Rodent Models Of Epilepsy Research Articles

Effects of rapamycin and curcumin on inflammation and oxidative stress in vitro and in vivo \u2014 in search of potential anti-epileptogenic strategies for temporal lobe epilepsy

BackgroundPrevious studies in various rodent epilepsy models have suggested that mammalian target of rapamycin (mTOR) inhibition with rapamycin has anti-epileptogenic potential. Since treatment with rapamycin produces unwanted side effects, there is growing interest to study alternatives to rapamycin as anti-epileptogenic drugs. Therefore, we investigated curcumin, the main component of the natural spice turmeric. Curcumin is known to have anti-inflammatory and anti-oxidant effects and has been reported to inhibit the mTOR pathway. These properties make it a potential anti-epileptogenic compound and an alternative for rapamycin.MethodsTo study the anti-epileptogenic potential of curcumin compared to rapamycin, we first studied the effects of both compounds on mTOR activation, inflammation, and oxidative stress in vitro, using cell cultures of human fetal astrocytes and the neuronal cell line SH-SY5Y. Next, we investigated the effects of rapamycin and intracerebrally applied curcumin on status epilepticus (SE)—induced inflammation and oxidative stress in hippocampal tissue, during early stages of epileptogenesis in the post-electrical SE rat model for temporal lobe epilepsy (TLE).ResultsRapamycin, but not curcumin, suppressed mTOR activation in cultured astrocytes. Instead, curcumin suppressed the mitogen-activated protein kinase (MAPK) pathway. Quantitative real-time PCR analysis revealed that curcumin, but not rapamycin, reduced the levels of inflammatory markers IL-6 and COX-2 in cultured astrocytes that were challenged with IL-1β. In SH-SY5Y cells, curcumin reduced reactive oxygen species (ROS) levels, suggesting anti-oxidant effects. In the post-SE rat model, however, treatment with rapamycin or curcumin did not suppress the expression of inflammatory and oxidative stress markers 1 week after SE.ConclusionsThese results indicate anti-inflammatory and anti-oxidant properties of curcumin, but not rapamycin, in vitro. Intracerebrally applied curcumin modified the MAPK pathway in vivo at 1 week after SE but failed to produce anti-inflammatory or anti-oxidant effects. Future studies should be directed to increasing the bioavailability of curcumin (or related compounds) in the brain to assess its anti-epileptogenic potential in vivo.

A companion to the preclinical common data elements on neurobehavioral comorbidities of epilepsy: a report of the TASK3 behavior working group of the ILAE/AES Joint Translational Task Force.

SummaryThe provided companion has been developed by the Behavioral Working Group of the Joint Translational Task Force of the International League Against Epilepsy (ILAE) and the American Epilepsy Society (AES) with the purpose of assisting the implementation of Preclinical Common Data Elements (CDE) for studying and for reporting neurobehavioral comorbidities in rodent models of epilepsy. Case Report Forms (CRFs) are provided, which should be completed on a per animal/per test basis, whereas the CDEs are a compiled list of the elements that should be reported. This companion is not designed as a list of recommendations, or guidelines for how the tests should be run—rather, it describes the different types of assessments, and highlights the importance of rigorous data collection and transparency in this regard. The tests are divided into 7 categories for examining behavioral dysfunction on the syndrome level: deficits in learning and memory; depression; anxiety; autism; attention deficit/hyperactivity disorder; psychosis; and aggression. Correspondence and integration of these categories into the National Institute of Mental Health (NIMH) Research Domain Criteria (RDoC) is introduced. Developmental aspects are addressed through the introduction of developmental milestones. Discussion includes complexities, limitations, and biases associated with neurobehavioral testing, especially when performed in animals with epilepsy, as well as the importance of rigorous data collection and of transparent reporting. This represents, to our knowledge, the first such resource dedicated to preclinical CDEs for behavioral testing of rodents.

Biochemical autoregulatory gene therapy for focal epilepsy.

Despite the introduction of over a dozen new antiepileptic drugs in the last 20 years, approximately one third of people who develop epilepsy continue to have seizures on mono- or polytherapy1. Viral-vector mediated gene transfer offers the opportunity to design a rational treatment that builds on mechanistic understanding of seizure generation and that can be targeted to specific neuronal populations in epileptogenic foci2. Several such strategies show encouraging results in different animal models, although clinical translation is limited by possible effects on circuits underlying cognitive, mnemonic, sensory or motor function. Here we describe an autoregulatory anti-epileptic gene therapy, which relies on neuronal inhibition in response to elevations of extracellular glutamate. It is effective in a rodent model of focal epilepsy, and well tolerated, thus lowering the barrier to clinical translation.

