preferences for contextual and partner-related cues associated with the reward state. We then examine whether physiological and behavioral data from observations of male and female rats during copulation, and in sexually-conditioned place- and partner-preference paradigms, are consistent with these criteria. Results Both male and female rats display behavioral patterns consistent with OLRs. Conclusions The ability to infer OLRs in rats offers new possibilities to study the phenomenon in neurobiological and molecular detail, and to provide both comparative and translational perspectives that would be useful for both basic and clinical research. PMID:27799081

  6. The Rat Race

    CERN Multimedia

    Stephen Haywood

    Dear Muriel, Being an animal, you are probably more familiar with rats than most of us. Yet it seems to me that our Community (not just ATLAS) is stuck in a huge "rat race". I am somewhat mystified as to how we have got ourselves into this and I wonder whether you or your readers could explain this - I give my own observations below. In HEP and ATLAS specifically, we are all working long hours and we are all becoming exhausted. There are people at Point 1 who are working day and night, every day of the week; there are people writing software who send emails round the clock, including weekends. It is one thing to have bursts of activity which require us to put in some longer hours, but in ATLAS, the bursts last months or years. I have been on ATLAS 14 years and it has felt like one endless rush. Why do we do this? We are all highly motivated, we love our work and want to succeed individually and collectively. We are parts of various teams, and we do not want to let the side down. We worked hard at school an...

  7. Rat myocardial protein degradation.

    Science.gov (United States)

    Steer, J H; Hopkins, B E

    1981-07-01

    1. Myocardial protein degradation rates were determined by following tyrosine release from rat isolated left hemi-atria in vitro. 2. After two 20 min preincubations the rate of tyrosine release from hemi-atria was constant for 4 h. 3. Skeletal muscle protein degradation was determined by following tyrosine release from rat isolated hemi-diaphragm (Fulks, Li & Goldberg, 1975). 4. Insulin (10(-7) M) inhibited tyrosine release from hemi-atria and hemi-diaphragm to a similar extent. A 48 h fast increased tyrosine release rate from hemi-diaphragm and decreased tyrosine release rate from hemi-atria. Hemi-diaphragm tyrosine release was inhibited by 15 mmol/l D-glucose but a variety of concentrations of D-glucose (0, 5, 15 mmol/l) had no effect on tyrosine release from hemi-atria. Five times the normal plasma levels of the branched-chain amino acids leucine, isoleucine and valine had no effect on tyrosine release from either hemi-atria or hemi-diaphragm.

  8. Male rat sexual behavior.

    Science.gov (United States)

    Agmo, A

    1997-05-01

    The male rat's sexual behavior constitutes a highly ordered sequence of motor acts involving both striate and smooth muscles. It is spontaneously displayed by most adult made rats in the presence of a sexually receptive female. Although the behavior is important for the survival of the species it is not necessary for survival of the individual. In that way it is different from other spontaneous behaviors such as eating, drinking, avoidance of pain, respiration or thermoregulation. Among other things, this means that it is difficult to talk about sexual deprivation or need. Nevertheless, studies of male sex behavior distinguish sexual motivation (the ease by which behavior is activated, "libido") from the execution of copulatory acts (performance, "potency") (Meisel, R.L. and Sachs, B.D., The physiology of male sexual behavior. In: E. Knobil and J.D. Neill (Eds.), The Physiology of Reproduction, 2nd Edn., Vol. 2, Raven Press, New York, 1994, pp. 3-105 [13]). The hormonal control of male sexual behavior has been extensively studied. It is clear that steroid hormones, androgens and estrogens, act within the central nervous system, modifying neuronal excitability. The exact mechanism by which these hormones activate sex behavior remains largely unknown. However, there exists a considerable amount of knowledge concerning the brain structures important for sexual motivation and for the execution of sex behavior. The modulatory role of some non-steroid hormones is partly known, as well as the consequences of manipulations of several neurotransmitter systems.

  9. Rat traps: filling the toolbox for manipulating the rat genome

    NARCIS (Netherlands)

    van Boxtel, R.; Cuppen, E.

    2010-01-01

    The laboratory rat is rapidly gaining momentum as a mammalian genetic model organism. Although traditional forward genetic approaches are well established, recent technological developments have enabled efficient gene targeting and mutant generation. Here we outline the current status, possibilities

  10. Morphogenesis of rat myotendinous junction.

    Science.gov (United States)

    Curzi, Davide; Ambrogini, Patrizia; Falcieri, Elisabetta; Burattini, Sabrina

    2013-10-01

    Myotendinous junction (MTJ) is the highly specialized complex which connects the skeletal muscle to the tendon for transmitting the contractile force between the two tissues. The purpose of this study was to investigate the MTJ development and rat EDL was chosen as a model. 1, 15, 30 day animals were considered and the junctions were analyzed by light and electron microscopy. The MTJ interface architecture increased during the development, extending the interaction between muscle and tendon. 1-day-old rats showed disorganized myofibril bundles, spread cytosol and incomplete rough endoplasmic reticulum, features partially improved in 15-day-old rats, and completely developed in 30-day-old animals. These findings indicate that muscle-tendon interface displays, during rat lifetime, numerically increased and longer tendon interdigitations, correlated with an improved organization of both tissues and with a progressive acquirement of full functionality.

  11. infarction in rats

    Directory of Open Access Journals (Sweden)

    Keyvan Yousefi

    2014-03-01

    Full Text Available Introduction: Nowadays, finding new therapeutic compounds from natural products for treatment and prevention of a variety of diseases including cardiovascular disorders is getting a great deal of attention. This approach would result in finding new drugs which are more effective and have fewer side effects than the conventional medicines. The present study was designed to investigate the anti-inflammatory effect of the methanolic extract of Marrubium vulgare, a popular traditional medicinal herb, on isoproterenol-induced myocardial infarction (MI in rat model. Methods: Male Wistar rats were assigned to 6 groups of control, sham, isoproterenol, and treatment with 10, 20, and 40 mg/kg/12h of the extract given orally concurrent with MI induction. A subcutaneous injection of isoproterenol (100 mg/kg/day for two consecutive days was used to induce MI. Then, histopathological changes and inflammatory markers were evaluated. Results: Isoproterenol injection increased inflammatory response, as shown by a significant increase in peripheral neutrophil count, myocardial myeloperoxidase (MPO activity and serum levels of creatinine kinase-MB (CK-MB and TNF-α (pM.vulgare extract serum CK-MB was subsided by 55.4%, 52.2% and 69%, respectively. Also treatment with the extract (40 mg/kg significantly reduced (p<0.001 MPO activity in MI group. The levels of TNF-α was also considerably declined in the serums of MI group (p<0.001. In addition, peripheral neutrophil count, was significantly lowered by all doses of the extract (p<0.001. Interstitial fibrosis significantly was attenuated in treated groups compared with control MI group.Conclusion:The results of study demonstrate that the M. vulgare extract has strong protective effects against isoproterenol-induced myocardial infarction and it seems possible that this protection is due to its anti-inflammatory effects.

  12. Senescence-accelerated OXYS rats

    Science.gov (United States)

    Stefanova, Natalia A; Kozhevnikova, Oyuna S; Vitovtov, Anton O; Maksimova, Kseniya Yi; Logvinov, Sergey V; Rudnitskaya, Ekaterina A; Korbolina, Elena E; Muraleva, Natalia A; Kolosova, Nataliya G

    2014-01-01

    Senescence-accelerated OXYS rats are an experimental model of accelerated aging that was established from Wistar stock via selection for susceptibility to cataractogenic effects of a galactose-rich diet and via subsequent inbreeding of highly susceptible rats. Currently, we have the 102nd generation of OXYS rats with spontaneously developing cataract and accelerated senescence syndrome, which means early development of a phenotype similar to human geriatric disorders, including accelerated brain aging. In recent years, our group found strong evidence that OXYS rats are a promising model for studies of the mechanisms of brain aging and neurodegenerative processes similar to those seen in Alzheimer disease (AD). The manifestation of behavioral alterations and learning and memory deficits develop since the fourth week of age, i.e., simultaneously with first signs of neurodegeneration detectable on magnetic resonance imaging and under a light microscope. In addition, impaired long-term potentiation has been demonstrated in OXYS rats by the age of 3 months. With age, neurodegenerative changes in the brain of OXYS rats become amplified. We have shown that this deterioration happens against the background of overproduction of amyloid precursor protein (AβPP), accumulation of β-amyloid (Aβ), and hyperphosphorylation of the tau protein in the hippocampus and cortex. The development of AMD-like retinopathy in OXYS rats is also accompanied by increased accumulation of Aβ in the retina. These published data suggest that the OXYS strain may serve as a spontaneous rat model of AD-like pathology and could help to decipher the pathogenesis of AD. PMID:24552807

  13. The thymus reconstituted nude rat

    DEFF Research Database (Denmark)

    Hougen, H P; Klausen, B

    1987-01-01

    The monoclonal antibodies OX6, OX19, W3/13, OX7, OX8, and W3/25 were used to gain information about the distribution of different lymphocyte subpopulations in peripheral lymphoid organs of neonatally isogeneic and allogeneic thymus reconstituted nude rats. Splenic mitogen responsiveness, xenogene...... cell response is far better following isografting. We, therefore, conclude that isogeneic thymus grafting is an easy method of reconstituting the nude rat immunologically....

  14. EXPERIMENTAL PARACOCCIDIOIDOMYCOSIS IN PREGNANT RATS

    Science.gov (United States)

    LOTH, Eduardo Alexandre; CECATTO, Vanessa; BIAZIM, Samia Khalil; FERREIRA, José Henrique Fermino; DANIELLI, Caroline; GENSKE, Rodrigo Daniel; GANDRA, Rinaldo Ferreira; de FRANCO, Marcello Fabiano

    2015-01-01

    Paracoccidioidomycosis (PCM), caused by the dimorphic fungus Paracoccidioides brasiliensis (Pb), is the most prevalent systemic mycosis in Latin America. There are few reports in the literature about the disease damages during pregnancy and the consequences to the fetuses and breeding. This study evaluated the implications of PCM during pregnancy on offspring and mothers in Wistar rats. Groups of rats were submitted to systemic Pb infection, by intraperitoneal infusion, and mated 30 days after the infection date. Immediately after birth, rats and neonates were sacrificed to obtain organs for standard histological examination, morphometric analysis, fungi recovery by plating (CFU) and dosing of anti-Pb antibodies by ELISA. There were no stillbirths or miscarriages, however, the fetuses from infected pregnant rats had lower body and organ weight but the fertility rate was 100%. The largest number of CFU was recovered from the organ of pregnant rats, the pathological examination revealed more severe infection in the same group, further on the largest number of granulomas and fungal field. It can be concluded that the PCM was more severe in the group of pregnant rats, with implications to the weight of offspring. PMID:27049707

  15. EXPERIMENTAL PARACOCCIDIOIDOMYCOSIS IN PREGNANT RATS.

    Science.gov (United States)

    Loth, Eduardo Alexandre; Cecatto, Vanessa; Biazim, Samia Khalil; Ferreira, José Henrique Fermino; Danielli, Caroline; Genske, Rodrigo Daniel; Gandra, Rinaldo Ferreira; Franco, Marcello Fabiano de

    2015-12-01

    Paracoccidioidomycosis (PCM), caused by the dimorphic fungus Paracoccidioides brasiliensis (Pb), is the most prevalent systemic mycosis in Latin America. There are few reports in the literature about the disease damages during pregnancy and the consequences to the fetuses and breeding. This study evaluated the implications of PCM during pregnancy on offspring and mothers in Wistar rats. Groups of rats were submitted to systemic Pb infection, by intraperitoneal infusion, and mated 30 days after the infection date. Immediately after birth, rats and neonates were sacrificed to obtain organs for standard histological examination, morphometric analysis, fungi recovery by plating (CFU) and dosing of anti-Pb antibodies by ELISA. There were no stillbirths or miscarriages, however, the fetuses from infected pregnant rats had lower body and organ weight but the fertility rate was 100%. The largest number of CFU was recovered from the organ of pregnant rats, the pathological examination revealed more severe infection in the same group, further on the largest number of granulomas and fungal field. It can be concluded that the PCM was more severe in the group of pregnant rats, with implications to the weight of offspring.

  16. EXPERIMENTAL PARACOCCIDIOIDOMYCOSIS IN PREGNANT RATS

    Directory of Open Access Journals (Sweden)

    Eduardo Alexandre LOTH

    2015-12-01

    Full Text Available Paracoccidioidomycosis (PCM, caused by the dimorphic fungus Paracoccidioides brasiliensis (Pb, is the most prevalent systemic mycosis in Latin America. There are few reports in the literature about the disease damages during pregnancy and the consequences to the fetuses and breeding. This study evaluated the implications of PCM during pregnancy on offspring and mothers in Wistar rats. Groups of rats were submitted to systemic Pb infection, by intraperitoneal infusion, and mated 30 days after the infection date. Immediately after birth, rats and neonates were sacrificed to obtain organs for standard histological examination, morphometric analysis, fungi recovery by plating (CFU and dosing of anti-Pb antibodies by ELISA. There were no stillbirths or miscarriages, however, the fetuses from infected pregnant rats had lower body and organ weight but the fertility rate was 100%. The largest number of CFU was recovered from the organ of pregnant rats, the pathological examination revealed more severe infection in the same group, further on the largest number of granulomas and fungal field. It can be concluded that the PCM was more severe in the group of pregnant rats, with implications to the weight of offspring.

  17. 强直电刺激大鼠海马-颞叶新皮质神经通路致癫放电中突触传递可塑性及其癫靶行为的表达研究%Synaptic modification of epileptiform discharges in response to repeti tive tetani into hippocampal-temporal neocortex neural pathway and their target-behavior expression associated with epileptic seizures in rats

    Institute of Scientific and Technical Information of China (English)

    张先荣; 韩丹; 唐岳枫; 刘买利; 刘维泽; 杨芳; 王晓云

    2000-01-01

    强直电刺激诱发大鼠急、慢性在体和离体脑片癫模型.观察癫电活动的突触可塑性以及癫发作的行为表达特征.结果表明:慢性癫大鼠原发性湿狗样抖的频率先增加后减少及潜伏期逐步缩短,并相继出现继发性湿狗样抖和"点燃”效应,称之为行为改变的可塑性,即"长时程”效应;急性在体癫模型上反复强直电刺激海马,颞叶新皮质区细胞外场电位原发性后放的潜伏期逐渐缩短及幅度逐级增大,此效应在脑室内微量注射东莨菪碱后逐渐消失;离体脑片上强直电刺激海马Schaeffer侧枝,CA1神经元膜电位原发性后放电及阵发性爆发放电的潜伏期明显缩短,表现为突触传递的"长时程增强”.推测癫发作行为的可塑性变化可能是复杂神经网络多级突触传递长时程效应的整体靶行为表现.

  18. DOPA, norepinephrine, and dopamine in rat tissues

    DEFF Research Database (Denmark)

    Eldrup, E; Richter, Erik; Christensen, N J

    1989-01-01

    We studied the effect of unilateral sympathectomy on rat quadriceps and gastrocnemius muscle concentrations of endogenous dihydroxyphenylalanine (DOPA), dopamine (DA), and norepinephrine (NE) and assessed the relationships between these catecholamines in several rat tissues. Catecholamines were...

  19. Continuous enteral feeding in uremic rats.

    Science.gov (United States)

    Maniar, S; Laouari, D; Motel, V; Kleinknecht, C

    1996-01-01

    Because of constant uremia-induced anorexia, food restriction of normal rats is generally used to study the consequences of uremia. The effects of a normal food supply in uremic rats has never been tested, since no author has succeeded in providing normal intakes. Uremic rats either fed ad lib (U rats, n = 12) or force-fed through a gastric catheter (UF rats, n = 10), and sham-operated rats (C rats, n = 10) were compared from days 7 to 21 after surgery. U rats had lower food intake (13.8 vs. 17 g/day), weight gain (5.16 vs. 6.23 g/day), length gain (4 vs. 5 mm/day), nitrogen balance (228 vs. 279 mg/day) and muscle fractional protein synthesis rate (9.5 vs. 10.6%) measured in vivo by 3H-phenylalanine injection (p feeding may provide a model for normal nutritional supply in uremia.

  20. Morphological and neurohistological changes in adolescent rats ...

    African Journals Online (AJOL)

    olayemitoyin

    abnormalities in the cytoarchitecture of the parietal and temporal cortices of young rats. The gestational ... smaller left anterior cingulated volume and lower gray matter .... the temporal and parietal lobes of the cerebral cortex of the rats in the ...

  1. Antiulcer Effects of Melatonin in Wistar Rats

    African Journals Online (AJOL)

    Dr Olaleye

    The effect of melatonin was investigated on indomethacin-induced gastric ulcer and gastric mucus cell counts in rats were measured. ..... N. (2004): Protective effects of melatonin on the ionizing radiation induced DNA damage in the rat brain.

  2. Cannabidivarin-rich cannabis extracts are anticonvulsant in mouse and rat via a CB1 receptor-independent mechanism.

    Science.gov (United States)

    Hill, T D M; Cascio, M-G; Romano, B; Duncan, M; Pertwee, R G; Williams, C M; Whalley, B J; Hill, A J

    2013-10-01

    Epilepsy is the most prevalent neurological disease and is characterized by recurrent seizures. Here, we investigate (i) the anticonvulsant profiles of cannabis-derived botanical drug substances (BDSs) rich in cannabidivarin (CBDV) and containing cannabidiol (CBD) in acute in vivo seizure models and (ii) the binding of CBDV BDSs and their components at cannabinoid CB1 receptors. The anticonvulsant profiles of two CBDV BDSs (50-422 mg·kg(-1) ) were evaluated in three animal models of acute seizure. Purified CBDV and CBD were also evaluated in an isobolographic study to evaluate potential pharmacological interactions. CBDV BDS effects on motor function were also investigated using static beam and grip strength assays. Binding of CBDV BDSs to cannabinoid CB1 receptors was evaluated using displacement binding assays. CBDV BDSs exerted significant anticonvulsant effects in the pentylenetetrazole (≥100 mg·kg(-1) ) and audiogenic seizure models (≥87 mg·kg(-1) ), and suppressed pilocarpine-induced convulsions (≥100 mg·kg(-1) ). The isobolographic study revealed that the anticonvulsant effects of purified CBDV and CBD were linearly additive when co-administered. Some motor effects of CBDV BDSs were observed on static beam performance; no effects on grip strength were found. The Δ(9) -tetrahydrocannabinol and Δ(9) -tetrahydrocannabivarin content of CBDV BDS accounted for its greater affinity for CB1 cannabinoid receptors than purified CBDV. CBDV BDSs exerted significant anticonvulsant effects in three models of seizure that were not mediated by the CB1 cannabinoid receptor and were of comparable efficacy with purified CBDV. These findings strongly support the further clinical development of CBDV BDSs for the treatment of epilepsy. © 2013 The British Pharmacological Society.

  3. False Context Fear Memory in Rats

    Science.gov (United States)

    Bae, Sarah; Holmes, Nathan M.; Westbrook, R. Frederick

    2015-01-01

    Four experiments used rats to study false context fear memories. In Experiment 1, rats were pre-exposed to a distinctive chamber (context A) or to a control environment (context C), shocked after a delay in a second chamber (context B) and tested either in B or A. Rats pre-exposed to A froze just as much as control rats in B but more than control…

  4. False Context Fear Memory in Rats

    Science.gov (United States)

    Bae, Sarah; Holmes, Nathan M.; Westbrook, R. Frederick

    2015-01-01

    Four experiments used rats to study false context fear memories. In Experiment 1, rats were pre-exposed to a distinctive chamber (context A) or to a control environment (context C), shocked after a delay in a second chamber (context B) and tested either in B or A. Rats pre-exposed to A froze just as much as control rats in B but more than control…

  5. EFFECT OF ETHANOL ON HEPATOBILIARY TRANSPORT OF CATIONIC DRUGS - A STUDY IN THE ISOLATED-PERFUSED RAT-LIVER, RAT HEPATOCYTES AND RAT MITOCHONDRIA

    NARCIS (Netherlands)

    STEEN, H; MEIJER, DKF; Merema, M.T.

    1994-01-01

    The effect of ethanol on the hepatic uptake of various cationic drugs was studied in isolated perfused rat livers, isolated rat hepatocytes and isolated rat liver mitochondria. In isolated rat hepatocytes and in isolated perfused rat livers, the uptake of the model organic cation tri-n-butylmethylam

  6. Tuberculosis Detection by Giant African Pouched Rats

    Science.gov (United States)

    Poling, Alan; Weetjens, Bart; Cox, Christophe; Beyene, Negussie; Durgin, Amy; Mahoney, Amanda

    2011-01-01

    In recent years, operant discrimination training procedures have been used to teach giant African pouched rats to detect tuberculosis (TB) in human sputum samples. This article summarizes how the rats are trained and used operationally, as well as their performance in studies published to date. Available data suggest that pouched rats, which can…

  7. The serotonin transporter knockout rat : A review

    NARCIS (Netherlands)

    Olivier, Jocelien; Cools, Alexander; Ellenbroek, Bart A.; Cuppen, E.; Homberg, Judith; Kalueff, Allan V.; LaPorte, Justin L.

    2010-01-01

    This chapter dicusses the most recent data on the serotonin transporter knock-out rat, a unique rat model that has been generated by target-selected N-ethyl-N-nitrosourea (ENU) driven mutagenesis. The knock-out rat is the result of a premature stopcodon in the serotonin transporter gene, and the abs

  8. Tuberculosis Detection by Giant African Pouched Rats

    Science.gov (United States)

    Poling, Alan; Weetjens, Bart; Cox, Christophe; Beyene, Negussie; Durgin, Amy; Mahoney, Amanda

    2011-01-01

    In recent years, operant discrimination training procedures have been used to teach giant African pouched rats to detect tuberculosis (TB) in human sputum samples. This article summarizes how the rats are trained and used operationally, as well as their performance in studies published to date. Available data suggest that pouched rats, which can…

  9. 惊厥持续状态幼年大鼠海马CHOP水平的动态变化及依达拉奉对其表达的影响%Dynamic Changes in Expression of CHOP in Juvenile Rat Hippocampus after Status Convulsion and Effects of Edaravone on Its Expression

    Institute of Scientific and Technical Information of China (English)

    李婷婷; 王海萍; 李光乾

    2011-01-01

    - Dawley ( SD) rats were randomly divided into 3 groups. Each group were further divided into 5 subgroups in different executed time points (2 h,12 h,24 h,48 h,72 h) .including 9 g·L"1 saline control group(NS group) ,status epilepticus group(SC group)and ED treatment group ( ED group) after SC. The rats in SC group were kindled into epilepsy by lithium - pilocarpine chemical method. The expression of CHOP mRNA was detected with reverse transcription - polymerase chain reaction(RT - PCR) method. Expression of CHOP protein was detected with immunohistochemistry methods. The neuron apoptosis was observed by TdT - mediated dUTP nick end labeling. Results 1. After RT-PCR assay,the expression of CHOP mRNA in the hippocampus in SC group began increasing at 2 h,and reached a maximum at 12 h,and then began decreasing at 24 h. There were significant differences between SC group and NS group(P, <0.01). And the expression of CHOP mRNA in ED group was much lower than that in SC group(P. <0.05,0.01).2. Measured by immunohistochemistry, the value of optical density of CHOP positive cells began increasing in SC group at 2 h,and reached a maximum at 12 h,and decreased remarkably at 24 h. There was significant difference compared with NS group ( P, <0.01). And the value of optical density of CHOP positive cells in ED group was much lower than that in SC group( P. < 0.01,0.05 ). 3. The TUNEL positive cells in hippocampus CA1 of SC group were more than those in NS group after the SC 12 h(P, <0.01) ,TUNEL positive cells showed a significant drop in SC group at 12 -48 h time points,and reached its highest level at 48 h ( P < 0. 01,0. 05). There were different degrees degeneration and cell loss in hippocampus neurons in SC group,and the changes were similar with the TUNEL. Conclusions Earlier brain injury induced by SC may trigger the apoptotic signal pathway mediated by CHOP in the endoplasmic reticulum stress. ED decreased expression of CHOP by pilocarpine - induced seizures in rat

  10. Teratology studies in the rat.

    Science.gov (United States)

    Leroy, Mariline; Allais, Linda

    2013-01-01

    The rat is the rodent species of choice for the regulatory safety testing of xenobiotics, such as medicinal products, food additives, and other chemicals. Many decades of experience and extensive data have accumulated for both general and developmental toxicology investigations in this species. The high fertility and large litter size of the rat are advantages for teratogenicity testing. The study designs are well defined in the regulatory guidelines and are relatively standardized between testing laboratories across the world. Teratology studies address maternal- and embryo-toxicity following exposure during the period of organogenesis. This chapter describes the design and conduct of a teratology study in the rat in compliance with the regulatory guidelines. The procedures for the handling and housing of the pregnant animals, the caesarean examinations and the sampling of fetuses for morphological examinations are described. The utility and design of preliminary studies and the inclusion of satellite animals in the main study for toxicokinetic sampling are discussed.

  11. Magnetocardiogram Measurement of Laboratory Rat

    Energy Technology Data Exchange (ETDEWEB)

    Kim, I. S.; Ahn, San; Kwon, H. C. [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of); Song, J. H. [Chungnam National University, Daejeon (Korea, Republic of)

    2010-04-15

    We have developed a high-Tc SQUID magnetocardiogram (MCG) system for small laboratory animals. White noise of the measurement system was about 30 fT/ Hz{sup 1/2}when measured in a magnetically shielded room. We optimized the measurement position to obtain clear MCG wave from rat's small heart by using grid measurements. With the optimization, the MCG signal was successfully detected with the peak amplitude of about 30 pT. We could observe well defined P-, QRS-, and T-waves from the rat MCG. The results suggest that the developed system has a strong potential to monitor the progress of the heart disease model by using a laboratory rat.

  12. Metabolism of Deltamethrin in Rats

    Institute of Scientific and Technical Information of China (English)

    S.EL-MAGHRABY

    2007-01-01

    Objective To study the membolism of 14C-deltamethrin in rats. Methods Rats were dosed orally and i.p.with a single dose of 14C-deltamethrin(0.64 mg/Kg)body weight.The required dose was applied daily for 3 days.At the end of the experiment,selected organs,such as liver,kidney,fat,intestine,and blood were excised for radioassay of 14C-content.Results Deltamethrin was almost eliminated from the body within 1-3 days.The main portion of 14C-residues Was extracted from urine(38%,32%)and feces(20%,24%)with a little amount remained in various organs. Conclusion The elimination and distribution of 14C-radioactivity in rats treated orally and intraperitoneally signify th6at deltamethrin is bioavailable in urine and feces.

  13. Renal Function and Hemodynamic Study in Obese Zucker Rats

    OpenAIRE

    Park, Sung Kwang; Kang, Sung Kyew

    1995-01-01

    Objectives To investigate the renal function and hemodynamic changes in obesity and hyperinsulinemia which are characteristics of type II diabetes. Methods Studies were carried out in two groups of female Zucker rats. Group 1 rats were obese Zucker rats with hereditary insulin resistance. Group 2 rats were lean Zucker rats and served as controls. In comparison with lean Zucker rats, obese Zucker rats exhibited hyperinsulinemia but normoglycemia. Micropuncture studies and morphologic studies w...

  14. Disposition of fipronil in rats

    OpenAIRE

    Delous, Georges; Zalko, Daniel; Viguie, Catherine; Debrauwer, Laurent

    2013-01-01

    In the scientific literature, little attention has been paid to the disposition of fipronil, a phenyl pyrazole insecticide. In this study, the tissue distribution, the metabolic fate, and the elimination of fipronil was investigated in rats using radiolabeled fipronil. When a single oral dose of (14)C-fipronil (10 mg kg(-1) b.w.) was given to rats, the proportion of dose eliminated in urine and feces 72 h after dosing was ca 4% for each route. At the end of the experiment the highest levels o...

  15. RGST - Rat Gene Symbol Tracker, a database for defining official rat gene symbols

    Directory of Open Access Journals (Sweden)

    Ståhl Fredrik

    2008-01-01

    Full Text Available Abstract Background The names of genes are central in describing their function and relationship. However, gene symbols are often a subject of controversy. In addition, the discovery of mammalian genes is now so rapid that a proper use of gene symbol nomenclature rules tends to be overlooked. This is currently the situation in the rat and there is a need for a cohesive and unifying overview of all rat gene symbols in use. Based on the experiences in rat gene symbol curation that we have gained from running the "Ratmap" rat genome database, we have now developed a database that unifies different rat gene naming attempts with the accepted rat gene symbol nomenclature rules. Description This paper presents a newly developed database known as RGST (Rat Gene Symbol Tracker. The database contains rat gene symbols from three major sources: the Rat Genome Database (RGD, Ensembl, and NCBI-Gene. All rat symbols are compared with official symbols from orthologous human genes as specified by the Human Gene Nomenclature Committee (HGNC. Based on the outcome of the comparisons, a rat gene symbol may be selected. Rat symbols that do not match a human ortholog undergo a strict procedure of comparisons between the different rat gene sources as well as with the Mouse Genome Database (MGD. For each rat gene this procedure results in an unambiguous gene designation. The designation is presented as a status level that accompanies every rat gene symbol suggested in the database. The status level describes both how a rat symbol was selected, and its validity. Conclusion This database fulfils the important need of unifying rat gene symbols into an automatic and cohesive nomenclature system. The RGST database is available directly from the RatMap home page: http://ratmap.org.

  16. Peculiarities of osteoarthritis in rats

    Directory of Open Access Journals (Sweden)

    Maria Drahulian

    2016-05-01

    Full Text Available Was received model of osteoarthritis in the rat line Wistar, by a one-time injection of CH3COOI acid into the knee joint. There changes in joint studied histological and clinical methods.On the 7-th day of the experiment was installed resemblance to similar changes in the joints of humans with acquired osteoarthritis

  17. Trigeminovascular stimulation in conscious rats

    NARCIS (Netherlands)

    Kemper, RHA; Meijler, WJ; TerHorst, GJ

    1997-01-01

    INTRACISTERNAL infusion of capsaicin was used to induce intracranial trigeminovascular stimulation in conscious rats. Both behaviour and trigeminal nucleus caudalis c-fos expression were examined. Exploratory behaviour was dose-dependently reduced and different types of behaviours were induced with

  18. CCl4 cirrhosis in rats

    DEFF Research Database (Denmark)

    Fischer-Nielsen, A; Poulsen, H E; Hansen, B A

    1991-01-01

    Cirrhosis of the rat liver was induced by a 12 week individualized CCl4/phenobarbital treatment. After treatment, all surviving animals (81%) showed cirrhosis of the liver. The cirrhosis induced was irreversible when evaluated 24 weeks after cessation of treatment. Quantitative liver function...

  19. in wistar rats (Rattus Novergicus)

    African Journals Online (AJOL)

    traction in fresh wounds inflicted on wistar rats was car- ried out. Method: Twenty .... be pertinent in addition to its effect on specific fibroblast cell lines like myofibroblast. ... nism of wound contraction: first that the contractile force is located in the ...

  20. WHEAT FLOUR (DUBBIE) IN RATS

    African Journals Online (AJOL)

    food product to be widely distributed was a blend of wheat, defatted soy flour, .... drops of blood from the retroocular capillary bed (under light diethyl ether ..... Bioavaiiability to rats of the iron contents in selected cereals and pulses. Nutr. Rep.

  1. State Space Methods in RATS

    Directory of Open Access Journals (Sweden)

    Thomas Doan

    2011-05-01

    Full Text Available This paper uses several examples to show how the econometrics program RATS can be used to analyze state space models. It demonstrates Kalman filtering and smoothing, estimation of hyperparameters, unconditional and conditional simulation. It also provides a more complicated example where a dynamic simultaneous equations model is transformed into a proper state space representation and its unknown parameters are estimated.

  2. The rat GPRC6A

    DEFF Research Database (Denmark)

    Wellendorph, Petrine; Burhenne, Nicole; Christiansen, Bolette

    2007-01-01

    orthologue of GPRC6A. Full-length cloning of rat GPRC6A (rGPRC6A) was accomplished using amplification of cDNA from taste tissue, and the identity of rGPRC6A confirmed at both the genomic and the protein level by similarity studies. Using selective primers, reverse transcriptase polymerase chain reaction...