Imaging correlates of behavioral impairments: An experimental PET study in the rat pilocarpine epilepsy model

Psychiatric comorbidities are prevalent in patients with epilepsy and greatly contribute to the overall burden of disease. The availability of reliable biomarkers to diagnose epilepsy-associated comorbidities would allow for effective treatment and improved disease management. Due to their non-invasive nature, molecular imaging techniques such as positron emission tomography (PET) are ideal tools to measure pathologic changes. In the current study we investigated the potential of [18F]fluoro-2-deoxy-d-glucose ([18F]FDG) and 2′-methoxyphenyl-(N-2′-pyridinyl)-p-18F-fluoro-benzamidoethylpiperazine ([18F]MPPF) as imaging correlates of neurobehavioral comorbidities in the pilocarpine rat model of epilepsy. Findings from rats with epilepsy revealed a regional reduction in [18F]FDG uptake indicating thalamic hypometabolism. In addition, an increase in septal [18F]MPPF binding was observed in rats with spontaneous recurrent seizures. Both thalamic [18F]FDG and septal [18F]MPPF data proved to correlate with behavioral alterations including decreases in luxury behavior such as burrowing and social interaction, and changes in behavioral patterns in anxiety tests. A correlation with seizure frequency was confirmed for thalamic [18F]FDG data. Moreover, thalamic [18F]FDG and septal [18F]MPPF data exhibited a correlation with brain-derived neurotrophic factor (BDNF) serum concentrations, which were lowered in rats with epilepsy.In conclusion, μPET data from rats with pilocarpine-induced epileptogenesis indicate altered septal 5-HT1A receptor binding. Further research is necessary assessing whether septal 5-HT1A receptor binding may serve as an imaging correlate of neuropsychiatric comorbidities in epilepsy patients and for severity assessment in rodent epilepsy models. In contrast, we obtained evidence that [18F]FDG uptake also reflects the severity of epilepsy and, thus, might not constitute a biomarker with sufficient specificity for psychiatric comorbidities. Evidence has been obtained that BDNF might serve as a peripheral circulatory biomarker. Further experimental and clinical assessment is necessary for validation of the marker candidates.

Signaling Pathways and Cellular Mechanisms Regulating Mossy Fiber Sprouting in the Development of Epilepsy.

The sprouting of hippocampal dentate granule cell axons, termed mossy fibers, into the dentate inner molecular layer is one of the most consistent findings in tissue from patients with mesial temporal lobe epilepsy. Decades of research in animal models have revealed that mossy fiber sprouting creates de novo recurrent excitatory connections in the hippocampus, fueling speculation that the pathology may drive temporal lobe epileptogenesis. Conducting definitive experiments to test this hypothesis, however, has been challenging due to the difficulty of dissociating this sprouting from the many other changes occurring during epileptogenesis. The field has been largely driven, therefore, by correlative data. Recently, the development of powerful transgenic mouse technologies and the discovery of novel drug targets has provided new tools to assess the role of mossy fiber sprouting in epilepsy. We can now selectively manipulate hippocampal granule cells in rodent epilepsy models, providing new insights into the granule cell subpopulations that participate in mossy fiber sprouting. The cellular pathways regulating this sprouting are also coming to light, providing new targets for pharmacological intervention. Surprisingly, many investigators have found that blocking mossy fiber sprouting has no effect on seizure occurrence, while seizure frequency can be reduced by treatments that have no effect on this sprouting. These results raise new questions about the role of mossy fiber sprouting in epilepsy. Here, we will review these findings with particular regard to the contributions of new granule cells to mossy fiber sprouting and the regulation of this sprouting by the mTOR signaling pathway.