  3. Diminished hormonal responses to exercise in trained rats

    DEFF Research Database (Denmark)

    Galbo, H; Richter, Erik; Holst, J J

    1977-01-01

    Male rats (120 g) either were subjected to a 12-wk physical training program (T rats) or were sedentary controls (C rats). Subsequently the rats were killed at rest or after a 45- or 90-min forced swim. At rest, T rats had higher liver and muscle glycogen concentrations but lower plasma insulin. ...

  4. Trace elements and rat pouchitis.

    Science.gov (United States)

    Drzymała-Czyż, Sławomira; Banasiewicz, Tomasz; Walas, Stanisław; Kościński, Tomasz; Wenska-Chyży, Ewa; Drews, Michał; Walkowiak, Jarosław

    2012-01-01

    The procedure of restorative proctocolectomy is associated with a complete removal of the colon and slight reduction of ileum length, which together can lead to systemic shortages of trace elements. Inflammatory changes in the pouch mucosa may also have some impact. However, there is no data on trace elements in pouchitis. Therefore, in the present study we aimed to assess the effect of acute pouchitis on the status of selected trace elements in rats. Restorative proctocolectomy with the construction of intestinal J-pouch was performed in twenty-four Wistar rats. Three weeks after the surgery, pouchitis was induced. Eight untreated rats created the control group. Liver concentrations of selected micronutrients (Zn, Cu, Co, Mn, Se) were measured in both groups six weeks later, using inductively coupled plasma mass spectrometry. Liver concentrations of trace elements did not differ between the study and the control groups. However, copper, cobalt and selenium concentrations [μg/g] were statistically lower (p<0.02, p<0.05 and p<0.04, respectively) in rats with severe pouchitis (n=9) as compared with rats with mild pouchitis (n=7) [median (range): Cu--7.05 (3.02-14.57) vs 10.47 (5.16-14.97); Co--0.55 (0.37-0.96) vs 0.61 (0.52-0.86); Se--1.17 (0.69-1.54) vs 1.18 (0.29-1.91)]. In conclusion, it seems that acute pouchitis can lead to a significant deficiency of trace elements.

  5. Assessment of the progressive nature of cell damage in the pilocarpine model of epilepsy

    Directory of Open Access Journals (Sweden)

    L. Covolan

    2006-07-01

    Full Text Available Pilocarpine-induced (320 mg/kg, ip status epilepticus (SE in adult (2-3 months male Wistar rats results in extensive neuronal damage in limbic structures. Here we investigated whether the induction of a second SE (N = 6 would generate damage and cell loss similar to that seen after a first SE (N = 9. Counts of silver-stained (indicative of cell damage cells, using the Gallyas argyrophil III method, revealed a markedly lower neuronal injury in animals submitted to re-induction of SE compared to rats exposed to a single episode of pilocarpine-induced SE. This effect could be explained as follows: 1 the first SE removes the vulnerable cells, leaving behind resistant cells that are not affected by the second SE; 2 the first SE confers increased resistance to the remaining cells, analogous to the process of ischemic tolerance. Counting of Nissl-stained cells was performed to differentiate between these alternative mechanisms. Our data indicate that different neuronal populations react differently to SE induction. For some brain areas most, if not all, of the vulnerable cells are lost after an initial insult leaving only relatively resistant cells and little space for further damage or cell loss. For some other brain areas, in contrast, our data support the hypothesis that surviving cells might be modified by the initial insult which would confer a sort of excitotoxic tolerance. As a consequence of both mechanisms, subsequent insults after an initial insult result in very little damage regardless of their intensity.

  6. Effects of Transcutaneous Electrostimulation of Auricular Points on Behavior and Hippocampal IL-1 βand TNF-αExpression in Temporal Lobe Epilepsy Rats%耳穴区经皮电刺激对颞叶癫痫大鼠癫痫发作频率及海马区白介素-1β、肿瘤坏死因子-α表达的影响

    Institute of Scientific and Technical Information of China (English)

    杨海龙; 乔丽娜; 谭连红; 杨娇娇; 陈忠; 张永臣; 杨永升

    2016-01-01

    Objective To observe the effect of transcutaneous otopoint electrostimulation (TCOES)on behavior and ex-pression of hippocampal interleukin-1 β (IL-1 β)and tumor necrosis factor-α (TNF-α)expression in lithium-pilocarpine induced chronic spontaneous temporal lobe epilepsy (TLE)rats,so as to investigate its antiepileptic mechanism.Methods Thirty-six SD rats were randomly divided into control,model and TCOES groups (n = 1 2 in each group).The epilepsy model was estab-lished by intraperitoneal injection of lithium chloride (1 27.2 mg/kg),scopolamine(1 mg/kg,20 h after the 1 st injection)and pilo-carpine (1 0 mg/kg,30 min after scopolamine injection).Rats of the control group were treated by injection of normal saline (i.p.i.). Transcutaneous electrostimulation (1 mA,20 Hz)was applied to bilateral otopoints “Heart”“Lung”and “Subcortex”for 20 min, once daily for 6 weeks except the weekends.The behavior reactions were observed by a video monitoring system.The expres-sion of IL-1 βand TNF-αproteins and genes in the hippocampus were determined by immunofluorescence and quantitative real-time PCR,separately.Results Behavioral observation showed that after TCOES intervention,the frequency of epilepsy attack was significantly decreased in comparison with pre-treatment (P <0.05).Immunofluorescence and real-time PCR showed that com-pared with the control group,the immunoactivity of IL-1 βand TNF-α in both hippocampal CA 1 and CA 3 regions and hippocampal IL-1 βand TNF-αgene expression were obviously increased in the model group (P <0.05,P <0.0 1 ).Following TCOES,the in-creased hippocampal IL-1 β and TNF-α and IL-1 β mRNA and TNF-α mRNA expression levels were all suppressed (P <0.05, P <0.0 1 ).Conclusion TCOES intervention has an antiepileptogenic effect in temporal lobe epilepsy rats,which may be relat-ed to its effects in down-regulating expression of proinflammatory cytokine IL-1 βand TNF-α in the hippocampus.%目的::通过观察经皮电

  7. A comparison of lipolysis and lipogenesis in sheep and rats

    African Journals Online (AJOL)

    (a) hormone sensitive lipase is four times more active in rat epididymal fat than in ... Keywords: Sheep, rats, epinephrine, adipose tissue, rate- limiting enzymes ... Methods. Animals. Male laboratory white rats aged 2 - 3 months and fed high.

  8. Immortalized Rat Astrocyte Strain Genetically Modified by Rat Preprogalanin Gene

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    To construct an immortalized rat astrocyte strain genetically modified by rat preprogalanin gene (IAST/GAL) and detect its galanin (GAL) expression and secretion, a cDNA fragment of rat GAL in plasmid of pBS KS(+)-GAL was inserted into eukaryotic expression vector pcDNA3.1(+) by DNA recombinant technology, then the restriction enzyme digestion and DNA sequencing were carried out to evaluate the recombinant. The pcDNA3.1 (+)-GAL and pcDNA3.1 (+) construct were transfected into immortalized rat astrocyte strain (IAST) by lipofectamine and the population of cells which stably integrated the construct was selected with 600 μg/mL G418. Individual clones were screened and expanded into clonal cell strains. Detection of Neo gene was used to validate the success of the transfection. Immunocytochemical staining, RT-PCR and radioimmunoassay were used to detect the expression and secretion level of GAL. The recombinant had been successfully constructed by restriction enzyme digestion and DNA sequencing. Detection of Neo gene showed that the pcDNA3.1 (+)-GAL and pcDNA3.1 (+) have been successfully transfected into IAST. After selection by using G418, IAST/GAL and IAST/Neo cell strains were obtained.IAST/GAL, IAST/Neo and IAST were immunostained positively for GAL, but the GAL average optical density of IAST/GAL was significantly higher than that of IAST/Neo and IAST (P<0.01). The level of GAL mRNA expression and the supernatant concentration of GAL in cultured IAST/GAL were significantly higher than those of IAST and IAST/Neo (P<0.01), but no significant differences were found between the IAST and IAST/Neo (P>0.05). It was concluded that IAST/GAL strain was constructed successfully and it might provide a basis for the further study of pain therapy.

  9. Chronic study on BHT in rats

    DEFF Research Database (Denmark)

    Würtzen, G.; Olsen, P.

    1986-01-01

    Groups of 40, 29, 39 and 44 F0 rats of each sex were fed a semi-synthetic diet containing butylated hydroxytoluene (BHT) in concentrations to provide intakes of 0, 25, 100 or 500 mg/kg body weight/day, respectively. The F0 rats were mated, and groups of 100, 80, 80 and 100 F1 rats of each sex were...... formed. After weaning, the highest dose of BHT was lowered to 250 mg/kg/day for the F1 rats. At weaning the BHT-treated F1 rats, especially the males, had lower body weights than the controls and the effect was dose related. The survival of the BHT-treated rats of both sexes was higher than...

  10. Genome Editing in Rats Using TALE Nucleases.

    Science.gov (United States)

    Tesson, Laurent; Remy, Séverine; Ménoret, Séverine; Usal, Claire; Thinard, Reynald; Savignard, Chloé; De Cian, Anne; Giovannangeli, Carine; Concordet, Jean-Paul; Anegon, Ignacio

    2016-01-01

    The rat is an important animal model to understand gene function and model human diseases. Since recent years, the development of gene-specific nucleases has become important for generating new rat models of human diseases, to analyze the role of genes and to generate human antibodies. Transcription activator-like (TALE) nucleases efficiently create gene-specific knockout rats and lead to the possibility of gene targeting by homology-directed recombination (HDR) and generating knock-in rats. We describe a detailed protocol for generating knockout and knock-in rats via microinjection of TALE nucleases into fertilized eggs. This technology is an efficient, cost- and time-effective method for creating new rat models.

  11. High rat food vitamin E content improves nerve function in streptozotocin-diabetic rats

    NARCIS (Netherlands)

    Gispen, W.H.; Dam, P.S. van; Bravenboer, B.; Asbeck, B.S. van; Marx, J.J.

    1999-01-01

    Antioxidants can improve nerve dysfunction in hyperglycaemic rats. We evaluated whether the standard supplementation of rat food with vitamin E (normally added for preservation purposes) or high-dose vitamin E treatment improves nerve conduction in maturing streptozotocin-diabetic rats, a model

  12. Isolation of rat adrenocortical mitochondria

    Energy Technology Data Exchange (ETDEWEB)

    Solinas, Paola [Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Department of Medicine, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Fujioka, Hisashi [Electron Microscopy Facility, Department of Pharmacology, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Tandler, Bernard [Department of Biological Sciences, School of Dental Medicine, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Hoppel, Charles L., E-mail: charles.hoppel@case.edu [Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Department of Medicine, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States)

    2012-10-12

    Highlights: Black-Right-Pointing-Pointer A method for isolation of adrenocortical mitochondria from the adrenal gland of rats is described. Black-Right-Pointing-Pointer The purified isolated mitochondria show excellent morphological integrity. Black-Right-Pointing-Pointer The properties of oxidative phosphorylation are excellent. Black-Right-Pointing-Pointer The method increases the opportunity of direct analysis of adrenal mitochondria from small animals. -- Abstract: This report describes a relatively simple and reliable method for isolating adrenocortical mitochondria from rats in good, reasonably pure yield. These organelles, which heretofore have been unobtainable in isolated form from small laboratory animals, are now readily accessible. A high degree of mitochondrial purity is shown by the electron micrographs, as well as the structural integrity of each mitochondrion. That these organelles have retained their functional integrity is shown by their high respiratory control ratios. In general, the biochemical performance of these adrenal cortical mitochondria closely mirrors that of typical hepatic or cardiac mitochondria.

  13. Rats Train As Landmine Detectors

    Institute of Scientific and Technical Information of China (English)

    单献心

    2000-01-01

    鼠,也有“改邪归正”之日!比利时的研究人员正在训练老鼠当地雷侦察员。收效甚奇:Trained rats may be the best and cheapest form of landmine(地雷)detector. 不过,老鼠心甘情愿地去发现地雷,并非被灌输了什么“为民除害”的思想,而是为了食物,为了生存: Once the minefield has been mapped,the rats sniff out a landmine and sitbeside it waiting to be rewarded with food.

  14. Phosphodiesterases in the rat ovary

    DEFF Research Database (Denmark)

    Petersen, Tonny Studsgaard; Stahlhut, Martin; Andersen, Claus Yding

    2015-01-01

    Phosphodiesterases (PDEs) are important regulators of the intracellular cAMP concentration, which is a central second messenger that affects a multitude of intracellular functions. In the ovaries, cAMP exerts diverse functions, including regulation of ovulation and it has been suggested...... that augmented cAMP levels stimulate primordial follicle growth. The present study examined the gene expression, enzyme activity and immunolocalization of the different cAMP hydrolysing PDEs families in the rat ovary. Further, the effect of PDE4 inhibition on primordial follicle activation in cultured neonatal...... and PDE2A in the corpora lutea. Incubating neonatal rat ovaries with PDE4 inhibitors did not increase primordial follicle activation or change the expression of the developing follicle markers Gdf9, Amh, Inha, the proliferation marker Mki67 or the primordial follicle marker Tmeff2. In addition, the cAMP...

  15. Analysis of Heme oxygenase isomers in rat

    Institute of Scientific and Technical Information of China (English)

    Yun-ZhuLi; Wen-JunCui; Xue-HongZhang; Qing-XiangShen; JianWang; She

    2002-01-01

    AIM:To purify and identify heme oxygenase(HO) isomers which exist in rat liver,spleen and brain treated with hematin and phenylhydrazine and in untrated rat liver and to investigate the characteristics of HO isomers,to isolate and confirm the rat HO-1 cDNA that actually encodes HO-1 by expressing cDNA in monkey Kidney cells(COS-1 cells),to prepare the rat heme oxygenase-1(HO-1)mutant and to detect inhibition of HO-1 mutated enzyme.

  16. Renal function in streptozotocin-diabetic rats

    DEFF Research Database (Denmark)

    Jensen, P K; Christiansen, J S; Steven, K

    1981-01-01

    Renal function was examined with micropuncture methods in the insulin-treated streptozotocin-diabetic rat. Kidney glomerular filtration rate was significantly higher in the diabetic rats (1.21 ml/min) than in the control group (0.84 ml/min) Nephron glomerular filtration rate increased in proportion...... to the rise in kidney glomerular filtration rate (diabetic rats: 37.0 nl/min; control rats: 27.9 nl/min). Likewise renal plasma flow was significantly higher in the diabetic rats (4.1 ml/min) than in the control group (3.0 ml/min). Glomerular capillary pressure was identical in both groups (56.0 and 56.0 mm......-1mmHg-1). Kidney weight was significantly higher in the diabetic rats (1.15 g; control rats: 0.96 g) while body weight was similar in both groups (diabetic rats: 232 g; control rats: 238 g). Calculations indicate that the increases in transglomerular hydraulic pressure, renal plasma flow...

  17. Automatic Training of Rat Cyborgs for Navigation.

    Science.gov (United States)

    Yu, Yipeng; Wu, Zhaohui; Xu, Kedi; Gong, Yongyue; Zheng, Nenggan; Zheng, Xiaoxiang; Pan, Gang

    2016-01-01

    A rat cyborg system refers to a biological rat implanted with microelectrodes in its brain, via which the outer electrical stimuli can be delivered into the brain in vivo to control its behaviors. Rat cyborgs have various applications in emergency, such as search and rescue in disasters. Prior to a rat cyborg becoming controllable, a lot of effort is required to train it to adapt to the electrical stimuli. In this paper, we build a vision-based automatic training system for rat cyborgs to replace the time-consuming manual training procedure. A hierarchical framework is proposed to facilitate the colearning between rats and machines. In the framework, the behavioral states of a rat cyborg are visually sensed by a camera, a parameterized state machine is employed to model the training action transitions triggered by rat's behavioral states, and an adaptive adjustment policy is developed to adaptively adjust the stimulation intensity. The experimental results of three rat cyborgs prove the effectiveness of our system. To the best of our knowledge, this study is the first to tackle automatic training of animal cyborgs.