Forebrain glutamate uptake and behavioral parameters are altered in adult zebrafish after the induction of Status Epilepticus by kainic acid

The development of new antiepileptic drugs is a high-risk/high-cost research field, which is made even riskier if the behavioral epileptic seizure profile is the unique approach on which the development is based. In order to increase the effectiveness of the screening conducted in the zebrafish model of status epilepticus (SE), the evaluation of neurochemical markers of SE would be of great relevance. Epilepsy is associated with changes in the glutamatergic system, and glutamate uptake is one of the critical parameters of this process. Therefore, we evaluated the levels of glutamate uptake in the zebrafish brain and analyzed its correlation with the progression of behavioral changes in zebrafish at different times after the administration of kainic acid (5 mg/kg). The results showed that the zebrafish suffered with lethargy while swimming for up to 72 h after SE, had reduced levels of GFAP cells 12 h after SE, reduced levels of S100B up to 72 h after SE, and reduced levels of glutamate uptake in the forebrain between 3 h and 12 h after SE. The forebrain region of adult zebrafish after SE present similar changes to the neurochemical limbic alterations that are seen in rodent models of SE. This study demonstrated that there is a time window in which to use the KA zebrafish model of SE to explore some of the known neurochemical alterations that have been observed in rodent models of epilepsy and epileptic human patients.

Toward evidence-based severity assessment in rat models with repeated seizures: I. Electrical kindling.

Rodent epilepsy models can significantly contribute to our understanding of pathophysiological mechanisms and to validation of biomarker and target candidates. Evidence-based severity assessment is a presupposition for the ethical evaluation of animal experimentation allowances as well as for the development of efficacious refinement concepts. Aiming to improve our understanding of the impact of experimental procedures and repeated seizures, we have completed a comprehensive behavioral and biochemical analysis assessing various parameters that can inform about the influence of an electrical kindling paradigm on well-being in rats. Thereby, we have focused on the immediate effects of phases with focal and generalized seizures with behavioral testing during kindling acquisition. Electrode implantation exerted mild effects on anxiety-associated behavior and reduced serum corticosterone at 3 weeks, but not 7 weeks, following surgery. Analysis in kindled rats excluded any relevant impact of focal seizures on behavioral and biochemical parameters. Assessment in rats with generalized seizures revealed an impact on nest complexity scores, nest soiling, and selected parameters in paradigms evaluating anxiety-associated behavior. Moreover, serum corticosterone levels, but neither hair corticosterone nor fecal corticosterone metabolite concentrations were lowered as a consequence of repeated generalized seizures. The assessment of various other behavioral and biochemical parameters did not reveal any other relevant effects of generalized seizures. Cross-correlation analysis suggested that assessment of nest building and maintenance can provide information comparable to that from more elaborate behavioral assays. This finding provides first evidence that nest scoring might serve as a simple and valid approach to evaluate rat well-being during routine assessment schemes. The findings argue against a persistent level of pronounced distress and suggest a classification of the kindling paradigm as a model with moderate severity based on a longer-lasting mild impact on animal behavioral patterns. This suggestion provides a basis for a prospective and retrospective case-by-case severity assessment.

Phase-amplitude coupling and epileptogenesis in an animal model of mesial temporal lobe epilepsy

Polyrhythmic coupling of oscillatory components in electrophysiological signals results from the interactions between neuronal sub-populations within and between cell assemblies. Since the mechanisms underlying epileptic disorders should affect such interactions, abnormal level of cross-frequency coupling is expected to provide a signal marker of epileptogenesis. We measured phase-amplitude coupling (PAC), a form of cross-frequency coupling between neural oscillations, in a rodent model of mesial temporal lobe epilepsy. Sprague-Dawley rats (n = 4, 250–300 g) were injected with pilocarpine (380 mg/kg, i.p) to induce a status epilepticus (SE) that was stopped after 1 h with diazepam (5 mg/kg, s.c.) and ketamine (50 mg/kg, s.c.). Control animals (n = 6) did not receive any injection or treatment. Three days after SE, all animals were implanted with bipolar electrodes in the hippocampal CA3 subfield, entorhinal cortex, dentate gyrus and subiculum. Continuous video/EEG recordings were performed 24/7 at a sampling rate of 2 kHz, over 15 consecutive days. Pilocarpine-treated animals showed interictal spikes (5.25 (±2.5) per minute) and seizures (n = 32) that appeared 7 (±0.8) days after SE. We found that CA3 was the seizure onset zone in most epileptic animals, with stronger ongoing PAC coupling between seizures than in controls (Kruskal-Wallis test: chi2 (1,36) = 46.3, Bonferroni corrected, p < 0.001). Strong PAC in CA3 occurred between the phase of slow-wave oscillations (<1 Hz) and the amplitude of faster rhythms (50–180 Hz), with the strongest bouts of high-frequency activity occurring preferentially on the ascending phase of the slow wave. We also identified that cross-frequency coupling in CA3 (rho = 0.44, p < 0.001) and subiculum (rho = 0.41, p < 0.001) was positively correlated with the daily number of seizures. Overall, our study demonstrates that cross-frequency coupling may represent a signal marker in epilepsy and suggests that this methodology could be transferred to clinical scalp MEG and EEG recordings.

The prescribable drugs with efficacy in experimental epilepsies (PDE3) database for drug repurposing research in epilepsy.

Current antiepileptic drugs (AEDs) have several shortcomings. For example, they fail to control seizures in 30% of patients. Hence, there is a need to identify new AEDs. Drug repurposing is the discovery of new indications for approved drugs. This drug "recycling" offers the potential of significant savings in the time and cost of drug development. Many drugs licensed for other indications exhibit antiepileptic efficacy in animal models. Our aim was to create a database of "prescribable" drugs, approved for other conditions, with published evidence of efficacy in animal models of epilepsy, and to collate data that would assist in choosing the most promising candidates for drug repurposing. The database was created by the following: (1) computational literature-mining using novel software that identifies Medline abstracts containing the name of a prescribable drug, a rodent model of epilepsy, and a phrase indicating seizure reduction; then (2) crowdsourced manual curation of the identified abstracts. The final database includes 173 drugs and 500 abstracts. It is made freely available at www.liverpool.ac.uk/D3RE/PDE3. The database is reliable: 94% of the included drugs have corroborative evidence of efficacy in animal models (for example, evidence from multiple independent studies). The database includes many drugs that are appealing candidates for repurposing, as they are widely accepted by prescribers and patients-the database includes half of the 20 most commonly prescribed drugs in England-and they target many proteins involved in epilepsy but not targeted by current AEDs. It is important to note that the drugs are of potential relevance to human epilepsy-the database is highly enriched with drugs that target proteins of known causal human epilepsy genes (Fisher's exact test P-value<3×10-5 ). We present data to help prioritize the most promising candidates for repurposing from the database. The PDE3 database is an important new resource for drug repurposing research in epilepsy.

The Role of Innate Immune System Receptors in Epilepsy Research.

Epilepsy is one of the most complex neurological disorders and its study requires a broad knowledge of neurology and neuroscience. It comprises a diverse group of neurological disorders that share the central feature of spontaneous recurrent seizures, and are often accompanied by cognitive deficits and mood disorder. This condition is one of the most common neurological disorders. Until recently, alterations of neuronal activities had been the focus of epilepsy research. This neurocentric emphasis did not address issues that arise in more complex models of epileptogenesis. An important factor in epilepsy that is not regulated directly by neurons is inflammation and the immune response of the brain. Recent evidence obtained in rodent epilepsy models supports the role of immune responses in the initiation and maintenance of epilepsy. Recognition of exogenous pathogens by the innate immune system is mediated by some pattern recognition receptors such as Toll-like receptors leading to cell activation and cytokine production. Currently, these receptors have been the focus of epilepsy studies looking to determine whether the innate immune activation is neuroprotective or neurotoxic for the brain. Here, we present the evidence in the literature of the involvement of key innate immune receptors in the development of epilepsy. We address some of the contradictory findings in these studies and also mention possible avenues for research into epilepsy treatments that target these receptors.

Viral tracing of presynaptic inputs to newly born dentate granule cells in a rodent model of mesial temporal lobe epilepsy.

Viral tracing of presynaptic inputs to newly born dentate granule cells in a rodent model of mesial temporal lobe epilepsy.

Effects of Jasminum multiflorum leaf extract on rodent models of epilepsy, motor coordination and anxiety

Jasmine flowers and leaves are used extensively in folk medicine in different parts of the world to treat a variety of diseases. However, there are very few published reports on the neuropsychiatric effects of Jasmine extracts. Hence, the objectives of the present study were to examine the effects of an alcohol extract of Jasminum multiflorum leaves on topically-applied bicuculline (a model of acute simple partial epilepsy) and maximal electroshock (MES, a model of generalized tonic-clonic seizure) in male Sprague-Dawley rats. The objectives also included an examination of the anxiolytic properties of the extract using an elevated plus maze and the effect of the extract on motor coordination using a rotarod treadmill. Phytochemical analysis of the extract showed the presence of three flavonoids and four additional compounds belonging to the steroid, terpenoid, phenol or sugar classes of compounds. The Jasmine alcohol extract, diluted with water and given orally or intraperitoneally, reduced the number of bicuculline-induced epileptiform discharges in a dose-dependent manner. The extract did not cause a significant increase in the current needed to induce hind limb extension in MES experiments. The extract significantly affected motor coordination when injected at 500mg/kg but not at 200mg/kg. At the latter dose, the extract increased open-arm entries and duration in the elevated plus maze to a level comparable to that of diazepam at 2mg/kg. We conclude that Jasmine leaf extract has a beneficial effect against an animal model of acute partial complex epilepsy, and significant anxiolytic effect at a dose that does not affect motor co-ordination.