  18. Pathophysiology of the Belgrade Rat

    Directory of Open Access Journals (Sweden)

    Tania eVeuthey

    2014-04-01

    Full Text Available The Belgrade rat is an animal model of Divalent Metal Transporter-1 (DMT1 deficiency. This strain originates from an X-irradiation experiment first reported in 1966. Since then, the Belgrade rat’s pathophysiology has helped to reveal the importance of iron balance and the role of DMT1. This review discusses our current understanding of iron transport homeostasis and summarizes molecular details of DMT1 function. We describe how studies of the Belgrade rat have revealed key roles for DMT1 in iron distribution to red blood cells as well as duodenal iron absorption. The Belgrade rat’s pathology has extended our knowledge of hepatic iron handling, pulmonary and olfactory iron transport as well as brain iron uptake and renal iron handling. For example, relationships between iron and manganese metabolism have been discerned since both are essential metals transported by DMT1. Pathophysiologic features of the Belgrade rat provide us with a unique and interesting animal model to understand iron homeostasis.

  19. Developmental toxicity of isomalt in rats.

    Science.gov (United States)

    Waalkens-Berendsen, D H; Koëter, H B; Schlüter, G; Renhof, M

    1989-10-01

    The sugar replacer isomalt, a 1:1 mixture of the disaccharides glucopyranosylsorbitol and glucopyranosylmannitol, was incorporated in the diet of rats. Female Bay FB:30 rats were adapted to isomalt by feeding them a diet containing a gradually increasing amount of isomalt for several days, prior to mating. Subsequently, they were mated. Isomalt was fed continuously in concentrations of 2.5, 5 and 10% up to day 20 of pregnancy. In addition, one group of female Wistar rats was mated and fed 10% isomalt incorporated in the diet from day 0 up to day 20 of pregnancy, without previous adaptation to isomalt. Finally, one group of untreated female Wistar rats served as controls. Half of the number of females in each group was selected for caesarian section on day 20 of pregnancy. The other half was allowed to litter and rear their pups for 2 weeks (Wistar rats) or 3 weeks (Bay FB:30 rats). In the females of the Bay FB:30 rats, a decreased body-weight gain and food consumption were observed in the 5 and 10% isomalt group. Minor retardation in the development of the foetuses was observed in the 10% isomalt group only with the Bay FB:30 rats and was therefore considered to be related to maternal toxicity. In addition, a dose-related increase in the incidence of wavy ribs occurred in foetuses of the Bay FB:30 rats. However, none of the observed effects were persistent in neonates. Isomalt appeared to have slight toxic effects in the dams of the Bay FB:30 strain but no toxicity in the offspring. In Wistar rats no toxicity and no effects on maternal performance or on embryonic, foetal or neonatal development were seen. Isomalt, when fed at dietary levels up to 10%, did not induce structural or functional teratogenic effects in rats of either the Wistar or the Bay FB:30 strain.

  20. Modulation of rat behaviour by using a rat-like robot.

    Science.gov (United States)

    Shi, Qing; Ishii, Hiroyuki; Kinoshita, Shinichi; Takanishi, Atsuo; Okabayashi, Satoshi; Iida, Naritoshi; Kimura, Hiroshi; Shibata, Shigenobu

    2013-12-01

    In this paper, we study the response of a rat to a rat-like robot capable of generating different types of behaviour (stressful, friendly, neutral). Experiments are conducted in an open-field where a rat-like robot called WR-4 is put together with live rats. The activity level of each rat subject is evaluated by scoring its locomotor activity and frequencies of performing rearing (rising up on its hind limbs) and body grooming (body cuddling and head curling) actions, whereas the degree of preference of that is indicated by the robot-rat distance and the frequency of contacting WR-4. The moving speed and behaviour of WR-4 are controlled in real-time based on the feedback from rat motion. The activity level and degree of preference of rats for each experimental condition are analysed and compared to understand the influence of robot behaviour. The results of this study show that the activity level and degree of preference of the rat decrease when exposed to a stressful robot, and increase when the robot exhibit friendly behaviour, suggesting that a rat-like robot can modulate rat behaviour in a controllable, predictable way.

  1. A Novel Rat Model of Type 2 Diabetes: The Zucker Fatty Diabetes Mellitus ZFDM Rat

    Directory of Open Access Journals (Sweden)

    Norihide Yokoi

    2013-01-01

    Full Text Available The Zucker fatty (ZF rat harboring a missense mutation (fatty, fa in the leptin receptor gene (Lepr develops obesity without diabetes; Zucker diabetic fatty (ZDF rats derived from the ZF strain exhibit obesity with diabetes and are widely used for research on type 2 diabetes (T2D. Here we establish a novel diabetic strain derived from normoglycemic ZF rats. In our ZF rat colony, we incidentally found fa/fa homozygous male rats having reproductive ability, which is generally absent in these animals. During maintenance of this strain by mating fa/fa males and fa/+ heterozygous females, we further identified fa/fa male rats exhibiting diabetes. We then performed selective breeding using the fa/fa male rats that exhibited relatively high blood glucose levels at 10 weeks of age, resulting in establishment of a diabetic strain that we designated Hos:ZFDM-Leprfa (ZFDM. These fa/fa male rats developed diabetes as early as 10 weeks of age, reaching 100% incidence by 21 weeks of age, while none of the fa/+ male rats developed diabetes. The phenotypic characteristics of this diabetic strain are distinct from those of normoglycemic ZF rats. ZFDM rat strain having high reproductive efficiency should serve as a more useful animal model of T2D.

  2. Laparoscopy of rats with experimental liver metastases

    DEFF Research Database (Denmark)

    Kobaek-Larsen, Morten; Rud, Lene; Østergaard-Sørensen, Finn

    2004-01-01

    condition. Liver metastases were modelled by hepatic subcapsular injection of a syngeneic rat colon cancer cell line (DHD/K12-PROb) in BDIX/OrlIco rats. In this study, we present a detailed description of a laparoscopic technique for the direct inspection of liver metastases. That way a qualitative...

  3. Adrenergic blockade in diabetic and uninephrectomized rats

    DEFF Research Database (Denmark)

    Thulesen, J; Poulsen, Steen Seier; Jørgensen, P E

    1999-01-01

    The present study reports on the effects of adrenergic blocking agents on the renal growth and on the renal content and urinary excretion of epidermal growth factor (EGF) in streptozotocin-induced diabetic or uninephrectomized rats. Diabetic and uninephrectomized rats were allocated to groups...

  4. Grooming behavior of spontaneously hypertensive rats

    NARCIS (Netherlands)

    Buuse, M. van den; Jong, Wybren de

    1987-01-01

    In an open field spontaneously hypertensive rats (SHR) exhibited lower scores for grooming when compared to their normotensive controls, the Wistar Kyoto rats (WKY). After i.c.v. injection of 1 μg ACTH1–24 cumulative 50-min grooming scores were lower in SHR. Analysis of subscores indicated that the

  5. Multigeneration reproduction study of isomalt in rats.

    Science.gov (United States)

    Waalkens-Berendsen, D H; Koëter, H B; Sinkeldam, E J

    1990-01-01

    The sugar replacer isomalt was fed to Wistar rats of both sexes throughout three successive generations at concentrations of 0, 2.5, 5 and 10% in the diet. A group of rats fed a diet containing 10% sucrose served as an additional control group. The initial mating was of 100 rats of each sex in each group. For subsequent matings 20 rats of each sex from each group were used. For each generation two litters were reared until they were at least 3 wk old. Feeding isomalt to rats for three successive generations did not induce any adverse effects on fertility, reproductive performance or development compared with control animals fed diets containing maize starch and sucrose instead of isomalt. The second litter of third-generation rats was given detailed gross and microscopic examinations 4 wk after weaning. A marked treatment-related change was an increase in the relative weight of the caecum (filled and empty), 4 wk after weaning in the second litter of third-generation rats fed 10% isomalt. There was also an increase in the relative weight of the filled caecum in males of the 5% isomalt group. These findings were not accompanied by diarrhoea or histological changes in the caecum. The results of the present study did not demonstrate any deleterious effects on the reproduction, maternal performance or development of rats fed isomalt at dietary levels of up to 10% over three successive generations.

  6. Same-Different Categorization in Rats

    Science.gov (United States)

    Wasserman, Edward A.; Castro, Leyre; Freeman, John H.

    2012-01-01

    Same-different categorization is a fundamental feat of human cognition. Although birds and nonhuman primates readily learn same-different discriminations and successfully transfer them to novel stimuli, no such demonstration exists for rats. Using a spatial discrimination learning task, we show that rats can both learn to discriminate arrays of…

  7. Attachment in rat pups, an experimental approach

    NARCIS (Netherlands)

    Gispen, W.H.; Sigling, H.; Engeland, H. van; Spruijt, B.M.

    1998-01-01

    John Bowlby's attachment theory states that attachment behavior has been strengthened throughout evolution as a consequence of its adaptive value. We investigated the presence of attachment-like behavior in rat pups, by offering a choice between the home nest and a same aged other nest. Rat pups sho

  8. Autoprotection in acetaminophen intoxication in rats

    DEFF Research Database (Denmark)

    Dalhoff, K; Laursen, H; Bangert, K;

    2001-01-01

    Autoprotection by acetaminophen, i.e. increased resistance to toxic effects caused by pretreatment, is a well-known phenomenon. The purpose of the present work was to identify mechanisms for increased acetaminophen tolerance induced by pretreatment of rats. One group of female Wistar rats (pretre...

  9. Attachment in rat pups, an experimental approach

    NARCIS (Netherlands)

    Gispen, W.H.; Sigling, H.; Engeland, H. van; Spruijt, B.M.

    1998-01-01

    John Bowlby's attachment theory states that attachment behavior has been strengthened throughout evolution as a consequence of its adaptive value. We investigated the presence of attachment-like behavior in rat pups, by offering a choice between the home nest and a same aged other nest. Rat pups

  10. Experimental Salmonella typhimurium infections in rats. I

    DEFF Research Database (Denmark)

    Hougen, H P; Jensen, E T; Klausen, B

    1989-01-01

    The course of experimentally induced Salmonella typhimurium infection was studied in three groups of inbred LEW rats: homozygous +/+, athymic rnu/rnu and isogeneic thymus-grafted rnu/rnu rats. In the first experiment the animals were inoculated intraperitoneally with 10(8) bacteria and all animal...

  11. Automatic Training of Rat Cyborgs for Navigation

    Directory of Open Access Journals (Sweden)

    Yipeng Yu

    2016-01-01

    Full Text Available A rat cyborg system refers to a biological rat implanted with microelectrodes in its brain, via which the outer electrical stimuli can be delivered into the brain in vivo to control its behaviors. Rat cyborgs have various applications in emergency, such as search and rescue in disasters. Prior to a rat cyborg becoming controllable, a lot of effort is required to train it to adapt to the electrical stimuli. In this paper, we build a vision-based automatic training system for rat cyborgs to replace the time-consuming manual training procedure. A hierarchical framework is proposed to facilitate the colearning between rats and machines. In the framework, the behavioral states of a rat cyborg are visually sensed by a camera, a parameterized state machine is employed to model the training action transitions triggered by rat’s behavioral states, and an adaptive adjustment policy is developed to adaptively adjust the stimulation intensity. The experimental results of three rat cyborgs prove the effectiveness of our system. To the best of our knowledge, this study is the first to tackle automatic training of animal cyborgs.

  12. Characterization of rat lung ICAM-1

    DEFF Research Database (Denmark)

    Beck-Schimmer, B; Schimmer, R C; Schmal, H;

    1998-01-01

    OBJECTIVE AND DESIGN: We expressed soluble rat ICAM-1, generated a polyclonal anti-ICAM-1 antibody, and studied ICAM-1 upregulation in lung inflammatory conditions. Bacterial and baculovirus expression systems were employed. MATERIAL: 250 g adult, male Long Evans rats were used. For in vitro stud...

  13. Cytidine 5'-diphosphocholine (CDP-choline) adversely effects on pilocarpine seizure-induced hippocampal neuronal death.

    Science.gov (United States)

    Kim, Jin Hee; Lee, Dong Won; Choi, Bo Young; Sohn, Min; Lee, Song Hee; Choi, Hui Chul; Song, Hong Ki; Suh, Sang Won

    2015-01-21

    Citicoline (CDP-choline; cytidine 5'-diphosphocholine) is an important intermediate in the biosynthesis of cell membrane phospholipids. Citicoline serves as a choline donor in the biosynthetic pathways of acetylcholine and neuronal membrane phospholipids, mainly phosphatidylcholine. The ability of citicoline to reverse neuronal injury has been tested in animal models of cerebral ischemia and clinical trials have been performed in stroke patients. However, no studies have examined the effect of citicoline on seizure-induced neuronal death. To clarify the potential therapeutic effects of citicoline on seizure-induced neuronal death, we used an animal model of pilocarpine-induced epilepsy. Temporal lobe epilepsy (TLE) was induced by intraperitoneal injection of pilocarpine (25mg/kg) in adult male rats. Citicoline (100 or 300 mg/kg) was injected into the intraperitoneal space two hours after seizure onset and a second injection was performed 24h after the seizure. Citicoline was injected once per day for one week after pilocarpine- or kainate-induced seizure. Neuronal injury and microglial activation were evaluated at 1 week post-seizure. Surprisingly, rather than offering protection, citicoline treatment actually enhanced seizure-induced neuronal death and microglial activation in the hippocampus compared to vehicle treated controls. Citicoline administration after seizure-induction increased immunoglobulin leakage via BBB disruption in the hippocampus compared with the vehicle-only group. To clarify if this adverse effect of citicoline is generalizable across alternative seizure models, we induced seizure by kainate injection (10mg/kg, i.p.) and then injected citicoline as in pilocarpine-induced seizure. We found that citicoline did not modulate kainate seizure-induced neuronal death, BBB disruption or microglial activation. These results suggest that citicoline may not have neuroprotective effects after seizure and that clinical application of citicoline after

  14. Cryopreservation and orthotopic transplantation of rat ovaries.

    Science.gov (United States)

    Dorsch, Martina; Wedekind, Dirk

    2010-01-01

    The number of rat strains increased considerably in the last decade and will increase continuously during the next years. This requires enough space for maintaining vital strains and techniques for cryobanking, which can be applied not only in specialised rat resource centres but also in regular animal houses. Here we describe an easy and fast method for the cryopreservation and transplantation of frozen-thawed ovaries of the rat. With dimethyl sulfoxide as cryoprotectant rat ovaries can be stored at -196 degrees C for unlimited time. For revitalisation thawed ovaries have to be orthotopically transplanted into appropriate ovarectomised recipients. Reestablishment of the reproductive cycle in the recipients can be confirmed by vaginal cytology shortly after transplantation. The recipients are able to produce 2-3 litters after mating with males of an appropriate strain. Cyropreservation of ovaries thus can be considered a reliable method to preserve scientifically and economically important stocks and strains of rats that are currently not required.

  15. Epileptiform seizures revealing neurocysticercosis:report of two clinical cases in Libreville, Gabon

    Institute of Scientific and Technical Information of China (English)

    Okome-Nkoumou MML; Ondounda M; Dzeing-Ella A; Mounguengui D; Nziengui Madjinou MI; Magne C; Nzenze JR

    2010-01-01

    Neurocysticercosis(NCC)is recognized as a cause of neurologic disease worldwide. We reported two cases (one co-infected with theHIV) ofNCC. Medical treatment led to recovery. NCC should be considered in tropical countries as a cause of epilepsy and included in the diagnosis of neurologic infections inHIV patients.

  16. Comparing Epileptiform Behavior of Mesoscale Detailed Models and Population Models of Neocortex

    NARCIS (Netherlands)

    Visser, Sid; Meijer, Hil G.E.; Lee, Hyong C.; Drongelen, van Wim; Putten, van Michel J.A.M; Gils, van Stephan A.

    2010-01-01

    Two models of the neocortex are developed to study normal and pathologic neuronal activity. One model contains a detailed description of a neocortical microcolumn represented by 656 neurons, including superficial and deep pyramidal cells, four types of inhibitory neurons, and realistic synaptic cont

  17. Calcium-dependent potassium current following penicillin-induced epileptiform discharges in the hippocampal slice.

    Science.gov (United States)

    Domann, R; Dorn, T; Witte, O W

    1989-01-01

    Penicillin-induced paroxysmal depolarization shifts (PDS) are followed by prolonged afterhyperpolarizations of about 2 seconds duration. Intracellular injection of EGTA blocked a late component of the afterhyperpolarizations; an early one lasting up to one second was only slightly reduced by EGTA. It is concluded that afterhyperpolarizations following penicillin-induced PDS comprise different components: an initial one lasting up to one second which is not Ca2+-dependent and a slow one lasting up to two seconds which is caused by a Ca2+-dependent K+ current.