The Repeated Flurothyl Seizure Model in Mice.

Development of spontaneous seizures is the hallmark of human epilepsy. There is a critical need for new epilepsy models in order to elucidate mechanisms responsible for leading to the development of spontaneous seizures and for testing new anti-epileptic compounds. Moreover, rodent models of epilepsy have clearly demonstrated that there are two independent seizure systems in the brain: 1) the forebrain seizure network required for the expression of clonic seizures mediated by forebrain neurocircuitry, and 2) the brainstem seizure network necessary for the expression of brainstem or tonic seizures mediated by brainstem neurocircuitry. In seizure naïve animals, these two systems are separate, but developing models that can explore the intersection of the forebrain and brainstem seizure systems or for elucidating mechanisms responsible for bringing these two seizure systems together may aid in our understanding of: 1) how seizures can become more complex overtime, and 2) sudden unexpected death in epilepsy (SUDEP) since propagation of seizure discharge from the forebrain seizure system to the brainstem seizure system may have an important role in SUDEP because many cardiorespiratory systems are localized in the brainstem. The repeated flurothyl seizure model of epileptogenesis, as described here, may aid in providing insight into these important epilepsy issues in addition to understanding how spontaneous seizures develop.

Changes in functional brain networks during epileptogenesis in a rodent model of temporal lobe epilepsy

Changes in functional brain networks during epileptogenesis in a rodent model of temporal lobe epilepsy

P.3.c.011 - The antipsychotic-like activity of VU152100, a muscarinic M4 receptor positive allosteric modulator, in animal models of schizophrenia

Metabotropic glutamate (mGlu) receptors have multiple actions on neuronal excitability through G-protein-linked modifications of enzymes and ion channels. They act presynaptically to modify glutamatergic and γ-aminobutyric acid (GABA)-ergic transmission and can contribute to long-term changes in synaptic function. The recent identification of subtype-selective agonists and antagonists has permitted evaluation of mGlu receptors as potential targets in the treatment of epilepsy. Agonists acting on group I mGlu receptors (mGlu1 and mGlu5) are convulsant. Antagonists acting on mGlu1 or mGlu5 receptors are anticonvulsant against 3,5-dihydroxyphenylglycine (DHPG)-induced seizures and in mouse models of generalized motor seizures and absence seizures. The competitive, phenylglycine mGlu1/5 receptor antagonists generally require intracerebroventricular administration for potent anticonvulsant efficacy but noncompetitive antagonists, e.g., (3aS,6aS)-6a-naphthalen-2-ylmethyl-5-methyliden-hexahydrocyclopenta[c]furan-1-on (BAY36-7620), 2-methyl-6-(phenylethynyl)pyridine hydrochloride (MPEP), and 2-methyl-6-(2-phenylethenyl)pyridine (SIB-1893) block generalized seizures with systemic administration. Agonists acting on group II mGlu receptors (mGlu2, mGlu3) to reduce glutamate release are anticonvulsant, e.g., 2R,4R-aminopyrrolidine-2,4-dicarboxylate [(2R,4R)-APDC], (+)-2-aminobicyclo[3.1.0]hexane-2,6-dicarboxylic acid (LY354740), and (−)-2-oxa-4-aminobicyclo[3.1.0]hexane-4,6-dicarboxylate (LY379268). The classical agonists acting on group III mGlu receptors such as l-(+)-2-amino-4-phosphonobutyric acid, and l-serine-O-phosphate are acutely proconvulsant with some anticonvulsant activity. The more recently identified agonists (R,S)-4-phosphonophenylglycine [(R,S)-PPG] and (S)-3,4-dicarboxyphenylglycine [(S)-3,4-DCPG] and (1S,3R,4S)-1-aminocyclopentane-1,2,4-tricarboxylic acid [ACPT-1] are all anticonvulsant without proconvulsant effects. Studies in animal models of kindling reveal some efficacy of mGlu receptor ligands against fully kindled limbic seizures. In genetic mouse models, mGlu1/5 antagonists and mGlu2/3 agonists are effective against absence seizures. Thus, antagonists at group I mGlu receptors and agonists at groups II and III mGlu receptors are potential antiepileptic agents, but their clinical usefulness will depend on their acute and chronic side effects. Potential also exists for combining mGlu receptor ligands with other glutamatergic and non-glutamatergic agents to produce an enhanced anticonvulsant effect. This review also discusses what is known about mGlu receptor expression and function in rodent epilepsy models and human epileptic conditions.