  18. Is there a chronic change of the "Mozart effect" on epileptiform activity? A case study.

    Science.gov (United States)

    Hughes, J R; Fino, J J; Melyn, M A

    1999-04-01

    This report shows that a patient with the Lennox-Gastaut Syndrome had fewer clinical seizures and also fewer generalized bilateral spike and wave complexes over a 24-hour period while exposed to Mozart music (K.448) for 10 minutes every hour during wakefulness.

  19. Enhanced Synaptic Connectivity in the Dentate Gyrus during Epileptiform Activity: Network Simulation

    Science.gov (United States)

    França, Keite Lira de Almeida; Guimarães de Almeida, Antônio-Carlos; Infantosi, Antonio Fernando Catelli; Duarte, Mario Antônio; da Silveira, Gilcélio Amaral; Scorza, Fulvio Alexandre; Arida, Ricardo Mario; Cavalheiro, Esper Abrão; Rodrigues, Antônio Márcio

    2013-01-01

    Structural rearrangement of the dentate gyrus has been described as the underlying cause of many types of epilepsies, particularly temporal lobe epilepsy. It is said to occur when aberrant connections are established in the damaged hippocampus, as described in human epilepsy and experimental models. Computer modelling of the dentate gyrus circuitry and the corresponding structural changes has been used to understand how abnormal mossy fibre sprouting can subserve seizure generation observed in experimental models when epileptogenesis is induced by status epilepticus. The model follows the McCulloch-Pitts formalism including the representation of the nonsynaptic mechanisms. The neuronal network comprised granule cells, mossy cells, and interneurons. The compensation theory and the Hebbian and anti-Hebbian rules were used to describe the structural rearrangement including the effects of the nonsynaptic mechanisms on the neuronal activity. The simulations were based on neuroanatomic data and on the connectivity pattern between the cells represented. The results suggest that there is a joint action of the compensation theory and Hebbian rules during the inflammatory process that accompanies the status epilepticus. The structural rearrangement simulated for the dentate gyrus circuitry promotes speculation about the formation of the abnormal mossy fiber sprouting and its role in epileptic seizures. PMID:23431287

  20. Enhanced Synaptic Connectivity in the Dentate Gyrus during Epileptiform Activity: Network Simulation

    Directory of Open Access Journals (Sweden)

    Keite Lira de Almeida França

    2013-01-01

    Full Text Available Structural rearrangement of the dentate gyrus has been described as the underlying cause of many types of epilepsies, particularly temporal lobe epilepsy. It is said to occur when aberrant connections are established in the damaged hippocampus, as described in human epilepsy and experimental models. Computer modelling of the dentate gyrus circuitry and the corresponding structural changes has been used to understand how abnormal mossy fibre sprouting can subserve seizure generation observed in experimental models when epileptogenesis is induced by status epilepticus. The model follows the McCulloch-Pitts formalism including the representation of the nonsynaptic mechanisms. The neuronal network comprised granule cells, mossy cells, and interneurons. The compensation theory and the Hebbian and anti-Hebbian rules were used to describe the structural rearrangement including the effects of the nonsynaptic mechanisms on the neuronal activity. The simulations were based on neuroanatomic data and on the connectivity pattern between the cells represented. The results suggest that there is a joint action of the compensation theory and Hebbian rules during the inflammatory process that accompanies the status epilepticus. The structural rearrangement simulated for the dentate gyrus circuitry promotes speculation about the formation of the abnormal mossy fiber sprouting and its role in epileptic seizures.

  1. GAD65 is essential for synthesis of GABA destined for tonic inhibition regulating epileptiform activity

    DEFF Research Database (Denmark)

    Walls, Anne B; Nilsen, Linn Hege; Eyjolfsson, Elvar M;

    2010-01-01

    ABSTRACT: GABA is synthesized from glutamate by glutamate decarboxylase (GAD), which exists in two isoforms, that is, GAD65 and GAD67. In line with GAD65 being located in the GABAergic synapse, several studies have demonstrated that this isoform is important during sustained synaptic transmission....... In contrast, the functional significance of GAD65 in the maintenance of GABA destined for extrasynaptic tonic inhibition is less well studied. Using GAD65-/- and wild type GAD65+/+ mice, this was examined employing the cortical wedge preparation, a model suitable for investigating extrasynaptic GABA......(A) receptor activity. An impaired tonic inhibition in GAD65-/- mice was revealed demonstrating a significant role of GAD65 in the synthesis of GABA acting extrasynaptically. The correlation between an altered tonic inhibition and metabolic events as well as the functional and metabolic role of GABA...

  2. ideal hepatotoxicity model in rats using carbon tetrachloride (ccl4)

    African Journals Online (AJOL)

    DR. AMINU

    twenty five (25) rats each; rats in group I are negative control, were not induced with lipid peroxidation. Rats in ... MDA after 96 hours of CCl4 treatment compared with control group. However, rats treated ... EXPERIMENTAL DESIGN. Experimental ... Biochemical Analysis ... these parameters was shown to be proportional to.

  3. Social exclusion intensifies anxiety-like behavior in adolescent rats.

    Science.gov (United States)

    Lee, Hyunchan; Noh, Jihyun

    2015-05-01

    Social connection reduces the physiological reactivity to stressors, while social exclusion causes emotional distress. Stressful experiences in rats result in the facilitation of aversive memory and induction of anxiety. To determine the effect of social interaction, such as social connection, social exclusion and equality or inequality, on emotional change in adolescent distressed rats, the emotional alteration induced by restraint stress in individual rats following exposure to various social interaction circumstances was examined. Rats were assigned to one of the following groups: all freely moving rats, all rats restrained, rats restrained in the presence of freely moving rats and freely moving rats with a restrained rat. No significant difference in fear-memory and sucrose consumption between all groups was found. Change in body weight significantly increased in freely moving rats with a restrained rat, suggesting that those rats seems to share the stressful experience of the restrained rat. Interestingly, examination of the anxiety-like behavior revealed only rats restrained in the presence of freely moving rats to have a significant increase, suggesting that emotional distress intensifies in positions of social exclusion. These results demonstrate that unequally excluded social interaction circumstances could cause the amplification of distressed status and anxiety-related emotional alteration.

  4. Variation in rat sciatic nerve anatomy: implications for a rat model of neuropathic pain.

    Science.gov (United States)

    Asato, F; Butler, M; Blomberg, H; Gordh, T

    2000-03-01

    We discovered a variation of rat sciatic nerve anatomy as an incidental finding during the anatomical exploration of the nerve lesion site in a rat neuropathic pain model. To confirm the composition and distribution of rat sciatic nerve, macroscopic anatomical investigation was performed in both left and right sides in 24 adult Sprague-Dawley rats. In all rats, the L4 and L5 spinal nerves were fused tightly to form the sciatic nerve. However, the L6 spinal nerve did not fuse with this nerve completely as a part of the sciatic nerve, but rather sent a thin branch to it in 13 rats (54%), whereas in the remaining 11 rats (46%), L6 ran separately along with the sciatic nerve. Also, the L3 spinal nerve sent a thin branch to the L4 spinal nerve or sciatic nerve in 6 rats (25%). We conclude that the components of sciatic nerve in Sprague-Dawley rats vary from L3 to L6; however, the major components are L4 and L5 macroscopically. This finding is in contrast to the standard textbooks of rat anatomy which describe the sciatic nerve as having major contributions from L4, L5, and L6.

  5. Diminished hormonal responses to exercise in trained rats

    DEFF Research Database (Denmark)

    Galbo, H; Richter, Erik; Holst, J J

    1977-01-01

    Male rats (120 g) either were subjected to a 12-wk physical training program (T rats) or were sedentary controls (C rats). Subsequently the rats were killed at rest or after a 45- or 90-min forced swim. At rest, T rats had higher liver and muscle glycogen concentrations but lower plasma insulin....... In trained rats the hormonal response to exercise is blunted partly due to higher glucose concentrations. In these rats adipose tissue sensitivity to catecholamines is increased, and changes in glucagon and insulin concentrations are not necessary for increased lipolysis and hepatic glycogen depletion during...

  6. Habituation in the rat fetus.

    Science.gov (United States)

    Smotherman, W P; Robinson, S R

    1992-04-01

    Rat fetuses exhibit motor and cardiac responses to chemosensory stimulation on Days 20 and 21 of gestation. The first experiment demonstrated that fetuses exhibit an increase in overall motor activity and decrease in heartrate in response to an initial intraoral infusion of a lemon solution. After a series of nine exposures, however, fetuses no longer exhibit motor or cardiac responses to lemon infusion, suggesting the existence of a habituation-like process. Responsiveness recovers spontaneously following a 3- to 9-min period without stimulation. In a second experiment, a dishabituation treatment was administered to distinguish habituation, which is a centrally mediated decrement in response, from effector fatigue, sensory adaptation, and other peripheral mechanisms that can result in reduced responsiveness. A single infusion of mint following a series of nine lemon exposures was effective in reinstating fetal motor responses to lemon on both Days 20 and 21, but reinstated cardiac responses only on Day 21. Rat fetuses habituate to repeated chemosensory stimulation, suggesting the utility of the habituation paradigm in measuring CNS development during the perinatal period.

  7. Lessons From Experiments in Rats

    Directory of Open Access Journals (Sweden)

    Albert Gramsbergen

    2001-01-01

    Full Text Available In this essay a few relevant aspects of the neural and behavioral development of the brain in the human and in the rat are reviewed and related to the consequences of lesions in the central and peripheral nervous system at early and later age. Movements initially are generated by local circuits in the spinal cord and without the involvement of descending projections. After birth, both in humans and in rats it seems that the devlopment of postural control is the limiting factor for several motor behaviors to mature. Strong indications exist that the cerebellum is significantly involved in this control. Lesions in the CNS at early stages interfere with fundamental processes of neural development, such as the establishment of fiber connections and cell death patterns. Consequently, the functional effects are strongly dependent on the stage of development. The young and undisturbed CNS, on the other hand, has a much greater capacity than the adult nervous system for compensating abnormal reinnervation in the peripheral nervous system. Animal experiments indicated that the cerebellar cortex might play an important part in this compensation. This possibility should be investigated further as it might offer important perspectives for treatment in the human.

  8. Culture of cryopreserved rat hepatocyte

    Institute of Scientific and Technical Information of China (English)

    Haitao Yin; Gaojun Teng; Lifeng Wang; Baorui Liu; Xiaoping Qian

    2006-01-01

    Objective: To study the method of cryopreserving rat hepatocytes and double collagen gel culture measurement after its cryopreservation. Methods: Rat hepatocytes, isolated by two-step perfusion with collagenase using an extra corporeal perfusion apparatus, were cryopreserved in double collagen gel with culture medium added by epidermal growth factor(EGF).The expression of cell function and cellular morphology were examined during culture. Results: The hepatocytes cryopreserved in double collagen gel concluding EGF showed good morphology and biological characteristics. After thawing, the MTT metabolism and protein synthesis of hepatocytes in sandwich ± EGF groups were better than those in control group. And the morphology and function of hepatocytes in sandwich group was better than that in EGF group(P < 0.05). Conclusion: Double collagen gel culture can keep hepatocyte's activities. Thawed hepatocytes can be cultivated with collagenous matrix, which provides an environment that more closely resembles that in vivo and maintain the expression of certain liver-specific function of hepatocytes.

  9. Embryolethality of butyl benzyl phthalate in rats

    Energy Technology Data Exchange (ETDEWEB)

    Ema, N.; Itami, T.; Kawasaki, H. (National Inst. Hyg. Science, Osaka (Japan))

    1991-03-15

    The developmental toxicity of butyl benzyl phthalate (BBP) was studied in Wistar rats. Pregnant rats were given BBP at a dosage of 0, 0.25, 0.5, 1.0 or 2.0% in the diet from day 0 to day 20 of pregnancy. Morphological examinations of the fetuses revealed no evidence of teratogenesis. In the 2.0% group, all dams exhibited complete resorption of all the implanted embryos, and their food consumption, body weight gain and adjusted weight gain during pregnancy were markedly lowered. To determine whether the embryolethality was the result of reduced food consumption during pregnancy, a pair-feeding study was performed in which the pregnant rats received the same amount of diet consumed by the 2.0% BBP-treated pregnant rats. The pair-fed and 2.0 % BBP-treated pregnant rats showed significant and comparable reductions in the adjusted weight gain. The number of live fetuses was lowered in the pair-fed group. However, the complete resorption of all the implanted embryos was not found in any of the pair-fed pregnant rats. The data suggest that the embryolethality observed in the 2.0 % BBP-treated pregnant rats is attributable to the effects o dietary BBP.

  10. Characteristic anatomical structures of rat temporal bone

    Institute of Scientific and Technical Information of China (English)

    Peng Li; Kelei Gao; Dalian Ding; Richard Salvi

    2015-01-01

    As most gene sequences and functional structures of internal organs in rats have been well studied, rat models are widely used in experi-mental medical studies. A large number of descriptions and atlas of the rat temporal bone have been published, but some detailed anatomy of its surface and inside structures remains to be studied. By focusing on some unique characteristics of the rat temporal bone, the current paper aims to provide more accurate and detailed information on rat temporal bone anatomy in an attempt to complete missing or unclear areas in the existed knowledge. We also hope this paper can lay a solid foundation for experimental rat temporal bone surgeries, and promote information exchange among colleagues, as well as providing useful guidance for novice researchers in the field of hearing research involving rats. Copyright © 2015 The Authors. Production & hosting by Elsevier (Singapore) Pte Ltd On behalf of PLA General Hospital Department of Otolaryngology Head and Neck Surgery. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

  11. Muscle bioenergetics in obese Zucker rats.

    Science.gov (United States)

    Klein, M; Kaminsky, P; Walker, P M; Straczek, J; Barbe, F; Duc, M; Burlet, C

    1994-03-01

    The purpose of this study was to investigate the energetic metabolism in obese Zucker rats, using phosphorus nuclear magnetic resonance spectroscopy at rest and during a 2-Hz muscle stimulation and subsequent recovery. Animals were anesthetized with ketamine (150 mg/kg ip). Fed obese rats and 2-day-fasted obese rats were compared with their normally fed and 2-day-fasted lean litter mates. No differences were found between the two groups for ATP, total creatine, phosphocreatine (PCr), and intracellular pH. Starvation in lean rats resulted in a significant fall in inorganic phosphate (Pi), increased resting ADP level, and decreased PCr and ADP recovery after stimulation. The obese rats exhibited a decreased PCr/Pi and increased ADP at rest and a decreased PCr resynthesis and ADP metabolization rate after stimulation. Muscle stimulation in fasted obese rats induced higher PCr depletion and more pronounced acidosis. These results suggest an in vivo mitochondrial metabolism dysfunction in fasted lean as well as in fed and fasted obese rats.

  12. Population Structure of Rat-Derived Pneumocystis carinii in Danish Wild Rats

    DEFF Research Database (Denmark)

    Palmer, Robert J.; Settnes, Osvald P.; Lodal, Jens

    2000-01-01

    samples. We report a lack of variation in the ITS1 and ITS2 regions that is consistent with an evolutionary bottleneck in the P. carinii f. sp. carinii population. This study shows that human- and rat-derived P. carinii organisms are very different, not population. This study shows that human- and rat......The rat model of Pneumocystis carinii pneumonia is frequently used to study human P. carinii infection, but there are many differences between the rat and human infections. We studied naturally acquired P. carinii in wild rats to examine the relevance of the rat model for human infection. P......-derived organisms are very different, not only in genetic composition but also in population structure and natural history....