The Anticonvulsant Activity of a Flavonoid-Rich Extract from Orange Juice Involves both NMDA and GABA-Benzodiazepine Receptor Complexes.

The usage of dietary supplements and other natural products to treat neurological diseases has been growing over time, and accumulating evidence suggests that flavonoids possess anticonvulsant properties. The aim of this study was to examine the effects of a flavonoid-rich extract from orange juice (OJe) in some rodent models of epilepsy and to explore its possible mechanism of action. The genetically audiogenic seizures (AGS)-susceptible DBA/2 mouse, the pentylenetetrazole (PTZ)-induced seizures in ICR-CD1 mice and the WAG/Rij rat as a genetic model of absence epilepsy with comorbidity of depression were used. Our results demonstrate that OJe was able to exert anticonvulsant effects on AGS-sensible DBA/2 mice and to inhibit PTZ-induced tonic seizures, increasing their latency. Conversely, it did not have anti-absence effects on WAG/Rij rats. Our experimental findings suggest that the anti-convulsant effects of OJe are likely mediated by both an inhibition of NMDA receptors at the glycine-binding site and an agonistic activity on benzodiazepine-binding site at GABAA receptors. This study provides evidences for the antiepileptic activity of OJe, and its results could be used as scientific basis for further researches aimed to develop novel complementary therapy for the treatment of epilepsy in a context of a multitarget pharmacological strategy.

Confounding effect of EEG implantation surgery: Inadequacy of surgical control in a two hit model of temporal lobe epilepsy

In rodent models of epilepsy, EEG implantation surgery is an essential modality to evaluate electrographic seizures. The inflammatory consequences of EEG electrode-implantation and their resultant effects on seizure susceptibility are unclear. We evaluated electrode-implantation in a two-hit model of epileptogenesis in C57BL/6 mice that included brief, recurrent febrile seizures (FS) at P14 and kainic acid induced seizures (KA-SZ) at P28. During KA-SZ, latencies to first electrographic and behavioral seizures, seizure severity, and KA dose sensitivity were measured. Mice that received subdural screw electrode implants at P25 for EEG monitoring at P28 had significantly shorter latencies to seizures than sham mice, regardless of early life seizure experience. Electrode-implanted mice were sensitive to low dose KA as shown by high mortality rate at KA doses above 10mg/kg. We then directly compared electrode-implantation and KA-SZ in seizure naive CX3CR1GFP/+ transgenic C57BL/6 mice, wherein microglia express green fluorescent protein (GFP), to determine if microglia activation related to surgery was associated with the increased seizure susceptibility in electrode-implanted mice from the two-hit model. Hippocampal microglia activation, as demonstrated by percent area GFP signal and GFP positive cell counts, prior to seizures was indistinguishable between electrode-implanted mice and controls, but was significantly greater in electrode-implanted mice following seizures. Electrode-implantation had a confounding priming effect on the inflammatory response to subsequent seizures.

Effects of a ketogenic diet on ADHD-like behavior in dogs with idiopathic epilepsy.