  13. Pulpal and periodontal diseases increase triglyceride levels in diabetic rats.

    Science.gov (United States)

    Cintra, Luciano Tavares Angelo; da Silva Facundo, Aguinaldo Cândido; Azuma, Mariane Maffei; Sumida, Dóris Hissako; Astolphi, Rafael Dias; Bomfim, Suely Regina Mogami; Narciso, Luís Gustavo; Gomes-Filho, João Eduardo

    2013-07-01

    The aim of this study was to evaluate triglyceride and cholesterol levels in diabetic rats and their relationship with pulpal and periodontal diseases. Eighty male rats (Rattus norvegicus albinus, Wistar) were divided into the following eight groups comprising ten animals each: normal rats (G1), rats with pulpal diseases (G2), rats with periodontal diseases (G3), rats with both pulpal and periodontal diseases (G4), diabetic rats (G5), diabetic rats with pulpal diseases (G6), diabetic rats with periodontal diseases (G7), and diabetic rats with both periodontal and pulpal diseases (G8). Diabetes was induced by injecting streptozotocin, periapical lesions were induced by exposing pulpal tissue to the oral environment, and periodontal diseases were induced by periodontal ligature. The animals were killed after 30 days, and lipid profile was enzymatically measured using Trinder's method. The total assessed values were statistically analyzed by analysis of variance and Tukey test (p triglyceride levels of diabetic rats with periodontal disease and of diabetic rats with both periodontal and pulpal diseases were significantly higher than those of normal rats and nondiabetic group rats, respectively. The differences in the cholesterol levels among the groups were not significant. We found that the association of pulpal and periodontal diseases with diabetes increased triglyceride levels in rats. Changes in lipid profile may be related to the presence of oral infections and diabetes.

  14. Efficient single nucleotide polymorphism discovery in laboratory rat strains using wild rat-derived SNP candidates

    OpenAIRE

    Hedrich Hans J; Wedekind Dirk; Zeegers Dimphy; Guryev Victor; Smits Bart MG; Cuppen Edwin

    2005-01-01

    Abstract Background The laboratory rat (Rattus norvegicus) is an important model for studying many aspects of human health and disease. Detailed knowledge on genetic variation between strains is important from a biomedical, particularly pharmacogenetic point of view and useful for marker selection for genetic cloning and association studies. Results We show that Single Nucleotide Polymorphisms (SNPs) in commonly used rat strains are surprisingly well represented in wild rat isolates. Shotgun ...

  15. Neurotoxicity and toxicokinetics of norfloxacin in conscious rats%诺氟沙星在清醍大鼠的神经毒性和毒代动力学

    Institute of Scientific and Technical Information of China (English)

    张莉蓉; 王永铭; 陈斌艳; 程能能

    2003-01-01

    目的:研究诺氟沙星(norfloxacin,NFLX)在清醒大鼠的神经毒性和毒代动力学.方法:大鼠随机分为4组,分别ivNS,NFLX 50,100和200 mg/kg.连续记录自由活动大鼠的脑电图(EEG).用微生物法测定血清中NFLX浓度,检测菌为大肠杆菌441102.结果:(1)NFLX各组大鼠均出现痫样放电,并伴有局部抽搐、全身强直痉挛发作的行为学改变,呈剂量依赖性.脑电相对总功率增加(P<0.05).(2)NFLX的药时曲线符合二室模型,CL,Vc和T1/2β与给药剂量无关,Cmax和AUC0→∞呈剂量依赖性.(3)脑电总功率的增加与剂量、Cmax和AUCo→∞呈正相关(r分别为0.88,0.92,0.94).结论:本研究为量化诺氟沙星的中枢兴奋作用提供了可行的方法,与AUC0→∞相关的脑电相对总功率的变化可作为中枢毒性效应判定和预测的一项客观指标.%AIM: To study the neurotoxicity and toxicokinetics of norfloxacin (NFLX) in freely moving rats. METHODS:Rats were assigned randomly to four treatment groups that received a single iv dose of 50, 100, 200 mg/kg ofNFLX and 0.9 % saline, respectively. Electroencephalogram (EEG) was continuously recorded with a computer-ized system in freely moving rats. Venous blood samples were collected for determination of the NFLX concentra-tion by microbioassay method with Escherichia coli 441102 as the test strain. Toxicokinetic parameters weredetermined from serum concentration-time data with the 3p97 program. RESULTS: (1) The epileptiform dis-charges appeared in all NFLX groups with different latent periods, accompanied with limb twitching and clonic-tonic seizures. The relative total power of the EEG increased. (2) Drug serum concentration-time curves ofdifferent doses conformed to a two-compartmental model. The values of clearance, volume of distribution, andterminal half-life were dose-independent, while maximum serum concentrations (Cmax) and the areas under theconcentration-time curve (AUC0→∞) of NFLX increased with dosage. (3

  16. The rat STSL locus: characterization, chromosomal assignment, and genetic variations in sitosterolemic hypertensive rats

    Directory of Open Access Journals (Sweden)

    Klein Richard

    2003-06-01

    Full Text Available Abstract Background Elevated plant sterol accumulation has been reported in the spontaneously hypertensive rat (SHR, the stroke-prone spontaneously hypertensive rat (SHRSP and the Wistar-Kyoto (WKY rat. Additionally, a blood pressure quantitative trait locus (QTL has been mapped to rat chromosome 6 in a New Zealand genetically hypertensive rat strain (GH rat. ABCG5 and ABCG8 (encoding sterolin-1 and sterolin-2 respectively have been shown to be responsible for causing sitosterolemia in humans. These genes are organized in a head-to-head configuration at the STSL locus on human chromosome 2p21. Methods To investigate whether mutations in Abcg5 or Abcg8 exist in SHR, SHRSP, WKY and GH rats, we initiated a systematic search for the genetic variation in coding and non-coding region of Abcg5 and Abcg8 genes in these strains. We isolated the rat cDNAs for these genes and characterized the genomic structure and tissue expression patterns, using standard molecular biology techniques and FISH for chromosomal assignments. Results Both rat Abcg5 and Abcg8 genes map to chromosome band 6q12. These genes span ~40 kb and contain 13 exons and 12 introns each, in a pattern identical to that of the STSL loci in mouse and man. Both Abcg5 and Abcg8 were expressed only in liver and intestine. Analyses of DNA from SHR, SHRSP, GH, WKY, Wistar, Wistar King A (WKA and Brown Norway (BN rat strains revealed a homozygous G to T substitution at nucleotide 1754, resulting in the coding change Gly583Cys in sterolin-1 only in rats that are both sitosterolemic and hypertensive (SHR, SHRSP and WKY. Conclusions The rat STSL locus maps to chromosome 6q12. A non-synonymous mutation in Abcg5, Gly583Cys, results in sitosterolemia in rat strains that are also hypertensive (WKY, SHR and SHRSP. Those rat strains that are hypertensive, but not sitosterolemic (e.g. GH rat do not have mutations in Abcg5 or Abcg8. This mutation allows for expression and apparent apical targeting of Abcg5

  17. Rat embryonic stem cells create new era in development of genetically manipulated rat models

    Institute of Scientific and Technical Information of China (English)

    Kazushi; Kawaharada; Masaki; Kawamata; Takahiro; Ochiya

    2015-01-01

    Embryonic stem(ES) cells are isolated from theinner cell mass of a blastocyst, and are used for the generation of gene-modified animals. In mice, the transplantation of gene-modified ES cells into recipient blastocysts leads to the creation of gene-targeted mice such as knock-in and knock-out mice; these gene-targeted mice contribute greatly to scientific development. Although the rat is considered a useful laboratory animal alongside the mouse, fewer genemodified rats have been produced due to the lack of robust establishment methods for rat ES cells. A new method for establishing rat ES cells using signaling inhibitors was reported in 2008. By considering the characteristics of rat ES cells, recent research has made progress in improving conditions for the stable culture of rat ES cells in order to generate gene-modified rats efficiently. In this review, we summarize several advanced methods to maintain rat ES cells and generate gene-targeted rats.

  18. Efficient single nucleotide polymorphism discovery in laboratory rat strains using wild rat-derived SNP candidates

    Directory of Open Access Journals (Sweden)

    Hedrich Hans J

    2005-11-01

    Full Text Available Abstract Background The laboratory rat (Rattus norvegicus is an important model for studying many aspects of human health and disease. Detailed knowledge on genetic variation between strains is important from a biomedical, particularly pharmacogenetic point of view and useful for marker selection for genetic cloning and association studies. Results We show that Single Nucleotide Polymorphisms (SNPs in commonly used rat strains are surprisingly well represented in wild rat isolates. Shotgun sequencing of 814 Kbp in one wild rat resulted in the identification of 485 SNPs as compared with the Brown Norway genome sequence. Genotyping 36 commonly used inbred rat strains showed that 84% of these alleles are also polymorphic in a representative set of laboratory rat strains. Conclusion We postulate that shotgun sequencing in a wild rat sample and subsequent genotyping in multiple laboratory or domesticated strains rather than direct shotgun sequencing of multiple strains, could be the most efficient SNP discovery approach. For the rat, laboratory strains still harbor a large portion of the haplotypes present in wild isolates, suggesting a relatively recent common origin and supporting the idea that rat inbred strains, in contrast to mouse inbred strains, originate from a single species, R. norvegicus.

  19. Establishment of a novel dwarf rat strain: cartilage calcification insufficient (CCI) rats.

    Science.gov (United States)

    Tanaka, Masami; Watanabe, Minoru; Yokomi, Izuru; Matsumoto, Naoki; Sudo, Katsuko; Satoh, Hitoshi; Igarashi, Tsuneo; Seki, Azusa; Amano, Hitoshi; Ohura, Kiyoshi; Ryu, Kakei; Shibata, Shunichi; Nagayama, Motohiko; Tanuma, Jun-ichi

    2015-01-01

    Rats with dwarfism accompanied by skeletal abnormalities, such as shortness of the limbs, tail, and body (dwarf rats), emerged in a Jcl-derived Sprague-Dawley rat colony maintained at the Institute for Animal Experimentation, St. Marianna University Graduate School of Medicine. Since the dwarfism was assumed to be due to a genetic mutation based on its frequency, we bred the dwarf rats and investigated their characteristics in order to identify the causative factors of their phenotypes and whether they could be used as a human disease model. One male and female that produced dwarf progeny were selected, and reproduction was initiated by mating the pair. The incidence of dwarfism was 25.8% among the resultant litter, and dwarfism occurred in both genders, suggesting that it was inherited in an autosomal recessive manner. At 12 weeks of age, the body weights of the male and female dwarf rats were 40% and 57% of those of the normal rats, respectively. In soft X-ray radiographic and histological examinations, shortening and hypoplasia of the long bones, such as the tibia and femur, were observed, which were suggestive of endochondral ossification abnormalities. An immunohistochemical examination detected an aggrecan synthesis disorder, which might have led to delayed calcification and increased growth plate thickening in the dwarf rats. We hypothesized that the principal characteristics of the dwarf rats were systemically induced by insufficient cartilage calcification in their long bones; thus, we named them cartilage calcification insufficient (CCI) rats.

  20. Alveolar ridge augmentation by osteoinduction in rats

    DEFF Research Database (Denmark)

    Pinholt, E M; Bang, G; Haanaes, H R

    1990-01-01

    performed subperiosteally on the premaxilla and heterotopically in the abdominal muscles of rats. Light microscopic evaluations revealed that all allogenic, demineralized, and lyophilized dentin and bone implants induced new bone formation. No inflammatory or foreign body reactions were observed....

  1. Intestinal microecology in rats with ulcerative colitis

    Institute of Scientific and Technical Information of China (English)

    韩晓霞

    2013-01-01

    Objective To study the abundance and diversity ofthe gut flora in rats with dextran sulfate sodium(DSS)-induced ulcerative colitis(UC)to provide new knowledge about the pathogenesis of this disease.Methods Twenty-six

  2. [Individual sensitivity of Wistar rats to piracetam].

    Science.gov (United States)

    Nikol'skaia, K A; Kondrashevskaia, M V; Eremina, L V

    2007-11-01

    Effects of repeated piracetam (PIR) injections in a dose of 40 and 250 mg/kg/day on the learning in Water rats were studied. It has been found that character of the effects depends on typological features of the animals. Rats with strong predominance of excitation (choleric type) showed low sensitivity to PIR. Small dose of PIR provoked clear negative effect in rats with relative balance of the basic nervous processes: excitation and inhibition (sanguine and phlegmatic types). Despite of expressed activation of associative process, it complicated integrative activity. Small dose of PIR showed anxiolytic and psycho-stimulant actions only in initially unlearned rats characterized by high level of fear. Large dose of PIR had negative influence on the learning process in all animals, irrespective of typological features. Thus, the results of this study allow to suppose that the individual sensitivity of an animal to action of a pharmacological medication is caused by morpho-functional and neurochemical intraspecific heterogeneity.

  3. Hypergravity induced prolactin surge in female rats

    Science.gov (United States)

    Megory, E.; Oyama, J.

    1985-01-01

    Acute initial exposure to hypergravity (HG) was previously found to induce prolonged diestrous in rats, which was followed by return to normal estrous cycling upon more prolonged exposure to continuous HG. Bromergocryptine was found to prevent this prolonged diestrous. In this study it is found that in female rats 20 h of 3.14 G exposure (D-1 1200 h until D-2 0800 h) can induce prolactin surge at D-2 1600 h. Shorter exposure time (8 h), or exposure during a different part of the estrous cycle (19 h: from D-1 0700 h until D-2 0200 h) could not elicit this prolactin surge. Similar exposure of male rats of HG did not alter significantly their prolactin levels. It is possible that the hypothalamus of male and female rats responds differently to stimulation by HG.

  4. growing African giant rats Cricetomys gambianus

    African Journals Online (AJOL)

    bolism, conductance and evaporative water loss changes in relation to physical and behavioural development in growing giant rat pups ... evaporation) into dry air was collected in a pre-weighed column of silica ..... Principles and adaptation.

  5. Rat sperm motility analysis: methodologic considerations

    Science.gov (United States)

    The objective of these studies was to optimize conditions for computer-assisted sperm analysis (CASA) of rat epididymal spermatozoa. Methodologic issues addressed include sample collection technique, sampling region within the epididymis, type of diluent medium used, and sample c...

  6. A Music Preference Test System for Rats

    Institute of Scientific and Technical Information of China (English)

    Chun-Peng Zhang; Guang-Zhan Fang; Yang Xia; Tie-Jun Liu; De-Zhong Yao

    2009-01-01

    In music preference experiments,housing conditions and the control of parameters for animals can affect experimental results.However,the needs of animals are indeed insufficiently considered in many reports of animal experiments.In order to evaluate which music rats prefer,we developed a new music preference test system.Dwelling time and visiting frequency can be recorded automatically when rats moving among different compartments of the system.We can also observe the behaviors of rats captured by a video camera.By this system,the music preference can be found,and then the related music can be used in following various studies.In this paper,we described the design of this music preference test system of rat,and some primary results were reported.

  7. Morphological and neurohistological changes in adolescent rats ...

    African Journals Online (AJOL)

    ... preventable diseases affecting various organs and systems of the body, including the ... The current study was conducted to demonstrate the histological changes ... Pregnancy was confirmed and the pregnant rats were divided into 3 groups ...

  8. Penile autotransplantation in rats: An animal model

    Directory of Open Access Journals (Sweden)

    Raouf M Seyam

    2013-01-01

    Conclusions: Penile autotransplantation in rats is feasible and provides the basis for evaluation of the corpora cavernosa in an allotransplantation model. Long-term urethral continuity and dorsal neurovascular bundle survival in this model is difficult to establish.

  9. Rat Bite Fever Resembling Rheumatoid Arthritis

    Directory of Open Access Journals (Sweden)

    Ripa Akter

    2016-01-01

    Full Text Available Rat bite fever is rare in Western countries. It can be very difficult to diagnose as blood cultures are typically negative and a history of rodent exposure is often missed. Unless a high index of suspicion is maintained, the associated polyarthritis can be mistaken for rheumatoid arthritis. We report a case of culture-positive rat bite fever in a 46-year-old female presenting with fever and polyarthritis. The clinical presentation mimicked rheumatoid arthritis. Infection was complicated by discitis, a rare manifestation. We discuss the diagnosis and management of this rare zoonotic infection. We also review nine reported cases of rat bite fever, all of which had an initial presumptive diagnosis of a rheumatological disorder. Rat bite fever is a potentially curable infection but can have a lethal course if left untreated.

  10. Black ginseng extract ameliorates hypercholesterolemia in rats

    Directory of Open Access Journals (Sweden)

    Evelyn Saba

    2016-04-01

    Conclusion: Administration of BG extracts to Sprague Dawley rats fed with high-cholesterol diet ameliorated hypercholesterolemia, which was mediated via modulation of cholesterol-metabolizing marker genes. This data throw a light on BG's cardioprotective effects.

  11. Serum testosterone concentration in chloroquine- treated rats ...

    African Journals Online (AJOL)

    ONOS

    2010-07-05

    Jul 5, 2010 ... male reproductive functions. For instance ... had been observed to protect human epididymis and ... Animal model ... to the development of resistance against it induced by ... and differentiation in rats and other animal species.

  12. How rats combine temporal cues.

    Science.gov (United States)

    Guilhardi, Paulo; Keen, Richard; MacInnis, Mika L M; Church, Russell M

    2005-05-31

    The procedures for classical and operant conditioning, and for many timing procedures, involve the delivery of reinforcers that may be related to the time of previous reinforcers and responses, and to the time of onsets and terminations of stimuli. The behavior resulting from such procedures can be described as bouts of responding that occur in some pattern at some rate. A packet theory of timing and conditioning is described that accounts for such behavior under a wide range of procedures. Applications include the food searching by rats in Skinner boxes under conditions of fixed and random reinforcement, brief and sustained stimuli, and several response-food contingencies. The approach is used to describe how multiple cues from reinforcers and stimuli combine to determine the rate and pattern of response bouts.

  13. A digital rat atlas of sectional anatomy

    Science.gov (United States)

    Yu, Li; Liu, Qian; Bai, Xueling; Liao, Yinping; Luo, Qingming; Gong, Hui

    2006-09-01

    This paper describes a digital rat alias of sectional anatomy made by milling. Two healthy Sprague-Dawley (SD) rat weighing 160-180 g were used for the generation of this atlas. The rats were depilated completely, then euthanized by Co II. One was via vascular perfusion, the other was directly frozen at -85 °C over 24 hour. After that, the frozen specimens were transferred into iron molds for embedding. A 3% gelatin solution colored blue was used to fill the molds and then frozen at -85 °C for one or two days. The frozen specimen-blocks were subsequently sectioned on the cryosection-milling machine in a plane oriented approximately transverse to the long axis of the body. The surface of specimen-blocks were imaged by a scanner and digitalized into 4,600 x2,580 x 24 bit array through a computer. Finally 9,475 sectional images (arterial vessel were not perfused) and 1,646 sectional images (arterial vessel were perfused) were captured, which made the volume of the digital atlas up to 369.35 Gbyte. This digital rat atlas is aimed at the whole rat and the rat arterial vessels are also presented. We have reconstructed this atlas. The information from the two-dimensional (2-D) images of serial sections and three-dimensional (3-D) surface model all shows that the digital rat atlas we constructed is high quality. This work lays the foundation for a deeper study of digital rat.

  14. MODELING OPERANT BEHAVIOR IN THE PARKINSONIAN RAT

    OpenAIRE

    Avila, Irene; Reilly, Mark P; Sanabria, Federico; Posadas-Sánchez, Diana; Chavez, Claudia L.; Banerjee, Nikhil; Killeen, Peter; Castañeda, Edward

    2008-01-01

    Mathematical principles of reinforcement (MPR; Killeen, 1994) is a quantitative model of operant behavior that contains 3 parameters representing motor capacity (δ), motivation (a), and short term memory (λ). The present study applied MPR to characterize the effects of bilateral infusions of 6-OHDA into the substantia nigra pars compacta in the rat, a model of Parkinson’s disease. Rats were trained to lever press under a 5-component fixed ratio (5, 15, 30, 60, and 100) schedule of food reinfo...

  15. Epidermal growth factor in the rat prostate

    DEFF Research Database (Denmark)

    Tørring, Niels; Jørgensen, P E; Poulsen, Steen Seier;

    1998-01-01

    Epidermal growth factor (EGF) induces proliferation in prostate epithelial and stromal cells in primary culture. This investigation was set up to characterize the time and spatial expression of EGF in the rat prostate.......Epidermal growth factor (EGF) induces proliferation in prostate epithelial and stromal cells in primary culture. This investigation was set up to characterize the time and spatial expression of EGF in the rat prostate....

  16. Streptozotocin induced diabetes in lyon hypertensive rats

    Institute of Scientific and Technical Information of China (English)

    LeaEMONNOT; JeanSASSARD; MingLO

    2004-01-01

    AIM: Lyon hypertensive (LH) rats, compared to their normotensive controls (LL) exhibit an increased blood pressure (BP)associated with a marked proteinuria and a metabolic syndrom including elevated plasma lipids and insulin/glucose ratio. The aim of the present work was to determine wether a type 2 diabetes could be induced in LH rats so as to obtain a model suitable for study of the relationships between diabetes and hypertension.

  17. Modeling diabetic sensory neuropathy in rats.

    Science.gov (United States)

    Calcutt, Nigel A

    2004-01-01

    The procedures to induce insulin-deficient diabetes in rats using streptozotocin are described along with a number of insulin treatment regimes that can be used to maintain these animals at different degrees of glycemia for periods of weeks to months. Streptozotocin-diabetic rats develop tactile allodynia, hyperalgesia following paw formalin injection and abnormal responses to thermal stimulation and the detailed methods used to evaluate these behavioral indices of abnormal sensory function are provided.

  18. Male rats play a repeated donation game.

    Science.gov (United States)

    Li, Grace; Wood, Ruth I

    2017-05-15

    While previous studies have demonstrated direct and generalized reciprocity in female Norway rats [26], the present study determined if unrelated male laboratory rats respond on behalf of a partner in an iterated sequential game. Pairs of rats worked for food reward in an operant chamber, where participants alternated as Donor and Responder in successive trials. In each trial, the Donor chose between variable and constant reward levers, where the constant reward lever delivered 1 pellet, and the variable reward lever triggered insertion of Responder lever(s); the Donor received 2 pellets when the Responder made any response. In forced-choice constant (FC) trials, the Responder also received 1 pellet for responding on the constant reward lever. In forced-choice variable (FV) trials, the Responder received no pellets for responding on the variable reward lever. In free-choice (FR) trials, the Responder chose between constant (1 pellet) and variable reward levers (0 pellets). With their cagemate, rats earned 61.4±2.0 pellets (64.0±2.1% of 96 possible pellets). As Donor in FC trials, rats preferred the variable reward lever, and the Responder responded frequently. In FV trials, Donor preference for the variable reward lever declined as Responder lever responses decreased. In FR trials, rats alternated responding on variable and constant reward levers as Donor and Responder, respectively. When paired with a new partner, there was no effect on Donor responses, but responses by the Responder decreased in the FV block. Similar effects were observed when paired with a maximally-cooperative stooge. Importantly, rats did not adjust their behavior as Donor to receive more pellets. Results suggest that unrelated male rats will work on behalf of a partner, and that their behavior is sensitive to familiarity, and to cooperative responses by their partner. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Experimental model of anal fistula in rats

    OpenAIRE

    Arakaki, Mariana Sousa; Santos,Carlos Henrique Marques dos; Falcão, Gustavo Ribeiro; Cassino,Pedro Carvalho; Nakamura, Ricardo Kenithi; Gomes,Nathália Favero; Santos,Ricardo Gasparin Coutinho dos

    2013-01-01

    INTRODUCTION: the management of anal fistula remains debatable. The lack of a standard treatment free of complications stimulates the development of new options. OBJECTIVE: to develop an experimental model of anal fistula in rats. METHODS: to surgically create an anal fistula in 10 rats with Seton introduced through the anal sphincter musculature. The animals were euthanized for histological fistula tract assessment. RESULTS: all ten specimens histologically assessed had a lumen and surroundi...

  20. Experimental coccidioidomycosis in the immunosuppressed rat

    OpenAIRE

    Mirta C. Remesar; Jorgelina L. Blejer; Negroni,Ricardo; Nejamkis,Marta R.

    1992-01-01

    C. immitis inoculated rats are known to develop infection restricted to lung whereas cyclophosphamide (CY) treatment leads to widespread dissemination with considerable mortality. In this study, an attempt was made to elucidate the mechanisms involved in such behaviour. With this aim, spleen cells were transferred from infected CY-treated to infected untreated rats, achieving significant specific inhibition in footpad swelling to coccidioidin in recipients, attributable to a suppressor T cell...

  1. Collagenous skeleton of the rat mystacial pad.

    Science.gov (United States)

    Haidarliu, Sebastian; Simony, Erez; Golomb, David; Ahissar, Ehud

    2011-05-01

    Anatomical and functional integrity of the rat mystacial pad (MP) is dependent on the intrinsic organization of its extracellular matrix. By using collagen autofluorescence, in the rat MP, we revealed a collagenous skeleton that interconnects whisker follicles, corium, and deep collagen layers. We suggest that this skeleton supports MP tissues, mediates force transmission from muscles to whiskers, facilitates whisker retraction after protraction, and limits MP extensibility.

  2. Expression of somatostatin mRNA and peptide in rat hippocampus after cerebral ischemia

    DEFF Research Database (Denmark)

    Bering, Robert; Johansen, Flemming Fryd

    1993-01-01

    Somatostatin, ischemia, hippocampus, rat, in situ hybridisation, immunocytochemistry, neuropathology......Somatostatin, ischemia, hippocampus, rat, in situ hybridisation, immunocytochemistry, neuropathology...

  3. Vestibular loss disrupts daily rhythm in rats.

    Science.gov (United States)

    Martin, T; Mauvieux, B; Bulla, J; Quarck, G; Davenne, D; Denise, P; Philoxène, B; Besnard, S

    2015-02-01

    Hypergravity disrupts the circadian regulation of temperature (Temp) and locomotor activity (Act) mediated through the vestibular otolithic system in mice. In contrast, we do not know whether the anatomical structures associated with vestibular input are crucial for circadian rhythm regulation at 1 G on Earth. In the present study we observed the effects of bilateral vestibular loss (BVL) on the daily rhythms of Temp and Act in semipigmented rats. Our model of vestibular lesion allowed for selective peripheral hair cell degeneration without any other damage. Rats with BVL exhibited a disruption in their daily rhythms (Temp and Act), which were replaced by a main ultradian period (τ <20 h) for 115.8 ± 68.6 h after vestibular lesion compared with rats in the control group. Daily rhythms of Temp and Act in rats with BVL recovered within 1 wk, probably counterbalanced by photic and other nonphotic time cues. No correlation was found between Temp and Act daily rhythms after vestibular lesion in rats with BVL, suggesting a direct influence of vestibular input on the suprachiasmatic nucleus. Our findings support the hypothesis that the vestibular system has an influence on daily rhythm homeostasis in semipigmented rats on Earth, and raise the question of whether daily rhythms might be altered due to vestibular pathology in humans. Copyright © 2015 the American Physiological Society.

  4. Peripheral Neuropathy in Rats Exposed to Dichloroacetate

    Science.gov (United States)

    Calcutt, Nigel A.; Lopez, Veronica L.; Bautista, Arjel D.; Mizisin, Leah M.; Torres, Brenda R.; Shroads, Albert L.; Mizisin, Andrew P.; Stacpoole, Peter W.

    2009-01-01

    The use of dichloroacetate (DCA) for treating patients with mitochondrial diseases is limited by the induction of peripheral neuropathy. The mechanisms of DCA-induced neuropathy are not known. Oral DCA treatment (50–500 mg/kg/day for up to 16 weeks) induced tactile allodynia in both juvenile and adult rats; concurrent thermal hypoalgesia developed at higher doses. Both juvenile and adult rats treated with DCA developed nerve conduction slowing that was more pronounced in adult rats. No overt axonal or glial cell abnormalities were identified in peripheral nerves or spinal cord of any DCA-treated rats but morphometric analysis identified a reduction of mean axonal caliber of peripheral nerve myelinated fibers. DCA treatment also caused accumulation of oxidative stress markers in the nerves. These data indicate that behavioral, functional and structural indices of peripheral neuropathy may be induced in both juvenile and adult rats treated with DCA at doses similar to those in clinical use. DCA-induced peripheral neuropathy primarily afflicts axons and involves both metabolic and structural disorders. The DCA-treated rat may provide insight into the pathogenesis of peripheral neuropathy and facilitate development of adjuvant therapeutics to prevent this disorder that currently restricts the clinical use of DCA. PMID:19680144

  5. Elimination of mercury from amalgam in rats

    Energy Technology Data Exchange (ETDEWEB)

    Galic, N. [Dept. of Dental Pathology, School of Dentistry, Zagreb (Croatia); Prpic-Mehicic, G.; Prester, Lj.; Blanusa, M. [Inst. for Medical Research and Occupational Health, Zagreb (Croatia); Krnic, Z.; Erceg, D. [Pliva Pharmaceutical Co., Biomedicine Research Inst. ' ' Pliva' ' , Zagreb (Croatia)

    2001-07-01

    The aim of this study was to measure the urinary mercury excretion in rats exposed to amalgam over a two months period. Animals were either exposed to mercury from 4 dental amalgams or fed the diet containing powdered amalgams. The results showed significantly higher mercury amount in urine of both exposed groups than in control. Even two months after the amalgam had been placed in rats teeth, the amount of mercury in the urine remained 4-5 times higher than in control, and 4 times higher than in rats exposed to diet containing powdered amalgam. The elevated urinary Hg amount was accompanied by an increased level of total protein in urine. In the same exposure period the excretion of total protein in urine of rats with amalgam fillings was 2 times higher than in control and 1.5 times higher than in rats exposed to amalgam through diet. Concentrations of mercury in the sera of all groups were below the detection limit of the method. The results show that amount of mercury and protein in the urine of rats were related to the mercury release from dental amalgam. (orig.)

  6. Thermoregulation in hypergravity-acclimated rats

    Science.gov (United States)

    Monson, Conrad B.; Patterson, Susan L.; Horowitz, John M.; Oyama, Jiro

    1989-01-01

    The effect of acclimation to hypergravity on thermoregulatory responses of rats was determined by comparing data on core temperature, T(c), tail temperature, and O2 consumption in rats raised at 1 G (C) and at 2.1 G. It was found that, when C rats were exposed to an ambient temperature of 9 C concurrently with exposure to 2.1 G, the T(c) fell by about 6 C, while in rats acclimated to 2.1 G, the T(c) fell only by 1 C. Results of O2 consumption measurements showed that C rats exposed simultaneously to cold and hypergravity were not activating their thermogenic mechanism sufficiently to prevent a fall in T(c). In other experiments, rats acclimated to either 1 or 2.1 G were found to lack the ability to maintain their T(c) when exposed to a 5.8-G field or when cold-stressed at 1 G for extended times.

  7. Antioxidant mechanisms of iso-6-cassine in suppressing seizures induced by pilocarpine

    Directory of Open Access Journals (Sweden)

    Rivelilson Mendes de Freitas

    2011-06-01

    Full Text Available The aim of this study was to evaluate the in vitro antioxidant effects of 12-[(2R,5R,6R-5-hydroxy-6-methylpiperidin-2-yl]dodecan-2-one (iso-6-cassine; ISO and the anticonvulsant effects of ISO on pilocarpine-induced seizures in rats. Wistar rats were treated with 0.9% saline (i.p., control group, pilocarpine (400 mg/kg, i.p., pilocarpine group, and the association of ISO (1.0 mg/kg, i.p. plus pilocarpine (400 mg/kg, i.p., 30 min after administration of ISO (ISO plus pilocarpine group. After the treatments all groups were observed for 1h. The antioxidant effect of ISO on the pilocarpine model was assessed by determining the activity of glutathione peroxidase (GPx, glutathione-S-transferase (GST and catalase (CAT as well as the levels of reactive species (RS and lipid peroxidation (LP. In vitro, ISO (5 μM reduced RS and LP. ISO (1.0 mg/kg and abolished seizures and death induced by pilocarpine in rats. ISO protected against the increase in the RS and LP levels, GST activity as well as the inhibition of GPx activity caused by pilocarpine. In addition, ISO increased the catalase activity in hippocampus of seized rats. In conclusion, the dta suggest that ISO can present anticonvulsant and antioxidant properties in the pilocarpine model of seizures in rats.

  8. Classical clinical signs in rats experimemtally infected with Trypanosoma brucei

    Institute of Scientific and Technical Information of China (English)

    Nwoha Rosemary Ijeoma Ogechi; Omamegbe Joseph Omolathebu

    2015-01-01

    Objective:To investigate clinical signs in Trypanosoma brucei infection in albino rats. Methods:Fourteen rats grouped into 2 with 7 rats in each group were used to determine classical clinical manifestation of Trypanosoma brucei infection in rats. Group A rats were uninfected control and Group B rats were infected with Trypanosoma brucei. Results:Parasitaemia was recorded in Group B by (3.86±0.34) d and the peak of parasitaemia was observed at Day 5 post infection. Classical signs observed included squint eyes, raised whiskers, lethargy, no weight loss, pyrexia, isolation from the other rats, and starry hair coat. Conclusions:These signs could be diagnostic or aid in diagnosis of Trypanosoma brucei infection in rats.