Epilepsy in humans and rodent models of epilepsy can be associated with behavioral comorbidities including an increased prevalence of attention-deficit/hyperactivity disorder (ADHD). Attention-deficit/hyperactivity disorder symptoms and seizure frequency have been successfully reduced in humans and rodents using a ketogenic diet (KD). The aims of this study were (i) to describe the behavioral profile of dogs with idiopathic epilepsy (IE) while on a standardized nonketogenic placebo diet, to determine whether ADHD-like behaviors are present, and (ii) to examine the effect of a ketogenic medium chain triglyceride diet (MCTD) on the behavioral profile of dogs with idiopathic epilepsy (IE) compared with the standardized placebo control diet, including ADHD-like behaviors. A 6-month prospective, randomized, double-blinded, placebo-controlled, crossover dietary trial comparing the effects of the MCTD with a standardized placebo diet on canine behavior was carried out. Dogs diagnosed with IE, with a seizure frequency of at least 3 seizures in the past 3months (n=21), were fed the MCTD or placebo diet for 3months and were then switched to the alternative diet for 3months. Owners completed a validated behavioral questionnaire to measure 11 defined behavioral factors at the end of each diet period to report their dogs' behavior, with three specific behaviors hypothesized to be related to ADHD: excitability, chasing, and trainability. The highest scoring behavioral factors in the placebo and MCTD periods were excitability (mean±SE: 1.910±0.127) and chasing (mean±SE: 1.824±0.210). A markedly lower trainability score (mean±SE: 0.437±0.125) than that of previously studied canine populations was observed. The MCTD resulted in a significant improvement in the ADHD-related behavioral factor chasing and a reduction in stranger-directed fear (p<0.05) compared with the placebo diet. The latter effect may be attributed to previously described anxiolytic effects of a KD. These data support the supposition that dogs with IE may exhibit behaviors that resemble ADHD symptoms seen in humans and rodent models of epilepsy and that a MCTD may be able to improve some of these behaviors, along with potentially anxiolytic effects.

Intractable Epilepsy (IE) and Responses to Anakinra, a Human Recombinant IL-1 Receptor Agonist (IL-1ra): Case Reports

Patients with intractable seizures (IE) who failed to respond currently available treatment measures are clinically challenging, causing significant morbidity and even mortality. Better understanding of contributing factors for IE will be helpful for exploring additional treatment options. A role of inflammation has long been suspected in pathogenesis of epilepsy, especially in idiopathic epilepsy with diffuse epileptic activity. In rodent models of epilepsy, blockage of inflammatory mediators such as interleukin 1-β (IL-1β) and IL-6 attenuates epileptic activities. However, therapeutic effects of blockers of such inflammatory mediators have not been addressed in patients with IE.This manuscript reports 4 IE cases in which anakira, a human recombinant IL-1 receptor antagonist (IL-1ra), was clinically effective in controlling their epileptic activity in a dose-dependent manner. In these patients, we also observed changes in ratios of IL-1β/IL-10 produced by peripheral blood monocytes, surrogates of bone marrow derived microglial cells. These findings could be associated with seizure control status.These presented cases indicate a possible therapeutic use of a commercially available IL-1β blocker (anakinra) and therapeutic utility of the IL-1β/IL-10 ratios produced by peripheral blood monocytes for assessing responses to this immune-modulating agent.

The Genetic Absence Epilepsy Rats from Strasbourg model of absence epilepsy exhibits alterations in fear conditioning and latent inhibition consistent with psychiatric comorbidities in humans.

Behavioural, neurological, and genetic similarities exist in epilepsies, their psychiatric comorbidities, and various psychiatric illnesses, suggesting common aetiological factors. Rodent models of epilepsy are used to characterize the comorbid symptoms apparent in epilepsy and their neurobiological mechanisms. The present study was designed to assess Pavlovian fear conditioning and latent inhibition in a polygenetic rat model of absence epilepsy, i.e. Genetic Absence Epilepsy Rats from Strasbourg (GAERS) and the non-epileptic control (NEC) strain. Electrophysiological recordings confirmed the presence of spike-wave discharges in young adult GAERS but not NEC rats. A series of behavioural tests designed to assess anxiety-like behaviour (elevated plus maze, open field, acoustic startle response) and cognition (Pavlovian conditioning and latent inhibition) was subsequently conducted on male and female offspring. Results showed that GAERS exhibited significantly higher anxiety-like behaviour, a characteristic reported previously. In addition, using two protocols that differed in shock intensity, we found that both sexes of GAERS displayed exaggerated cued and contextual Pavlovian fear conditioning and impaired fear extinction. Fear reinstatement to the conditioned stimuli following unsignalled footshocks did not differ between the strains. Male GAERS also showed impaired latent inhibition in a paradigm using Pavlovian fear conditioning, suggesting that they may have altered attention, particularly related to previously irrelevant stimuli in the environment. Neither the female GAERS nor NEC rats showed evidence of latent inhibition in our paradigm. Together, the results suggest that GAERS may be a particularly useful model for assessing therapeutics designed to improve the emotional and cognitive disturbances associated with absence epilepsy.