  9. INTERCEPTIVE EFFECTS OF EPOSTANE IN RATS AND RHESUS MONKEYS

    Institute of Scientific and Technical Information of China (English)

    LINZhong-Ming; LIUChang-Guan; CHENHui-Qing; LIWei-Kang; XURui-Ying

    1989-01-01

    Interceptives arc defined as agents which interrupt pregnancy after implantation.Epostane, a potent 3β-hydroxysteruid dehydrogenase inhibitor, possessed interceptive activities in rats and rhesus monkeys. In rats, day 10 and day 11 of pregnancy were the

  10. Classical clinical signs in rats experimemtally infected with Trypanosoma brucei

    Directory of Open Access Journals (Sweden)

    Nwoha Rosemary Ijeoma Ogechi

    2015-02-01

    Full Text Available Objective: To investigate clinical signs in Trypanosoma brucei infection in albino rats. Methods: Fourteen rats grouped into 2 with 7 rats in each group were used to determine classical clinical manifestation of Trypanosoma brucei infection in rats. Group A rats were uninfected control and Group B rats were infected with Trypanosoma brucei. Results: Parasitaemia was recorded in Group B by (3.86±0.34 d and the peak of parasitaemia was observed at Day 5 post infection. Classical signs observed included squint eyes, raised whiskers, lethargy, no weight loss, pyrexia, isolation from the other rats, and starry hair coat. Conclusions: These signs could be diagnostic or aid in diagnosis of Trypanosoma brucei infection in rats.

  11. National BioResource Project-Rat and related activities.

    Science.gov (United States)

    Serikawa, Tadao; Mashimo, Tomoji; Takizawa, Akiko; Okajima, Ryoko; Maedomari, Naoki; Kumafuji, Kenta; Tagami, Fumi; Neoda, Yuki; Otsuki, Mito; Nakanishi, Satoshi; Yamasaki, Ken-ichi; Voigt, Birger; Kuramoto, Takashi

    2009-07-01

    In order to establish a system to facilitate the systematic collection, preservation, and provision of laboratory rats (Rattus norvegicus) and their derivates, the National BioResource Project-Rat (NBRP-Rat) was launched in July 2002. By the end of 2008, more than 500 rat strains had been collected and preserved as live animals, embryos, or sperm. These rat resources are supplied to biomedical scientists in Japan as well as in other countries. This review article introduces NBRP-Rat and highlights the phenome project, recombinant inbred strains, BAC clone libraries, and the ENU-mutant archive, named the Kyoto University Rat Mutant Archive (KURMA). The future direction of rat resources are also discussed.

  12. Control of glomerular hypertension by insulin administration in diabetic rats.

    OpenAIRE

    Scholey, J.W.; Meyer, T W

    1989-01-01

    Micropuncture studies were performed in Munich Wistar rats made diabetic with streptozotocin and in normal control rats. Diabetic rats received daily ultralente insulin to maintain moderate hyperglycemia (approximately 300 mg/dl). Group 1 diabetic rats studied after routine micropuncture preparation exhibited elevation of the single nephron glomerular filtration rate (SNGFR) due to increases in the glomerular transcapillary hydraulic pressure difference and glomerular plasma flow rate. In gro...

  13. Biochemical effect of curcumin on hyperlipidemia induced in rats

    OpenAIRE

    Omayma A.R.; Ragab A.; Abdel-Majeed A.D; Hassanin K.M.; Abdelghaffar M.M.

    2016-01-01

    This study was performed to investigate the effect of oral supplementation of curcumin, garlic extract and olive oil on lipid profile, nitric oxide, adiponectin, endothelin-1, blood glucose and some inflammatory markers in normal, diabetic and hyperlipidemic rats supplementing high fat and cholesterol-enriched diet. Forty female adult albino rats were divided into four equal groups of 10 rats each. Group (1): negative control received normal diet only, group (2): rats fed on normal diet and r...

  14. Chronotoxicity of nedaplatin in rats.

    Science.gov (United States)

    Cui, Yimin; Sugimoto, Koh-Ichi; Kawai, Yoshiko; Sudoh, Toshiaki; Gemba, Munekazu; Fujimura, Akio

    2004-07-01

    Chronotoxicologic profiles of nedaplatin, a platinum compound, were evaluated in rats maintained under a 12 light/12 dark cycle with light from 07:00h to 19:00 h. Nedaplatin (5 mg/kg) was injected intravenously, once a week for 5 weeks at 08:00h or 20:00h. The suppression of body weight gain and reduction of creatinine clearance were significantly greater with the 20:00h than 08:00h treatment. Accumulation of nedaplatin in the renal cortex and bone marrow were also greater with 20:00 h treatment. There were significant relationships between the nedaplatin content in the kidney and bone marrow and degree of injury to each. These results suggest that the nedaplatin-induced toxicity depends on its dosing-time, and it is greater with treatment at 20:00 h, during the active phase. The dosing-time dependency in the accumulation of nedaplatin in the tissue of the organs might be involved in this chronotoxicologic phenomenon.

  15. Radioimmunoimaging of pneumocystis carinii infection in rats

    Energy Technology Data Exchange (ETDEWEB)

    Vallabhajosula, S.; Shane, L.B.; Goldsmith, S.J.; Lipszyc, H.; Walzer, P.

    1984-01-01

    Pneumocystis carinil pneumonia (PCP) is seen in patients with impaired immunity due to chemotherapeutic suppression or to a primary disorder, congenital or AIDS. Although radiogallium imaging has been helpful in the workup of PCP, it is non-specific. Since there is no early specific non-invasive method to diagnose PCP, the authors are developing an imaging technique using radiolabeled antibodies. Fulminant PCP was induced in rats by injecting cortisone, 20mg 2-3 times/wk for 8 wks. PC cells isolated from rat lung were injected into rabbits. The antiserum thus derived was separated and purified using Protein-A bound sepharose column with identification of IgG by polyacrylamide gel electrophoresis. Both rabbit antipneumocystis antibodies and purified IgG(Sigma) were iodinated with I-131 to a high specific activity (3-5..mu..Ci/ug) using a lactoperoxidase method. /sup 131/I-labeled specific and non-specific IgG were injected into rats with PC infection and imaged with an Anger camera. After sacrifice, I-131 activity/gram tissue (lung, liver, heart) was determined and expressed as organ ratios. An increased uptake of specific antibody in lungs of rats with PCP was demonstrated by organ counting and imaging. This increase was not seen in normal controls or rats injected with non-specific IgG. These data provide a basis for radioimmunoimaging of infectious diseases.

  16. Diabetic rat testes: morphological and functional alterations.

    Science.gov (United States)

    Ricci, G; Catizone, A; Esposito, R; Pisanti, F A; Vietri, M T; Galdieri, M

    2009-12-01

    Reproductive dysfunction is a consequence of diabetes, but the underlying mechanisms are poorly understood. This study investigated the histological and molecular alterations in the testes of rats injected with streptozotocin at prepuperal (SPI rats) and adult age (SAI rats) to understand whether diabetes affects testicular tissue with different severity depending on the age in which this pathological condition starts. The testes of diabetic animals showed frequent abnormal histology, and seminiferous epithelium cytoarchitecture appeared altered as well as the occludin distribution pattern. The early occurrence of diabetes increased the percentage of animals with high number of damaged tubules. The interstitial compartment of the testes was clearly hypertrophic in several portions of the organs both in SPI and SAI rats. Interestingly, fully developed Leydig cells were present in all the treated animals although abnormally distributed. Besides the above-described damages, we found a similar decrease in plasma testosterone levels both in SPI and SAI rats. Oxidative stress (OS) is involved in the pathogenesis of various diabetic complications, and in our experimental models we found that manganese superoxide dismutase was reduced in diabetic animals. We conclude that in STZ-induced diabetes, the altered spermatogenesis, more severe in SPI animals, is possibly due to the effect of OS on Leydig cell function which could cause the testosterone decrease responsible for the alterations found in the seminiferous epithelium of diabetic animals.

  17. A rat model for hepatitis E virus

    Science.gov (United States)

    Mishra, Niraj; Verbeken, Erik; Ramaekers, Kaat; Dallmeier, Kai

    2016-01-01

    ABSTRACT Hepatitis E virus (HEV) is one of the prime causes of acute viral hepatitis, and chronic hepatitis E is increasingly recognized as an important problem in the transplant setting. Nevertheless, the fundamental understanding of the biology of HEV replication is limited and there are few therapeutic options. The development of such therapies is partially hindered by the lack of a robust and convenient animal model. We propose the infection of athymic nude rats with the rat HEV strain LA-B350 as such a model. A cDNA clone, pLA-B350, was constructed and the infectivity of its capped RNA transcripts was confirmed in vitro and in vivo. Furthermore, a subgenomic replicon, pLA-B350/luc, was constructed and validated for in vitro antiviral studies. Interestingly, rat HEV proved to be less sensitive to the antiviral activity of α-interferon, ribavirin and mycophenolic acid than genotype 3 HEV (a strain that infects humans). As a proof-of-concept, part of the C-terminal polymerase sequence of pLA-B350/luc was swapped with its genotype 3 HEV counterpart: the resulting chimeric replicon replicated with comparable efficiency as the wild-type construct, confirming that LA-B350 strain is amenable to humanization (replacement of certain sequences or motifs by their counterparts from human HEV strains). Finally, ribavirin effectively inhibited LA-B350 replication in athymic nude rats, confirming the suitability of the rat model for antiviral studies. PMID:27483350

  18. A rat model for hepatitis E virus

    Directory of Open Access Journals (Sweden)

    Yannick Debing

    2016-10-01

    Full Text Available Hepatitis E virus (HEV is one of the prime causes of acute viral hepatitis, and chronic hepatitis E is increasingly recognized as an important problem in the transplant setting. Nevertheless, the fundamental understanding of the biology of HEV replication is limited and there are few therapeutic options. The development of such therapies is partially hindered by the lack of a robust and convenient animal model. We propose the infection of athymic nude rats with the rat HEV strain LA-B350 as such a model. A cDNA clone, pLA-B350, was constructed and the infectivity of its capped RNA transcripts was confirmed in vitro and in vivo. Furthermore, a subgenomic replicon, pLA-B350/luc, was constructed and validated for in vitro antiviral studies. Interestingly, rat HEV proved to be less sensitive to the antiviral activity of α-interferon, ribavirin and mycophenolic acid than genotype 3 HEV (a strain that infects humans. As a proof-of-concept, part of the C-terminal polymerase sequence of pLA-B350/luc was swapped with its genotype 3 HEV counterpart: the resulting chimeric replicon replicated with comparable efficiency as the wild-type construct, confirming that LA-B350 strain is amenable to humanization (replacement of certain sequences or motifs by their counterparts from human HEV strains. Finally, ribavirin effectively inhibited LA-B350 replication in athymic nude rats, confirming the suitability of the rat model for antiviral studies.

  19. Glutamine synthetase induced spinal seizures in rats.

    Science.gov (United States)

    Shin, Dong Won; Yoon, Young Sul; Matsumoto, Masato; Huang, Wencheng; Ceraulo, Phil; Young, Wise

    2003-02-01

    Glutamine synthetase (GS) is a key enzyme in the regulation of glutamate neurotransmission in the central nervous system. It is responsible for converting glutamate to glutamine, consuming one ATP and NH3 in the process. Glutamate is neurotoxic when it accumulates in extracellular fluids. We investigated the effects of GS in both a spinal cord injury (SCI) model and normal rats. 0.1-ml of low (2- micro M) and high (55- micro M) concentrations of GS were applied, intrathecally, to the spinal cord of rats under pentobarbital anesthesia. Immediately after an intrathecal injection into the L1-L3 space, the rats developed convulsive movements. These movements initially consisted of myoclonic twitches of the paravertebral muscles close to the injection site, repeated tonic and clonic contractions and extensions of the hind limbs (hind limb seizures) that spread to the fore limbs, and finally rotational axial movements of the body. An EMG of the paravertebral muscles, fore and hind limbs, showed the extent of the muscle activities. GS (2- micro M) caused spinal seizures in the rats after the SCI, and GS (6- micro M) produced seizures in the uninjured anesthetized rats. Denatured GS (70 degrees C, 1 hour) also produced spinal seizures, although higher concentrations were required. We suggest that GS may be directly blocking the release of GABA, or the receptors, in the spinal cord.

  20. Intracranial localization of arachnoid granulations in rats

    Institute of Scientific and Technical Information of China (English)

    Yanan Dong; Min Yu; Lei Meng; Yong Jiang; Jun Gao; Honghai Peng; Jianguo Shi

    2008-01-01

    BACKGROUND: This paper describes histomorphologic studies on arachnoid granulations in rats, which have not been investigated in China to our knowledge.OBJECTIVE: To observe the distribution of intracranial arachnoid granulations in rats. DESIGN, TIME AND SETTING: The observational experiment was performed in the Academy of Life Sciences of Shandong Taishan Medical College from May to August 2004.MATERIALS: Thirty healthy adult Wistar rats (3-4 months old) of SPF grade, equal numbers of each sex, were selected for this study. Methylene blue parenteral solution was provided by Jiangsu Jichuan Pharmaceutical Company (China), and an optical microscope (Type: CH20; Olympus Co. Ltd., Japan) was used for observation of the histomorphology of the arachnoid granulations.METHOD: Injection of methylene blue parenteral solution into the cerebellomedullary cistern of rats.MAIN OUTCOME MEASURE: The blue stained parts of the lateral sinus were sectioned, stained by hematoxylin and eosin, and then observed under the microscope.RESULTS: The cavitas subarachnoidealis had extensive blue staining after methylene blue injection, while the arachnoid and dura were without dye accumulation. The blue dye indicated the location of the arachnoid granulations. The location of these granulations was fixed, mainly in the lateral sinus at both sides of confluence within 4 mm of the internal jugular vein.CONCLUSION: The arachnoid granulations of the rat were located mainly in the lateral sinuses of the dura mater.

  1. Proteomic analysis of hippocampus in the rat

    Institute of Scientific and Technical Information of China (English)

    ZHANG Bo; WANG Ren-zhi; LIAN Zhi-gang; YAO Yong

    2004-01-01

    Objective To analyze the protein expression in the rat hippocampus by the proteomic approach.Methods Proteins from hippocampal tissue homogenates of the rat were separated by two-dimensional gel electrophoresis(2-DE),and stained with colloidal Coomassie blue to produce a high-resolution map of the rat hippocampus proteome.Selected proteins from this map were digested with trypsin,and the resulting tryptic peptides were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF-MS).The mass spectrometric data were used to identify the proteins through searches of the NCBI protein sequence database.Results 37 prominent proteins with various functional characteristics were identified.The identified brain protein classes covered metabolism enzymes,cytoskeleton proteins,heat shock proteins,antioxidant proteins,signalling proteins,proteasome-related proteins,neuron-specific proteins and glial-associated proteins.Furthermore,3 hypothetical proteins,unknown proteins so far only proposed from their nucleic acid structure,were identified.Conclusion This study provides the first unbiased characterization of proteins of the rat hippocampus and will be used for future studies of differential protein expression in rat models of neurological disorders.

  2. Modeling Alzheimer's disease in transgenic rats.

    Science.gov (United States)

    Do Carmo, Sonia; Cuello, A Claudio

    2013-10-25

    Alzheimer's disease (AD) is the most common form of dementia. At the diagnostic stage, the AD brain is characterized by the accumulation of extracellular amyloid plaques, intracellular neurofibrillary tangles and neuronal loss. Despite the large variety of therapeutic approaches, this condition remains incurable, since at the time of clinical diagnosis, the brain has already suffered irreversible and extensive damage. In recent years, it has become evident that AD starts decades prior to its clinical presentation. In this regard, transgenic animal models can shed much light on the mechanisms underlying this "pre-clinical" stage, enabling the identification and validation of new therapeutic targets. This paper summarizes the formidable efforts to create models mimicking the various aspects of AD pathology in the rat. Transgenic rat models offer distinctive advantages over mice. Rats are physiologically, genetically and morphologically closer to humans. More importantly, the rat has a well-characterized, rich behavioral display. Consequently, rat models of AD should allow a more sophisticated and accurate assessment of the impact of pathology and novel therapeutics on cognitive outcomes.